Recording medium, drawing method, and drawing system

Abstract

Provided is a recording medium capable of performing intended drawing. The recording medium includes a first recording layer configured to be able to draw with first laser light having a first peak wavelength, and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength. The first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye. The first recording layer and the second recording layer have different recording methods. At least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a recording medium, a drawing method, and a drawing system.BACKGROUND ART

[0002] In recent years, a recording medium including a first recording layer and a second recording layer having different recording methods has been studied. For example, Patent Document 1 describes a laminate including a laminated film colored in cyan (C), magenta (M), and yellow (Y) by a pigment, and a near infrared laser marking layer for compensating grayscale.CITATION LISTPATENT DOCUMENT

[0003] Patent Document 1: WO 2019 / 129527 ASUMMARY OF THE INVENTIONPROBLEMS TO BE SOLVED BY THE INVENTION

[0004] However, in the conventional recording medium including a first recording layer and a second recording layer having different recording methods, intended drawing cannot be performed in some cases.

[0005] An object of the present disclosure is to provide a recording medium, a drawing method, and a drawing system by which intended drawing can be performed.SOLUTIONS TO PROBLEMS

[0006] In order to solve the above problem, a recording medium according to the present disclosure includes: a first recording layer configured to be able to draw with first laser light having a first peak wavelength; and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0007] A drawing method according to the present disclosure includes: irradiating a first recording layer of a recording medium with first laser light having a first peak wavelength to draw a first image; and irradiating a second recording layer of the recording medium with second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0008] A drawing system according to the present disclosure includes: a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength; a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength; and a control apparatus configured to be able to control the first irradiation apparatus and the second irradiation apparatus, in which the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image. BRIEF DESCRIPTION OF DRAWINGS

[0009] Fig. 1 is a perspective view of a recording medium according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along a line II-II in Fig. 1. Fig. 3 is a cross-sectional view of a recording layer. Fig. 4 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 5 is a block diagram of a drawing system. Fig. 6 is a flowchart for describing an example of a method for generating a first drawing setting file. Fig. 7 is a flowchart for describing an example of a method for generating a second drawing setting file. Fig. 8 is a flowchart for describing an example of a drawing method. Fig. 9 is a cross-sectional view of a recording medium according to a second embodiment of the present disclosure. Fig. 10 is a schematic view of a first image, a second image, a visible image, and an infrared image. Figs. 11A and 11B are views for describing an example of the drawing method. Fig. 12 is a view for describing an example of an imaging method. Fig. 13 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 14 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 15 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 16 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 17 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 18 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 19 is a cross-sectional view of a recording medium according to a modification. Fig. 20 is a cross-sectional view of a recording medium according to a modification. Fig. 21 is a cross-sectional view of a recording medium according to a modification. Fig. 22 is a cross-sectional view of a first modification of intermediate layers. Fig. 23 is a cross-sectional view of a second modification of intermediate layers. MODE FOR CARRYING OUT THE INVENTION

[0010] Embodiments of the present disclosure are described in the following order. Note that the same or corresponding portions will be denoted by the same reference signs in all the drawings of the following embodiments. 1 Description of Outline of Recording Medium According to Present Disclosure 2 First embodiment (example of recording medium) 2.1 Configuration of recording medium 2.2 Method of Manufacturing Recording Medium 2.3 Configuration of Drawing System 2.4 Method of Generating First Drawing Setting File 2.5 Method of Generating Second Drawing Setting File 2.6 Drawing Method of Recording Medium 2.7 Operation and Effect 3 Second Embodiment (Example of Recording Medium) 3.1 Configuration of Recording Medium 3.2 Operation and Effect 4 Modifications <1 Description of Outline of Recording Medium According to Present Disclosure>

[0011] A recording medium according to the present disclosure includes: a first recording layer configured to be able to draw with first laser light having a first peak wavelength; and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0012] In the conventional recording medium, since the drawing conditions (wavelengths) of the laser light of the first recording layer and the second recording layer are the same, if at least parts of the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, the other recording layer may be unintentionally drawn. On the other hand, in the recording medium according to the present disclosure, since the drawing conditions (wavelengths) of the laser light of the first recording layer and the second recording layer are different, even if at least parts of the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, the other recording layer can be suppressed from being unintentionally drawn.

[0013] In the recording medium according to the present disclosure, at least parts of the first recording layer and the second recording layer overlap each other in the thickness direction of the recording medium, so that a first image drawn on the first recording layer and a second image drawn on the second recording layer can be superimposed. Therefore, the second image can be used for authenticity determination of the recording medium. Furthermore, a composite image can be formed by the first image and the second image.

[0014] In order to enhance the security of the recording medium, it is preferable that a first image visible under visible light is drawn on the first recording layer, a second image capable of being captured under light irradiation other than visible light is drawn on the second recording layer, and the first image and the second image overlap each other. Here, examples of light other than visible light include ultraviolet rays and infrared rays, and an imaging method using infrared rays is generally often used.

[0015] However, since the first recording layer has translucency with respect to visible light even after the first image is drawn, in a case where the second recording layer is provided on the back surface side of the first recording layer, the second image may be visually recognized behind the first image. In this case, there is a possibility that the visibility of the first image of the first recording layer decreases, and the display quality of the recording medium deteriorates. Specifically, for example, in a case where the first image is a multi-color image such as a full-color image and the second image is a monochrome image (monochromatic image) such as a black image or a brown image, there is a possibility that the display quality of the recording medium deteriorates because the color-developed portion of the first image becomes difficult to see or the first image appears dark.

[0016] On the other hand, in a case where the second recording layer is provided on the front surface side of the first recording layer, there is a possibility that the first image of the first recording layer is covered with the second image of the second recording layer, and the display quality of the recording medium deteriorates. Specifically, for example, in a case where the first image is a multi-color image such as a full-color image and the second image is a monochrome image (monochromatic image) such as a black image or a brown image, there is a possibility that the first image that is a multi-color image is hidden by the second image that is a monochrome image, and the display quality of the recording medium deteriorates.

[0017] In order to suppress the deterioration of the display quality described above, the second image is preferably an image including a part of the first image. If the second image is an image including a part of the first image, an overlapping portion between the first image and the second image can be reduced. Therefore, in a case where the second recording layer is provided on the back surface side of the first recording layer, it is possible to suppress the second image from being visually recognized behind the first image. On the other hand, in a case where the second recording layer is provided on the front surface side of the first recording layer, it is possible to suppress the first image of the first recording layer from being covered with the second image of the second recording layer. Therefore, the deterioration of the display quality of the recording medium can be suppressed. The second image preferably includes, as a part of the first image, at least one selected from the group consisting of a contour of the first image, a color-developed portion having a prescribed color development density or more in the first image, a background portion of the first image, and the like. The color-developed portion having a prescribed color development density or more in the first image may include a substantially maximum color development density portion in the first image or a black portion of the first image.

[0018] In the recording medium according to the present disclosure, it is preferable that the second recording layer is configured to be able to draw a second image visible under visible light and capable of being captured under infrared rays. Therefore, the recording medium is imaged by the imaging apparatus, and the presence or absence of the second image drawn on the second recording layer is confirmed, whereby the authenticity of the recording medium can be determined. Furthermore, the second image drawn on the second recording layer is captured by the imaging apparatus and compared with a reference image, whereby the authenticity of the recording medium can also be determined. The reference image is, for example, the first image drawn on the first recording layer, an original image of the first image stored on a network such as a cloud server, or an original image of the first image stored in a terminal device.

[0019] In the recording medium according to the present disclosure, it is preferable that a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, the second image includes a part of the first image, and the part of the first image included in the second image overlaps the first image of the first recording layer. Therefore, the authenticity of the recording medium can be determined by comparing an overlapping portion between the first image and the second image, that is, a common portion between the first image and the second image.

[0020] In order to suppress the deterioration of the display quality of the recording medium due to the overlap between the first image and the second image, it is preferable that a part of the first image includes at least one of a contour of the first image or a color-developed portion having a prescribed color development density or more in the first image. The color-developed portion having a prescribed color development density or more in the first image may include a substantially maximum color development density portion in the first image or a black portion of the first image. The part of the first image described above may include a contour of the first image and a key plate portion of the first image.

[0021] In the recording medium according to the present disclosure, it is preferable that the first recording layer is provided on an upper side of the second recording layer, and at least a part of the second image is hidden by the first image of the first recording layer under visible light. Therefore, it is possible to determine the authenticity of the recording medium by capturing the second image by the imaging apparatus under infrared rays and confirming at least a part of the second image hidden under visible light.

[0022] In the recording medium according to the present disclosure, it is preferable that a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, and a composite image is formed by the first image and the second image. Therefore, it is possible to determine the authenticity of the recording medium by capturing the composite image by the imaging apparatus under infrared rays and confirming the presence or absence of the second image. Furthermore, it is also possible to determine the authenticity of the recording medium by capturing the composite image by the imaging apparatus under infrared rays and comparing the composite image with a reference image. The reference image is, for example, the first image drawn on the first recording layer, an original image of the first image stored on a network such as a cloud server, or an original image of the first image stored in a terminal device.

[0023] In a case where a composite image is formed by the first image and the second image, the second image preferably includes at least one of a black portion of the composite image or a background portion of the composite image.

[0024] In the recording medium according to the present disclosure, the first color development layer preferably further contains at least one selected from the group consisting of a matrix resin, a developer, and a photothermal conversion agent, and more preferably further contains a matrix resin, a developer, and a photothermal conversion agent.

[0025] In the recording medium according to the present disclosure, it is preferable that the first recording layer is configured to be able to draw with third laser light having a third peak wavelength and fourth laser light having a fourth peak wavelength, the first recording layer further includes: a second color development layer configured to be able to develop color with the third laser light and containing a second leuco dye; and a third color development layer configured to be able to develop color with the fourth laser light and containing a third leuco dye, and the first peak wavelength, the second peak wavelength, the third peak wavelength, and the fourth peak wavelength are different from each other.

[0026] Since the first recording layer further includes the second color development layer and the third color development layer, the first image can be formed by the color-developed portions of the first color development layer, the second color development layer, and the third color development layer. Therefore, a multi-color image can be drawn as the first image on the first recording layer. For example, in a case where the first color development layer, the second color development layer, and the third color development layer are configured to be able to develop a cyan color, a magenta color, and a yellow color, respectively, a full-color image can be drawn as the first image on the first recording layer.

[0027] In the recording medium according to the present disclosure, the second color development layer and the third color development layer each independently preferably further contain at least one selected from the group consisting of a matrix resin, a developer, and a photothermal conversion agent, and more preferably further contain a matrix resin, a developer, and a photothermal conversion agent.

[0028] In the recording medium according to the present disclosure, the first recording layer may be provided above the second recording layer, or the first recording layer may be provided below the second recording layer. In order to suppress the deterioration of the display quality of the first image under visible light, the first recording layer is preferably provided above the second recording layer. The recording medium may have a first surface on which the drawn first image and second image are visually recognized and a second surface opposite to the first surface. The upper side may represent the first surface side, and the lower side may represent the second surface side.

[0029] In the recording medium according to the present disclosure, the first recording layer may be in contact with the second recording layer, or the first recording layer and the second recording layer may be separated from each other. In a case where the first recording layer is in contact with the second recording layer, the first recording layer and the second recording layer may be fusion-bonded. In a case where the first recording layer and the second recording layer are separated from each other, a bonding adhesive layer or an adhesive layer may be provided between the first recording layer and the second recording layer, or an intermediate layer having translucency or wavelength selectivity may be provided between the first recording layer and the second recording layer. The intermediate layer having translucency is, for example, an organic material layer, an inorganic material layer, or an organic-inorganic hybrid material layer. The intermediate layer having wavelength selectivity is preferably configured to be able to reflect visible light and transmit infrared light. The intermediate layer having wavelength selectivity is, for example, a dielectric multilayer film.

[0030] In the recording medium according to the present disclosure, from the viewpoint of improving the security of the recording medium, the peel strength between the respective layers constituting the recording medium is preferably 3.5 N / cm 2< or more and more preferably 5.0 N / cm 2< .

[0031] In the recording medium according to the present disclosure, an area of the first recording layer in plan view and an area of the second recording layer in plan view may be substantially the same or different. In a case where the area of the first recording layer is different from the area of the second recording layer, the area of the first recording layer may be larger than the area of the second recording layer, or the area of the first recording layer may be smaller than the area of the second recording layer.

[0032] The area of the first recording layer in plan view may be substantially the same as the area of the recording medium in plan view, or may be smaller than the area of the recording medium in plan view. The recording medium may further include a first base material layer that accommodates the first recording layer, and the first base material layer may have substantially the same area as the recording medium in plan view. In a case where the area of the first recording layer is smaller than the area of the recording medium, the first recording layer may be accommodated in an accommodation part of the first base material layer.

[0033] The area of the second recording layer in plan view may be substantially the same as the area of the recording medium in plan view, or may be smaller than the area of the recording medium in plan view. The recording medium may further include a second base material layer that accommodates the second recording layer, and the second base material layer may have substantially the same area as the recording medium in plan view. In a case where the area of the second recording layer is smaller than the area of the recording medium, the second recording layer may be accommodated in an accommodation part of the second base material layer.

[0034] In the recording medium according to the present disclosure, a reflection layer is preferably further provided below the first recording layer and the second recording layer from the viewpoint of improving the visibility of the first image and the second image.

[0035] The recording medium according to the present disclosure may further include at least one layer selected from the group consisting of a cover layer, an overlay layer, a protective layer, and the like. The at least one layer is provided, for example, on at least one of the first surface side of the recording medium, the second surface side of the recording medium, or the lateral surface side of the recording medium.

[0036] A drawing method according to the present disclosure includes: irradiating a first recording layer of a recording medium with first laser light having a first peak wavelength to draw a first image; and irradiating a second recording layer of the recording medium with second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0037] In the drawing method according to the present disclosure, since the drawing conditions (wavelengths) of the laser light of the first recording layer and the second recording layer are different, even if the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, the other recording layer can be suppressed from being unintentionally drawn.

[0038] In the drawing method according to the present disclosure, the order of drawing of the first image and drawing of the second image is not limited, and the second image may be drawn after the first image is drawn, the first image may be drawn after the second image is drawn, or the first image and the second image may be drawn simultaneously.

[0039] In the drawing method of the present disclosure, it is preferable that the second image includes a part of the first image, and drawing of the first image and drawing of the second image are performed such that the part of the first image included in the second image overlaps the first image. Therefore, the second image can be used for authenticity determination of the recording medium. Furthermore, a composite image can be formed by the first image and the second image.

[0040] The drawing method according to the present disclosure preferably further includes extracting second image information for drawing the second image from first image information for drawing the first image. Therefore, the drawing of the first image and the drawing of the second image can be performed such that a part of the first image overlaps the second image.

[0041] The drawing method according to the present disclosure preferably further includes correcting first image information for drawing the first image such that the first image becomes brighter. Therefore, it is possible to prevent the first image from appearing dark due to the overlapping of the first image and the second image.

[0042] A drawing system according to the present disclosure includes: a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength; a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength; and a control apparatus configured to be able to control the first irradiation apparatus and the second irradiation apparatus, in which the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image.

[0043] In the drawing system according to the present disclosure, since the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light having a first peak wavelength and causing a first leuco dye contained in the first color development layer of the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, even if the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, it is possible to suppress unintentional drawing of the other recording layer.

[0044] In the drawing system according to the present disclosure, the order of drawing of the first image and drawing of the second image is not limited, and the control apparatus may execute drawing of the second image after drawing of the first image, may execute drawing of the first image after drawing of the second image, or may simultaneously execute drawing of the first image and the second image.

[0045] In the drawing system according to the present disclosure, it is preferable that the control apparatus further executes extracting second image information for drawing the second image from first image information for drawing the first image. Therefore, the drawing of the first image and the drawing of the second image can be performed such that a part of the first image overlaps the second image.

[0046] In the drawing system according to the present disclosure, it is preferable that the control apparatus further executes correcting first image information for drawing the first image such that the first image becomes brighter. Therefore, it is possible to prevent the first image from appearing dark due to the overlapping of the first image and the second image.<2 First Embodiment>[2.1 Configuration of Recording Medium]

[0047] Fig. 1 is a perspective view of a recording medium 20 according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along a line II-II in Fig. 1. The recording medium 20 sequentially includes a base material 21, an underlayer 22, an intermediate layer 23 including a recording layer (first recording layer) 10, and a recording layer (second recording layer) 24.

[0048] The base material 21 and the underlayer 22 may be bonded to each other by fusion bonding or an adhesive. The underlayer 22 and the intermediate layer 23 may be bonded to each other by fusion bonding or an adhesive. The intermediate layer 23 and the recording layer 24 may be bonded to each other by fusion bonding or an adhesive.

[0049] The recording medium 20 may be a card such as a security card, a financial payment card (for example, a credit card, a cash card, or the like), an ID card (for example, an employee ID card, a membership card, a student ID card, or the like), or a personal transaction card (for example, a prepaid card, a points card, or the like). The recording medium 20 may be a sheet constituting a booklet such as a passport. The recording medium 20 may be a housing of an electronic device or the like.

[0050] The recording medium 20 includes a drawing region R1 and a drawing region R2. The drawing region R1 is a region for drawing first information. The first information is, for example, image information such as a face photograph. In the first embodiment, an example in which the image information is color image information will be described. However, the image information is not limited to the color image information, and may be monochromatic image information (monochrome image information). The drawing region R1 is a region in which information can be recorded on both the recording layer 10 and the recording layer 24.

[0051] The drawing region R2 is a region for drawing second information. The second information is, for example, character information. The second information may further include image information such as a pattern and a picture. The drawing region R2 is a region in which information can be recorded on the recording layer 24.(Base Material 21)

[0052] The base material 21 is a support that supports the underlayer 22, the intermediate layer 23, and the recording layer 24. The base material 21 may be a card, a sheet, paper, a housing, or the like. The base material 21 may have a color such as white. In the base material 21, a pattern, a picture, a photograph, a character, a combination of two or more thereof, or the like (hereinafter, referred to as a "pattern or the like") may be printed on a surface on a side on which the underlayer 22, the intermediate layer 23, and the recording layer 24 are provided.

[0053] The base material 21 contains, for example, plastic. The base material 21 may contain at least one selected from the group consisting of a colorant, an antistatic agent, a flame retardant, a surface modifier, and the like as necessary.

[0054] The plastic includes, for example, at least one selected from the group including an ester resin, an amide resin, an olefin resin, a vinyl resin, an acrylic resin, an imide resin, a styrenic resin, an engineering plastic, and the like. In a case where the base material 21 contains two or more resins, the two or more resins may be mixed, copolymerized, or laminated.

[0055] The ester resin includes, for example, at least one selected from the group including a polyethylene terephthalate (PET) resin, a polybutylene terephthalate (PBT) resin, a polyethylene naphthalate (PEN) resin, a polyethylene terephthalate-isophthalate copolymer resin, a terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer resin, and the like. The amide resin includes, for example, at least one selected from the group including a nylon 6 resin, a nylon 66 resin, a nylon 610 resin, and the like. The olefin resin includes, for example, at least one selected from the group including a polyethylene (PE) resin, a polypropylene (PP) resin, a polymethylpentene (PMP) resin, and the like. The vinyl resin includes, for example, a polyvinyl chloride (PVC) resin.

[0056] The acrylic resin includes, for example, at least one selected from the group including a polyacrylate resin, a polymethacrylate resin, a polymethyl methacrylate (PMMA) resin, and the like. The imide resin includes, for example, at least one selected from the group including a polyimide (PI) resin, a polyamideimide (PAI) resin, a polyetherimide (PEI) resin, and the like. The styrenic resin includes, for example, at least one selected from the group including a polystyrene (PS) resin, a high-impact polystyrene resin, an acrylonitrile-styrene resin (AS resin), an acrylonitrile-butadienestyrene resin (ABS resin), and the like. The engineering plastic includes, for example, at least one selected from the group including a polycarbonate (PC) resin, a polyarylate (PAR) resin, a polysulfone (PSF) resin, a polyethersulfone (PES) resin, a polyphenylene ether (PPE) resin, a polyphenylene sulfide (PPS) resin, a polyether ketone (PEK) resin, a polyether-ether ketone (PEEK) resin, a polyphenylene oxide (PPO) resin, a polyether sulfite resin, and the like.(Underlayer 22)

[0057] The underlayer 22 is provided between the base material 21 and the intermediate layer 23. The underlayer 22 may be translucent with respect to visible light. As a material of the underlayer 22, a material similar to that of the base material 21 can be exemplified. A pattern or the like may be printed on the underlayer 22.(Intermediate Layer 23)

[0058] The intermediate layer 23 is provided between the underlayer 22 and the recording layer 24. The intermediate layer 23 includes an accommodation part 23HL for accommodating the recording layer 10. Since the recording layer 10 is accommodated in the accommodation part 23HL of the intermediate layer 23, it is possible to suppress generation of a gap between the underlayer 22 and the recording layer 24. The accommodation part 23HL may be a through hole penetrating in the thickness direction of the intermediate layer 23. The accommodation part 23HL may be configured to be able to fit the recording layer 10.

[0059] The intermediate layer 23 may have substantially the same thickness as the recording layer 10. The intermediate layer 23 may have a film shape. The intermediate layer 23 may be translucent with respect to visible light. As a material of the intermediate layer 23, a material similar to that of the base material 21 can be exemplified.(Recording Layer 10)

[0060] The recording layer 10 is accommodated in the accommodation part 23HL of the intermediate layer 23. The recording layer 10 is configured to draw a multi-color image by laser light L 1 having a peak wavelength λ 1 , laser light L 2 having a peak wavelength λ 2 , and laser light L 3 having a peak wavelength λ 3 . The multi-color image is visible under visible light. The color of a first color-developed portion formed by irradiation with the laser light L 1 , the color of a second color-developed portion formed by irradiation with the laser light L 2 , and the color of a third color-developed portion formed by irradiation with the laser light L 3 are different from each other. Therefore, a multi-color image can be drawn on the recording layer 10.

[0061] In the first embodiment, an example in which the multi-color image is a full-color image will be described. The recording layer 10 is configured to be changeable in its colored state in response to irradiation with laser light (external stimulus). This change in the colored state allows for drawing of a full-color image on the recording layer 10. The full-color image may be, for example, a photograph such as a face photograph, may be a pattern, a color pattern, or the like, or may be a text such as a character or a symbol. The full-color image may be configured by a combination of two or more types of photographs, patterns, color patterns, and texts. The recording layer 10 and the recording layer 24 have different recording methods. At least parts of the recording layer 10 and the recording layer 24 overlap each other in a thickness direction of the recording medium 20.

[0062] The change in the colored state may be a reversible change or an irreversible change. That is, the recording layer 10 may be of a rewritable type which allows for rewriting of an image or the like, or may be of a write once type which allows for writing of an image or the like only once. From the viewpoint of preventing tampering, the change in the colored state is preferably an irreversible change.

[0063] Fig. 3 is a cross-sectional view of the recording layer 10. The recording layer 10 sequentially includes a base material 11, an intermediate layer 12A, a color development layer 13A, an intermediate layer 12B, a color development layer 13B, an intermediate layer 12C, a color development layer 13C, an intermediate layer 12D, and a cover layer 14. Note that the intermediate layer 12A, the intermediate layer 12D, and the cover layer 14 are provided as necessary. In the present specification, in a case where the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are collectively referred to without being distinguished, they may be referred to as an intermediate layer 12. Similarly, in a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C are collectively referred to without being distinguished, they may be referred to as a color development layer 13. One layer arbitrarily selected from the color development layer 13A, the color development layer 13B, and the color development layer 13C is an example of the first color development layer in the claims, and the remaining two layers are examples of the second color development layer and the third color development layer in the claims. The recording layer 10 may be accommodated in the accommodation part 23HL of the intermediate layer 23 such that the cover layer 14 is on the side of the recording layer 24, or may be accommodated in the accommodation part 23HL of the intermediate layer 23 such that the base material 11 is on the side of the recording layer 24. In a case where the base material 11 is not translucent with respect to visible light, it is preferable that the cover layer 14 is accommodated in the accommodation part 23HL of the intermediate layer 23 so as to be on the side of the recording layer 24.(Base Material 11)

[0064] The base material 11 supports the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14. The base material 11 preferably contains a material having excellent heat resistance and excellent dimensional stability in the in-plane direction of the base material 11. The base material 11 may have either translucent or non-translucent characteristics with respect to visible light. In the present specification, visible light refers to light in a wavelength range of 360 nm or more and 780 nm or less. The base material 11 may have a predetermined color such as white. The base material 11 has, for example, a plate shape or a film shape. Note that the film is defined to include a sheet in the present disclosure.

[0065] The base material 11 may have, for example, rigidity or flexibility. In a case where the base material 11 has flexibility, a flexible recording layer 10 can be realized. Examples of the base material 11 having rigidity include a wafer, a glass substrate, and the like. Examples of the base material 11 having flexibility include flexible glass, a film, paper, and the like.

[0066] The base material 11 contains, for example, at least one selected from the group including an inorganic material, a metal material, a polymer material, and the like. The inorganic material includes, for example, at least one selected from the group including silicon (Si), silicon oxide (SiO X ), silicon nitride (SiN X ), aluminum oxide (AlO X ), and the like. The silicon oxide includes, for example, at least one selected from the group including glass, spin-on-glass (SOG), and the like. The metal material includes, for example, at least one selected from the group including aluminum (Al), nickel (Ni), stainless steel, and the like. The polymer material includes, for example, at least one selected from the group including polycarbonate (PC) resin, polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polyethyl ether ketone (PEEK) resin, polyvinyl chloride (PVC) resin, and the like.

[0067] Note that a reflection layer (not illustrated) may be provided on at least one of a first surface or a second surface of the base material 11, or the base material 11 itself may also function as a reflection layer. The base material 11 having such a configuration enables clearer color display.(Color Development Layer 13A, Color Development Layer 13B, and Color Development Layer 13C)

[0068] The color development layer 13A, the color development layer 13B, and the color development layer 13C in a recorded state are in a color-developed state, and the color development layer 13A and the color development layers 13B and 13C in a non-recorded state are in a non-colored state. The color development layer 13A, the color development layer 13B, and the color development layer 13C can be changed from the non-colored state to a color-developed state by irradiation with laser light.

[0069] The color development layer 13A, the color development layer 13B, and the color development layer 13C each can exhibit hues different from each other in the color-developed state. Specifically, the color development layer 13A can exhibit a magenta color in the color-developed state. The color development layer 13B can exhibit a cyan color in the color-developed state. The color development layer 13C can exhibit a yellow color in the color-developed state. Magenta color, cyan color, and yellow color are examples of the first primary color, the second primary color, and the third primary color, respectively. The first primary color, the second primary color, and the third primary color may be three primary colors. The first primary color, the second primary color, and the third primary color may be colors other than magenta color, cyan color, and yellow color. The laser light L 1 capable of changing the color development layer 13A to the color-developed state, the laser light L 2 capable of changing the color development layer 13B to the color-developed state, and the laser light L 3 capable of changing the color development layer 13C to the color-developed state have peak wavelengths different from each other.

[0070] The thicknesses of the color development layer 13A, the color development layer 13B, and the color development layer 13C are each independently preferably 1 µm or more and 20 µm or less, and more preferably 2 µm or more and 15 µm or less. With the color development layer 13A, the color development layer 13B, and the color development layer 13C having a thickness of 1 µm or more, the color development density can be improved. On the other hand, with the color development layer 13A, the color development layer 13B, and the color development layer 13C having a thickness of 20 µm or less, an increase in the heat utilization amount of the color development layer 13A, the color development layer 13B, and the color development layer 13C can be prevented, and deterioration in color developability can be prevented.

[0071] The color development layer 13A is configured to be able to perform recording with the laser light L 1 having a peak wavelength λ 1 . The color development layer 13A contains a first coloring compound having an electron-donating property, a first developer having an electron-accepting property, and a first photothermal conversion agent. The color development layer 13A preferably further contains a first matrix resin.

[0072] The color development layer 13B is configured to be able to perform recording with second laser light having a peak wavelength λ 2 . The color development layer 13B contains a second coloring compound having an electron-donating property, a second developer having an electron-accepting property, and a second photothermal conversion agent. The color development layer 13B preferably further contains a second matrix resin.

[0073] The color development layer 13C is configured to be able to perform recording with third laser light having a peak wavelength λ 3 . The color development layer 13C contains a third coloring compound having an electron-donating property, a third developer having an electron-accepting property, and a third photothermal conversion agent. The color development layer 13C preferably further contains a third matrix resin.

[0074] The laser light L 1 , the laser light L 2 , and the laser light L 3 are preferably near-infrared laser light. The peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are preferably included in a near-infrared range. Upper limit values of the peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are, for example, less than 1000 nm and preferably 915 nm or less. Lower limit values of the peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are, for example, 760 nm or more.

[0075] The peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are different from each other. Therefore, the color development layer 13A, the color development layer 13B, and the color development layer 13C can be independently caused to develop color. One of the laser light L 1 having a peak wavelength λ 1 , the laser light L 2 having a peak wavelength λ 2 , and the laser light L 3 having a peak wavelength λ 3 is an example of the first laser light having a first peak wavelength in the claims, and the remaining two laser light beams are examples of the third laser light having a third peak wavelength and the fourth laser light having a fourth peak wavelength in the claims.(First Coloring Compound, Second Coloring Compound, and Third Coloring Compound)

[0076] The first coloring compound, the second coloring compound, and the third coloring compound can develop color by reacting with the first developer, the second developer, and the third developer, respectively. The first coloring compound, the second coloring compound, and the third coloring compound can exhibit hues different from each other in the color-developed state. Specifically, the first coloring compound can exhibit a magenta color in the color-developed state. The second coloring compound can exhibit a cyan color in the color-developed state. The third coloring compound can exhibit a yellow color in the color-developed state.

[0077] The first coloring compound, the second coloring compound, and the third coloring compound are, for example, leuco dyes. The leuco dye develops color when a lactone ring in a molecule reacts with an acid to be ring-opened. The leuco dye may be decolored when the open lactone ring reacts with a base to be ring-closed. The leuco dye may be, for example, an existing dye for thermosensitive paper.

[0078] The first coloring compound, the second coloring compound, and the third coloring compound can be appropriately selected according to the purpose, without any limitation. The first coloring compound, the second coloring compound, and the third coloring compound each independently contain, for example, at least one selected from the group including fluoran compounds, triphenylmethane phthalide compounds, azaphthalide compounds, phenothiazine compounds, leucoauramine compounds, indolinophthalide compounds, and the like. Besides, the first coloring compound, the second coloring compound, and the third coloring compound may each independently contain, for example, at least one selected from the group consisting of 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-di(n-butylamino) fluoran, 2-anilino-3-methyl-6-(N-n-propyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-isopropyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-isobutyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-n-amyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-sec-butyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-n-amyl-N-ethylamino) fluoran, 2-anilino-3-methyl-6-(N-iso-amyl-N-ethylamino) fluoran, 2-anilino-3-methyl-6-(N-n-propyl-N-isopropylamino)fluoran, 2-anilino-3-methyl-6-(N-cyclohexyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-ethyl-p-toluidino)fluoran, 2-anilino-3-methyl-6-(N-methyl-p-toluidino)fluoran, 2-(m-trichloromethylanilino)-3-methyl-6-diethylaminofluoran, 2-(m-trifluoromethylanilino)-3-methyl-6-diethylaminofluoran, 2-(m-trichloromethylanilino)-3-methyl-6-(N-cyclohexyl-N-methylamino)fluoran, 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluoran, 2-(N-ethyl-p-toluidino)-3-methyl-6-(N-ethylanilino)fluoran, 2-(N-ethyl-p-toluidino)-3-methyl-6-(N-propyl-p-toluidino)fluoran, 2-anilino-6-(N-n-hexyl-N-ethylamino)fluoran, 2-(o-chloroanilino)-6-diethylaminofluoran, 2-(o-chloroanilino)-6-dibutylaminofluoran, 2-(m-trifluoromethylanilino)-6-diethylaminofluoran, 2,3-dimethyl-6-dimethylaminofluoran, 3-methyl-6-(N-ethyl-p-toluidino)fluoran, 2-chloro-6-diethylaminofluoran, 2-bromo-6-diethylaminofluoran, 2-chloro-6-dipropylaminofluoran, 3-chloro-6-cyclohexylaminofluoran, 3-bromo-6-cyclohexylaminofluoran, 2-chloro-6-(N-ethyl-N-isoamylamino)fluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-chloro-6-diethylaminofluoran, 2-(o-chloroanilino)-3-chloro-6-cyclohexylaminofluoran, 2-(m-trifluoromethylanilino)-3-chloro-6-diethylaminofluoran, 2-(2,3-dichloroanilino)-3-chloro-6-diethylaminofluoran, 1,2-benzo-6-diethylaminofluoran, 3-diethylamino-6-(m-trifluoromethylanilino)fluoran, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-7-azaphthalide, 3-(1-octyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-7-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-N-n-amyl-N-methylaminophenyl)-4-azaphthalide, 3-(1-methyl-2-methylindol-3-yl)-3-(2-hexyloxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-7-azaphthalide, 2-(p-acetylanilino)-6-(N-n-amyl-N-n-butylamino)fluoran, 2-benzylamino-6-(N-ethyl-p-toluidino)fluoran, 2-benzylamino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-benzylamino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-benzylamino-6-(N-methyl-p-toluidino)fluoran, 2-benzylamino-6-(N-ethyl-p-toluidino)fluoran, 2-(di-p-methylbenzylamino)-6-(N-ethyl-p-toluidino)fluoran, 2-(α-phenylethylamino)-6-(N-ethyl-p-toluidino)fluoran, 2-methylamino-6-(N-methylanilino)fluoran, 2-methylamino-6-(N-ethylanilino)fluoran, 2-methylamino-6-(N-propylanilino)fluoran, 2-ethylamino-6-(N-methyl-p-toluidino)fluoran, 2-methylamino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-ethylamino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-dimethylamino-6-(N-methylanilino) fluoran, 2-dimethylamino-6-(N-ethylanilino)fluoran, 2-diethylamino-6-(N-methyl-p-toluidino)fluoran, 2-diethylamino-6-(N-ethyl-p-toluidino)fluoran, 2-dipropylamino-6-(N-methylanilino) fluoran, 2-dipropylamino-6-(N-ethylanilino)fluoran, 2-amino-6-(N-methylanilino)fluoran, 2-amino-6-(N-ethylanilino)fluoran, 2-amino-6-(N-propylanilino)fluoran, 2-amino-6-(N-methyl-p-toluidino)fluoran, 2-amino-6-(N-ethyl-p-toluidino)fluoran, 2-amino-6-(N-propyl-p-toluidino)fluoran, 2-amino-6-(N-methyl-p-ethylanilino)fluoran, 2-amino-6-(N-ethyl-p-ethylanilino)fluoran, 2-amino-6-(N-propyl-p-ethylanilino)fluoran, 2-amino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-propyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-methyl-p-chloroanilino)fluoran, 2-amino-6-(N-ethyl-p-chloroanilino) fluoran, 2-amino-6-(N-propyl-p-chloroanilino)fluoran, 1,2-benzo-6-(N-ethyl-N-isoamylamino)fluoran, 1,2-benzo-6-dibutylaminofluoran, 1,2-benzo-6-(N-methyl-N-cyclohexylamino)fluoran, 1,2-benzo-6-(N-ethyl-N-toluidino)fluoran, and the like.(First Developer, Second Developer, and Third Developer)

[0079] The first developer, the second developer, and the third developer can cause the first coloring compound, the second coloring compound, and the third coloring compound in the non-colored state to develop color, respectively. The types of the first developer, the second developer, and the third developer may be the same, or the types of the first developer, the second developer, and the third developer may be different from each other. The first developer, the second developer, and the third developer are compounds including an electron-accepting group in the molecule. The electron-accepting moieties of the first developer, the second developer, and the third developer react with the lactone rings of the first coloring compound, the second coloring compound, and the third coloring compound, respectively, and the lactone rings are ring-opened, whereby the first coloring compound, the second coloring compound, and the third coloring compound develop color. The first developer, the second developer, and the third developer each independently contain, for example, at least one selected from the group including a phenol derivative, a salicylic acid derivative, a urea derivative, and the like. In the following description, in a case where the first developer, the second developer, and the third developer are collectively referred to without being distinguished, they may be simply referred to as a developer.

[0080] Specifically, for example, the developer contains a compound represented by the following formula (1): (where, in the formula (1), X 0< is a divalent group including at least one benzene ring; Y 01< and Y 02< are each independently a monovalent group; n01 and n02 are each independently an integer of any one of 0 to 5; in a case where n01 is an integer of any one of 2 to 5, Y 01< may be the same as or different from each other; in a case where n02 is an integer of any one of 2 to 5, Y 02< may be the same as or different from each other; and Z 01< and Z 02< are each independently a hydrogen bonding group).

[0081] With X 0< including at least one benzene ring, the melting point can be increased as compared with a case where X 0< is an aliphatic hydrocarbon group (for example, a normal alkyl chain), so that the color development retention characteristics at the time of high temperature and high humidity storage (hereinafter, referred to as "high temperature and high humidity storage characteristics") can be improved. From the viewpoint of improving the high temperature and high humidity storage characteristics and heat resistance, X 0< preferably includes at least two benzene rings. The high temperature and high humidity storage characteristics are, for example, storage characteristics under an environment of 80°C and 60% RH. The increase in the heat resistance leads to an improvement in the resistance of the recording layer 10 to a severe process (for example, heat-pressing, integral molding using a molten resin or the like, or the like). In a case where X 0< includes at least two benzene rings, the at least two benzene rings may be fused. For example, naphthalene, anthracene, or the like may be used.

[0082] With Z 01< and Z 02< being each independently a hydrogen bonding group, the developers are likely to be present while being gathered to some extent via hydrogen bonds, and therefore stability of the developers in the color development layer 13 is improved. In the present specification, the hydrogen bonding group means a functional group including an atom capable of hydrogen bonding with an atom present in another functional group, another compound, or the like.

[0083] The developer preferably contains a compound represented by the following formula (2): (where, in the formula (2), X 1< is a divalent group including at least one benzene ring; Y 11< , Y 12< , Y 13< , and Y 14< are each independently a monovalent group; and Z 11< and Z 12< are each independently a hydrogen bonding group).

[0084] With X 1< including at least one benzene ring, the melting point can be increased as compared with a case where X 1< is an aliphatic hydrocarbon group (for example, a normal alkyl chain), so that the high temperature and high humidity storage characteristics can be improved. From the viewpoint of improving the high temperature and high humidity storage characteristics and heat resistance, X 1< preferably includes at least two benzene rings. In a case where X 1< includes at least two benzene rings, the at least two benzene rings may be fused. For example, naphthalene, anthracene, or the like may be used.

[0085] With Z 11< and Z 12< being each independently a hydrogen bonding group, the developers are likely to be present while being gathered to some extent via hydrogen bonds, and therefore stability of the developers in the color development layer 13 is improved.

[0086] In a case where the formula (1) and the formula (2) include a hydrocarbon group, the hydrocarbon group is a generic term for groups including carbon (C) and hydrogen (H), and may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The saturated hydrocarbon group is an aliphatic hydrocarbon group having no carbon-carbon multiple bond, and the unsaturated hydrocarbon group is an aliphatic hydrocarbon group having a carbon-carbon multiple bond (carbon-carbon double bond or carbon-carbon triple bond).

[0087] In a case where the formula (1) and the formula (2) include a hydrocarbon group, the hydrocarbon group may be a chain or may include one or two or more rings. The chain may be a linear chain, or may be a branched chain having one or two or more side chains or the like.(X 0< and X 1< with One Benzene Ring)

[0088] X 0< in the formula (1) and X 1< in the formula (2) are, for example, a divalent group including one benzene ring. The divalent group is represented by, for example, the following formula (3): (where, in the formula (3), X 21< may be present or absent, and in a case where X 21< is present, X 21< is a divalent group; X 22< may be present or absent, and in a case where X 22< is present, X 22< is a divalent group; R 21< is a monovalent group; n21 is an integer of any one of 0 to 4; in a case where n21 is an integer of any one of 2 to 4, R 21< may be the same as or different from each other; and * denotes a bonding portion).

[0089] In the formula (3), the bonding positions of X 21< and X 22< on the benzene ring are not limited. That is, the bonding positions of X 21< and X 22< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0090] From the viewpoint of improving high temperature and high humidity storage characteristics, the above-described divalent group including one benzene ring is preferably represented by the following formula (4): (where, in the formula (4), R 22< is a monovalent group; n22 is an integer of any one of 0 to 4; in a case where n22 is an integer of any one of 2 to 4, R 22< may be the same as or different from each other; and * denotes a bonding portion).

[0091] In a case where X 0< in the formula (1) is a divalent group including one benzene ring, the bonding positions of Z 01< and Z 02< on the benzene ring in the formula (4) are not limited. That is, the bonding positions of Z 01< and Z 02< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0092] In a case where X 1< in the formula (2) is a divalent group including one benzene ring, the bonding positions of Z 11< and Z 12< on the benzene ring in the formula (4) are not limited. That is, the bonding positions of Z 11< and Z 12< on the benzene ring may be any of ortho positions, meta positions, and para positions.(X 21< and X 22< )

[0093] X 21< and X 22< in the formula (3) are only required to be each independently a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is preferably in a chain form. With the hydrocarbon group in a chain form, the melting point of the developer can be reduced, allowing the developer to be dissolved by irradiation with laser light, and therefore the coloring compound readily develops a color. From the viewpoint of reducing the melting point of the developer, a normal alkyl chain is particularly preferable among the chain hydrocarbon groups.

[0094] The number of carbon atoms of the hydrocarbon group optionally having a substituent is, for example, 1 or more and 15 or less, 1 or more and 13 or less, 1 or more and 12 or less, 1 or more and 10 or less, 1 or more and 6 or less, or 1 or more and 3 or less.

[0095] In a case where X 21< and X 22< in the formula (3) are normal alkyl groups, the number of carbon atoms of the normal alkyl group is preferably 8 or less, more preferably 6 or less, still more preferably 5 or less, and particularly preferably 3 or less from the viewpoint of high temperature storage stability. It is considered that in a case where the number of carbon atoms of the normal alkyl group is 8 or less, due to the short length of the normal alkyl group, thermal disturbance is less likely to occur in the developer during high temperature storage, and a site that interacts with the coloring compound such as a leuco dye at the time of color development is less likely to be separated. Therefore, the coloring compound such as a leuco dye is less likely to be decolored during high temperature storage, and thus high temperature storage stability is improved.

[0096] Examples of the substituent that the hydrocarbon group optionally has include a halogen group (for example, a fluorine group), and an alkyl group having a halogen group (for example, a fluorine group). The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of carbon atoms of the hydrocarbon group (for example, a part of carbon atoms included in a main chain of the hydrocarbon group) with an element such as oxygen.(R 21< )

[0097] R 21< in the formula (3) is only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent.

[0098] The halogen group is, for example, a fluorine group (-F), a chlorine group (-Cl), a bromine group (-Br), or an iodine group (-I).

[0099] The number of carbon atoms of the hydrocarbon group optionally having a substituent is, for example, 1 or more and 15 or less, 1 or more and 13 or less, 1 or more and 12 or less, 1 or more and 10 or less, 1 or more and 6 or less, or 1 or more and 3 or less.

[0100] Examples of the substituent that the hydrocarbon group optionally has include a halogen group (for example, a fluorine group), and an alkyl group having a halogen group (for example, a fluorine group). The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of carbon atoms of the hydrocarbon group (for example, a part of carbon atoms included in a main chain of the hydrocarbon group) with an element such as oxygen.(R 22< )

[0101] R 22< in the formula (4) is only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for R 21< in the above formula (3).(X 0< and X 1< with Two Benzene Rings)

[0102] X 0< in the formula (1) and X 1< in the formula (2) are, for example, divalent groups including two benzene rings. The divalent group is represented by, for example, the following formula (5): (where, in the formula (5), X 31< may be present or absent, and in a case where X 31< is present, X 31< is a divalent group; X 32< may be present or absent, and in a case where X 32< is present, X 32< is a divalent group; X 33< may be present or absent, and in a case where X 33< is present, X 33< is a divalent group; R 31< and R 32< are each independently a monovalent group; n31 and n32 are each independently an integer of any one of 0 to 4; in a case where n31 is an integer of any one of 2 to 4, R 31< may be the same as or different from each other; in a case where n32 is an integer of any one of 2 to 4, R 32< may be the same as or different from each other; and * denotes a bonding portion).

[0103] In the formula (5), the bonding positions of X 31< and X 32< on the benzene ring are not limited. That is, the bonding positions of X 31< and X 32< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (5), the bonding positions of X 32< and X 33< on the benzene ring are not limited. That is, the bonding positions of X 32< and X 33< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0104] From the viewpoint of improving high temperature and high humidity storage characteristics, the above-described divalent group including two benzene rings is preferably represented by the following formula (6): (where, in the formula (6), X 34< is a divalent group; R 33< and R 34< are each independently a monovalent group; n33 and n34 are each independently an integer of any one of 0 to 4; in a case where n33 is an integer of any one of 2 to 4, R 33< may be the same as or different from each other; in a case where n34 is an integer of any one of 2 to 4, R 34< may be the same as or different from each other; and * denotes a bonding portion).

[0105] In a case where X 0< in the formula (1) is a divalent group including two benzene rings, the bonding positions of Z 01< and X 34< on the benzene ring in the formula (6) are not limited. That is, the bonding positions of Z 01< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (6), the bonding positions of Z 02< and X 34< on the benzene ring are not limited. That is, the bonding positions of Z 02< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0106] In a case where X 1< in the formula (2) is a divalent group including two benzene rings, the bonding positions of Z 11< and X 34< on the benzene ring in the formula (6) are not limited. That is, the bonding positions of Z 11< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (6), the bonding positions of Z 12< and X 34< on the benzene ring are not limited. That is, the bonding positions of Z 12< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions.(X 31< , X 32< , and X 33< )

[0107] X 31< , X 32< , and X 33< in the formula (5) are only required to be each independently a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is similar to that for X 21< and X 22< in the above formula (3).(X 34< )

[0108] X 34< in the formula (6) is only required to be a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is similar to that for X 21< and X 22< in the above formula (3).(R 31< and R 32< )

[0109] R 31< and R 32< in the formula (5) are only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for R 21< in the above formula (3).(R 33< and R 34< )

[0110] R 33< and R 34< in the formula (6) are only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for R 21< in the above formula (3).(Y 01< and Y 02< )

[0111] Y 01< and Y 02< in the formula (1) are each independently, for example, a hydrogen group (-H), a hydroxy group (-OH), a halogen group (-X), a carboxy group (-COOH), an ester group (-COOR), or a hydrocarbon group optionally having a substituent.

[0112] The halogen group is, for example, a fluorine group (-F), a chlorine group (-Cl), a bromine group (-Br), or an iodine group (-I).

[0113] The number of carbon atoms of the hydrocarbon group optionally having a substituent is, for example, 1 or more and 15 or less, 1 or more and 13 or less, 1 or more and 12 or less, 1 or more and 10 or less, 1 or more and 6 or less, or 1 or more and 3 or less.

[0114] Examples of the substituent that the hydrocarbon group optionally has include a halogen group (for example, a fluorine group), and an alkyl group having a halogen group (for example, a fluorine group). The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of carbon atoms of the hydrocarbon group (for example, a part of carbon atoms included in a main chain of the hydrocarbon group) with an element such as oxygen.

[0115] In the formula (1), it is preferable that one of (Y 01< ) n01 and / or one of (Y 02< ) n02 is a hydroxy group (-OH). With one of (Y 01< ) n01 and / or one of (Y 02< ) n02 being a hydroxy group (-OH), display quality and light resistance can be improved.(Y 11< , Y 12< , Y 13< , and Y 14< )

[0116] In the formula (2), the bonding positions of Y 11< and Y 12< on the benzene ring are not limited. That is, the bonding positions of Y 11< and Y 12< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (2), the bonding positions of Y 13< and Y 14< on the benzene ring are also not limited. That is, the bonding positions of Y 13< and Y 14< on the benzene ring may be any of ortho positions, meta positions, and para positions. In the formula (2), the bonding positions of Y 11< and Y 12< on one benzene and the bonding positions of Y 13< and Y 14< on the other benzene may be the same or different.

[0117] Y 11< , Y 12< , Y 13< , and Y 14< in the formula (2) each independently represent, for example, a hydrogen group (-H), a hydroxy group (-OH), a halogen group, a carboxy group (-COOH), an ester group (-COOR), or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for Y 01< and Y 02< in the above formula (1).

[0118] In the formula (2), Y 11< and / or Y 13< is preferably a hydroxy group (-OH). With Y 11< and / or Y 13< being a hydroxy group (-OH), display quality and light resistance can be improved.(Z 01< and Z 02< )

[0119] Z 01< and Z 02< in the formula (1) are each independently, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-), or a hydrazide bond (-NHCOCONH-). From the viewpoint of improving the high temperature and high humidity storage characteristics, Z 01< and Z 02< are preferably urea bonds. In a case where Z 01< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene. In a case where Z 02< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene.(Z 11< and Z 12< )

[0120] Z 11< and Z 12< in the formula (2) are each independently, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-), or a hydrazide bond (-NHCOCONH-). From the viewpoint of improving the high temperature and high humidity storage characteristics, Z 11< and Z 12< are preferably urea bonds. In a case where Z 11< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene. In a case where Z 12< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene.(Specific Examples of Developer)

[0121] Specifically, the developer in which X 0< in the formula (1) and X 1< in the formula (2) include one benzene ring contains, for example, at least one selected from the group consisting of compounds represented by the following formulas (7-1) to (7-6).

[0122] Specifically, the developer in which X 0< in the formula (1) and X 1< in the formula (2) include two benzene rings contains, for example, at least one selected from the group consisting of compounds represented by the following formulas (8-1) to (8-8). (First Photothermal Conversion Agent, Second Photothermal Conversion Agent, and Third Photothermal Conversion Agent)

[0123] The first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent can generate heat by absorbing light in a predetermined wavelength region such as a near-infrared region. The first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent have absorption wavelength peaks different from each other. Specifically, the first photothermal conversion agent has an absorption wavelength peak at about wavelength λ 1 . The second photothermal conversion agent has an absorption wavelength peak at about wavelength λ 2 . The third photothermal conversion agent has an absorption wavelength peak at about wavelength λ 3 . The wavelengths λ 1 , X 2 , and λ 3 are different from each other. The absorption wavelength peak is preferably in the near-infrared region. The near-infrared region is, for example, in a wavelength range of 700 nm or more and 2000 nm or less. As described above, since the first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent have absorption wavelength peaks different from each other, a desired layer among the color development layer 13A, the color development layer 13B, and the color development layer 13C can be selectively caused to develop color by irradiation with laser light. A near-infrared absorbing dye having almost no absorption in the visible region is preferably employed as the first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent.

[0124] The first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent each independently contain, for example, at least one selected from the group consisting of a compound having a phthalocyanine skeleton (phthalocyanine dye), a compound having a squarylium skeleton (squarylium dye), an inorganic compound, and the like.

[0125] The inorganic compound includes, for example, at least one selected from the group including metal complexes such as dithio complexes, diimmonium salts, aminium salts, graphite, carbon black, metal powder particles, metal oxides such as tricobalt tetraoxide, iron oxide, chromium oxide, copper oxide, titanium black, and indium tin oxide (ITO), metal nitrides such as niobium nitride, metal carbides such as tantalum carbide, metal sulfides, various magnetic powders, and the like. In addition, the inorganic compound may include a compound having a cyanine skeleton (cyanine dye) having excellent light resistance and heat resistance. Note that the excellent light resistance, as used herein, means that it is not decomposed by, for example, irradiation with light of a fluorescent lamp or the like under a use environment. The excellent heat resistance means that, for example, a film formed together with a polymer material does not change in maximum absorption peak value of the absorption spectrum by 20% or more after being stored at 150°C for 30 minutes, for example. Examples of such a compound having a cyanine skeleton include a compound having, in a molecule thereof, at least one of a counter ion being any one of SbF 6 , PF 6 , BF 4 , ClO 4 , CF 3 SO 3 , or (CF 3 SO 3 ) 2 N or a methine chain including a 5-membered ring or a 6-membered ring. Note that, although the compound having a cyanine skeleton used for the recording layer 10 in the first embodiment preferably has both any one of the above-described counter ions and a cyclic structure such as a 5-membered ring and a 6-membered ring in a methine chain, sufficient light resistance and heat resistance are secured as long as the compound has at least one of the counter ion or the cyclic structure.(First Matrix Resin, Second Matrix Resin, and Third Matrix Resin)

[0126] The first matrix resin, the second matrix resin, and the third matrix resin preferably have a function as a binder. The first matrix resin is preferably one in which the first coloring compound, the first developer, and the first photothermal conversion agent are likely to be uniformly dispersed. The second matrix resin is preferably one in which the second coloring compound, the second developer, and the second photothermal conversion agent are likely to be uniformly dispersed. The third matrix resin is preferably one in which the third coloring compound, the third developer, and the third photothermal conversion agent are likely to be uniformly dispersed. The types of the first matrix resin, the second matrix resin, and the third matrix resin may be the same, and the types of the first matrix resin, the second matrix resin, and the third matrix resin may be different from each other.

[0127] The first matrix resin, the second matrix resin, and the third matrix resin each independently contain, for example, at least one selected from the group consisting of a thermosetting resin, a thermoplastic resin, and the like. The first matrix resin, the second matrix resin, and the third matrix resin preferably contain a polycarbonate resin. With the first matrix resin, the second matrix resin, and the third matrix resin containing a polycarbonate resin, the light resistance of the background of the recording layer 10 can be improved. Here, the polycarbonate resin is a resin having a carbonate group (-O-(C=O)-O-) as a structural unit at least in the main chain. Therefore, other structural units may be included in the main chain in addition to the carbonate group.

[0128] The first matrix resin, the second matrix resin, and the third matrix resin may each independently contain, instead of or together with the polycarbonate resin, at least one selected from the group consisting of polyvinyl chloride, polyvinyl acetate, a vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, a styrenic copolymer, a phenoxy resin, polyester, an aromatic polyester, polyurethane, a polyacrylate, a polymethacrylate, an acrylic acid copolymer, a maleic acid polymer, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, and the like.(Additive)

[0129] The color development layer 13A, the color development layer 13B, and the color development layer 13C may further contain at least one additive selected from the group consisting of a sensitizer, an ultraviolet absorber, and the like as necessary. The color development layer 13A, the color development layer 13B, and the color development layer 13C preferably contain an amine compound from the viewpoint of preventing coloring of the background.

[0130] In a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C contain an amine compound, it is preferable that the color development layer 13A, the color development layer 13B, and the color development layer 13C contain at least one compound selected from the group consisting of an epoxy compound and a carbodiimide compound together with the amine compound. In a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C contain an amine compound, there is a possibility that the reliability of the color-developed portion during high temperature and high humidity storage is deteriorated; however, in a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C contain at least one compound selected from the group consisting of an epoxy compound and a carbodiimide compound together with the amine compound, the deterioration in reliability of the color-developed portion during high temperature and high humidity storage due to the amine compound can be prevented.(Intermediate Layer 12A, Intermediate Layer 12B, Intermediate Layer 12C, and Intermediate Layer 12D)

[0131] The intermediate layer 12A is provided between the base material 11 and the color development layer 13A. The intermediate layer 12A can thermally insulate the base material 11 and the color development layer 13A from each other and can suppress diffusion of a constituent material between the base material 11 and the color development layer 13A. The intermediate layer 12B is provided between the color development layer 13A and the color development layer 13B. The intermediate layer 12B can thermally insulate the color development layer 13A and the color development layer 13B from each other and can suppress diffusion of a constituent material between the color development layer 13A and the color development layer 13B. The intermediate layer 12C is provided between the color development layer 13B and the color development layer 13C. The intermediate layer 12C can thermally insulate the color development layer 13B and the color development layer 13C from each other and can suppress diffusion of a constituent material between the color development layer 13B and the color development layer 13C. The intermediate layer 12D is provided between the color development layer 13C and the cover layer 14. The intermediate layer 12D can thermally insulate the color development layer 13C and the cover layer 14 from each other and can suppress diffusion of a constituent material between the color development layer 13C and the cover layer 14.

[0132] The intermediate layer 12A may be either translucent or non-translucent with respect to laser light used for drawing on the recording layer 10 and visible light. The intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are translucent with respect to laser light used for drawing on the recording layer 10 and visible light.

[0133] Thicknesses of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are each independently preferably 3 µm or more and 100 µm or less, and more preferably 5 µm or more and 50 µm or less. With the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D having a thickness of 3 µm or more, a sufficient heat insulating effect can be obtained, and a sufficient diffusion suppressing effect can be obtained. On the other hand, with the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D having a thickness of 100 µm or less, deterioration of translucency with respect to visible light can be suppressed. Furthermore, it is also possible to suppress a decrease in bending resistance of the recording layer 10 and to make defects such as cracks less likely to occur. The thicknesses of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D may be the same or different from each other.

[0134] The intermediate layer 12A sequentially includes a bonding adhesive layer 12A 1 and an ultraviolet-curable resin layer 12A 2 on the base material 11. The bonding adhesive layer 12A 1 bonds the base material 11 and the ultraviolet-curable resin layer 12A 2 . The bonding adhesive layer 12A 1 may be capable of thermally insulating the base material 11 and the color development layer 13A from each other. The ultraviolet-curable resin layer 12A 2 can thermally insulate the base material 11 and the color development layer 13A from each other and can suppress diffusion of a constituent material (for example, the first coloring compound or the like) between the base material 11 and the color development layer 13A. However, the order of lamination of the bonding adhesive layer 12A 1 and the ultraviolet-curable resin layer 12A 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0135] The intermediate layer 12B sequentially includes a bonding adhesive layer 12B 1 and an ultraviolet-curable resin layer 12B 2 on the color development layer 13A. The bonding adhesive layer 12B 1 bonds the color development layer 13A and the ultraviolet-curable resin layer 12B 2 . The bonding adhesive layer 12B 1 may be capable of thermally insulating the color development layer 13A and the color development layer 13B from each other. The ultraviolet-curable resin layer 12B 2 can thermally insulate the color development layer 13A and the color development layer 13B from each other and can suppress diffusion of a constituent material (for example, the first coloring compound, the second coloring compound, or the like) between the color development layer 13A and the color development layer 13B. However, the order of lamination of the bonding adhesive layer 12B 1 and the ultraviolet-curable resin layer 12B 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0136] The intermediate layer 12C sequentially includes a bonding adhesive layer 12C 1 and an ultraviolet-curable resin layer 12C 2 on the color development layer 13B. The bonding adhesive layer 12C 1 bonds the color development layer 13B and the ultraviolet-curable resin layer 12C 2 . The bonding adhesive layer 12C 1 may be capable of thermally insulating the color development layer 13B and the color development layer 13C from each other. The ultraviolet-curable resin layer 12C 2 can thermally insulate the color development layer 13B and the color development layer 13C from each other and can suppress diffusion of a constituent material (for example, the second or third coloring compound, or the like) between the color development layer 13B and the color development layer 13C. However, the order of lamination of the bonding adhesive layer 12C 1 and the ultraviolet-curable resin layer 12C 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0137] The intermediate layer 12D sequentially includes a bonding adhesive layer 12D 1 and an ultraviolet-curable resin layer 12D 2 on the color development layer 13C. The bonding adhesive layer 12D 1 bonds the color development layer 13C and the ultraviolet-curable resin layer 12D 2 . The bonding adhesive layer 12D 1 may be capable of thermally insulating the color development layer 13C and the cover layer 14 from each other. The ultraviolet-curable resin layer 12D 2 can thermally insulate the color development layer 13C and the cover layer 14 from each other and can suppress diffusion of a constituent material (for example, the third coloring compound or the like) between the color development layer 13C and the cover layer 14. However, the order of lamination of the bonding adhesive layer 12D 1 and the ultraviolet-curable resin layer 12D 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0138] The bonding adhesive layer 12A 1 , the bonding adhesive layer 12B 1 , the bonding adhesive layer 12C 1 , and the bonding adhesive layer 12D 1 are, for example, double-sided sticky films such as an optical clear adhesive (OCA).

[0139] The ultraviolet-curable resin layer 12A 2 , the ultraviolet-curable resin layer 12B 2 , the ultraviolet-curable resin layer 12C 2 , and the ultraviolet-curable resin layer 12D 2 contain an ultraviolet-curable resin solidified by a polymerization reaction. More specifically, for example, the ultraviolet-curable resin layer 12A 2 , the ultraviolet-curable resin layer 12B 2 , the ultraviolet-curable resin layer 12C 2 , and the ultraviolet-curable resin layer 12D 2 contain a polymer of a polymerizable compound and a polymerization initiator whose structure is changed by generation of an active species by irradiation with external energy (ultraviolet ray). The ultraviolet-curable resin composition contains, for example, at least one selected from the group consisting of a radically polymerized ultraviolet-curable resin composition, a cationically polymerized ultraviolet-curable resin composition, and the like. The ultraviolet-curable resin composition may contain at least one selected from the group consisting of a sensitizer, a filler, a stabilizer, a leveling agent, an antifoaming agent, a viscosity modifier, and the like as necessary. The ultraviolet-curable resin layer 12A 2 , the ultraviolet-curable resin layer 12B 2 , the ultraviolet-curable resin layer 12C 2 , and the ultraviolet-curable resin layer 12D 2 are provided as necessary, and may not be provided. The ultraviolet-curable resin layer 12D 2 may have a function of cutting ultraviolet rays due to thermal curing.(Recording Layer 24)

[0140] The recording layer 24 is provided on the intermediate layer 23, and covers the intermediate layer 23 and the recording layer 10 included in the intermediate layer 23. The recording layer 24 is configured to be able to draw a monochromatic image (monochrome image) with laser light L 4 having a peak wavelength λ 4 . The monochromatic image can be visually recognized under visible light and can be imaged by an imaging apparatus under infrared rays. Examples of the color of a drawing portion (laser irradiation portion) of the monochromatic image include black and brown, but are not limited to these colors.

[0141] A lower limit value of the peak wavelength λ 4 is, for example, 1000 nm or more. An upper limit value of the peak wavelength λ 4 is, for example, 11 µm or less. Specifically, the peak wavelength λ 4 is, for example, about 1064 nm. The laser light L 4 having a peak wavelength λ 4 is an example of the second laser light having a second peak wavelength in the claims.

[0142] The recording layer 24 may have a film shape. The recording layer 24 may be translucent with respect to visible light in an initial state before recording. The recording layer 24 may have absorbability in the visible light region by irradiation with laser light, or may have absorbability in the visible light region from the beginning without irradiation with laser light. The recording layer 24 is preferably a laser marking layer. The laser marking layer may be a known laser marking sheet. Many of known laser marking sheets have absorbability in the visible light region by irradiation with laser light, or have absorbability in the visible light region from the beginning without irradiation with laser light. The laser marking layer is configured to be capable of laser marking by, for example, at least one of the following methods (1) to (5). However, the laser marking layer may be configured to be capable of laser marking by a method other than the following methods (1) to (5). (1) Method of foaming a resin material to develop color (2) Method of adding an additive that absorbs laser light to a resin material to develop color of the additive itself (3) Method of adding an additive that absorbs laser light to a resin material to cause the additive to generate heat and carbonize the surrounding resin material to develop color (4) Method of etching a surface of a resin layer by laser irradiation and utilizing a change in a surface state (5) Method of marking by sublimating (decomposing) a colorant (carbon black) to be decolored (to expose the base color of a resin material) by irradiating a resin material colored in black or a dark color system with laser light

[0143] Specifically, the laser marking layer contains, for example, a photothermal conversion agent and a resin material. The photothermal conversion agent contains, for example, carbon. The resin material includes, for example, a polycarbonate resin.

[0144] The peak wavelength λ 1 , the peak wavelength λ 2 , the peak wavelength λ 3 , and the peak wavelength λ 4 preferably satisfy a relationship of λ 3 < λ 2 < λ 1 < λ 4 . Therefore, the recording layer 10 and the recording layer 24 can be independently drawn.(Image of Drawing Region R1)

[0145] An image may be drawn in the drawing region R1 of the recording medium 20. Characters and the like may be drawn in a drawing region R2 of the recording medium 20. Hereinafter, an image drawn in the drawing region R1 will be described with reference to Fig. 4. Note that, in Fig. 4, a first image P1 and a visible image P3 are monochromatic images (black-and-white images), but may be multi-color images such as full-color images.

[0146] The image of the drawing region R1 is formed by overlapping the first image P1 drawn on the recording layer 10 and a second image P2 drawn on the recording layer 24 in the thickness direction of the recording medium 20. That is, the image of the drawing region R1 is a composite image of the first image P1 and the second image P2.

[0147] The first image P1 is a face photograph or the like. The first image P1 is, for example, a monochromatic image or a multi-color image. The multi-color image may be a full-color image. The first image P1 is visible under visible light, but cannot be captured under infrared rays.

[0148] The second image P2 is an image obtained by extracting a portion of the first image P1 where the contrast greatly changes as compared with the surroundings, more specifically, a contour (a part of the first image P1) extracted from the first image P1. The second image P2 may further include an image other than the contour. The second image P2 is, for example, a monochromatic image. The color of the monochromatic image is, for example, black or brown. The second image P2 can be visually recognized under visible light and can be imaged by an imaging apparatus under infrared rays.

[0149] The visible image P3 represents a visible image in a case where the image of the drawing region R1 is viewed under visible light. As the visible image P3, an image (composite image) obtained by superimposing the first image P1 and the second image P2 is visually recognized or captured. More specifically, for example, an image in which the contour of the first image P1 is black or brown is visually recognized as the visible image P3.

[0150] An infrared image (IR image) P4 represents a captured image in a case where an image of the drawing region R1 is captured by the imaging apparatus under infrared rays. As the infrared image P4, substantially the same image as the second image P2 is captured. In the present specification, substantially the same includes the same.[2.2 Method of Manufacturing Recording Medium]

[0151] Next, an example of a method of manufacturing the recording medium 20 according to the first embodiment of the present disclosure will be described.

[0152] First, the recording layer 10 is manufactured by forming the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14 on the base material 11. However, the order of formation of these layers on the base material 11 is not particularly limited, and may not be the order of the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14. Next, the base material 21 on which the underlayer 22 is formed is prepared. Next, after the intermediate layer 23 is placed on the underlayer 22, the recording layer 10 is fitted into the accommodation part 23HL of the intermediate layer 23. Note that the intermediate layer 23 in which the recording layer 10 is fitted in advance in the accommodation part 23HL may be placed on the underlayer 22. Next, the recording layer 24 is placed on the intermediate layer 23.

[0153] Next, the laminate obtained as described above is sandwiched between metal plates and pressurized while being heated, thereby thermally fusing the underlayer 22 and the intermediate layer 23 together, and the intermediate layer 23 and the recording layer 24 together. A temperature applied to the laminate during the thermal fusion is preferably 130°C or higher and 200°C or lower. If the temperature applied to the laminate is 130°C or higher, a sufficient fusion strength can be obtained. On the other hand, if the temperature applied to the laminate is 200°C or lower, damage to the recording layer 10 can be reduced. As a result, a target recording medium 20 is obtained.[2.3 Configuration of Drawing System]

[0154] Next, an example of a configuration of a drawing system 50 used for drawing on the recording medium 20 will be described with reference to Fig. 5. The drawing system 50 includes a control apparatus 51, an imaging apparatus 52, a colorimeter 53, a display unit 54, an operation unit 55, a laser light irradiation apparatus (first irradiation apparatus) 56, and a laser light irradiation apparatus (second irradiation apparatus) 57.(Imaging Apparatus 52)

[0155] The imaging apparatus 52 captures an image such as a face photograph to be drawn on the recording medium 20 on the basis of the control of the control apparatus 51. The imaging apparatus 52 may include a control unit. In this case, the control unit of the imaging apparatus 52 may execute the imaging operation on the basis of a command of the control apparatus 51.(Colorimeter 53)

[0156] The colorimeter 53 colorimetrically measures a color chart drawn on a sample on the basis of the control of the control apparatus 51. The sample may have the same configuration as the recording medium 20. The colorimeter 53 may include a control unit. In this case, the control unit of the colorimeter 53 may execute the colorimetric operation on the basis of a command of the control apparatus 51.(Display Unit 54)

[0157] The display unit 54 is, for example, a display such as a liquid crystal display or an organic electro luminescence (EL) display. These displays may be touch panel built-in displays. The display unit 54 displays an image under the control of the control apparatus 51. For example, the display unit 54 displays an operation menu of the drawing system 50, an image captured by the imaging apparatus 52, and the like.(Operation Unit 55)

[0158] The operation unit 55 is a user interface such as a keyboard and a pointing device. The operation unit 55 may be a voice input unit. The operation unit 55 may be a touch panel of the display unit 54. The operation unit 55 may be a physical button. The operation unit 55 is an interface that receives a user's operation. The operation unit 55 outputs operation data corresponding to a user's operation to a processing unit. The operation unit 55 may be capable of receiving an operation on the screen of the display unit 54.(Control Apparatus 51)

[0159] The control apparatus 51 controls an operation of the drawing system 50. Specifically, the control apparatus 51 controls operations of the imaging apparatus 52, the colorimeter 53, the display unit 54, the operation unit 55, the laser light irradiation apparatus 56, and the laser light irradiation apparatus 57.

[0160] The control apparatus 51 generates a first drawing setting file and a second drawing setting file from the measurement result of the reference color chart measured by the colorimeter 53, and stores the first drawing setting file and the second drawing setting file in the storage unit 511.

[0161] The control apparatus 51 converts the original image stored in the storage unit 511 into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 to generate drawing data (data of the driving voltage value) of the first image P1, on the basis of the first drawing setting file stored in the storage unit 511. The control apparatus 51 controls the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 to draw the first image P1 on the recording layer 10.

[0162] The control apparatus 51 processes the original image stored in the storage unit 511 and generates drawing data of the second image P2. More specifically, after extracting contour data from the original image stored in the storage unit 511, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 on the basis of the second drawing setting file stored in the storage unit 511 to generate drawing data (data of the driving voltage value) of the second image P2. The control apparatus 51 controls the laser light irradiation apparatus 57 on the basis of the drawing data of the second image P2 to draw the second image P2 on the recording layer 24.

[0163] The control apparatus 51 includes, for example, a processing unit 512, a storage unit 511, and an interface unit (hereinafter, referred to as "I / F unit") 513. The control apparatus 51 can be configured by, for example, an information processing device such as a personal computer.(Storage Unit 511)

[0164] The storage unit 511 includes, for example, a semiconductor memory, a magnetic storage device, or a combination thereof. The semiconductor memory includes, for example, a random access memory (RAM), a read only memory (ROM), an erasable programmable read only memory (EPROM), an electrically erasable and programmable read only memory (EEPRPM), a solid state drive (SSD), a flash memory, or a combination of two or more thereof. The magnetic storage device includes, for example, a hard disk drive (HDD). The storage unit 511 stores an operation program of the drawing system 50.

[0165] Furthermore, the storage unit 511 stores data of the color chart drawn on the sample and a measurement result of the color chart measured by the colorimeter 53. The storage unit 511 stores the image captured by the imaging apparatus 52 as an original image. Moreover, the storage unit 511 may store an image received from a cloud server or the like via the I / F unit 513 as an original image.

[0166] Furthermore, the storage unit 511 also stores the first drawing setting file and the second drawing setting file generated by the control apparatus 51. The first drawing setting file is a file for converting the original image into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 to generate drawing data (data of the driving voltage value) of the first image P1. The second drawing setting file is a file for converting the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 to generate drawing data (data of the driving voltage value) of the second image P2. The extracted data is data extracted from the original image stored in the storage unit 511, and is contour data of the original image stored in the storage unit 511 in the first embodiment.(Processing Unit 512)

[0167] The processing unit 512 is, for example, a central processing unit (CPU). The processing unit 512 is configured to perform various control operations by reading a program from the storage unit 511 and executing the read program. This program may be stored in the storage unit 511 in advance, or may be acquired and stored in the storage unit 511 when necessary. The program may be acquired, for example, by being read from various recording media readable by the control apparatus 51 or by being received via a communication line connected to the I / F unit 513.(I / F Unit 513)

[0168] The I / F unit 513 includes a communication module, and can transmit and receive information to and from the imaging apparatus 52, the colorimeter 53, the display unit 54, the operation unit 55, the laser light irradiation apparatus 56, and the laser light irradiation apparatus 57. The I / F unit 513 can also receive and transmit information with a server such as a cloud server via the Internet. The I / F unit 513 includes at least one of a wired interface or a wireless interface.(Laser Light Irradiation Apparatus 56)

[0169] The laser light irradiation apparatus 56 is for drawing the recording layer 10, and is configured to be able to irradiate the color development layer 13A with the laser light L 1 having a peak wavelength λ 1 , irradiate the color development layer 13B with the laser light L 2 having a peak wavelength λ 2 , and irradiate the color development layer 13C with the laser light L 3 having a peak wavelength λ 3 . The laser light irradiation apparatus 56 draws the first image P1 on the recording layer 10 on the basis of the drawing data of the recording layer 10 read from the storage unit 511 (that is, the drawing data of the first image P1) on the basis of the control of the control apparatus 51. The laser light irradiation apparatus 56 includes, for example, a semiconductor laser apparatus. The laser light irradiation apparatus 56 may include a control unit. In this case, the control unit of the laser light irradiation apparatus 56 may execute the drawing operation on the basis of a command of the control apparatus 51.(Laser Light Irradiation Apparatus 57)

[0170] The laser light irradiation apparatus 57 is for drawing the recording layer 24, and is configured to be able to irradiate the recording layer 24 with the laser light L 4 having a wavelength λ 4 . The laser light irradiation apparatus 57 draws the second image P2 on the recording layer 24 on the basis of the drawing data of the recording layer 24 read from the storage unit 511 (that is, the drawing data of the second image P2) on the basis of the control of the control apparatus 51. The laser light irradiation apparatus 57 includes, for example, a YAG laser apparatus, a YV04 laser apparatus, or a CO 2 laser apparatus. The laser light irradiation apparatus 57 may include a control unit. In this case, the control unit of the laser light irradiation apparatus 57 may perform the drawing operation on the basis of a command of the control apparatus 51.[2.4 Method of Generating First Drawing Setting File]

[0171] Next, an example of a method for generating a first drawing setting file will be described with reference to Fig. 6.

[0172] First, in step S11, the control apparatus 51 controls the laser light irradiation apparatus 56 on the basis of the data for reference color chart drawing stored in the storage unit 511, and draws the reference color chart on the recording layer 10 of a first sample. The first sample used for drawing in step S11 may have the same configuration as the recording medium 20, or may have a configuration in which the recording layer 24 is omitted from the recording medium 20. Next, in step S12, the control apparatus 51 controls the colorimeter 53 to measure the color of the reference color chart drawn on the recording layer 10 of the sample in step S11.

[0173] Next, in step S13, the control apparatus 51 generates a first grayscale voltage conversion table and international color consortium (ICC) profile on the basis of the colorimetric values measured in step S12. Next, in step S14, the control apparatus 51 generates a first drawing setting file by using the first grayscale voltage conversion table and the ICC profile generated in step S13, and stores the first drawing setting file in the storage unit 511. In the first grayscale voltage conversion table, a correspondence relationship between a grayscale value in the leuco color space and an output setting value is described. Therefore, an output setting value suitable for drawing the leuco image data is obtained. The ICC profile is a series of data that characterizes input / output devices and a color space related to color according to an ICC published standard in color management. The ICC profile is preferably used for excellent color reproduction, but may be omitted as necessary.[2.5 Method of Generating Second Drawing Setting File]

[0174] Next, an example of a method for generating a second drawing setting file will be described with reference to Fig. 7.

[0175] First, in step S21, the control apparatus 51 controls the laser light irradiation apparatus 57 on the basis of the data for reference color chart drawing stored in the storage unit 511, and draws the reference color chart on the recording layer 24 of a second sample. The second sample used for drawing in step S21 may have the same configuration as the recording medium 20, or may have a configuration in which the recording layer 10 is omitted from the recording medium 20. The reference color chart used for drawing in step S21 may be the same as or different from the reference color chart used for the method for generating the first drawing setting file. Next, in step S22, the control apparatus 51 controls the colorimeter 53 to measure the color of the reference color chart drawn on the recording layer 24 of the sample in step S21.

[0176] Next, in step S23, the control apparatus 51 generates a second grayscale voltage conversion table on the basis of the colorimetric values measured in step S22. Next, in step S24, the control apparatus 51 generates a second drawing setting file using the second grayscale voltage conversion table generated in step S23, and stores the second drawing setting file in the storage unit 511. In the second grayscale voltage conversion table, the correspondence relationship between the grayscale value and the output setting value is described.[2.6 Drawing Method of Recording Medium]

[0177] Next, an example of a drawing method of the recording medium 20 will be described with reference to Fig. 8.

[0178] In step S31, the control apparatus 51 controls the imaging apparatus 52 to capture an image such as a face photograph and to store the image in the storage unit 511 as an original image.

[0179] In step S32, using the first drawing setting file stored in the storage unit 511, the control apparatus 51 converts the original image stored in the storage unit 511 into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 to generate drawing data of the first image P1.

[0180] In step S33, after extracting contour data from the original image stored in the storage unit 511, the control apparatus 51 converts the extracted data into a driving voltage value of the laser light irradiation apparatus 57 using the second drawing setting file to generate drawing data of the second image P2.

[0181] In step S34, the control apparatus 51 controls the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32 to draw the first image P1 on the recording layer 10. Furthermore, the control apparatus 51 controls the laser light irradiation apparatus 57 on the basis of the drawing data of the second image P2 generated in step S33 to draw the second image P2 on the recording layer 24. At this time, the drawing of the first image P1 and the drawing of the second image P2 are performed such that the contour (part of the first image P1) of the first image P1 included in the second image P2 overlaps the first image P1 of the recording layer 10.

[0182] A drawing step of the recording layer 10 and a drawing step of the recording layer 24 may be performed simultaneously or may be performed at different timings. In a case where the drawing step of the recording layer 10 and the drawing step of the recording layer 24 are performed at different timings, the order of these drawing steps is not particularly limited, but it is preferable to perform the drawing step of the recording layer 10 before the drawing step of the recording layer 24. This is for the following reason. If the recording layer 24 is drawn, a drawing portion (color-developed portion) exhibits infrared absorbency. Therefore, if the drawing step of the recording layer 24 is performed before the drawing step of the recording layer 10, there is a possibility that the near-infrared laser light is absorbed by the drawing portion of the recording layer 24 at the time of drawing on the recording layer 10, and the drawing property of the recording layer 10 is affected. Thus, if the drawing step of the recording layer 10 is performed before the drawing step of the recording layer 24, it is possible to prevent the drawing portion of the recording layer 24 from affecting the drawing property of the recording layer 10.

[0183] Details of the drawing step of the first image P1 are as described below (step S35). Here, a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C exhibit a cyan color, a magenta color, and a yellow color, respectively, will be described as an example. As a scanning method of the laser light L 1 , the laser light L 2 , and the laser light L 3 , for example, a raster scanning method can be used, but the scanning method is not limited thereto.

[0184] The control apparatus 51 drives the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32, and irradiates the color development layer 13A with the laser light (near-infrared laser light) L 1 having a peak wavelength λ 1 . Therefore, the photothermal conversion material contained at the irradiation position of the color development layer 13A generates heat, a coloring reaction (color development reaction) occurs between the coloring compound and the developer, and the irradiation position of the color development layer 13A develops a cyan color.

[0185] The control apparatus 51 drives the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32, and irradiates the color development layer 13B with the laser light (near-infrared laser light) L 2 having a peak wavelength λ 2 . Therefore, a coloring reaction similar to that of the color development layer 13A described above occurs, and the irradiation position of the color development layer 13B develops a magenta color.

[0186] The control apparatus 51 drives the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32, and irradiates the color development layer 13C with the laser light (near-infrared laser light) L 3 having a peak wavelength λ 3 . Therefore, a coloring reaction similar to that of the color development layer 13A described above occurs, and the irradiation position of the color development layer 13C develops a yellow color.

[0187] As described above, the irradiation positions of the color development layer 13A, the color development layer 13B, and the color development layer 13C develop magenta, cyan, and yellow colors, respectively, whereby a desired first image P1 is drawn on the recording medium 20.

[0188] Note that, in a case where the laser light irradiation apparatus 56 irradiates the recording layer 24 with the laser light L 1 , the laser light L 2 and the laser light L 3 , the recording layer 24 is not laser-marked. This is because the recording layer 24 does not contain an additive that absorbs the laser light L 1 , the laser light L 2 , and the laser light L 3 .

[0189] The irradiation of the color development layer 13A with the laser light L 1 , the irradiation of the color development layer 13B with the laser light L 2 , and the irradiation of the color development layer 13C with the laser light L 3 may be performed simultaneously, or may be performed at different timings. In a case where the irradiation with the laser light L 1 , the laser light L 2 , and the laser light L 3 is performed at different timings, the order of the irradiation with the laser light L 1 , the laser light L 2 , and the laser light L 3 is arbitrary.

[0190] Details of the drawing step of the second image P2 are as described below (step S36). The laser light irradiation apparatus 57 drives the laser light irradiation apparatus 57 on the basis of the drawing data of the second image P2, and irradiates the recording layer 24 with the laser light L 4 having a peak wavelength λ 4 . Therefore, an additive (for example, a photothermal conversion agent) contained in a predetermined position of the recording layer 24 absorbs the laser light L 4 , and the predetermined position is laser-marked, so that the second image P2 is drawn. As a scanning method of the laser light L 4 , for example, a raster scanning method can be used, but the scanning method is not limited thereto.

[0191] Note that, in a case where the laser light irradiation apparatus 57 irradiates the recording layer 10 with the laser light L 4 , the recording layer 10 does not develop color. This is because the recording layer 10 does not contain an additive that absorbs the laser light L 4 .[2.7 Operation and Effect]

[0192] As described above, in the recording medium 20 according to the first embodiment, the recording layer (first recording layer) 10 is configured to be able to draw with the laser light L 1 , the laser light L 2 , and the laser light L 3 having a peak wavelength λ 1 , a peak wavelength λ 2 , and a peak wavelength λ 3 , respectively. On the other hand, the recording layer (second recording layer) 24 is configured to be able to draw with the laser light L 4 having a peak wavelength λ 4 . The peak wavelength λ 1 , the peak wavelength λ 2 , the peak wavelength λ 3 , and the peak wavelength λ 4 are set to different values. Therefore, since the drawing conditions of the laser light of the recording layer 10 and the recording layer 24 are different, when the recording layer 10 is drawn, it is possible to suppress that the recording layer 24 located on the upper side of the recording layer 10 is unintentionally drawn and drawing on the recording layer 10 becomes difficult. Therefore, it is possible to perform intended drawing on the recording layer 10.

[0193] In the recording medium 20 according to the first embodiment, an image may be drawn in the drawing region R1 of the recording medium 20. The image of the drawing region R1 is formed by overlapping the first image P1 drawn on the recording layer 10 and a second image P2 drawn on the recording layer 24 in the thickness direction of the recording medium 20. The first image P1 is visible under visible light, and cannot be captured by the imaging apparatus under infrared rays. The second image P2 can be visually recognized under visible light and can be imaged by an imaging apparatus under infrared rays. The second image P2 is a partial image of the first image P1, and is a contour image of the first image P1 in the first embodiment. Therefore, the authenticity of the recording medium 20 can be determined by comparing the visible image P3 of the drawing region R1 visually recognized under visible light with the infrared image P4 of the drawing region R1 captured under infrared rays and determining whether the infrared image P4 matches the contour of the visible image P3. Therefore, security of the recording medium 20 can be improved.

[0194] As shown in Fig. 4, since the second image P2 is a partial image of the first image P1, specifically, a contour image of the first image P1, even in a case where the second image P2 is drawn so as to overlap above the first image P1, it is possible to prevent the first image P1 that is a multi-color image from being hidden by the second image P2 that is a monochromatic image such as black or brown. Therefore, the deterioration of the display quality of the recording medium 20 can be suppressed.<3 Second Embodiment>[3.1 Configuration of Recording Medium]

[0195] Fig. 9 is a cross-sectional view of a recording medium 20A according to a second embodiment of the present disclosure. The recording medium 20A is different from the recording medium 20 in the first embodiment in sequentially including the recording layer 24, the intermediate layer 23, and a resin layer 25 on the base material 21.

[0196] The resin layer 25 is translucent with respect to visible light. The resin layer 25 is, for example, a film. As a material of the resin layer 25, a material similar to that of the base material 21 can be exemplified.

[0197] An image may be drawn in the drawing region R1 of the recording medium 20. The second image P2 may be a monochromatic image obtained by performing grayscale conversion or the like on the first image P1, or the second image P2 may be a partial image of the first image P1, for example, a contour image of the first image P1. However, from the viewpoint of suppressing deterioration in display quality of the recording medium 20, the second image P2 is preferably a partial image of the first image P1.

[0198] Here, the reason why it is preferable that the second image P2 is a partial image of the first image P1 will be described by exemplifying a case where the second image P2 is a contour image of the first image P1.

[0199] In Fig. 10, both the first image P1 and the second image P2 are monochromatic images, but actually, the first image P1 is a multi-color image such as a full-color image, and the second image P2 is a monochromatic image such as black or brown. Note that the interval of oblique lines attached to the first image P1 and the visible image P3 represents the brightness of the image, and the wider the interval of oblique lines, the brighter the image.

[0200] If the second image P2 is a monochromatic image obtained by subjecting the first image P1 to grayscale conversion or the like, the second image P2 that is a monochromatic image of black, brown, or the like may be seen behind the first image P1 that is a multi-color image such as a full-color image. In this case, as shown in Fig. 10, the visible image P3 in the drawing region R1 becomes darker than the first image P1 drawn on the recording layer 10, and there is a possibility that the display quality of the recording medium 20 deteriorates.

[0201] On the other hand, if the second image P2 is the contour image of the first image P1, as shown in Fig. 4, there is a possibility that the contour of the visible image P3 in the drawing region R1 is emphasized by the overlap between the first image P1 and the second image P2; however, it is possible to prevent the visible image P3 in the drawing region R1 from becoming darker than the first image P1 drawn on the recording layer 10. Therefore, the deterioration of the display quality of the recording medium 20 can be suppressed.[3.2 Operation and Effect]

[0202] In the recording medium 20A according to the second embodiment, the recording layer 24 and the recording layer 10 located on the upper side of the recording layer 24 have different drawing conditions by laser light. Therefore, when the recording layer 24 is drawn, it is possible to prevent the recording layer 10 located on the upper side of the recording layer 24 from being unintentionally drawn. Therefore, it is possible to perform intended drawing on the recording layer 24.

[0203] In the recording medium 20A according to the second embodiment, as shown in Fig. 11A, even in a case where a drawing region 10R is set to protrude from the peripheral edge of the recording layer 10 in plan view, it is possible to suppress color development of the recording layer 24 due to irradiation of the recording layer 10 with laser light for drawing. Therefore, as shown in Fig. 11B, an image such as a photograph can be drawn only on the recording layer 10. Furthermore, since the boundary between the recording layer 10 and the recording layer 24 in the in-plane direction of the recording medium 20A can be drawn without concern in a production line or the like, throughput and yield can be improved.

[0204] On the other hand, as shown in Fig. 12, in a recording medium 120A including a general full-color laser drawing sheet 110 instead of the recording layer 10, the drawing conditions of the full-color laser drawing sheet 110 and the recording layer 24 located below the full-color laser drawing sheet 110 are substantially the same. Therefore, in plan view, in a case where the drawing region 10R is set so as to protrude from the peripheral edge of the full-color laser drawing sheet 110, the recording layer 24 develops color by irradiation of the laser light for drawing of the full-color laser drawing sheet 110. Therefore, as shown in Fig. 12, an image such as a photograph is drawn out of the full-color laser drawing sheet 110. Furthermore, an image of a portion protruding from the full-color laser drawing sheet 110 is drawn in a color (for example, black or brown) different from that of the full-color laser drawing sheet 110.<4 Modifications>[Modification 1]

[0205] In the first embodiment and the second embodiment, an example in which the second image P2 of the recording layer 24 includes the contour of the first image P1 of the recording layer 10 has been described (see Fig. 4). However, the present disclosure is not limited to this example, and for example, as shown in Fig. 13, the second image P2 of the recording layer 24 may include a black portion of the first image P1 of the recording layer 10. Note that Fig. 13 shows an example in which the first image P1 is a face photograph and the second image P2 includes a hair and a pupil in the face photograph of the first image P1.

[0206] In a case where the second image P2 of the recording layer 24 includes a black portion of the first image P1 of the recording layer 10, substantially the same image as the first image P1 is visually recognized as the visible image P3 as shown in Fig. 13. As the infrared image P4, as shown in Fig. 13, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0207] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts the black portion from the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the black portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57, and generates drawing data of the second image P2.

[0208] The data corresponding to the black portion of the first image P1 is, for example, data equal to or more than a specified voltage value V th in the drawing data (data of the driving voltage value) of the first image P1. In a case where the maximum voltage value in the drawing data of the first image P1 is V max , the specified voltage value V th is, for example, V max × 0.8 or V max × 0.9.[Modification 2]

[0209] As shown in Fig. 14, the second image P2 of the recording layer 24 may include both a contour P21 of the first image P1 of the recording layer 10 and a black portion P22 of the first image P1 of the recording layer 10.

[0210] In a case where the second image P2 of the recording layer 24 includes both the contour P21 of the first image P1 of the recording layer 10 and the black portion P22 of the first image P1 of the recording layer 10, an image in which the contour of the first image P1 is black, brown, or the like is visually recognized as the visible image P3 as shown in Fig. 14. As the infrared image P4, as shown in Fig. 14, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0211] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts both the contour P21 of the first image P1 of the recording layer 10 and the black portion P22 from the first image P1, and combines the contour P21 and the black portion P22 to generate the second image P2. Details of the extraction processing of the contour of the first image P1 in the control apparatus 51 are as described in the first embodiment. Details of the extraction processing of the black portion of the first image P1 in the control apparatus 51 are as described in Modification 1.[Modification 3]

[0212] In Modification 2, an example in which the second image P2 of the recording layer 24 includes the contour P21 of the first image P1 of the recording layer 10 and the black portion P22 of the first image P1 of the recording layer 10 has been described (see Fig. 14). However, the present disclosure is not limited to this example, and for example, the second image P2 of the recording layer 24 may include a color-developed portion having a prescribed color development density or more in the first image P1 of the recording layer 10 instead of the black portion P22 of the first image P1 of the recording layer 10. The color-developed portion having a prescribed color development density or more may be a substantially maximum color development density portion. Alternatively, the color-developed portion having a prescribed color development density or more may be a color development density portion having a color density of 1.0 or more. This is because a very clear image can be obtained if the color density is 1.0 or more.

[0213] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts a color-developed portion having a prescribed color development density or more in the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the color-developed portion having a prescribed color development density or more in the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57, and generates drawing data of the second image P2.[Modification 4]

[0214] As shown in Fig. 15, the second image P2 of the recording layer 24 may include a key plate portion (K portion) of the first image P1 of the recording layer 10. In Fig. 15, both the first image P1 and the second image P2 are monochromatic images, but actually, the first image P1 is a multi-color image such as a full-color image, and the second image P2 is a monochromatic image such as black or brown. Note that the interval of oblique lines attached to the first image P1 and the visible image P3 represents the brightness of the image, and the wider the interval of oblique lines, the brighter the image.

[0215] In a case where the second image P2 of the recording layer 24 includes the key plate portion of the first image P1 of the recording layer 10, there is a possibility that an image slightly darker than the first image P1 is visually recognized as the visible image P3 as shown in Fig. 15. As the infrared image P4, as shown in Fig. 15, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0216] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts the key plate portion of the first image P1 of the recording layer 10 to generate the second image P2. More specifically, after extracting data corresponding to the key plate portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 to generate drawing data (data of the driving voltage value) of the second image P2.

[0217] After correcting the first image P1 to be bright, the control apparatus 51 may draw the corrected first image P1 on the recording layer 10. In this case, it is possible to prevent the visible image P3 from becoming a darker image than the first image P1 by combining the first image P1 and the second image P2.

[0218] Examples of the correction method for brightening the first image P1 include, but are not limited to, a correction method for increasing the brightness L* of the first image P1. It is preferable to correct the first image P1 so that the brightness, for example, the brightness L*, of the first image P1 before correction and the visible image P3 (the composite image of the first image P1 and the second image P2 after correction) becomes substantially the same.[Modification 5]

[0219] As shown in Fig. 16, a second image P2 of the recording layer 24 may include a background portion 17 of the first image P1 of the recording layer 10. The second image P2 of the recording layer 24 may further include at least one of the contour of the first image P1 of the recording layer 10 or the black portion of the first image P1 of the recording layer 10. In a case where the second image P2 of the recording layer 24 includes the background portion 17 of the first image P1 of the recording layer 10, the density of the background portion 17 of the second image P2 may be different from the density of the background portion 17 of the first image P1. For example, the density of the background portion 17 of the second image P2 may be higher than the density of the background portion 17 of the first image P1.

[0220] In a case where the second image P2 of the recording layer 24 includes the background portion 17 of the first image P1 of the recording layer 10, an image in which the background portion 17 is darker than the first image P1 is visually recognized as the visible image P3 as shown in Fig. 16. As the infrared image P4, as shown in Fig. 16, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0221] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts the background portion 17 of the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the background portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57, and generates drawing data of the second image P2.

[0222] The control apparatus 51 may extract the background portion of the first image P1 and at least one of the contour of the first image P1 or the black portion of the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the background portion of the first image P1 and data corresponding to at least one of the contour of the first image P1 or the black portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 may convert the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 to generate drawing data of the second image P2.[Modification 6]

[0223] As shown in Fig. 17, the second image P2 of the recording layer 24 may include the contour of the first image P1 of the recording layer 10 and identification information 15. The identification information 15 is added to a portion of the second image P2 corresponding to the black portion of the first image P1. The identification information 15 is information for determining authenticity of the recording medium 20, and may be a pattern or the like.

[0224] In a case where the recording layer 10 is provided on the upper side of the recording layer 24 and the second image P2 of the recording layer 24 includes the contour of the first image P1 of the recording layer 10 and the identification information 15, in the visible image P3, as shown in Fig. 17, the identification information 15 is hidden by the black portion of the first image P1 and cannot be visually recognized. In the infrared image P4, as shown in Fig. 17, the identification information 15 is not hidden by the black portion of the first image P1, and thus can be confirmed. Therefore, the authenticity of the recording medium 20 can be determined by confirming the identification information 15, which is hidden by the black portion in the visible image P3, by the infrared image P4.

[0225] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts both the contour of the first image P1 and the black portion from the first image P1. After replacing the extracted black portion with the identification information 15 of a pattern or the like, the control apparatus 51 generates the second image P2 by combining the contour of the extracted first image P1 and the replaced identification information 15 of a pattern or the like.[Modification 7]

[0226] As shown in Fig. 18, the first image P1 of the recording layer 10 may include identification information 16. The identification information 16 is information for determining authenticity of the recording medium 20, and may be, for example, a mark, a pattern or the like, or a combination thereof. Examples of the position of the identification information 16 in the first image P1 include, but are not limited to, a background portion.

[0227] In a case where the first image P1 of the recording layer 10 includes the identification information 16, the identification information 16 can be visually recognized in the visible image P3 as shown in Fig. 18. In the infrared image P4, as shown in Fig. 18, the identification information 16 cannot be confirmed. Therefore, the authenticity of the recording medium 20 can be determined by checking the presence or absence of the identification information 16 in the infrared image P4.

[0228] The control apparatus 51 of the drawing system 50 generates drawing data of the first image P1 as follows. That is, after adding the identification information 16 to the original image stored in the storage unit 511, the control apparatus 51 converts the original image to which the identification information 16 is added into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 using the first drawing setting file stored in the storage unit 511 to generate drawing data of the first image P1.[Modification 8]

[0229] In the first embodiment and the second embodiment, an example in which the size of the recording layer 10 in plan view is smaller than the size of the recording layer 24 in plan view has been described (see Figs. 2 and 9). However, the size of the recording layer 10 and the size of the recording layer 24 are not limited to this example.

[0230] For example, as shown in Fig. 19, the size of the recording layer 10 in plan view may be substantially the same as the size of the recording layer 24 in plan view. In this case, the sizes of the recording layer 10 and the recording layer 24 in plan view may be substantially the same as the sizes of the base material 21 and the underlayer 22 in plan view.

[0231] For example, as shown in Fig. 20, the size of the recording layer 10 in plan view may be larger than the size of the recording layer 24 in plan view. In this case, the recording layer 24 may be accommodated in the accommodation part 23HL of the intermediate layer 23, and the recording layer 10 may be provided between the base material 21 and the intermediate layer 23.[Modification 9]

[0232] In the second embodiment, an example in which the recording medium 20A includes the intermediate layer 23 including the recording layer 10 on the recording layer 24 has been described (see Fig. 9). However, the layer configuration of the recording medium 20A is not limited to this example. For example, as shown in Fig. 21, the recording medium 20A may further include a wavelength selection layer 26 between the intermediate layer 23 including the recording layer 10 and the recording layer 24. The wavelength selection layer 26 is configured to reflect visible light and to transmit near infrared rays (NIR). Examples of the wavelength selection layer 26 include, but are not limited to, a dielectric multilayer film.[Modification 10]

[0233] In the first embodiment and the second embodiment, an example in which the recording layer 10 includes three layers of the color development layer 13A, the color development layer 13B, and the color development layer 13C has been described (see Fig. 3). However, the layer configuration of the recording layer 10 is not limited thereto, and the recording layer 10 may include one, two, or three or more color development layers. In a case where the recording layer 10 includes one color development layer, the color development layer may be any color development layer of the color development layer 13A, the color development layer 13B, and the color development layer 13C, or may be a color development layer that can exhibit a color different from those layers in the color-developed state, for example, a color development layer that can exhibit a black color in the color-developed state.[Modification 11]

[0234] In the first embodiment, an example in which the recording medium 20 includes the base material 21 and the underlayer 22 has been described (see Fig. 2). However, the configuration is not limited to this example of the recording medium 20, and the recording medium 20 may not include at least one of the base material 21 or the underlayer 22.[Modification 12]

[0235] In the second embodiment, an example in which the recording medium 20A includes the base material 21 and the resin layer 25 has been described (see Fig. 9). However, the configuration is not limited to this example of the recording medium 20A, and the recording medium 20A may not include at least one of the base material 21 or the resin layer 25.[Modification 13]

[0236] In the first embodiment, an example in which the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14 are formed on the base material 11 has been described. However, the method of manufacturing the recording layer 10 is not limited thereto, and for example, the recording layer 10 may be manufactured as follows.

[0237] The recording layer 10 may be manufactured by using the cover layer 14 as a base material and forming the intermediate layer 12D, the color development layer 13C, the intermediate layer 12C, the color development layer 13B, the intermediate layer 12B, and the color development layer 13A on the cover layer 14. However, the order of formation of these layers on the cover layer 14 is not particularly limited, and may not be the order of the intermediate layer 12D, the color development layer 13C, the intermediate layer 12C, the color development layer 13B, the intermediate layer 12B, and the color development layer 13A. In the case of manufacturing the recording layer 10 as described above, the base material 11 and the intermediate layer 12A may be formed on the color development layer 13A or may not be formed. In a case where the base material 11 and the intermediate layer 12A are not formed on the color development layer 13A, the recording layer 10 can be thinned. On the other hand, in a case where the base material 11 and the intermediate layer 12A are formed on the color development layer 13A, since the base material 11 functions as a protective layer, the durability of the recording layer 10 can be improved.

[0238] The recording layer 10 may be manufactured by using the color development layer 13A as a base material and forming the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14 on the color development layer 13A. However, the order of formation of these layers on the color development layer 13A is not particularly limited, and may not be the order of the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14. In the case of manufacturing the recording layer 10 as described above, the base material 11 and the intermediate layer 12A may be formed below the color development layer 13A or may not be formed.[Modification 14]

[0239] In the first embodiment, an example in which the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D include a bonding adhesive layer and an ultraviolet-curable resin layer has been described. However, the configurations of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are not limited thereto, and for example, configurations described below can also be adopted.

[0240] Fig. 22 is a cross-sectional view of a first modification of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D. The intermediate layer 12A may include a bonding adhesive layer 12A 3 between the ultraviolet-curable resin layer 12A 2 and the color development layer 13A. The intermediate layer 12B may include a bonding adhesive layer 12B 3 between the ultraviolet-curable resin layer 12B 2 and the color development layer 13B. The intermediate layer 12C may include a bonding adhesive layer 12C 3 between the ultraviolet-curable resin layer 12C 2 and the color development layer 13C. The intermediate layer 12D may include a bonding adhesive layer 12D 3 between the ultraviolet-curable resin layer 12D 2 and a color development layer 13D. Although Fig. 22 shows an example in which the recording layer 10 includes the bonding adhesive layer 12A 3 , the bonding adhesive layer 12B 3 , the bonding adhesive layer 12C 3 , and the bonding adhesive layer 12D 3 , the recording layer 10 may include at least one of the bonding adhesive layer 12A 3 , the bonding adhesive layer 12B 3 , the bonding adhesive layer 12C 3 , or the bonding adhesive layer 12D 3 .[Modification 15]

[0241] Fig. 23 is a cross-sectional view of a second modification of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D. An intermediate layer 22A, an intermediate layer 22B, an intermediate layer 22C, and an intermediate layer 22D may be constituted by adhesive layers. The adhesive layer may be a thermal adhesive layer. The thermal adhesive layer contains a thermal adhesive resin that is softened or melted at a predetermined temperature to bond the layers. Other components contained in the thermal adhesive layer are not particularly limited. As the thermal adhesive resin, a thermoplastic resin that becomes soft when heated to a softening point or a melting point can be used. The thermoplastic resin is not particularly limited, and includes, for example, at least one selected from the group consisting of a polyamide resin, a polyester resin, a polyethylene resin, an ethylene-vinyl acetate copolymer (EVA), a polyurethane resin, an acrylic resin, and the like. The predetermined temperature varies depending on the type of the thermoplastic resin used for the thermal adhesive resin.

[0242] Fig. 23 shows an example in which all the layers of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are constituted by an adhesive layer, but at least one of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, or the intermediate layer 12D may be constituted by an adhesive layer. In a case where all the layers of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are constituted by thermal adhesive layers, the interlayer regions between the respective layers of the recording layer 10 can be collectively bonded by the thermal adhesive layers.[Modification 16]

[0243] In the first embodiment, the imaging apparatus 52 and the colorimeter 53 are not essential components in the drawing system 50, and at least one of the imaging apparatus 52 or the colorimeter 53 may not be included in the drawing system 50.

[0244] In a case where the imaging apparatus 52 is not included in the drawing system 50, the control apparatus 51 may acquire an image (for example, a picture, a photograph, or the like) used for drawing on the recording medium 20 from the outside of the drawing system 50 in a wired or wireless manner via the I / F unit 513. Specifically, for example, the control apparatus 51 may acquire an image to be used for drawing the recording medium 20 from a cloud server or the like, or from an external memory or the like. The control apparatus 51 may store the acquired image in the storage unit 511.

[0245] In a case where the colorimeter 53 is not included in the drawing system 50, the generation of the first drawing setting file and the second drawing setting file may be performed outside the drawing system 50. In this case, the control apparatus 51 may acquire the first drawing setting file and the second drawing setting file from the outside of the drawing system 50 in a wired or wireless manner via the I / F unit 513.[Modification 17]

[0246] In the first embodiment, the drawing system 50 may further include an external storage unit. In this case, the external storage unit may store the data of the color chart drawn on the sample and the measurement result of the color chart measured by the colorimeter 53. Furthermore, the external storage unit may store an image captured by the imaging apparatus 52, and the first drawing setting file and the second drawing setting file generated by the control apparatus 51.(Other Modifications)

[0247] The embodiments and modifications of the present disclosure have been specifically described above, but the present disclosure is not limited to the above-described embodiments and modifications, and various modifications based on the technical idea of the present disclosure may be made.

[0248] For example, configurations, methods, processes, shapes, materials, numerical values, and the like in the above-described embodiments and modifications are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, and the like may be employed as necessary.

[0249] The configurations, methods, steps, shapes, materials, and numerical values and the like of the above-described embodiments and modifications can be combined with each other without departing from the gist of the present disclosure.

[0250] In numerical value ranges described in stages in the above-described embodiments and modifications, an upper limit value or a lower limit value of a numerical value range of a certain stage may be replaced with an upper limit value or a lower limit value of a numerical value range of another stage.

[0251] The materials exemplified in the above embodiment and modifications may be used alone or in combination of two or more unless otherwise specified.

[0252] Furthermore, the present disclosure may also employ the following configurations. (1) A recording medium including: a first recording layer configured to be able to draw with first laser light having a first peak wavelength; and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium. (2) The recording medium according to (1), in which the second recording layer is configured to be able to draw an image visible under visible light and capable of being captured under infrared rays. (3) The recording medium according to (1) or (2), in which a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, the second image includes a part of the first image, and the part of the first image included in the second image overlaps the first image of the first recording layer. (4) The recording medium according to (3), in which the part of the first image includes a contour of the first image. (5) The recording medium according to (3), in which the part of the first image includes a color-developed portion having a prescribed color development density or more in the first image. (6) The recording medium according to (3), in which the part of the first image includes a substantially maximum color development density portion in the first image. (7) The recording medium according to (3), in which the part of the first image includes a black portion of the first image. (8) The recording medium according to (3), in which the part of the first image includes a contour of the first image and a black portion of the first image or a key plate portion of the first image. (9) The recording medium according to (3), in which the first recording layer is provided on an upper side of the second recording layer, and at least a part of the second image is hidden by the first image of the first recording layer under visible light. (10) The recording medium according to (1), in which a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, and a composite image is formed by the first image and the second image. (11) The recording medium according to (10), in which the second image includes at least one of a black portion of the composite image or a background portion of the composite image. (12) The recording medium according to any one of (1) to (11), in which the first color development layer further contains a matrix resin, a developer, and a photothermal conversion agent. (13) The recording medium according to any one of (1) to (12), in which the first recording layer is configured to be able to draw with third laser light having a third peak wavelength and fourth laser light having a fourth peak wavelength, the first recording layer further includes: a second color development layer configured to be able to develop color with the third laser light and containing a second leuco dye; and a third color development layer configured to be able to develop color with the fourth laser light and containing a third leuco dye, and the first peak wavelength, the second peak wavelength, the third peak wavelength, and the fourth peak wavelength are different from each other. (14) A drawing method including: irradiating a first recording layer of a recording medium with first laser light having a first peak wavelength to draw a first image; and irradiating a second recording layer of the recording medium with second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium. (15) The drawing method according to (14), in which the second image includes a part of the first image, and drawing of the first image and drawing of the second image are performed such that the part of the first image included in the second image overlaps the first image. (16) The drawing method according to (14) or (15), further including extracting second image information for drawing the second image from first image information for drawing the first image. (17) The drawing method according to any one of (14) to (16), further including correcting first image information for drawing the first image such that the first image becomes brighter. (18) A drawing system including: a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength; a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength; and a control apparatus configured to be able to control the first irradiation apparatus and the second irradiation apparatus, in which the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image. (19) The drawing system according to (18), in which the control apparatus further executes extracting second image information for drawing the second image from first image information for drawing the first image. (20) The drawing system according to (18) or (19), in which the control apparatus further executes correcting first image information for drawing the first image such that the first image becomes brighter. (21) A control apparatus capable of controlling a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength and a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength, the control apparatus executing: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image. REFERENCE SIGNS LIST

[0253] 10 Recording layer (first recording layer) 11 Base material 12A, 12B, 12C, 12D Intermediate layer 12A 1 , 12B 1 , 12C 1 , 12D 1 Bonding adhesive layer 12A 2 , 12B 2 , 12C 2 , 12D 2 Ultraviolet-curable resin layer 13A, 13B, 13C Color development layer 14 Cover layer 15, 16 Identification information 17 Background portion 20 Recording medium 21 Base material 22 Underlayer 23 Intermediate layer 23HL Accommodation part 24 Recording layer (second recording layer) 25 Resin layer 50 Drawing system 51 Control apparatus 52 Imaging apparatus 53 Colorimeter 54 Display unit 55 Operation unit 56 Laser light irradiation apparatus 57 Laser light irradiation apparatus 511 Storage unit 512 Processing unit 513 Network I / F R1, R2 Drawing region P1 First image P2 Second image P3 Visible image P4 Infrared image

Examples

first embodiment

[2.1 Configuration of Recording Medium]

[0047]Fig. 1 is a perspective view of a recording medium 20 according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along a line II-II in Fig. 1. The recording medium 20 sequentially includes a base material 21, an underlayer 22, an intermediate layer 23 including a recording layer (first recording layer) 10, and a recording layer (second recording layer) 24.

[0048]The base material 21 and the underlayer 22 may be bonded to each other by fusion bonding or an adhesive. The underlayer 22 and the intermediate layer 23 may be bonded to each other by fusion bonding or an adhesive. The intermediate layer 23 and the recording layer 24 may be bonded to each other by fusion bonding or an adhesive.

[0049]The recording medium 20 may be a card such as a security card, a financial payment card (for example, a credit card, a cash card, or the like), an ID card (for example, an employee ID card, a membership card, a stu...

second embodiment

[3.1 Configuration of Recording Medium]

[0195]Fig. 9 is a cross-sectional view of a recording medium 20A according to a second embodiment of the present disclosure. The recording medium 20A is different from the recording medium 20 in the first embodiment in sequentially including the recording layer 24, the intermediate layer 23, and a resin layer 25 on the base material 21.

[0196] The resin layer 25 is translucent with respect to visible light. The resin layer 25 is, for example, a film. As a material of the resin layer 25, a material similar to that of the base material 21 can be exemplified.

[0197]An image may be drawn in the drawing region R1 of the recording medium 20. The second image P2 may be a monochromatic image obtained by performing grayscale conversion or the like on the first image P1, or the second image P2 may be a partial image of the first image P1, for example, a contour image of the first image P1. However, from the viewpoint of suppressing deterioration in display...

modification 1

[Modification 1]

[0205]In the first embodiment and the second embodiment, an example in which the second image P2 of the recording layer 24 includes the contour of the first image P1 of the recording layer 10 has been described (see Fig. 4). However, the present disclosure is not limited to this example, and for example, as shown in Fig. 13, the second image P2 of the recording layer 24 may include a black portion of the first image P1 of the recording layer 10. Note that Fig. 13 shows an example in which the first image P1 is a face photograph and the second image P2 includes a hair and a pupil in the face photograph of the first image P1.

[0206]In a case where the second image P2 of the recording layer 24 includes a black portion of the first image P1 of the recording layer 10, substantially the same image as the first image P1 is visually recognized as the visible image P3 as shown in Fig. 13. As the infrared image P4, as shown in Fig. 13, substantially the same image as the second...

TECHNICAL FIELD

[0001] The present disclosure relates to a recording medium, a drawing method, and a drawing system.BACKGROUND ART

[0002] In recent years, a recording medium including a first recording layer and a second recording layer having different recording methods has been studied. For example, Patent Document 1 describes a laminate including a laminated film colored in cyan (C), magenta (M), and yellow (Y) by a pigment, and a near infrared laser marking layer for compensating grayscale.CITATION LISTPATENT DOCUMENT

[0003] Patent Document 1: WO 2019 / 129527 ASUMMARY OF THE INVENTIONPROBLEMS TO BE SOLVED BY THE INVENTION

[0004] However, in the conventional recording medium including a first recording layer and a second recording layer having different recording methods, intended drawing cannot be performed in some cases.

[0005] An object of the present disclosure is to provide a recording medium, a drawing method, and a drawing system by which intended drawing can be performed.SOLUTIONS TO PROBLEMS

[0006] In order to solve the above problem, a recording medium according to the present disclosure includes: a first recording layer configured to be able to draw with first laser light having a first peak wavelength; and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0007] A drawing method according to the present disclosure includes: irradiating a first recording layer of a recording medium with first laser light having a first peak wavelength to draw a first image; and irradiating a second recording layer of the recording medium with second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0008] A drawing system according to the present disclosure includes: a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength; a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength; and a control apparatus configured to be able to control the first irradiation apparatus and the second irradiation apparatus, in which the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image. BRIEF DESCRIPTION OF DRAWINGS

[0009] Fig. 1 is a perspective view of a recording medium according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along a line II-II in Fig. 1. Fig. 3 is a cross-sectional view of a recording layer. Fig. 4 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 5 is a block diagram of a drawing system. Fig. 6 is a flowchart for describing an example of a method for generating a first drawing setting file. Fig. 7 is a flowchart for describing an example of a method for generating a second drawing setting file. Fig. 8 is a flowchart for describing an example of a drawing method. Fig. 9 is a cross-sectional view of a recording medium according to a second embodiment of the present disclosure. Fig. 10 is a schematic view of a first image, a second image, a visible image, and an infrared image. Figs. 11A and 11B are views for describing an example of the drawing method. Fig. 12 is a view for describing an example of an imaging method. Fig. 13 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 14 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 15 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 16 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 17 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 18 is a schematic view of a first image, a second image, a visible image, and an infrared image. Fig. 19 is a cross-sectional view of a recording medium according to a modification. Fig. 20 is a cross-sectional view of a recording medium according to a modification. Fig. 21 is a cross-sectional view of a recording medium according to a modification. Fig. 22 is a cross-sectional view of a first modification of intermediate layers. Fig. 23 is a cross-sectional view of a second modification of intermediate layers. MODE FOR CARRYING OUT THE INVENTION

[0010] Embodiments of the present disclosure are described in the following order. Note that the same or corresponding portions will be denoted by the same reference signs in all the drawings of the following embodiments. 1 Description of Outline of Recording Medium According to Present Disclosure 2 First embodiment (example of recording medium) 2.1 Configuration of recording medium 2.2 Method of Manufacturing Recording Medium 2.3 Configuration of Drawing System 2.4 Method of Generating First Drawing Setting File 2.5 Method of Generating Second Drawing Setting File 2.6 Drawing Method of Recording Medium 2.7 Operation and Effect 3 Second Embodiment (Example of Recording Medium) 3.1 Configuration of Recording Medium 3.2 Operation and Effect 4 Modifications <1 Description of Outline of Recording Medium According to Present Disclosure>

[0011] A recording medium according to the present disclosure includes: a first recording layer configured to be able to draw with first laser light having a first peak wavelength; and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0012] In the conventional recording medium, since the drawing conditions (wavelengths) of the laser light of the first recording layer and the second recording layer are the same, if at least parts of the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, the other recording layer may be unintentionally drawn. On the other hand, in the recording medium according to the present disclosure, since the drawing conditions (wavelengths) of the laser light of the first recording layer and the second recording layer are different, even if at least parts of the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, the other recording layer can be suppressed from being unintentionally drawn.

[0013] In the recording medium according to the present disclosure, at least parts of the first recording layer and the second recording layer overlap each other in the thickness direction of the recording medium, so that a first image drawn on the first recording layer and a second image drawn on the second recording layer can be superimposed. Therefore, the second image can be used for authenticity determination of the recording medium. Furthermore, a composite image can be formed by the first image and the second image.

[0014] In order to enhance the security of the recording medium, it is preferable that a first image visible under visible light is drawn on the first recording layer, a second image capable of being captured under light irradiation other than visible light is drawn on the second recording layer, and the first image and the second image overlap each other. Here, examples of light other than visible light include ultraviolet rays and infrared rays, and an imaging method using infrared rays is generally often used.

[0015] However, since the first recording layer has translucency with respect to visible light even after the first image is drawn, in a case where the second recording layer is provided on the back surface side of the first recording layer, the second image may be visually recognized behind the first image. In this case, there is a possibility that the visibility of the first image of the first recording layer decreases, and the display quality of the recording medium deteriorates. Specifically, for example, in a case where the first image is a multi-color image such as a full-color image and the second image is a monochrome image (monochromatic image) such as a black image or a brown image, there is a possibility that the display quality of the recording medium deteriorates because the color-developed portion of the first image becomes difficult to see or the first image appears dark.

[0016] On the other hand, in a case where the second recording layer is provided on the front surface side of the first recording layer, there is a possibility that the first image of the first recording layer is covered with the second image of the second recording layer, and the display quality of the recording medium deteriorates. Specifically, for example, in a case where the first image is a multi-color image such as a full-color image and the second image is a monochrome image (monochromatic image) such as a black image or a brown image, there is a possibility that the first image that is a multi-color image is hidden by the second image that is a monochrome image, and the display quality of the recording medium deteriorates.

[0017] In order to suppress the deterioration of the display quality described above, the second image is preferably an image including a part of the first image. If the second image is an image including a part of the first image, an overlapping portion between the first image and the second image can be reduced. Therefore, in a case where the second recording layer is provided on the back surface side of the first recording layer, it is possible to suppress the second image from being visually recognized behind the first image. On the other hand, in a case where the second recording layer is provided on the front surface side of the first recording layer, it is possible to suppress the first image of the first recording layer from being covered with the second image of the second recording layer. Therefore, the deterioration of the display quality of the recording medium can be suppressed. The second image preferably includes, as a part of the first image, at least one selected from the group consisting of a contour of the first image, a color-developed portion having a prescribed color development density or more in the first image, a background portion of the first image, and the like. The color-developed portion having a prescribed color development density or more in the first image may include a substantially maximum color development density portion in the first image or a black portion of the first image.

[0018] In the recording medium according to the present disclosure, it is preferable that the second recording layer is configured to be able to draw a second image visible under visible light and capable of being captured under infrared rays. Therefore, the recording medium is imaged by the imaging apparatus, and the presence or absence of the second image drawn on the second recording layer is confirmed, whereby the authenticity of the recording medium can be determined. Furthermore, the second image drawn on the second recording layer is captured by the imaging apparatus and compared with a reference image, whereby the authenticity of the recording medium can also be determined. The reference image is, for example, the first image drawn on the first recording layer, an original image of the first image stored on a network such as a cloud server, or an original image of the first image stored in a terminal device.

[0019] In the recording medium according to the present disclosure, it is preferable that a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, the second image includes a part of the first image, and the part of the first image included in the second image overlaps the first image of the first recording layer. Therefore, the authenticity of the recording medium can be determined by comparing an overlapping portion between the first image and the second image, that is, a common portion between the first image and the second image.

[0020] In order to suppress the deterioration of the display quality of the recording medium due to the overlap between the first image and the second image, it is preferable that a part of the first image includes at least one of a contour of the first image or a color-developed portion having a prescribed color development density or more in the first image. The color-developed portion having a prescribed color development density or more in the first image may include a substantially maximum color development density portion in the first image or a black portion of the first image. The part of the first image described above may include a contour of the first image and a key plate portion of the first image.

[0021] In the recording medium according to the present disclosure, it is preferable that the first recording layer is provided on an upper side of the second recording layer, and at least a part of the second image is hidden by the first image of the first recording layer under visible light. Therefore, it is possible to determine the authenticity of the recording medium by capturing the second image by the imaging apparatus under infrared rays and confirming at least a part of the second image hidden under visible light.

[0022] In the recording medium according to the present disclosure, it is preferable that a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, and a composite image is formed by the first image and the second image. Therefore, it is possible to determine the authenticity of the recording medium by capturing the composite image by the imaging apparatus under infrared rays and confirming the presence or absence of the second image. Furthermore, it is also possible to determine the authenticity of the recording medium by capturing the composite image by the imaging apparatus under infrared rays and comparing the composite image with a reference image. The reference image is, for example, the first image drawn on the first recording layer, an original image of the first image stored on a network such as a cloud server, or an original image of the first image stored in a terminal device.

[0023] In a case where a composite image is formed by the first image and the second image, the second image preferably includes at least one of a black portion of the composite image or a background portion of the composite image.

[0024] In the recording medium according to the present disclosure, the first color development layer preferably further contains at least one selected from the group consisting of a matrix resin, a developer, and a photothermal conversion agent, and more preferably further contains a matrix resin, a developer, and a photothermal conversion agent.

[0025] In the recording medium according to the present disclosure, it is preferable that the first recording layer is configured to be able to draw with third laser light having a third peak wavelength and fourth laser light having a fourth peak wavelength, the first recording layer further includes: a second color development layer configured to be able to develop color with the third laser light and containing a second leuco dye; and a third color development layer configured to be able to develop color with the fourth laser light and containing a third leuco dye, and the first peak wavelength, the second peak wavelength, the third peak wavelength, and the fourth peak wavelength are different from each other.

[0026] Since the first recording layer further includes the second color development layer and the third color development layer, the first image can be formed by the color-developed portions of the first color development layer, the second color development layer, and the third color development layer. Therefore, a multi-color image can be drawn as the first image on the first recording layer. For example, in a case where the first color development layer, the second color development layer, and the third color development layer are configured to be able to develop a cyan color, a magenta color, and a yellow color, respectively, a full-color image can be drawn as the first image on the first recording layer.

[0027] In the recording medium according to the present disclosure, the second color development layer and the third color development layer each independently preferably further contain at least one selected from the group consisting of a matrix resin, a developer, and a photothermal conversion agent, and more preferably further contain a matrix resin, a developer, and a photothermal conversion agent.

[0028] In the recording medium according to the present disclosure, the first recording layer may be provided above the second recording layer, or the first recording layer may be provided below the second recording layer. In order to suppress the deterioration of the display quality of the first image under visible light, the first recording layer is preferably provided above the second recording layer. The recording medium may have a first surface on which the drawn first image and second image are visually recognized and a second surface opposite to the first surface. The upper side may represent the first surface side, and the lower side may represent the second surface side.

[0029] In the recording medium according to the present disclosure, the first recording layer may be in contact with the second recording layer, or the first recording layer and the second recording layer may be separated from each other. In a case where the first recording layer is in contact with the second recording layer, the first recording layer and the second recording layer may be fusion-bonded. In a case where the first recording layer and the second recording layer are separated from each other, a bonding adhesive layer or an adhesive layer may be provided between the first recording layer and the second recording layer, or an intermediate layer having translucency or wavelength selectivity may be provided between the first recording layer and the second recording layer. The intermediate layer having translucency is, for example, an organic material layer, an inorganic material layer, or an organic-inorganic hybrid material layer. The intermediate layer having wavelength selectivity is preferably configured to be able to reflect visible light and transmit infrared light. The intermediate layer having wavelength selectivity is, for example, a dielectric multilayer film.

[0030] In the recording medium according to the present disclosure, from the viewpoint of improving the security of the recording medium, the peel strength between the respective layers constituting the recording medium is preferably 3.5 N / cm 2< or more and more preferably 5.0 N / cm 2< .

[0031] In the recording medium according to the present disclosure, an area of the first recording layer in plan view and an area of the second recording layer in plan view may be substantially the same or different. In a case where the area of the first recording layer is different from the area of the second recording layer, the area of the first recording layer may be larger than the area of the second recording layer, or the area of the first recording layer may be smaller than the area of the second recording layer.

[0032] The area of the first recording layer in plan view may be substantially the same as the area of the recording medium in plan view, or may be smaller than the area of the recording medium in plan view. The recording medium may further include a first base material layer that accommodates the first recording layer, and the first base material layer may have substantially the same area as the recording medium in plan view. In a case where the area of the first recording layer is smaller than the area of the recording medium, the first recording layer may be accommodated in an accommodation part of the first base material layer.

[0033] The area of the second recording layer in plan view may be substantially the same as the area of the recording medium in plan view, or may be smaller than the area of the recording medium in plan view. The recording medium may further include a second base material layer that accommodates the second recording layer, and the second base material layer may have substantially the same area as the recording medium in plan view. In a case where the area of the second recording layer is smaller than the area of the recording medium, the second recording layer may be accommodated in an accommodation part of the second base material layer.

[0034] In the recording medium according to the present disclosure, a reflection layer is preferably further provided below the first recording layer and the second recording layer from the viewpoint of improving the visibility of the first image and the second image.

[0035] The recording medium according to the present disclosure may further include at least one layer selected from the group consisting of a cover layer, an overlay layer, a protective layer, and the like. The at least one layer is provided, for example, on at least one of the first surface side of the recording medium, the second surface side of the recording medium, or the lateral surface side of the recording medium.

[0036] A drawing method according to the present disclosure includes: irradiating a first recording layer of a recording medium with first laser light having a first peak wavelength to draw a first image; and irradiating a second recording layer of the recording medium with second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

[0037] In the drawing method according to the present disclosure, since the drawing conditions (wavelengths) of the laser light of the first recording layer and the second recording layer are different, even if the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, the other recording layer can be suppressed from being unintentionally drawn.

[0038] In the drawing method according to the present disclosure, the order of drawing of the first image and drawing of the second image is not limited, and the second image may be drawn after the first image is drawn, the first image may be drawn after the second image is drawn, or the first image and the second image may be drawn simultaneously.

[0039] In the drawing method of the present disclosure, it is preferable that the second image includes a part of the first image, and drawing of the first image and drawing of the second image are performed such that the part of the first image included in the second image overlaps the first image. Therefore, the second image can be used for authenticity determination of the recording medium. Furthermore, a composite image can be formed by the first image and the second image.

[0040] The drawing method according to the present disclosure preferably further includes extracting second image information for drawing the second image from first image information for drawing the first image. Therefore, the drawing of the first image and the drawing of the second image can be performed such that a part of the first image overlaps the second image.

[0041] The drawing method according to the present disclosure preferably further includes correcting first image information for drawing the first image such that the first image becomes brighter. Therefore, it is possible to prevent the first image from appearing dark due to the overlapping of the first image and the second image.

[0042] A drawing system according to the present disclosure includes: a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength; a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength; and a control apparatus configured to be able to control the first irradiation apparatus and the second irradiation apparatus, in which the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image.

[0043] In the drawing system according to the present disclosure, since the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light having a first peak wavelength and causing a first leuco dye contained in the first color development layer of the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, even if the first recording layer and the second recording layer overlap each other, when one recording layer of the first recording layer or the second recording layer is drawn, it is possible to suppress unintentional drawing of the other recording layer.

[0044] In the drawing system according to the present disclosure, the order of drawing of the first image and drawing of the second image is not limited, and the control apparatus may execute drawing of the second image after drawing of the first image, may execute drawing of the first image after drawing of the second image, or may simultaneously execute drawing of the first image and the second image.

[0045] In the drawing system according to the present disclosure, it is preferable that the control apparatus further executes extracting second image information for drawing the second image from first image information for drawing the first image. Therefore, the drawing of the first image and the drawing of the second image can be performed such that a part of the first image overlaps the second image.

[0046] In the drawing system according to the present disclosure, it is preferable that the control apparatus further executes correcting first image information for drawing the first image such that the first image becomes brighter. Therefore, it is possible to prevent the first image from appearing dark due to the overlapping of the first image and the second image.<2 First Embodiment>[2.1 Configuration of Recording Medium]

[0047] Fig. 1 is a perspective view of a recording medium 20 according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along a line II-II in Fig. 1. The recording medium 20 sequentially includes a base material 21, an underlayer 22, an intermediate layer 23 including a recording layer (first recording layer) 10, and a recording layer (second recording layer) 24.

[0048] The base material 21 and the underlayer 22 may be bonded to each other by fusion bonding or an adhesive. The underlayer 22 and the intermediate layer 23 may be bonded to each other by fusion bonding or an adhesive. The intermediate layer 23 and the recording layer 24 may be bonded to each other by fusion bonding or an adhesive.

[0049] The recording medium 20 may be a card such as a security card, a financial payment card (for example, a credit card, a cash card, or the like), an ID card (for example, an employee ID card, a membership card, a student ID card, or the like), or a personal transaction card (for example, a prepaid card, a points card, or the like). The recording medium 20 may be a sheet constituting a booklet such as a passport. The recording medium 20 may be a housing of an electronic device or the like.

[0050] The recording medium 20 includes a drawing region R1 and a drawing region R2. The drawing region R1 is a region for drawing first information. The first information is, for example, image information such as a face photograph. In the first embodiment, an example in which the image information is color image information will be described. However, the image information is not limited to the color image information, and may be monochromatic image information (monochrome image information). The drawing region R1 is a region in which information can be recorded on both the recording layer 10 and the recording layer 24.

[0051] The drawing region R2 is a region for drawing second information. The second information is, for example, character information. The second information may further include image information such as a pattern and a picture. The drawing region R2 is a region in which information can be recorded on the recording layer 24.(Base Material 21)

[0052] The base material 21 is a support that supports the underlayer 22, the intermediate layer 23, and the recording layer 24. The base material 21 may be a card, a sheet, paper, a housing, or the like. The base material 21 may have a color such as white. In the base material 21, a pattern, a picture, a photograph, a character, a combination of two or more thereof, or the like (hereinafter, referred to as a "pattern or the like") may be printed on a surface on a side on which the underlayer 22, the intermediate layer 23, and the recording layer 24 are provided.

[0053] The base material 21 contains, for example, plastic. The base material 21 may contain at least one selected from the group consisting of a colorant, an antistatic agent, a flame retardant, a surface modifier, and the like as necessary.

[0054] The plastic includes, for example, at least one selected from the group including an ester resin, an amide resin, an olefin resin, a vinyl resin, an acrylic resin, an imide resin, a styrenic resin, an engineering plastic, and the like. In a case where the base material 21 contains two or more resins, the two or more resins may be mixed, copolymerized, or laminated.

[0055] The ester resin includes, for example, at least one selected from the group including a polyethylene terephthalate (PET) resin, a polybutylene terephthalate (PBT) resin, a polyethylene naphthalate (PEN) resin, a polyethylene terephthalate-isophthalate copolymer resin, a terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer resin, and the like. The amide resin includes, for example, at least one selected from the group including a nylon 6 resin, a nylon 66 resin, a nylon 610 resin, and the like. The olefin resin includes, for example, at least one selected from the group including a polyethylene (PE) resin, a polypropylene (PP) resin, a polymethylpentene (PMP) resin, and the like. The vinyl resin includes, for example, a polyvinyl chloride (PVC) resin.

[0056] The acrylic resin includes, for example, at least one selected from the group including a polyacrylate resin, a polymethacrylate resin, a polymethyl methacrylate (PMMA) resin, and the like. The imide resin includes, for example, at least one selected from the group including a polyimide (PI) resin, a polyamideimide (PAI) resin, a polyetherimide (PEI) resin, and the like. The styrenic resin includes, for example, at least one selected from the group including a polystyrene (PS) resin, a high-impact polystyrene resin, an acrylonitrile-styrene resin (AS resin), an acrylonitrile-butadienestyrene resin (ABS resin), and the like. The engineering plastic includes, for example, at least one selected from the group including a polycarbonate (PC) resin, a polyarylate (PAR) resin, a polysulfone (PSF) resin, a polyethersulfone (PES) resin, a polyphenylene ether (PPE) resin, a polyphenylene sulfide (PPS) resin, a polyether ketone (PEK) resin, a polyether-ether ketone (PEEK) resin, a polyphenylene oxide (PPO) resin, a polyether sulfite resin, and the like.(Underlayer 22)

[0057] The underlayer 22 is provided between the base material 21 and the intermediate layer 23. The underlayer 22 may be translucent with respect to visible light. As a material of the underlayer 22, a material similar to that of the base material 21 can be exemplified. A pattern or the like may be printed on the underlayer 22.(Intermediate Layer 23)

[0058] The intermediate layer 23 is provided between the underlayer 22 and the recording layer 24. The intermediate layer 23 includes an accommodation part 23HL for accommodating the recording layer 10. Since the recording layer 10 is accommodated in the accommodation part 23HL of the intermediate layer 23, it is possible to suppress generation of a gap between the underlayer 22 and the recording layer 24. The accommodation part 23HL may be a through hole penetrating in the thickness direction of the intermediate layer 23. The accommodation part 23HL may be configured to be able to fit the recording layer 10.

[0059] The intermediate layer 23 may have substantially the same thickness as the recording layer 10. The intermediate layer 23 may have a film shape. The intermediate layer 23 may be translucent with respect to visible light. As a material of the intermediate layer 23, a material similar to that of the base material 21 can be exemplified.(Recording Layer 10)

[0060] The recording layer 10 is accommodated in the accommodation part 23HL of the intermediate layer 23. The recording layer 10 is configured to draw a multi-color image by laser light L 1 having a peak wavelength λ 1 , laser light L 2 having a peak wavelength λ 2 , and laser light L 3 having a peak wavelength λ 3 . The multi-color image is visible under visible light. The color of a first color-developed portion formed by irradiation with the laser light L 1 , the color of a second color-developed portion formed by irradiation with the laser light L 2 , and the color of a third color-developed portion formed by irradiation with the laser light L 3 are different from each other. Therefore, a multi-color image can be drawn on the recording layer 10.

[0061] In the first embodiment, an example in which the multi-color image is a full-color image will be described. The recording layer 10 is configured to be changeable in its colored state in response to irradiation with laser light (external stimulus). This change in the colored state allows for drawing of a full-color image on the recording layer 10. The full-color image may be, for example, a photograph such as a face photograph, may be a pattern, a color pattern, or the like, or may be a text such as a character or a symbol. The full-color image may be configured by a combination of two or more types of photographs, patterns, color patterns, and texts. The recording layer 10 and the recording layer 24 have different recording methods. At least parts of the recording layer 10 and the recording layer 24 overlap each other in a thickness direction of the recording medium 20.

[0062] The change in the colored state may be a reversible change or an irreversible change. That is, the recording layer 10 may be of a rewritable type which allows for rewriting of an image or the like, or may be of a write once type which allows for writing of an image or the like only once. From the viewpoint of preventing tampering, the change in the colored state is preferably an irreversible change.

[0063] Fig. 3 is a cross-sectional view of the recording layer 10. The recording layer 10 sequentially includes a base material 11, an intermediate layer 12A, a color development layer 13A, an intermediate layer 12B, a color development layer 13B, an intermediate layer 12C, a color development layer 13C, an intermediate layer 12D, and a cover layer 14. Note that the intermediate layer 12A, the intermediate layer 12D, and the cover layer 14 are provided as necessary. In the present specification, in a case where the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are collectively referred to without being distinguished, they may be referred to as an intermediate layer 12. Similarly, in a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C are collectively referred to without being distinguished, they may be referred to as a color development layer 13. One layer arbitrarily selected from the color development layer 13A, the color development layer 13B, and the color development layer 13C is an example of the first color development layer in the claims, and the remaining two layers are examples of the second color development layer and the third color development layer in the claims. The recording layer 10 may be accommodated in the accommodation part 23HL of the intermediate layer 23 such that the cover layer 14 is on the side of the recording layer 24, or may be accommodated in the accommodation part 23HL of the intermediate layer 23 such that the base material 11 is on the side of the recording layer 24. In a case where the base material 11 is not translucent with respect to visible light, it is preferable that the cover layer 14 is accommodated in the accommodation part 23HL of the intermediate layer 23 so as to be on the side of the recording layer 24.(Base Material 11)

[0064] The base material 11 supports the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14. The base material 11 preferably contains a material having excellent heat resistance and excellent dimensional stability in the in-plane direction of the base material 11. The base material 11 may have either translucent or non-translucent characteristics with respect to visible light. In the present specification, visible light refers to light in a wavelength range of 360 nm or more and 780 nm or less. The base material 11 may have a predetermined color such as white. The base material 11 has, for example, a plate shape or a film shape. Note that the film is defined to include a sheet in the present disclosure.

[0065] The base material 11 may have, for example, rigidity or flexibility. In a case where the base material 11 has flexibility, a flexible recording layer 10 can be realized. Examples of the base material 11 having rigidity include a wafer, a glass substrate, and the like. Examples of the base material 11 having flexibility include flexible glass, a film, paper, and the like.

[0066] The base material 11 contains, for example, at least one selected from the group including an inorganic material, a metal material, a polymer material, and the like. The inorganic material includes, for example, at least one selected from the group including silicon (Si), silicon oxide (SiO X ), silicon nitride (SiN X ), aluminum oxide (AlO X ), and the like. The silicon oxide includes, for example, at least one selected from the group including glass, spin-on-glass (SOG), and the like. The metal material includes, for example, at least one selected from the group including aluminum (Al), nickel (Ni), stainless steel, and the like. The polymer material includes, for example, at least one selected from the group including polycarbonate (PC) resin, polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polyethyl ether ketone (PEEK) resin, polyvinyl chloride (PVC) resin, and the like.

[0067] Note that a reflection layer (not illustrated) may be provided on at least one of a first surface or a second surface of the base material 11, or the base material 11 itself may also function as a reflection layer. The base material 11 having such a configuration enables clearer color display.(Color Development Layer 13A, Color Development Layer 13B, and Color Development Layer 13C)

[0068] The color development layer 13A, the color development layer 13B, and the color development layer 13C in a recorded state are in a color-developed state, and the color development layer 13A and the color development layers 13B and 13C in a non-recorded state are in a non-colored state. The color development layer 13A, the color development layer 13B, and the color development layer 13C can be changed from the non-colored state to a color-developed state by irradiation with laser light.

[0069] The color development layer 13A, the color development layer 13B, and the color development layer 13C each can exhibit hues different from each other in the color-developed state. Specifically, the color development layer 13A can exhibit a magenta color in the color-developed state. The color development layer 13B can exhibit a cyan color in the color-developed state. The color development layer 13C can exhibit a yellow color in the color-developed state. Magenta color, cyan color, and yellow color are examples of the first primary color, the second primary color, and the third primary color, respectively. The first primary color, the second primary color, and the third primary color may be three primary colors. The first primary color, the second primary color, and the third primary color may be colors other than magenta color, cyan color, and yellow color. The laser light L 1 capable of changing the color development layer 13A to the color-developed state, the laser light L 2 capable of changing the color development layer 13B to the color-developed state, and the laser light L 3 capable of changing the color development layer 13C to the color-developed state have peak wavelengths different from each other.

[0070] The thicknesses of the color development layer 13A, the color development layer 13B, and the color development layer 13C are each independently preferably 1 µm or more and 20 µm or less, and more preferably 2 µm or more and 15 µm or less. With the color development layer 13A, the color development layer 13B, and the color development layer 13C having a thickness of 1 µm or more, the color development density can be improved. On the other hand, with the color development layer 13A, the color development layer 13B, and the color development layer 13C having a thickness of 20 µm or less, an increase in the heat utilization amount of the color development layer 13A, the color development layer 13B, and the color development layer 13C can be prevented, and deterioration in color developability can be prevented.

[0071] The color development layer 13A is configured to be able to perform recording with the laser light L 1 having a peak wavelength λ 1 . The color development layer 13A contains a first coloring compound having an electron-donating property, a first developer having an electron-accepting property, and a first photothermal conversion agent. The color development layer 13A preferably further contains a first matrix resin.

[0072] The color development layer 13B is configured to be able to perform recording with second laser light having a peak wavelength λ 2 . The color development layer 13B contains a second coloring compound having an electron-donating property, a second developer having an electron-accepting property, and a second photothermal conversion agent. The color development layer 13B preferably further contains a second matrix resin.

[0073] The color development layer 13C is configured to be able to perform recording with third laser light having a peak wavelength λ 3 . The color development layer 13C contains a third coloring compound having an electron-donating property, a third developer having an electron-accepting property, and a third photothermal conversion agent. The color development layer 13C preferably further contains a third matrix resin.

[0074] The laser light L 1 , the laser light L 2 , and the laser light L 3 are preferably near-infrared laser light. The peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are preferably included in a near-infrared range. Upper limit values of the peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are, for example, less than 1000 nm and preferably 915 nm or less. Lower limit values of the peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are, for example, 760 nm or more.

[0075] The peak wavelength λ 1 , the peak wavelength λ 2 , and the peak wavelength λ 3 are different from each other. Therefore, the color development layer 13A, the color development layer 13B, and the color development layer 13C can be independently caused to develop color. One of the laser light L 1 having a peak wavelength λ 1 , the laser light L 2 having a peak wavelength λ 2 , and the laser light L 3 having a peak wavelength λ 3 is an example of the first laser light having a first peak wavelength in the claims, and the remaining two laser light beams are examples of the third laser light having a third peak wavelength and the fourth laser light having a fourth peak wavelength in the claims.(First Coloring Compound, Second Coloring Compound, and Third Coloring Compound)

[0076] The first coloring compound, the second coloring compound, and the third coloring compound can develop color by reacting with the first developer, the second developer, and the third developer, respectively. The first coloring compound, the second coloring compound, and the third coloring compound can exhibit hues different from each other in the color-developed state. Specifically, the first coloring compound can exhibit a magenta color in the color-developed state. The second coloring compound can exhibit a cyan color in the color-developed state. The third coloring compound can exhibit a yellow color in the color-developed state.

[0077] The first coloring compound, the second coloring compound, and the third coloring compound are, for example, leuco dyes. The leuco dye develops color when a lactone ring in a molecule reacts with an acid to be ring-opened. The leuco dye may be decolored when the open lactone ring reacts with a base to be ring-closed. The leuco dye may be, for example, an existing dye for thermosensitive paper.

[0078] The first coloring compound, the second coloring compound, and the third coloring compound can be appropriately selected according to the purpose, without any limitation. The first coloring compound, the second coloring compound, and the third coloring compound each independently contain, for example, at least one selected from the group including fluoran compounds, triphenylmethane phthalide compounds, azaphthalide compounds, phenothiazine compounds, leucoauramine compounds, indolinophthalide compounds, and the like. Besides, the first coloring compound, the second coloring compound, and the third coloring compound may each independently contain, for example, at least one selected from the group consisting of 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-di(n-butylamino) fluoran, 2-anilino-3-methyl-6-(N-n-propyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-isopropyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-isobutyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-n-amyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-sec-butyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-n-amyl-N-ethylamino) fluoran, 2-anilino-3-methyl-6-(N-iso-amyl-N-ethylamino) fluoran, 2-anilino-3-methyl-6-(N-n-propyl-N-isopropylamino)fluoran, 2-anilino-3-methyl-6-(N-cyclohexyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-ethyl-p-toluidino)fluoran, 2-anilino-3-methyl-6-(N-methyl-p-toluidino)fluoran, 2-(m-trichloromethylanilino)-3-methyl-6-diethylaminofluoran, 2-(m-trifluoromethylanilino)-3-methyl-6-diethylaminofluoran, 2-(m-trichloromethylanilino)-3-methyl-6-(N-cyclohexyl-N-methylamino)fluoran, 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluoran, 2-(N-ethyl-p-toluidino)-3-methyl-6-(N-ethylanilino)fluoran, 2-(N-ethyl-p-toluidino)-3-methyl-6-(N-propyl-p-toluidino)fluoran, 2-anilino-6-(N-n-hexyl-N-ethylamino)fluoran, 2-(o-chloroanilino)-6-diethylaminofluoran, 2-(o-chloroanilino)-6-dibutylaminofluoran, 2-(m-trifluoromethylanilino)-6-diethylaminofluoran, 2,3-dimethyl-6-dimethylaminofluoran, 3-methyl-6-(N-ethyl-p-toluidino)fluoran, 2-chloro-6-diethylaminofluoran, 2-bromo-6-diethylaminofluoran, 2-chloro-6-dipropylaminofluoran, 3-chloro-6-cyclohexylaminofluoran, 3-bromo-6-cyclohexylaminofluoran, 2-chloro-6-(N-ethyl-N-isoamylamino)fluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-chloro-6-diethylaminofluoran, 2-(o-chloroanilino)-3-chloro-6-cyclohexylaminofluoran, 2-(m-trifluoromethylanilino)-3-chloro-6-diethylaminofluoran, 2-(2,3-dichloroanilino)-3-chloro-6-diethylaminofluoran, 1,2-benzo-6-diethylaminofluoran, 3-diethylamino-6-(m-trifluoromethylanilino)fluoran, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-7-azaphthalide, 3-(1-octyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-7-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-N-n-amyl-N-methylaminophenyl)-4-azaphthalide, 3-(1-methyl-2-methylindol-3-yl)-3-(2-hexyloxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-7-azaphthalide, 2-(p-acetylanilino)-6-(N-n-amyl-N-n-butylamino)fluoran, 2-benzylamino-6-(N-ethyl-p-toluidino)fluoran, 2-benzylamino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-benzylamino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-benzylamino-6-(N-methyl-p-toluidino)fluoran, 2-benzylamino-6-(N-ethyl-p-toluidino)fluoran, 2-(di-p-methylbenzylamino)-6-(N-ethyl-p-toluidino)fluoran, 2-(α-phenylethylamino)-6-(N-ethyl-p-toluidino)fluoran, 2-methylamino-6-(N-methylanilino)fluoran, 2-methylamino-6-(N-ethylanilino)fluoran, 2-methylamino-6-(N-propylanilino)fluoran, 2-ethylamino-6-(N-methyl-p-toluidino)fluoran, 2-methylamino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-ethylamino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-dimethylamino-6-(N-methylanilino) fluoran, 2-dimethylamino-6-(N-ethylanilino)fluoran, 2-diethylamino-6-(N-methyl-p-toluidino)fluoran, 2-diethylamino-6-(N-ethyl-p-toluidino)fluoran, 2-dipropylamino-6-(N-methylanilino) fluoran, 2-dipropylamino-6-(N-ethylanilino)fluoran, 2-amino-6-(N-methylanilino)fluoran, 2-amino-6-(N-ethylanilino)fluoran, 2-amino-6-(N-propylanilino)fluoran, 2-amino-6-(N-methyl-p-toluidino)fluoran, 2-amino-6-(N-ethyl-p-toluidino)fluoran, 2-amino-6-(N-propyl-p-toluidino)fluoran, 2-amino-6-(N-methyl-p-ethylanilino)fluoran, 2-amino-6-(N-ethyl-p-ethylanilino)fluoran, 2-amino-6-(N-propyl-p-ethylanilino)fluoran, 2-amino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-propyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-methyl-p-chloroanilino)fluoran, 2-amino-6-(N-ethyl-p-chloroanilino) fluoran, 2-amino-6-(N-propyl-p-chloroanilino)fluoran, 1,2-benzo-6-(N-ethyl-N-isoamylamino)fluoran, 1,2-benzo-6-dibutylaminofluoran, 1,2-benzo-6-(N-methyl-N-cyclohexylamino)fluoran, 1,2-benzo-6-(N-ethyl-N-toluidino)fluoran, and the like.(First Developer, Second Developer, and Third Developer)

[0079] The first developer, the second developer, and the third developer can cause the first coloring compound, the second coloring compound, and the third coloring compound in the non-colored state to develop color, respectively. The types of the first developer, the second developer, and the third developer may be the same, or the types of the first developer, the second developer, and the third developer may be different from each other. The first developer, the second developer, and the third developer are compounds including an electron-accepting group in the molecule. The electron-accepting moieties of the first developer, the second developer, and the third developer react with the lactone rings of the first coloring compound, the second coloring compound, and the third coloring compound, respectively, and the lactone rings are ring-opened, whereby the first coloring compound, the second coloring compound, and the third coloring compound develop color. The first developer, the second developer, and the third developer each independently contain, for example, at least one selected from the group including a phenol derivative, a salicylic acid derivative, a urea derivative, and the like. In the following description, in a case where the first developer, the second developer, and the third developer are collectively referred to without being distinguished, they may be simply referred to as a developer.

[0080] Specifically, for example, the developer contains a compound represented by the following formula (1): (where, in the formula (1), X 0< is a divalent group including at least one benzene ring; Y 01< and Y 02< are each independently a monovalent group; n01 and n02 are each independently an integer of any one of 0 to 5; in a case where n01 is an integer of any one of 2 to 5, Y 01< may be the same as or different from each other; in a case where n02 is an integer of any one of 2 to 5, Y 02< may be the same as or different from each other; and Z 01< and Z 02< are each independently a hydrogen bonding group).

[0081] With X 0< including at least one benzene ring, the melting point can be increased as compared with a case where X 0< is an aliphatic hydrocarbon group (for example, a normal alkyl chain), so that the color development retention characteristics at the time of high temperature and high humidity storage (hereinafter, referred to as "high temperature and high humidity storage characteristics") can be improved. From the viewpoint of improving the high temperature and high humidity storage characteristics and heat resistance, X 0< preferably includes at least two benzene rings. The high temperature and high humidity storage characteristics are, for example, storage characteristics under an environment of 80°C and 60% RH. The increase in the heat resistance leads to an improvement in the resistance of the recording layer 10 to a severe process (for example, heat-pressing, integral molding using a molten resin or the like, or the like). In a case where X 0< includes at least two benzene rings, the at least two benzene rings may be fused. For example, naphthalene, anthracene, or the like may be used.

[0082] With Z 01< and Z 02< being each independently a hydrogen bonding group, the developers are likely to be present while being gathered to some extent via hydrogen bonds, and therefore stability of the developers in the color development layer 13 is improved. In the present specification, the hydrogen bonding group means a functional group including an atom capable of hydrogen bonding with an atom present in another functional group, another compound, or the like.

[0083] The developer preferably contains a compound represented by the following formula (2): (where, in the formula (2), X 1< is a divalent group including at least one benzene ring; Y 11< , Y 12< , Y 13< , and Y 14< are each independently a monovalent group; and Z 11< and Z 12< are each independently a hydrogen bonding group).

[0084] With X 1< including at least one benzene ring, the melting point can be increased as compared with a case where X 1< is an aliphatic hydrocarbon group (for example, a normal alkyl chain), so that the high temperature and high humidity storage characteristics can be improved. From the viewpoint of improving the high temperature and high humidity storage characteristics and heat resistance, X 1< preferably includes at least two benzene rings. In a case where X 1< includes at least two benzene rings, the at least two benzene rings may be fused. For example, naphthalene, anthracene, or the like may be used.

[0085] With Z 11< and Z 12< being each independently a hydrogen bonding group, the developers are likely to be present while being gathered to some extent via hydrogen bonds, and therefore stability of the developers in the color development layer 13 is improved.

[0086] In a case where the formula (1) and the formula (2) include a hydrocarbon group, the hydrocarbon group is a generic term for groups including carbon (C) and hydrogen (H), and may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The saturated hydrocarbon group is an aliphatic hydrocarbon group having no carbon-carbon multiple bond, and the unsaturated hydrocarbon group is an aliphatic hydrocarbon group having a carbon-carbon multiple bond (carbon-carbon double bond or carbon-carbon triple bond).

[0087] In a case where the formula (1) and the formula (2) include a hydrocarbon group, the hydrocarbon group may be a chain or may include one or two or more rings. The chain may be a linear chain, or may be a branched chain having one or two or more side chains or the like.(X 0< and X 1< with One Benzene Ring)

[0088] X 0< in the formula (1) and X 1< in the formula (2) are, for example, a divalent group including one benzene ring. The divalent group is represented by, for example, the following formula (3): (where, in the formula (3), X 21< may be present or absent, and in a case where X 21< is present, X 21< is a divalent group; X 22< may be present or absent, and in a case where X 22< is present, X 22< is a divalent group; R 21< is a monovalent group; n21 is an integer of any one of 0 to 4; in a case where n21 is an integer of any one of 2 to 4, R 21< may be the same as or different from each other; and * denotes a bonding portion).

[0089] In the formula (3), the bonding positions of X 21< and X 22< on the benzene ring are not limited. That is, the bonding positions of X 21< and X 22< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0090] From the viewpoint of improving high temperature and high humidity storage characteristics, the above-described divalent group including one benzene ring is preferably represented by the following formula (4): (where, in the formula (4), R 22< is a monovalent group; n22 is an integer of any one of 0 to 4; in a case where n22 is an integer of any one of 2 to 4, R 22< may be the same as or different from each other; and * denotes a bonding portion).

[0091] In a case where X 0< in the formula (1) is a divalent group including one benzene ring, the bonding positions of Z 01< and Z 02< on the benzene ring in the formula (4) are not limited. That is, the bonding positions of Z 01< and Z 02< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0092] In a case where X 1< in the formula (2) is a divalent group including one benzene ring, the bonding positions of Z 11< and Z 12< on the benzene ring in the formula (4) are not limited. That is, the bonding positions of Z 11< and Z 12< on the benzene ring may be any of ortho positions, meta positions, and para positions.(X 21< and X 22< )

[0093] X 21< and X 22< in the formula (3) are only required to be each independently a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is preferably in a chain form. With the hydrocarbon group in a chain form, the melting point of the developer can be reduced, allowing the developer to be dissolved by irradiation with laser light, and therefore the coloring compound readily develops a color. From the viewpoint of reducing the melting point of the developer, a normal alkyl chain is particularly preferable among the chain hydrocarbon groups.

[0094] The number of carbon atoms of the hydrocarbon group optionally having a substituent is, for example, 1 or more and 15 or less, 1 or more and 13 or less, 1 or more and 12 or less, 1 or more and 10 or less, 1 or more and 6 or less, or 1 or more and 3 or less.

[0095] In a case where X 21< and X 22< in the formula (3) are normal alkyl groups, the number of carbon atoms of the normal alkyl group is preferably 8 or less, more preferably 6 or less, still more preferably 5 or less, and particularly preferably 3 or less from the viewpoint of high temperature storage stability. It is considered that in a case where the number of carbon atoms of the normal alkyl group is 8 or less, due to the short length of the normal alkyl group, thermal disturbance is less likely to occur in the developer during high temperature storage, and a site that interacts with the coloring compound such as a leuco dye at the time of color development is less likely to be separated. Therefore, the coloring compound such as a leuco dye is less likely to be decolored during high temperature storage, and thus high temperature storage stability is improved.

[0096] Examples of the substituent that the hydrocarbon group optionally has include a halogen group (for example, a fluorine group), and an alkyl group having a halogen group (for example, a fluorine group). The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of carbon atoms of the hydrocarbon group (for example, a part of carbon atoms included in a main chain of the hydrocarbon group) with an element such as oxygen.(R 21< )

[0097] R 21< in the formula (3) is only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent.

[0098] The halogen group is, for example, a fluorine group (-F), a chlorine group (-Cl), a bromine group (-Br), or an iodine group (-I).

[0099] The number of carbon atoms of the hydrocarbon group optionally having a substituent is, for example, 1 or more and 15 or less, 1 or more and 13 or less, 1 or more and 12 or less, 1 or more and 10 or less, 1 or more and 6 or less, or 1 or more and 3 or less.

[0100] Examples of the substituent that the hydrocarbon group optionally has include a halogen group (for example, a fluorine group), and an alkyl group having a halogen group (for example, a fluorine group). The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of carbon atoms of the hydrocarbon group (for example, a part of carbon atoms included in a main chain of the hydrocarbon group) with an element such as oxygen.(R 22< )

[0101] R 22< in the formula (4) is only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for R 21< in the above formula (3).(X 0< and X 1< with Two Benzene Rings)

[0102] X 0< in the formula (1) and X 1< in the formula (2) are, for example, divalent groups including two benzene rings. The divalent group is represented by, for example, the following formula (5): (where, in the formula (5), X 31< may be present or absent, and in a case where X 31< is present, X 31< is a divalent group; X 32< may be present or absent, and in a case where X 32< is present, X 32< is a divalent group; X 33< may be present or absent, and in a case where X 33< is present, X 33< is a divalent group; R 31< and R 32< are each independently a monovalent group; n31 and n32 are each independently an integer of any one of 0 to 4; in a case where n31 is an integer of any one of 2 to 4, R 31< may be the same as or different from each other; in a case where n32 is an integer of any one of 2 to 4, R 32< may be the same as or different from each other; and * denotes a bonding portion).

[0103] In the formula (5), the bonding positions of X 31< and X 32< on the benzene ring are not limited. That is, the bonding positions of X 31< and X 32< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (5), the bonding positions of X 32< and X 33< on the benzene ring are not limited. That is, the bonding positions of X 32< and X 33< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0104] From the viewpoint of improving high temperature and high humidity storage characteristics, the above-described divalent group including two benzene rings is preferably represented by the following formula (6): (where, in the formula (6), X 34< is a divalent group; R 33< and R 34< are each independently a monovalent group; n33 and n34 are each independently an integer of any one of 0 to 4; in a case where n33 is an integer of any one of 2 to 4, R 33< may be the same as or different from each other; in a case where n34 is an integer of any one of 2 to 4, R 34< may be the same as or different from each other; and * denotes a bonding portion).

[0105] In a case where X 0< in the formula (1) is a divalent group including two benzene rings, the bonding positions of Z 01< and X 34< on the benzene ring in the formula (6) are not limited. That is, the bonding positions of Z 01< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (6), the bonding positions of Z 02< and X 34< on the benzene ring are not limited. That is, the bonding positions of Z 02< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions.

[0106] In a case where X 1< in the formula (2) is a divalent group including two benzene rings, the bonding positions of Z 11< and X 34< on the benzene ring in the formula (6) are not limited. That is, the bonding positions of Z 11< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (6), the bonding positions of Z 12< and X 34< on the benzene ring are not limited. That is, the bonding positions of Z 12< and X 34< on the benzene ring may be any of ortho positions, meta positions, and para positions.(X 31< , X 32< , and X 33< )

[0107] X 31< , X 32< , and X 33< in the formula (5) are only required to be each independently a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is similar to that for X 21< and X 22< in the above formula (3).(X 34< )

[0108] X 34< in the formula (6) is only required to be a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is similar to that for X 21< and X 22< in the above formula (3).(R 31< and R 32< )

[0109] R 31< and R 32< in the formula (5) are only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for R 21< in the above formula (3).(R 33< and R 34< )

[0110] R 33< and R 34< in the formula (6) are only required to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for R 21< in the above formula (3).(Y 01< and Y 02< )

[0111] Y 01< and Y 02< in the formula (1) are each independently, for example, a hydrogen group (-H), a hydroxy group (-OH), a halogen group (-X), a carboxy group (-COOH), an ester group (-COOR), or a hydrocarbon group optionally having a substituent.

[0112] The halogen group is, for example, a fluorine group (-F), a chlorine group (-Cl), a bromine group (-Br), or an iodine group (-I).

[0113] The number of carbon atoms of the hydrocarbon group optionally having a substituent is, for example, 1 or more and 15 or less, 1 or more and 13 or less, 1 or more and 12 or less, 1 or more and 10 or less, 1 or more and 6 or less, or 1 or more and 3 or less.

[0114] Examples of the substituent that the hydrocarbon group optionally has include a halogen group (for example, a fluorine group), and an alkyl group having a halogen group (for example, a fluorine group). The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of carbon atoms of the hydrocarbon group (for example, a part of carbon atoms included in a main chain of the hydrocarbon group) with an element such as oxygen.

[0115] In the formula (1), it is preferable that one of (Y 01< ) n01 and / or one of (Y 02< ) n02 is a hydroxy group (-OH). With one of (Y 01< ) n01 and / or one of (Y 02< ) n02 being a hydroxy group (-OH), display quality and light resistance can be improved.(Y 11< , Y 12< , Y 13< , and Y 14< )

[0116] In the formula (2), the bonding positions of Y 11< and Y 12< on the benzene ring are not limited. That is, the bonding positions of Y 11< and Y 12< on the benzene ring may be any of ortho positions, meta positions, and para positions. Similarly, in the formula (2), the bonding positions of Y 13< and Y 14< on the benzene ring are also not limited. That is, the bonding positions of Y 13< and Y 14< on the benzene ring may be any of ortho positions, meta positions, and para positions. In the formula (2), the bonding positions of Y 11< and Y 12< on one benzene and the bonding positions of Y 13< and Y 14< on the other benzene may be the same or different.

[0117] Y 11< , Y 12< , Y 13< , and Y 14< in the formula (2) each independently represent, for example, a hydrogen group (-H), a hydroxy group (-OH), a halogen group, a carboxy group (-COOH), an ester group (-COOR), or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to that for Y 01< and Y 02< in the above formula (1).

[0118] In the formula (2), Y 11< and / or Y 13< is preferably a hydroxy group (-OH). With Y 11< and / or Y 13< being a hydroxy group (-OH), display quality and light resistance can be improved.(Z 01< and Z 02< )

[0119] Z 01< and Z 02< in the formula (1) are each independently, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-), or a hydrazide bond (-NHCOCONH-). From the viewpoint of improving the high temperature and high humidity storage characteristics, Z 01< and Z 02< are preferably urea bonds. In a case where Z 01< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene. In a case where Z 02< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene.(Z 11< and Z 12< )

[0120] Z 11< and Z 12< in the formula (2) are each independently, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-), or a hydrazide bond (-NHCOCONH-). From the viewpoint of improving the high temperature and high humidity storage characteristics, Z 11< and Z 12< are preferably urea bonds. In a case where Z 11< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene. In a case where Z 12< is an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene.(Specific Examples of Developer)

[0121] Specifically, the developer in which X 0< in the formula (1) and X 1< in the formula (2) include one benzene ring contains, for example, at least one selected from the group consisting of compounds represented by the following formulas (7-1) to (7-6).

[0122] Specifically, the developer in which X 0< in the formula (1) and X 1< in the formula (2) include two benzene rings contains, for example, at least one selected from the group consisting of compounds represented by the following formulas (8-1) to (8-8). (First Photothermal Conversion Agent, Second Photothermal Conversion Agent, and Third Photothermal Conversion Agent)

[0123] The first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent can generate heat by absorbing light in a predetermined wavelength region such as a near-infrared region. The first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent have absorption wavelength peaks different from each other. Specifically, the first photothermal conversion agent has an absorption wavelength peak at about wavelength λ 1 . The second photothermal conversion agent has an absorption wavelength peak at about wavelength λ 2 . The third photothermal conversion agent has an absorption wavelength peak at about wavelength λ 3 . The wavelengths λ 1 , X 2 , and λ 3 are different from each other. The absorption wavelength peak is preferably in the near-infrared region. The near-infrared region is, for example, in a wavelength range of 700 nm or more and 2000 nm or less. As described above, since the first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent have absorption wavelength peaks different from each other, a desired layer among the color development layer 13A, the color development layer 13B, and the color development layer 13C can be selectively caused to develop color by irradiation with laser light. A near-infrared absorbing dye having almost no absorption in the visible region is preferably employed as the first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent.

[0124] The first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent each independently contain, for example, at least one selected from the group consisting of a compound having a phthalocyanine skeleton (phthalocyanine dye), a compound having a squarylium skeleton (squarylium dye), an inorganic compound, and the like.

[0125] The inorganic compound includes, for example, at least one selected from the group including metal complexes such as dithio complexes, diimmonium salts, aminium salts, graphite, carbon black, metal powder particles, metal oxides such as tricobalt tetraoxide, iron oxide, chromium oxide, copper oxide, titanium black, and indium tin oxide (ITO), metal nitrides such as niobium nitride, metal carbides such as tantalum carbide, metal sulfides, various magnetic powders, and the like. In addition, the inorganic compound may include a compound having a cyanine skeleton (cyanine dye) having excellent light resistance and heat resistance. Note that the excellent light resistance, as used herein, means that it is not decomposed by, for example, irradiation with light of a fluorescent lamp or the like under a use environment. The excellent heat resistance means that, for example, a film formed together with a polymer material does not change in maximum absorption peak value of the absorption spectrum by 20% or more after being stored at 150°C for 30 minutes, for example. Examples of such a compound having a cyanine skeleton include a compound having, in a molecule thereof, at least one of a counter ion being any one of SbF 6 , PF 6 , BF 4 , ClO 4 , CF 3 SO 3 , or (CF 3 SO 3 ) 2 N or a methine chain including a 5-membered ring or a 6-membered ring. Note that, although the compound having a cyanine skeleton used for the recording layer 10 in the first embodiment preferably has both any one of the above-described counter ions and a cyclic structure such as a 5-membered ring and a 6-membered ring in a methine chain, sufficient light resistance and heat resistance are secured as long as the compound has at least one of the counter ion or the cyclic structure.(First Matrix Resin, Second Matrix Resin, and Third Matrix Resin)

[0126] The first matrix resin, the second matrix resin, and the third matrix resin preferably have a function as a binder. The first matrix resin is preferably one in which the first coloring compound, the first developer, and the first photothermal conversion agent are likely to be uniformly dispersed. The second matrix resin is preferably one in which the second coloring compound, the second developer, and the second photothermal conversion agent are likely to be uniformly dispersed. The third matrix resin is preferably one in which the third coloring compound, the third developer, and the third photothermal conversion agent are likely to be uniformly dispersed. The types of the first matrix resin, the second matrix resin, and the third matrix resin may be the same, and the types of the first matrix resin, the second matrix resin, and the third matrix resin may be different from each other.

[0127] The first matrix resin, the second matrix resin, and the third matrix resin each independently contain, for example, at least one selected from the group consisting of a thermosetting resin, a thermoplastic resin, and the like. The first matrix resin, the second matrix resin, and the third matrix resin preferably contain a polycarbonate resin. With the first matrix resin, the second matrix resin, and the third matrix resin containing a polycarbonate resin, the light resistance of the background of the recording layer 10 can be improved. Here, the polycarbonate resin is a resin having a carbonate group (-O-(C=O)-O-) as a structural unit at least in the main chain. Therefore, other structural units may be included in the main chain in addition to the carbonate group.

[0128] The first matrix resin, the second matrix resin, and the third matrix resin may each independently contain, instead of or together with the polycarbonate resin, at least one selected from the group consisting of polyvinyl chloride, polyvinyl acetate, a vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, a styrenic copolymer, a phenoxy resin, polyester, an aromatic polyester, polyurethane, a polyacrylate, a polymethacrylate, an acrylic acid copolymer, a maleic acid polymer, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, and the like.(Additive)

[0129] The color development layer 13A, the color development layer 13B, and the color development layer 13C may further contain at least one additive selected from the group consisting of a sensitizer, an ultraviolet absorber, and the like as necessary. The color development layer 13A, the color development layer 13B, and the color development layer 13C preferably contain an amine compound from the viewpoint of preventing coloring of the background.

[0130] In a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C contain an amine compound, it is preferable that the color development layer 13A, the color development layer 13B, and the color development layer 13C contain at least one compound selected from the group consisting of an epoxy compound and a carbodiimide compound together with the amine compound. In a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C contain an amine compound, there is a possibility that the reliability of the color-developed portion during high temperature and high humidity storage is deteriorated; however, in a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C contain at least one compound selected from the group consisting of an epoxy compound and a carbodiimide compound together with the amine compound, the deterioration in reliability of the color-developed portion during high temperature and high humidity storage due to the amine compound can be prevented.(Intermediate Layer 12A, Intermediate Layer 12B, Intermediate Layer 12C, and Intermediate Layer 12D)

[0131] The intermediate layer 12A is provided between the base material 11 and the color development layer 13A. The intermediate layer 12A can thermally insulate the base material 11 and the color development layer 13A from each other and can suppress diffusion of a constituent material between the base material 11 and the color development layer 13A. The intermediate layer 12B is provided between the color development layer 13A and the color development layer 13B. The intermediate layer 12B can thermally insulate the color development layer 13A and the color development layer 13B from each other and can suppress diffusion of a constituent material between the color development layer 13A and the color development layer 13B. The intermediate layer 12C is provided between the color development layer 13B and the color development layer 13C. The intermediate layer 12C can thermally insulate the color development layer 13B and the color development layer 13C from each other and can suppress diffusion of a constituent material between the color development layer 13B and the color development layer 13C. The intermediate layer 12D is provided between the color development layer 13C and the cover layer 14. The intermediate layer 12D can thermally insulate the color development layer 13C and the cover layer 14 from each other and can suppress diffusion of a constituent material between the color development layer 13C and the cover layer 14.

[0132] The intermediate layer 12A may be either translucent or non-translucent with respect to laser light used for drawing on the recording layer 10 and visible light. The intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are translucent with respect to laser light used for drawing on the recording layer 10 and visible light.

[0133] Thicknesses of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are each independently preferably 3 µm or more and 100 µm or less, and more preferably 5 µm or more and 50 µm or less. With the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D having a thickness of 3 µm or more, a sufficient heat insulating effect can be obtained, and a sufficient diffusion suppressing effect can be obtained. On the other hand, with the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D having a thickness of 100 µm or less, deterioration of translucency with respect to visible light can be suppressed. Furthermore, it is also possible to suppress a decrease in bending resistance of the recording layer 10 and to make defects such as cracks less likely to occur. The thicknesses of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D may be the same or different from each other.

[0134] The intermediate layer 12A sequentially includes a bonding adhesive layer 12A 1 and an ultraviolet-curable resin layer 12A 2 on the base material 11. The bonding adhesive layer 12A 1 bonds the base material 11 and the ultraviolet-curable resin layer 12A 2 . The bonding adhesive layer 12A 1 may be capable of thermally insulating the base material 11 and the color development layer 13A from each other. The ultraviolet-curable resin layer 12A 2 can thermally insulate the base material 11 and the color development layer 13A from each other and can suppress diffusion of a constituent material (for example, the first coloring compound or the like) between the base material 11 and the color development layer 13A. However, the order of lamination of the bonding adhesive layer 12A 1 and the ultraviolet-curable resin layer 12A 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0135] The intermediate layer 12B sequentially includes a bonding adhesive layer 12B 1 and an ultraviolet-curable resin layer 12B 2 on the color development layer 13A. The bonding adhesive layer 12B 1 bonds the color development layer 13A and the ultraviolet-curable resin layer 12B 2 . The bonding adhesive layer 12B 1 may be capable of thermally insulating the color development layer 13A and the color development layer 13B from each other. The ultraviolet-curable resin layer 12B 2 can thermally insulate the color development layer 13A and the color development layer 13B from each other and can suppress diffusion of a constituent material (for example, the first coloring compound, the second coloring compound, or the like) between the color development layer 13A and the color development layer 13B. However, the order of lamination of the bonding adhesive layer 12B 1 and the ultraviolet-curable resin layer 12B 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0136] The intermediate layer 12C sequentially includes a bonding adhesive layer 12C 1 and an ultraviolet-curable resin layer 12C 2 on the color development layer 13B. The bonding adhesive layer 12C 1 bonds the color development layer 13B and the ultraviolet-curable resin layer 12C 2 . The bonding adhesive layer 12C 1 may be capable of thermally insulating the color development layer 13B and the color development layer 13C from each other. The ultraviolet-curable resin layer 12C 2 can thermally insulate the color development layer 13B and the color development layer 13C from each other and can suppress diffusion of a constituent material (for example, the second or third coloring compound, or the like) between the color development layer 13B and the color development layer 13C. However, the order of lamination of the bonding adhesive layer 12C 1 and the ultraviolet-curable resin layer 12C 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0137] The intermediate layer 12D sequentially includes a bonding adhesive layer 12D 1 and an ultraviolet-curable resin layer 12D 2 on the color development layer 13C. The bonding adhesive layer 12D 1 bonds the color development layer 13C and the ultraviolet-curable resin layer 12D 2 . The bonding adhesive layer 12D 1 may be capable of thermally insulating the color development layer 13C and the cover layer 14 from each other. The ultraviolet-curable resin layer 12D 2 can thermally insulate the color development layer 13C and the cover layer 14 from each other and can suppress diffusion of a constituent material (for example, the third coloring compound or the like) between the color development layer 13C and the cover layer 14. However, the order of lamination of the bonding adhesive layer 12D 1 and the ultraviolet-curable resin layer 12D 2 is not limited to the above example, and the order of lamination of these layers may be the reverse order to the order of lamination.

[0138] The bonding adhesive layer 12A 1 , the bonding adhesive layer 12B 1 , the bonding adhesive layer 12C 1 , and the bonding adhesive layer 12D 1 are, for example, double-sided sticky films such as an optical clear adhesive (OCA).

[0139] The ultraviolet-curable resin layer 12A 2 , the ultraviolet-curable resin layer 12B 2 , the ultraviolet-curable resin layer 12C 2 , and the ultraviolet-curable resin layer 12D 2 contain an ultraviolet-curable resin solidified by a polymerization reaction. More specifically, for example, the ultraviolet-curable resin layer 12A 2 , the ultraviolet-curable resin layer 12B 2 , the ultraviolet-curable resin layer 12C 2 , and the ultraviolet-curable resin layer 12D 2 contain a polymer of a polymerizable compound and a polymerization initiator whose structure is changed by generation of an active species by irradiation with external energy (ultraviolet ray). The ultraviolet-curable resin composition contains, for example, at least one selected from the group consisting of a radically polymerized ultraviolet-curable resin composition, a cationically polymerized ultraviolet-curable resin composition, and the like. The ultraviolet-curable resin composition may contain at least one selected from the group consisting of a sensitizer, a filler, a stabilizer, a leveling agent, an antifoaming agent, a viscosity modifier, and the like as necessary. The ultraviolet-curable resin layer 12A 2 , the ultraviolet-curable resin layer 12B 2 , the ultraviolet-curable resin layer 12C 2 , and the ultraviolet-curable resin layer 12D 2 are provided as necessary, and may not be provided. The ultraviolet-curable resin layer 12D 2 may have a function of cutting ultraviolet rays due to thermal curing.(Recording Layer 24)

[0140] The recording layer 24 is provided on the intermediate layer 23, and covers the intermediate layer 23 and the recording layer 10 included in the intermediate layer 23. The recording layer 24 is configured to be able to draw a monochromatic image (monochrome image) with laser light L 4 having a peak wavelength λ 4 . The monochromatic image can be visually recognized under visible light and can be imaged by an imaging apparatus under infrared rays. Examples of the color of a drawing portion (laser irradiation portion) of the monochromatic image include black and brown, but are not limited to these colors.

[0141] A lower limit value of the peak wavelength λ 4 is, for example, 1000 nm or more. An upper limit value of the peak wavelength λ 4 is, for example, 11 µm or less. Specifically, the peak wavelength λ 4 is, for example, about 1064 nm. The laser light L 4 having a peak wavelength λ 4 is an example of the second laser light having a second peak wavelength in the claims.

[0142] The recording layer 24 may have a film shape. The recording layer 24 may be translucent with respect to visible light in an initial state before recording. The recording layer 24 may have absorbability in the visible light region by irradiation with laser light, or may have absorbability in the visible light region from the beginning without irradiation with laser light. The recording layer 24 is preferably a laser marking layer. The laser marking layer may be a known laser marking sheet. Many of known laser marking sheets have absorbability in the visible light region by irradiation with laser light, or have absorbability in the visible light region from the beginning without irradiation with laser light. The laser marking layer is configured to be capable of laser marking by, for example, at least one of the following methods (1) to (5). However, the laser marking layer may be configured to be capable of laser marking by a method other than the following methods (1) to (5). (1) Method of foaming a resin material to develop color (2) Method of adding an additive that absorbs laser light to a resin material to develop color of the additive itself (3) Method of adding an additive that absorbs laser light to a resin material to cause the additive to generate heat and carbonize the surrounding resin material to develop color (4) Method of etching a surface of a resin layer by laser irradiation and utilizing a change in a surface state (5) Method of marking by sublimating (decomposing) a colorant (carbon black) to be decolored (to expose the base color of a resin material) by irradiating a resin material colored in black or a dark color system with laser light

[0143] Specifically, the laser marking layer contains, for example, a photothermal conversion agent and a resin material. The photothermal conversion agent contains, for example, carbon. The resin material includes, for example, a polycarbonate resin.

[0144] The peak wavelength λ 1 , the peak wavelength λ 2 , the peak wavelength λ 3 , and the peak wavelength λ 4 preferably satisfy a relationship of λ 3 < λ 2 < λ 1 < λ 4 . Therefore, the recording layer 10 and the recording layer 24 can be independently drawn.(Image of Drawing Region R1)

[0145] An image may be drawn in the drawing region R1 of the recording medium 20. Characters and the like may be drawn in a drawing region R2 of the recording medium 20. Hereinafter, an image drawn in the drawing region R1 will be described with reference to Fig. 4. Note that, in Fig. 4, a first image P1 and a visible image P3 are monochromatic images (black-and-white images), but may be multi-color images such as full-color images.

[0146] The image of the drawing region R1 is formed by overlapping the first image P1 drawn on the recording layer 10 and a second image P2 drawn on the recording layer 24 in the thickness direction of the recording medium 20. That is, the image of the drawing region R1 is a composite image of the first image P1 and the second image P2.

[0147] The first image P1 is a face photograph or the like. The first image P1 is, for example, a monochromatic image or a multi-color image. The multi-color image may be a full-color image. The first image P1 is visible under visible light, but cannot be captured under infrared rays.

[0148] The second image P2 is an image obtained by extracting a portion of the first image P1 where the contrast greatly changes as compared with the surroundings, more specifically, a contour (a part of the first image P1) extracted from the first image P1. The second image P2 may further include an image other than the contour. The second image P2 is, for example, a monochromatic image. The color of the monochromatic image is, for example, black or brown. The second image P2 can be visually recognized under visible light and can be imaged by an imaging apparatus under infrared rays.

[0149] The visible image P3 represents a visible image in a case where the image of the drawing region R1 is viewed under visible light. As the visible image P3, an image (composite image) obtained by superimposing the first image P1 and the second image P2 is visually recognized or captured. More specifically, for example, an image in which the contour of the first image P1 is black or brown is visually recognized as the visible image P3.

[0150] An infrared image (IR image) P4 represents a captured image in a case where an image of the drawing region R1 is captured by the imaging apparatus under infrared rays. As the infrared image P4, substantially the same image as the second image P2 is captured. In the present specification, substantially the same includes the same.[2.2 Method of Manufacturing Recording Medium]

[0151] Next, an example of a method of manufacturing the recording medium 20 according to the first embodiment of the present disclosure will be described.

[0152] First, the recording layer 10 is manufactured by forming the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14 on the base material 11. However, the order of formation of these layers on the base material 11 is not particularly limited, and may not be the order of the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14. Next, the base material 21 on which the underlayer 22 is formed is prepared. Next, after the intermediate layer 23 is placed on the underlayer 22, the recording layer 10 is fitted into the accommodation part 23HL of the intermediate layer 23. Note that the intermediate layer 23 in which the recording layer 10 is fitted in advance in the accommodation part 23HL may be placed on the underlayer 22. Next, the recording layer 24 is placed on the intermediate layer 23.

[0153] Next, the laminate obtained as described above is sandwiched between metal plates and pressurized while being heated, thereby thermally fusing the underlayer 22 and the intermediate layer 23 together, and the intermediate layer 23 and the recording layer 24 together. A temperature applied to the laminate during the thermal fusion is preferably 130°C or higher and 200°C or lower. If the temperature applied to the laminate is 130°C or higher, a sufficient fusion strength can be obtained. On the other hand, if the temperature applied to the laminate is 200°C or lower, damage to the recording layer 10 can be reduced. As a result, a target recording medium 20 is obtained.[2.3 Configuration of Drawing System]

[0154] Next, an example of a configuration of a drawing system 50 used for drawing on the recording medium 20 will be described with reference to Fig. 5. The drawing system 50 includes a control apparatus 51, an imaging apparatus 52, a colorimeter 53, a display unit 54, an operation unit 55, a laser light irradiation apparatus (first irradiation apparatus) 56, and a laser light irradiation apparatus (second irradiation apparatus) 57.(Imaging Apparatus 52)

[0155] The imaging apparatus 52 captures an image such as a face photograph to be drawn on the recording medium 20 on the basis of the control of the control apparatus 51. The imaging apparatus 52 may include a control unit. In this case, the control unit of the imaging apparatus 52 may execute the imaging operation on the basis of a command of the control apparatus 51.(Colorimeter 53)

[0156] The colorimeter 53 colorimetrically measures a color chart drawn on a sample on the basis of the control of the control apparatus 51. The sample may have the same configuration as the recording medium 20. The colorimeter 53 may include a control unit. In this case, the control unit of the colorimeter 53 may execute the colorimetric operation on the basis of a command of the control apparatus 51.(Display Unit 54)

[0157] The display unit 54 is, for example, a display such as a liquid crystal display or an organic electro luminescence (EL) display. These displays may be touch panel built-in displays. The display unit 54 displays an image under the control of the control apparatus 51. For example, the display unit 54 displays an operation menu of the drawing system 50, an image captured by the imaging apparatus 52, and the like.(Operation Unit 55)

[0158] The operation unit 55 is a user interface such as a keyboard and a pointing device. The operation unit 55 may be a voice input unit. The operation unit 55 may be a touch panel of the display unit 54. The operation unit 55 may be a physical button. The operation unit 55 is an interface that receives a user's operation. The operation unit 55 outputs operation data corresponding to a user's operation to a processing unit. The operation unit 55 may be capable of receiving an operation on the screen of the display unit 54.(Control Apparatus 51)

[0159] The control apparatus 51 controls an operation of the drawing system 50. Specifically, the control apparatus 51 controls operations of the imaging apparatus 52, the colorimeter 53, the display unit 54, the operation unit 55, the laser light irradiation apparatus 56, and the laser light irradiation apparatus 57.

[0160] The control apparatus 51 generates a first drawing setting file and a second drawing setting file from the measurement result of the reference color chart measured by the colorimeter 53, and stores the first drawing setting file and the second drawing setting file in the storage unit 511.

[0161] The control apparatus 51 converts the original image stored in the storage unit 511 into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 to generate drawing data (data of the driving voltage value) of the first image P1, on the basis of the first drawing setting file stored in the storage unit 511. The control apparatus 51 controls the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 to draw the first image P1 on the recording layer 10.

[0162] The control apparatus 51 processes the original image stored in the storage unit 511 and generates drawing data of the second image P2. More specifically, after extracting contour data from the original image stored in the storage unit 511, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 on the basis of the second drawing setting file stored in the storage unit 511 to generate drawing data (data of the driving voltage value) of the second image P2. The control apparatus 51 controls the laser light irradiation apparatus 57 on the basis of the drawing data of the second image P2 to draw the second image P2 on the recording layer 24.

[0163] The control apparatus 51 includes, for example, a processing unit 512, a storage unit 511, and an interface unit (hereinafter, referred to as "I / F unit") 513. The control apparatus 51 can be configured by, for example, an information processing device such as a personal computer.(Storage Unit 511)

[0164] The storage unit 511 includes, for example, a semiconductor memory, a magnetic storage device, or a combination thereof. The semiconductor memory includes, for example, a random access memory (RAM), a read only memory (ROM), an erasable programmable read only memory (EPROM), an electrically erasable and programmable read only memory (EEPRPM), a solid state drive (SSD), a flash memory, or a combination of two or more thereof. The magnetic storage device includes, for example, a hard disk drive (HDD). The storage unit 511 stores an operation program of the drawing system 50.

[0165] Furthermore, the storage unit 511 stores data of the color chart drawn on the sample and a measurement result of the color chart measured by the colorimeter 53. The storage unit 511 stores the image captured by the imaging apparatus 52 as an original image. Moreover, the storage unit 511 may store an image received from a cloud server or the like via the I / F unit 513 as an original image.

[0166] Furthermore, the storage unit 511 also stores the first drawing setting file and the second drawing setting file generated by the control apparatus 51. The first drawing setting file is a file for converting the original image into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 to generate drawing data (data of the driving voltage value) of the first image P1. The second drawing setting file is a file for converting the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 to generate drawing data (data of the driving voltage value) of the second image P2. The extracted data is data extracted from the original image stored in the storage unit 511, and is contour data of the original image stored in the storage unit 511 in the first embodiment.(Processing Unit 512)

[0167] The processing unit 512 is, for example, a central processing unit (CPU). The processing unit 512 is configured to perform various control operations by reading a program from the storage unit 511 and executing the read program. This program may be stored in the storage unit 511 in advance, or may be acquired and stored in the storage unit 511 when necessary. The program may be acquired, for example, by being read from various recording media readable by the control apparatus 51 or by being received via a communication line connected to the I / F unit 513.(I / F Unit 513)

[0168] The I / F unit 513 includes a communication module, and can transmit and receive information to and from the imaging apparatus 52, the colorimeter 53, the display unit 54, the operation unit 55, the laser light irradiation apparatus 56, and the laser light irradiation apparatus 57. The I / F unit 513 can also receive and transmit information with a server such as a cloud server via the Internet. The I / F unit 513 includes at least one of a wired interface or a wireless interface.(Laser Light Irradiation Apparatus 56)

[0169] The laser light irradiation apparatus 56 is for drawing the recording layer 10, and is configured to be able to irradiate the color development layer 13A with the laser light L 1 having a peak wavelength λ 1 , irradiate the color development layer 13B with the laser light L 2 having a peak wavelength λ 2 , and irradiate the color development layer 13C with the laser light L 3 having a peak wavelength λ 3 . The laser light irradiation apparatus 56 draws the first image P1 on the recording layer 10 on the basis of the drawing data of the recording layer 10 read from the storage unit 511 (that is, the drawing data of the first image P1) on the basis of the control of the control apparatus 51. The laser light irradiation apparatus 56 includes, for example, a semiconductor laser apparatus. The laser light irradiation apparatus 56 may include a control unit. In this case, the control unit of the laser light irradiation apparatus 56 may execute the drawing operation on the basis of a command of the control apparatus 51.(Laser Light Irradiation Apparatus 57)

[0170] The laser light irradiation apparatus 57 is for drawing the recording layer 24, and is configured to be able to irradiate the recording layer 24 with the laser light L 4 having a wavelength λ 4 . The laser light irradiation apparatus 57 draws the second image P2 on the recording layer 24 on the basis of the drawing data of the recording layer 24 read from the storage unit 511 (that is, the drawing data of the second image P2) on the basis of the control of the control apparatus 51. The laser light irradiation apparatus 57 includes, for example, a YAG laser apparatus, a YV04 laser apparatus, or a CO 2 laser apparatus. The laser light irradiation apparatus 57 may include a control unit. In this case, the control unit of the laser light irradiation apparatus 57 may perform the drawing operation on the basis of a command of the control apparatus 51.[2.4 Method of Generating First Drawing Setting File]

[0171] Next, an example of a method for generating a first drawing setting file will be described with reference to Fig. 6.

[0172] First, in step S11, the control apparatus 51 controls the laser light irradiation apparatus 56 on the basis of the data for reference color chart drawing stored in the storage unit 511, and draws the reference color chart on the recording layer 10 of a first sample. The first sample used for drawing in step S11 may have the same configuration as the recording medium 20, or may have a configuration in which the recording layer 24 is omitted from the recording medium 20. Next, in step S12, the control apparatus 51 controls the colorimeter 53 to measure the color of the reference color chart drawn on the recording layer 10 of the sample in step S11.

[0173] Next, in step S13, the control apparatus 51 generates a first grayscale voltage conversion table and international color consortium (ICC) profile on the basis of the colorimetric values measured in step S12. Next, in step S14, the control apparatus 51 generates a first drawing setting file by using the first grayscale voltage conversion table and the ICC profile generated in step S13, and stores the first drawing setting file in the storage unit 511. In the first grayscale voltage conversion table, a correspondence relationship between a grayscale value in the leuco color space and an output setting value is described. Therefore, an output setting value suitable for drawing the leuco image data is obtained. The ICC profile is a series of data that characterizes input / output devices and a color space related to color according to an ICC published standard in color management. The ICC profile is preferably used for excellent color reproduction, but may be omitted as necessary.[2.5 Method of Generating Second Drawing Setting File]

[0174] Next, an example of a method for generating a second drawing setting file will be described with reference to Fig. 7.

[0175] First, in step S21, the control apparatus 51 controls the laser light irradiation apparatus 57 on the basis of the data for reference color chart drawing stored in the storage unit 511, and draws the reference color chart on the recording layer 24 of a second sample. The second sample used for drawing in step S21 may have the same configuration as the recording medium 20, or may have a configuration in which the recording layer 10 is omitted from the recording medium 20. The reference color chart used for drawing in step S21 may be the same as or different from the reference color chart used for the method for generating the first drawing setting file. Next, in step S22, the control apparatus 51 controls the colorimeter 53 to measure the color of the reference color chart drawn on the recording layer 24 of the sample in step S21.

[0176] Next, in step S23, the control apparatus 51 generates a second grayscale voltage conversion table on the basis of the colorimetric values measured in step S22. Next, in step S24, the control apparatus 51 generates a second drawing setting file using the second grayscale voltage conversion table generated in step S23, and stores the second drawing setting file in the storage unit 511. In the second grayscale voltage conversion table, the correspondence relationship between the grayscale value and the output setting value is described.[2.6 Drawing Method of Recording Medium]

[0177] Next, an example of a drawing method of the recording medium 20 will be described with reference to Fig. 8.

[0178] In step S31, the control apparatus 51 controls the imaging apparatus 52 to capture an image such as a face photograph and to store the image in the storage unit 511 as an original image.

[0179] In step S32, using the first drawing setting file stored in the storage unit 511, the control apparatus 51 converts the original image stored in the storage unit 511 into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 to generate drawing data of the first image P1.

[0180] In step S33, after extracting contour data from the original image stored in the storage unit 511, the control apparatus 51 converts the extracted data into a driving voltage value of the laser light irradiation apparatus 57 using the second drawing setting file to generate drawing data of the second image P2.

[0181] In step S34, the control apparatus 51 controls the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32 to draw the first image P1 on the recording layer 10. Furthermore, the control apparatus 51 controls the laser light irradiation apparatus 57 on the basis of the drawing data of the second image P2 generated in step S33 to draw the second image P2 on the recording layer 24. At this time, the drawing of the first image P1 and the drawing of the second image P2 are performed such that the contour (part of the first image P1) of the first image P1 included in the second image P2 overlaps the first image P1 of the recording layer 10.

[0182] A drawing step of the recording layer 10 and a drawing step of the recording layer 24 may be performed simultaneously or may be performed at different timings. In a case where the drawing step of the recording layer 10 and the drawing step of the recording layer 24 are performed at different timings, the order of these drawing steps is not particularly limited, but it is preferable to perform the drawing step of the recording layer 10 before the drawing step of the recording layer 24. This is for the following reason. If the recording layer 24 is drawn, a drawing portion (color-developed portion) exhibits infrared absorbency. Therefore, if the drawing step of the recording layer 24 is performed before the drawing step of the recording layer 10, there is a possibility that the near-infrared laser light is absorbed by the drawing portion of the recording layer 24 at the time of drawing on the recording layer 10, and the drawing property of the recording layer 10 is affected. Thus, if the drawing step of the recording layer 10 is performed before the drawing step of the recording layer 24, it is possible to prevent the drawing portion of the recording layer 24 from affecting the drawing property of the recording layer 10.

[0183] Details of the drawing step of the first image P1 are as described below (step S35). Here, a case where the color development layer 13A, the color development layer 13B, and the color development layer 13C exhibit a cyan color, a magenta color, and a yellow color, respectively, will be described as an example. As a scanning method of the laser light L 1 , the laser light L 2 , and the laser light L 3 , for example, a raster scanning method can be used, but the scanning method is not limited thereto.

[0184] The control apparatus 51 drives the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32, and irradiates the color development layer 13A with the laser light (near-infrared laser light) L 1 having a peak wavelength λ 1 . Therefore, the photothermal conversion material contained at the irradiation position of the color development layer 13A generates heat, a coloring reaction (color development reaction) occurs between the coloring compound and the developer, and the irradiation position of the color development layer 13A develops a cyan color.

[0185] The control apparatus 51 drives the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32, and irradiates the color development layer 13B with the laser light (near-infrared laser light) L 2 having a peak wavelength λ 2 . Therefore, a coloring reaction similar to that of the color development layer 13A described above occurs, and the irradiation position of the color development layer 13B develops a magenta color.

[0186] The control apparatus 51 drives the laser light irradiation apparatus 56 on the basis of the drawing data of the first image P1 generated in step S32, and irradiates the color development layer 13C with the laser light (near-infrared laser light) L 3 having a peak wavelength λ 3 . Therefore, a coloring reaction similar to that of the color development layer 13A described above occurs, and the irradiation position of the color development layer 13C develops a yellow color.

[0187] As described above, the irradiation positions of the color development layer 13A, the color development layer 13B, and the color development layer 13C develop magenta, cyan, and yellow colors, respectively, whereby a desired first image P1 is drawn on the recording medium 20.

[0188] Note that, in a case where the laser light irradiation apparatus 56 irradiates the recording layer 24 with the laser light L 1 , the laser light L 2 and the laser light L 3 , the recording layer 24 is not laser-marked. This is because the recording layer 24 does not contain an additive that absorbs the laser light L 1 , the laser light L 2 , and the laser light L 3 .

[0189] The irradiation of the color development layer 13A with the laser light L 1 , the irradiation of the color development layer 13B with the laser light L 2 , and the irradiation of the color development layer 13C with the laser light L 3 may be performed simultaneously, or may be performed at different timings. In a case where the irradiation with the laser light L 1 , the laser light L 2 , and the laser light L 3 is performed at different timings, the order of the irradiation with the laser light L 1 , the laser light L 2 , and the laser light L 3 is arbitrary.

[0190] Details of the drawing step of the second image P2 are as described below (step S36). The laser light irradiation apparatus 57 drives the laser light irradiation apparatus 57 on the basis of the drawing data of the second image P2, and irradiates the recording layer 24 with the laser light L 4 having a peak wavelength λ 4 . Therefore, an additive (for example, a photothermal conversion agent) contained in a predetermined position of the recording layer 24 absorbs the laser light L 4 , and the predetermined position is laser-marked, so that the second image P2 is drawn. As a scanning method of the laser light L 4 , for example, a raster scanning method can be used, but the scanning method is not limited thereto.

[0191] Note that, in a case where the laser light irradiation apparatus 57 irradiates the recording layer 10 with the laser light L 4 , the recording layer 10 does not develop color. This is because the recording layer 10 does not contain an additive that absorbs the laser light L 4 .[2.7 Operation and Effect]

[0192] As described above, in the recording medium 20 according to the first embodiment, the recording layer (first recording layer) 10 is configured to be able to draw with the laser light L 1 , the laser light L 2 , and the laser light L 3 having a peak wavelength λ 1 , a peak wavelength λ 2 , and a peak wavelength λ 3 , respectively. On the other hand, the recording layer (second recording layer) 24 is configured to be able to draw with the laser light L 4 having a peak wavelength λ 4 . The peak wavelength λ 1 , the peak wavelength λ 2 , the peak wavelength λ 3 , and the peak wavelength λ 4 are set to different values. Therefore, since the drawing conditions of the laser light of the recording layer 10 and the recording layer 24 are different, when the recording layer 10 is drawn, it is possible to suppress that the recording layer 24 located on the upper side of the recording layer 10 is unintentionally drawn and drawing on the recording layer 10 becomes difficult. Therefore, it is possible to perform intended drawing on the recording layer 10.

[0193] In the recording medium 20 according to the first embodiment, an image may be drawn in the drawing region R1 of the recording medium 20. The image of the drawing region R1 is formed by overlapping the first image P1 drawn on the recording layer 10 and a second image P2 drawn on the recording layer 24 in the thickness direction of the recording medium 20. The first image P1 is visible under visible light, and cannot be captured by the imaging apparatus under infrared rays. The second image P2 can be visually recognized under visible light and can be imaged by an imaging apparatus under infrared rays. The second image P2 is a partial image of the first image P1, and is a contour image of the first image P1 in the first embodiment. Therefore, the authenticity of the recording medium 20 can be determined by comparing the visible image P3 of the drawing region R1 visually recognized under visible light with the infrared image P4 of the drawing region R1 captured under infrared rays and determining whether the infrared image P4 matches the contour of the visible image P3. Therefore, security of the recording medium 20 can be improved.

[0194] As shown in Fig. 4, since the second image P2 is a partial image of the first image P1, specifically, a contour image of the first image P1, even in a case where the second image P2 is drawn so as to overlap above the first image P1, it is possible to prevent the first image P1 that is a multi-color image from being hidden by the second image P2 that is a monochromatic image such as black or brown. Therefore, the deterioration of the display quality of the recording medium 20 can be suppressed.<3 Second Embodiment>[3.1 Configuration of Recording Medium]

[0195] Fig. 9 is a cross-sectional view of a recording medium 20A according to a second embodiment of the present disclosure. The recording medium 20A is different from the recording medium 20 in the first embodiment in sequentially including the recording layer 24, the intermediate layer 23, and a resin layer 25 on the base material 21.

[0196] The resin layer 25 is translucent with respect to visible light. The resin layer 25 is, for example, a film. As a material of the resin layer 25, a material similar to that of the base material 21 can be exemplified.

[0197] An image may be drawn in the drawing region R1 of the recording medium 20. The second image P2 may be a monochromatic image obtained by performing grayscale conversion or the like on the first image P1, or the second image P2 may be a partial image of the first image P1, for example, a contour image of the first image P1. However, from the viewpoint of suppressing deterioration in display quality of the recording medium 20, the second image P2 is preferably a partial image of the first image P1.

[0198] Here, the reason why it is preferable that the second image P2 is a partial image of the first image P1 will be described by exemplifying a case where the second image P2 is a contour image of the first image P1.

[0199] In Fig. 10, both the first image P1 and the second image P2 are monochromatic images, but actually, the first image P1 is a multi-color image such as a full-color image, and the second image P2 is a monochromatic image such as black or brown. Note that the interval of oblique lines attached to the first image P1 and the visible image P3 represents the brightness of the image, and the wider the interval of oblique lines, the brighter the image.

[0200] If the second image P2 is a monochromatic image obtained by subjecting the first image P1 to grayscale conversion or the like, the second image P2 that is a monochromatic image of black, brown, or the like may be seen behind the first image P1 that is a multi-color image such as a full-color image. In this case, as shown in Fig. 10, the visible image P3 in the drawing region R1 becomes darker than the first image P1 drawn on the recording layer 10, and there is a possibility that the display quality of the recording medium 20 deteriorates.

[0201] On the other hand, if the second image P2 is the contour image of the first image P1, as shown in Fig. 4, there is a possibility that the contour of the visible image P3 in the drawing region R1 is emphasized by the overlap between the first image P1 and the second image P2; however, it is possible to prevent the visible image P3 in the drawing region R1 from becoming darker than the first image P1 drawn on the recording layer 10. Therefore, the deterioration of the display quality of the recording medium 20 can be suppressed.[3.2 Operation and Effect]

[0202] In the recording medium 20A according to the second embodiment, the recording layer 24 and the recording layer 10 located on the upper side of the recording layer 24 have different drawing conditions by laser light. Therefore, when the recording layer 24 is drawn, it is possible to prevent the recording layer 10 located on the upper side of the recording layer 24 from being unintentionally drawn. Therefore, it is possible to perform intended drawing on the recording layer 24.

[0203] In the recording medium 20A according to the second embodiment, as shown in Fig. 11A, even in a case where a drawing region 10R is set to protrude from the peripheral edge of the recording layer 10 in plan view, it is possible to suppress color development of the recording layer 24 due to irradiation of the recording layer 10 with laser light for drawing. Therefore, as shown in Fig. 11B, an image such as a photograph can be drawn only on the recording layer 10. Furthermore, since the boundary between the recording layer 10 and the recording layer 24 in the in-plane direction of the recording medium 20A can be drawn without concern in a production line or the like, throughput and yield can be improved.

[0204] On the other hand, as shown in Fig. 12, in a recording medium 120A including a general full-color laser drawing sheet 110 instead of the recording layer 10, the drawing conditions of the full-color laser drawing sheet 110 and the recording layer 24 located below the full-color laser drawing sheet 110 are substantially the same. Therefore, in plan view, in a case where the drawing region 10R is set so as to protrude from the peripheral edge of the full-color laser drawing sheet 110, the recording layer 24 develops color by irradiation of the laser light for drawing of the full-color laser drawing sheet 110. Therefore, as shown in Fig. 12, an image such as a photograph is drawn out of the full-color laser drawing sheet 110. Furthermore, an image of a portion protruding from the full-color laser drawing sheet 110 is drawn in a color (for example, black or brown) different from that of the full-color laser drawing sheet 110.<4 Modifications>[Modification 1]

[0205] In the first embodiment and the second embodiment, an example in which the second image P2 of the recording layer 24 includes the contour of the first image P1 of the recording layer 10 has been described (see Fig. 4). However, the present disclosure is not limited to this example, and for example, as shown in Fig. 13, the second image P2 of the recording layer 24 may include a black portion of the first image P1 of the recording layer 10. Note that Fig. 13 shows an example in which the first image P1 is a face photograph and the second image P2 includes a hair and a pupil in the face photograph of the first image P1.

[0206] In a case where the second image P2 of the recording layer 24 includes a black portion of the first image P1 of the recording layer 10, substantially the same image as the first image P1 is visually recognized as the visible image P3 as shown in Fig. 13. As the infrared image P4, as shown in Fig. 13, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0207] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts the black portion from the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the black portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57, and generates drawing data of the second image P2.

[0208] The data corresponding to the black portion of the first image P1 is, for example, data equal to or more than a specified voltage value V th in the drawing data (data of the driving voltage value) of the first image P1. In a case where the maximum voltage value in the drawing data of the first image P1 is V max , the specified voltage value V th is, for example, V max × 0.8 or V max × 0.9.[Modification 2]

[0209] As shown in Fig. 14, the second image P2 of the recording layer 24 may include both a contour P21 of the first image P1 of the recording layer 10 and a black portion P22 of the first image P1 of the recording layer 10.

[0210] In a case where the second image P2 of the recording layer 24 includes both the contour P21 of the first image P1 of the recording layer 10 and the black portion P22 of the first image P1 of the recording layer 10, an image in which the contour of the first image P1 is black, brown, or the like is visually recognized as the visible image P3 as shown in Fig. 14. As the infrared image P4, as shown in Fig. 14, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0211] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts both the contour P21 of the first image P1 of the recording layer 10 and the black portion P22 from the first image P1, and combines the contour P21 and the black portion P22 to generate the second image P2. Details of the extraction processing of the contour of the first image P1 in the control apparatus 51 are as described in the first embodiment. Details of the extraction processing of the black portion of the first image P1 in the control apparatus 51 are as described in Modification 1.[Modification 3]

[0212] In Modification 2, an example in which the second image P2 of the recording layer 24 includes the contour P21 of the first image P1 of the recording layer 10 and the black portion P22 of the first image P1 of the recording layer 10 has been described (see Fig. 14). However, the present disclosure is not limited to this example, and for example, the second image P2 of the recording layer 24 may include a color-developed portion having a prescribed color development density or more in the first image P1 of the recording layer 10 instead of the black portion P22 of the first image P1 of the recording layer 10. The color-developed portion having a prescribed color development density or more may be a substantially maximum color development density portion. Alternatively, the color-developed portion having a prescribed color development density or more may be a color development density portion having a color density of 1.0 or more. This is because a very clear image can be obtained if the color density is 1.0 or more.

[0213] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts a color-developed portion having a prescribed color development density or more in the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the color-developed portion having a prescribed color development density or more in the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57, and generates drawing data of the second image P2.[Modification 4]

[0214] As shown in Fig. 15, the second image P2 of the recording layer 24 may include a key plate portion (K portion) of the first image P1 of the recording layer 10. In Fig. 15, both the first image P1 and the second image P2 are monochromatic images, but actually, the first image P1 is a multi-color image such as a full-color image, and the second image P2 is a monochromatic image such as black or brown. Note that the interval of oblique lines attached to the first image P1 and the visible image P3 represents the brightness of the image, and the wider the interval of oblique lines, the brighter the image.

[0215] In a case where the second image P2 of the recording layer 24 includes the key plate portion of the first image P1 of the recording layer 10, there is a possibility that an image slightly darker than the first image P1 is visually recognized as the visible image P3 as shown in Fig. 15. As the infrared image P4, as shown in Fig. 15, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0216] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts the key plate portion of the first image P1 of the recording layer 10 to generate the second image P2. More specifically, after extracting data corresponding to the key plate portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 to generate drawing data (data of the driving voltage value) of the second image P2.

[0217] After correcting the first image P1 to be bright, the control apparatus 51 may draw the corrected first image P1 on the recording layer 10. In this case, it is possible to prevent the visible image P3 from becoming a darker image than the first image P1 by combining the first image P1 and the second image P2.

[0218] Examples of the correction method for brightening the first image P1 include, but are not limited to, a correction method for increasing the brightness L* of the first image P1. It is preferable to correct the first image P1 so that the brightness, for example, the brightness L*, of the first image P1 before correction and the visible image P3 (the composite image of the first image P1 and the second image P2 after correction) becomes substantially the same.[Modification 5]

[0219] As shown in Fig. 16, a second image P2 of the recording layer 24 may include a background portion 17 of the first image P1 of the recording layer 10. The second image P2 of the recording layer 24 may further include at least one of the contour of the first image P1 of the recording layer 10 or the black portion of the first image P1 of the recording layer 10. In a case where the second image P2 of the recording layer 24 includes the background portion 17 of the first image P1 of the recording layer 10, the density of the background portion 17 of the second image P2 may be different from the density of the background portion 17 of the first image P1. For example, the density of the background portion 17 of the second image P2 may be higher than the density of the background portion 17 of the first image P1.

[0220] In a case where the second image P2 of the recording layer 24 includes the background portion 17 of the first image P1 of the recording layer 10, an image in which the background portion 17 is darker than the first image P1 is visually recognized as the visible image P3 as shown in Fig. 16. As the infrared image P4, as shown in Fig. 16, substantially the same image as the second image P2 is captured by the imaging apparatus.

[0221] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts the background portion 17 of the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the background portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 converts the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57, and generates drawing data of the second image P2.

[0222] The control apparatus 51 may extract the background portion of the first image P1 and at least one of the contour of the first image P1 or the black portion of the first image P1 to generate the second image P2. More specifically, after extracting data corresponding to the background portion of the first image P1 and data corresponding to at least one of the contour of the first image P1 or the black portion of the first image P1 from the drawing data of the first image P1, the control apparatus 51 may convert the extracted data into a driving voltage value at the time of drawing by the laser light irradiation apparatus 57 to generate drawing data of the second image P2.[Modification 6]

[0223] As shown in Fig. 17, the second image P2 of the recording layer 24 may include the contour of the first image P1 of the recording layer 10 and identification information 15. The identification information 15 is added to a portion of the second image P2 corresponding to the black portion of the first image P1. The identification information 15 is information for determining authenticity of the recording medium 20, and may be a pattern or the like.

[0224] In a case where the recording layer 10 is provided on the upper side of the recording layer 24 and the second image P2 of the recording layer 24 includes the contour of the first image P1 of the recording layer 10 and the identification information 15, in the visible image P3, as shown in Fig. 17, the identification information 15 is hidden by the black portion of the first image P1 and cannot be visually recognized. In the infrared image P4, as shown in Fig. 17, the identification information 15 is not hidden by the black portion of the first image P1, and thus can be confirmed. Therefore, the authenticity of the recording medium 20 can be determined by confirming the identification information 15, which is hidden by the black portion in the visible image P3, by the infrared image P4.

[0225] The control apparatus 51 of the drawing system 50 generates the second image P2 as follows. That is, the control apparatus 51 extracts both the contour of the first image P1 and the black portion from the first image P1. After replacing the extracted black portion with the identification information 15 of a pattern or the like, the control apparatus 51 generates the second image P2 by combining the contour of the extracted first image P1 and the replaced identification information 15 of a pattern or the like.[Modification 7]

[0226] As shown in Fig. 18, the first image P1 of the recording layer 10 may include identification information 16. The identification information 16 is information for determining authenticity of the recording medium 20, and may be, for example, a mark, a pattern or the like, or a combination thereof. Examples of the position of the identification information 16 in the first image P1 include, but are not limited to, a background portion.

[0227] In a case where the first image P1 of the recording layer 10 includes the identification information 16, the identification information 16 can be visually recognized in the visible image P3 as shown in Fig. 18. In the infrared image P4, as shown in Fig. 18, the identification information 16 cannot be confirmed. Therefore, the authenticity of the recording medium 20 can be determined by checking the presence or absence of the identification information 16 in the infrared image P4.

[0228] The control apparatus 51 of the drawing system 50 generates drawing data of the first image P1 as follows. That is, after adding the identification information 16 to the original image stored in the storage unit 511, the control apparatus 51 converts the original image to which the identification information 16 is added into a driving voltage value at the time of drawing by the laser light irradiation apparatus 56 using the first drawing setting file stored in the storage unit 511 to generate drawing data of the first image P1.[Modification 8]

[0229] In the first embodiment and the second embodiment, an example in which the size of the recording layer 10 in plan view is smaller than the size of the recording layer 24 in plan view has been described (see Figs. 2 and 9). However, the size of the recording layer 10 and the size of the recording layer 24 are not limited to this example.

[0230] For example, as shown in Fig. 19, the size of the recording layer 10 in plan view may be substantially the same as the size of the recording layer 24 in plan view. In this case, the sizes of the recording layer 10 and the recording layer 24 in plan view may be substantially the same as the sizes of the base material 21 and the underlayer 22 in plan view.

[0231] For example, as shown in Fig. 20, the size of the recording layer 10 in plan view may be larger than the size of the recording layer 24 in plan view. In this case, the recording layer 24 may be accommodated in the accommodation part 23HL of the intermediate layer 23, and the recording layer 10 may be provided between the base material 21 and the intermediate layer 23.[Modification 9]

[0232] In the second embodiment, an example in which the recording medium 20A includes the intermediate layer 23 including the recording layer 10 on the recording layer 24 has been described (see Fig. 9). However, the layer configuration of the recording medium 20A is not limited to this example. For example, as shown in Fig. 21, the recording medium 20A may further include a wavelength selection layer 26 between the intermediate layer 23 including the recording layer 10 and the recording layer 24. The wavelength selection layer 26 is configured to reflect visible light and to transmit near infrared rays (NIR). Examples of the wavelength selection layer 26 include, but are not limited to, a dielectric multilayer film.[Modification 10]

[0233] In the first embodiment and the second embodiment, an example in which the recording layer 10 includes three layers of the color development layer 13A, the color development layer 13B, and the color development layer 13C has been described (see Fig. 3). However, the layer configuration of the recording layer 10 is not limited thereto, and the recording layer 10 may include one, two, or three or more color development layers. In a case where the recording layer 10 includes one color development layer, the color development layer may be any color development layer of the color development layer 13A, the color development layer 13B, and the color development layer 13C, or may be a color development layer that can exhibit a color different from those layers in the color-developed state, for example, a color development layer that can exhibit a black color in the color-developed state.[Modification 11]

[0234] In the first embodiment, an example in which the recording medium 20 includes the base material 21 and the underlayer 22 has been described (see Fig. 2). However, the configuration is not limited to this example of the recording medium 20, and the recording medium 20 may not include at least one of the base material 21 or the underlayer 22.[Modification 12]

[0235] In the second embodiment, an example in which the recording medium 20A includes the base material 21 and the resin layer 25 has been described (see Fig. 9). However, the configuration is not limited to this example of the recording medium 20A, and the recording medium 20A may not include at least one of the base material 21 or the resin layer 25.[Modification 13]

[0236] In the first embodiment, an example in which the intermediate layer 12A, the color development layer 13A, the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14 are formed on the base material 11 has been described. However, the method of manufacturing the recording layer 10 is not limited thereto, and for example, the recording layer 10 may be manufactured as follows.

[0237] The recording layer 10 may be manufactured by using the cover layer 14 as a base material and forming the intermediate layer 12D, the color development layer 13C, the intermediate layer 12C, the color development layer 13B, the intermediate layer 12B, and the color development layer 13A on the cover layer 14. However, the order of formation of these layers on the cover layer 14 is not particularly limited, and may not be the order of the intermediate layer 12D, the color development layer 13C, the intermediate layer 12C, the color development layer 13B, the intermediate layer 12B, and the color development layer 13A. In the case of manufacturing the recording layer 10 as described above, the base material 11 and the intermediate layer 12A may be formed on the color development layer 13A or may not be formed. In a case where the base material 11 and the intermediate layer 12A are not formed on the color development layer 13A, the recording layer 10 can be thinned. On the other hand, in a case where the base material 11 and the intermediate layer 12A are formed on the color development layer 13A, since the base material 11 functions as a protective layer, the durability of the recording layer 10 can be improved.

[0238] The recording layer 10 may be manufactured by using the color development layer 13A as a base material and forming the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14 on the color development layer 13A. However, the order of formation of these layers on the color development layer 13A is not particularly limited, and may not be the order of the intermediate layer 12B, the color development layer 13B, the intermediate layer 12C, the color development layer 13C, the intermediate layer 12D, and the cover layer 14. In the case of manufacturing the recording layer 10 as described above, the base material 11 and the intermediate layer 12A may be formed below the color development layer 13A or may not be formed.[Modification 14]

[0239] In the first embodiment, an example in which the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D include a bonding adhesive layer and an ultraviolet-curable resin layer has been described. However, the configurations of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are not limited thereto, and for example, configurations described below can also be adopted.

[0240] Fig. 22 is a cross-sectional view of a first modification of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D. The intermediate layer 12A may include a bonding adhesive layer 12A 3 between the ultraviolet-curable resin layer 12A 2 and the color development layer 13A. The intermediate layer 12B may include a bonding adhesive layer 12B 3 between the ultraviolet-curable resin layer 12B 2 and the color development layer 13B. The intermediate layer 12C may include a bonding adhesive layer 12C 3 between the ultraviolet-curable resin layer 12C 2 and the color development layer 13C. The intermediate layer 12D may include a bonding adhesive layer 12D 3 between the ultraviolet-curable resin layer 12D 2 and a color development layer 13D. Although Fig. 22 shows an example in which the recording layer 10 includes the bonding adhesive layer 12A 3 , the bonding adhesive layer 12B 3 , the bonding adhesive layer 12C 3 , and the bonding adhesive layer 12D 3 , the recording layer 10 may include at least one of the bonding adhesive layer 12A 3 , the bonding adhesive layer 12B 3 , the bonding adhesive layer 12C 3 , or the bonding adhesive layer 12D 3 .[Modification 15]

[0241] Fig. 23 is a cross-sectional view of a second modification of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D. An intermediate layer 22A, an intermediate layer 22B, an intermediate layer 22C, and an intermediate layer 22D may be constituted by adhesive layers. The adhesive layer may be a thermal adhesive layer. The thermal adhesive layer contains a thermal adhesive resin that is softened or melted at a predetermined temperature to bond the layers. Other components contained in the thermal adhesive layer are not particularly limited. As the thermal adhesive resin, a thermoplastic resin that becomes soft when heated to a softening point or a melting point can be used. The thermoplastic resin is not particularly limited, and includes, for example, at least one selected from the group consisting of a polyamide resin, a polyester resin, a polyethylene resin, an ethylene-vinyl acetate copolymer (EVA), a polyurethane resin, an acrylic resin, and the like. The predetermined temperature varies depending on the type of the thermoplastic resin used for the thermal adhesive resin.

[0242] Fig. 23 shows an example in which all the layers of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are constituted by an adhesive layer, but at least one of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, or the intermediate layer 12D may be constituted by an adhesive layer. In a case where all the layers of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are constituted by thermal adhesive layers, the interlayer regions between the respective layers of the recording layer 10 can be collectively bonded by the thermal adhesive layers.[Modification 16]

[0243] In the first embodiment, the imaging apparatus 52 and the colorimeter 53 are not essential components in the drawing system 50, and at least one of the imaging apparatus 52 or the colorimeter 53 may not be included in the drawing system 50.

[0244] In a case where the imaging apparatus 52 is not included in the drawing system 50, the control apparatus 51 may acquire an image (for example, a picture, a photograph, or the like) used for drawing on the recording medium 20 from the outside of the drawing system 50 in a wired or wireless manner via the I / F unit 513. Specifically, for example, the control apparatus 51 may acquire an image to be used for drawing the recording medium 20 from a cloud server or the like, or from an external memory or the like. The control apparatus 51 may store the acquired image in the storage unit 511.

[0245] In a case where the colorimeter 53 is not included in the drawing system 50, the generation of the first drawing setting file and the second drawing setting file may be performed outside the drawing system 50. In this case, the control apparatus 51 may acquire the first drawing setting file and the second drawing setting file from the outside of the drawing system 50 in a wired or wireless manner via the I / F unit 513.[Modification 17]

[0246] In the first embodiment, the drawing system 50 may further include an external storage unit. In this case, the external storage unit may store the data of the color chart drawn on the sample and the measurement result of the color chart measured by the colorimeter 53. Furthermore, the external storage unit may store an image captured by the imaging apparatus 52, and the first drawing setting file and the second drawing setting file generated by the control apparatus 51.(Other Modifications)

[0247] The embodiments and modifications of the present disclosure have been specifically described above, but the present disclosure is not limited to the above-described embodiments and modifications, and various modifications based on the technical idea of the present disclosure may be made.

[0248] For example, configurations, methods, processes, shapes, materials, numerical values, and the like in the above-described embodiments and modifications are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, and the like may be employed as necessary.

[0249] The configurations, methods, steps, shapes, materials, and numerical values and the like of the above-described embodiments and modifications can be combined with each other without departing from the gist of the present disclosure.

[0250] In numerical value ranges described in stages in the above-described embodiments and modifications, an upper limit value or a lower limit value of a numerical value range of a certain stage may be replaced with an upper limit value or a lower limit value of a numerical value range of another stage.

[0251] The materials exemplified in the above embodiment and modifications may be used alone or in combination of two or more unless otherwise specified.

[0252] Furthermore, the present disclosure may also employ the following configurations. (1) A recording medium including: a first recording layer configured to be able to draw with first laser light having a first peak wavelength; and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium. (2) The recording medium according to (1), in which the second recording layer is configured to be able to draw an image visible under visible light and capable of being captured under infrared rays. (3) The recording medium according to (1) or (2), in which a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, the second image includes a part of the first image, and the part of the first image included in the second image overlaps the first image of the first recording layer. (4) The recording medium according to (3), in which the part of the first image includes a contour of the first image. (5) The recording medium according to (3), in which the part of the first image includes a color-developed portion having a prescribed color development density or more in the first image. (6) The recording medium according to (3), in which the part of the first image includes a substantially maximum color development density portion in the first image. (7) The recording medium according to (3), in which the part of the first image includes a black portion of the first image. (8) The recording medium according to (3), in which the part of the first image includes a contour of the first image and a black portion of the first image or a key plate portion of the first image. (9) The recording medium according to (3), in which the first recording layer is provided on an upper side of the second recording layer, and at least a part of the second image is hidden by the first image of the first recording layer under visible light. (10) The recording medium according to (1), in which a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, and a composite image is formed by the first image and the second image. (11) The recording medium according to (10), in which the second image includes at least one of a black portion of the composite image or a background portion of the composite image. (12) The recording medium according to any one of (1) to (11), in which the first color development layer further contains a matrix resin, a developer, and a photothermal conversion agent. (13) The recording medium according to any one of (1) to (12), in which the first recording layer is configured to be able to draw with third laser light having a third peak wavelength and fourth laser light having a fourth peak wavelength, the first recording layer further includes: a second color development layer configured to be able to develop color with the third laser light and containing a second leuco dye; and a third color development layer configured to be able to develop color with the fourth laser light and containing a third leuco dye, and the first peak wavelength, the second peak wavelength, the third peak wavelength, and the fourth peak wavelength are different from each other. (14) A drawing method including: irradiating a first recording layer of a recording medium with first laser light having a first peak wavelength to draw a first image; and irradiating a second recording layer of the recording medium with second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, in which the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium. (15) The drawing method according to (14), in which the second image includes a part of the first image, and drawing of the first image and drawing of the second image are performed such that the part of the first image included in the second image overlaps the first image. (16) The drawing method according to (14) or (15), further including extracting second image information for drawing the second image from first image information for drawing the first image. (17) The drawing method according to any one of (14) to (16), further including correcting first image information for drawing the first image such that the first image becomes brighter. (18) A drawing system including: a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength; a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength; and a control apparatus configured to be able to control the first irradiation apparatus and the second irradiation apparatus, in which the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image. (19) The drawing system according to (18), in which the control apparatus further executes extracting second image information for drawing the second image from first image information for drawing the first image. (20) The drawing system according to (18) or (19), in which the control apparatus further executes correcting first image information for drawing the first image such that the first image becomes brighter. (21) A control apparatus capable of controlling a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength and a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength, the control apparatus executing: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image. REFERENCE SIGNS LIST

[0253] 10 Recording layer (first recording layer) 11 Base material 12A, 12B, 12C, 12D Intermediate layer 12A 1 , 12B 1 , 12C 1 , 12D 1 Bonding adhesive layer 12A 2 , 12B 2 , 12C 2 , 12D 2 Ultraviolet-curable resin layer 13A, 13B, 13C Color development layer 14 Cover layer 15, 16 Identification information 17 Background portion 20 Recording medium 21 Base material 22 Underlayer 23 Intermediate layer 23HL Accommodation part 24 Recording layer (second recording layer) 25 Resin layer 50 Drawing system 51 Control apparatus 52 Imaging apparatus 53 Colorimeter 54 Display unit 55 Operation unit 56 Laser light irradiation apparatus 57 Laser light irradiation apparatus 511 Storage unit 512 Processing unit 513 Network I / F R1, R2 Drawing region P1 First image P2 Second image P3 Visible image P4 Infrared image

Examples

first embodiment

[2.1 Configuration of Recording Medium]

[0047]Fig. 1 is a perspective view of a recording medium 20 according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along a line II-II in Fig. 1. The recording medium 20 sequentially includes a base material 21, an underlayer 22, an intermediate layer 23 including a recording layer (first recording layer) 10, and a recording layer (second recording layer) 24.

[0048]The base material 21 and the underlayer 22 may be bonded to each other by fusion bonding or an adhesive. The underlayer 22 and the intermediate layer 23 may be bonded to each other by fusion bonding or an adhesive. The intermediate layer 23 and the recording layer 24 may be bonded to each other by fusion bonding or an adhesive.

[0049]The recording medium 20 may be a card such as a security card, a financial payment card (for example, a credit card, a cash card, or the like), an ID card (for example, an employee ID card, a membership card, a stu...

second embodiment

[3.1 Configuration of Recording Medium]

[0195]Fig. 9 is a cross-sectional view of a recording medium 20A according to a second embodiment of the present disclosure. The recording medium 20A is different from the recording medium 20 in the first embodiment in sequentially including the recording layer 24, the intermediate layer 23, and a resin layer 25 on the base material 21.

[0196] The resin layer 25 is translucent with respect to visible light. The resin layer 25 is, for example, a film. As a material of the resin layer 25, a material similar to that of the base material 21 can be exemplified.

[0197]An image may be drawn in the drawing region R1 of the recording medium 20. The second image P2 may be a monochromatic image obtained by performing grayscale conversion or the like on the first image P1, or the second image P2 may be a partial image of the first image P1, for example, a contour image of the first image P1. However, from the viewpoint of suppressing deterioration in display...

modification 1

[Modification 1]

[0205]In the first embodiment and the second embodiment, an example in which the second image P2 of the recording layer 24 includes the contour of the first image P1 of the recording layer 10 has been described (see Fig. 4). However, the present disclosure is not limited to this example, and for example, as shown in Fig. 13, the second image P2 of the recording layer 24 may include a black portion of the first image P1 of the recording layer 10. Note that Fig. 13 shows an example in which the first image P1 is a face photograph and the second image P2 includes a hair and a pupil in the face photograph of the first image P1.

[0206]In a case where the second image P2 of the recording layer 24 includes a black portion of the first image P1 of the recording layer 10, substantially the same image as the first image P1 is visually recognized as the visible image P3 as shown in Fig. 13. As the infrared image P4, as shown in Fig. 13, substantially the same image as the second...

Claims

1. A recording medium comprising: a first recording layer configured to be able to draw with first laser light having a first peak wavelength; and a second recording layer configured to be able to draw with second laser light having a second peak wavelength different from the first peak wavelength, wherein the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

2. The recording medium according to claim 1, wherein the second recording layer is configured to be able to draw an image visible under visible light and capable of being captured under infrared rays.

3. The recording medium according to claim 1, wherein a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, the second image includes a part of the first image, and the part of the first image included in the second image overlaps the first image of the first recording layer.

4. The recording medium according to claim 3, wherein the part of the first image includes a contour of the first image.

5. The recording medium according to claim 3, wherein the part of the first image includes a color-developed portion having a prescribed color development density or more in the first image.

6. The recording medium according to claim 3, wherein the part of the first image includes a substantially maximum color development density portion in the first image.

7. The recording medium according to claim 3, wherein the part of the first image includes a black portion of the first image.

8. The recording medium according to claim 3, wherein the part of the first image includes a contour of the first image and a black portion of the first image or a key plate portion of the first image.

9. The recording medium according to claim 3, wherein the first recording layer is provided on an upper side of the second recording layer, and at least a part of the second image is hidden by the first image of the first recording layer under visible light.

10. The recording medium according to claim 1, wherein a first image visible under visible light is drawn on the first recording layer, a second image visible under visible light and capable of being captured under infrared rays is drawn on the second recording layer, and a composite image is formed by the first image and the second image.

11. The recording medium according to claim 10, wherein the second image includes at least one of a black portion of the composite image or a background portion of the composite image.

12. The recording medium according to claim 1, wherein the first color development layer further contains a matrix resin, a developer, and a photothermal conversion agent.

13. The recording medium according to claim 1, wherein the first recording layer is configured to be able to draw with third laser light having a third peak wavelength and fourth laser light having a fourth peak wavelength, the first recording layer further includes: a second color development layer configured to be able to develop color with the third laser light and containing a second leuco dye; and a third color development layer configured to be able to develop color with the fourth laser light and containing a third leuco dye, and the first peak wavelength, the second peak wavelength, the third peak wavelength, and the fourth peak wavelength are different from each other.

14. A drawing method comprising: irradiating a first recording layer of a recording medium with first laser light having a first peak wavelength to draw a first image; and irradiating a second recording layer of the recording medium with second laser light having a second peak wavelength different from the first peak wavelength to draw a second image, wherein the first recording layer includes a first color development layer configured to be able to develop color with the first laser light and containing a first leuco dye, the first recording layer and the second recording layer have different recording methods, and at least parts of the first recording layer and the second recording layer overlap each other in a thickness direction of the recording medium.

15. The drawing method according to claim 14, wherein the second image includes a part of the first image, and drawing of the first image and drawing of the second image are performed such that the part of the first image included in the second image overlaps the first image.

16. The drawing method according to claim 14, further comprising extracting second image information for drawing the second image from first image information for drawing the first image.

17. The drawing method according to claim 14, further comprising correcting first image information for drawing the first image such that the first image becomes brighter.

18. A drawing system comprising: a first irradiation apparatus configured to be able to emit first laser light having a first peak wavelength; a second irradiation apparatus configured to be able to emit second laser light having a second peak wavelength different from the first peak wavelength; and a control apparatus configured to be able to control the first irradiation apparatus and the second irradiation apparatus, wherein the control apparatus executes: irradiating a first recording layer of a recording medium with the first laser light and causing a first leuco dye contained in a first color development layer included in the first recording layer to develop color to draw a first image; and irradiating a second recording layer of the recording medium with the second laser light to draw a second image.

19. The drawing system according to claim 18, wherein the control apparatus further executes extracting second image information for drawing the second image from first image information for drawing the first image.

20. The drawing system according to claim 18, wherein the control apparatus further executes correcting first image information for drawing the first image such that the first image becomes brighter.

Images