Drawing system and drawing method

Abstract

A drawing system according to an embodiment of the present disclosure includes a light source section and a scanning section. The light source section generates a plurality of laser beams having wavelengths different from each other and corresponding to an absorption wavelength of a light-heat conversion agent contained in a recording medium. The scanning section scans a surface of the recording medium with the plurality of laser beams in a state in which irradiation spots of the plurality of laser beams are arranged side by side at predetermined intervals in a direction orthogonal or oblique to a scanning direction of the plurality of laser beams.

Description

Technical Field

[0001] This disclosure relates to drawing systems and drawing methods. Background Technology

[0002] As a display medium to replace printed materials, a recording medium that uses heat to reversibly record and erase information has been developed, namely a so-called reversible thermal recording medium. In a reversible thermal recording medium, for example, multiple reversible thermal recording layers with different photothermal conversion wavelengths are stacked, and a heat-insulating layer is inserted between them. The reversible thermal recording medium is irradiated with a laser beam of a predetermined wavelength, causing specific reversible thermal recording layers to selectively generate heat, and the generated heat causes color development or decolorization, thus recording or erasing information (see, for example, Patent Document 1).

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-188827 Summary of the Invention

[0006] However, when writing or erasing is performed simultaneously on the same pixel across reversible thermal recording layers, thermal crosstalk may occur between two adjacent reversible thermal recording layers in the stacking direction, leading to accidental writing or erasing. Therefore, there is a need for a drawing system and drawing method that makes accidental writing and erasing less likely to occur.

[0007] The drawing system according to embodiments of the present disclosure is a drawing system that performs drawing on a recording medium comprising a plurality of stacked recording layers, with a heat-insulating layer interposed between the plurality of recording layers. The plurality of recording layers comprise different colorimetric compounds and different photothermal conversion agents. The drawing system includes a light source unit and a scanning unit. The light source unit generates a plurality of laser beams having wavelengths that are different from each other and correspond to the absorption wavelengths of the photothermal conversion agents. The scanning unit irradiates the surface of the recording medium with the plurality of laser beams generated by the light source unit at predetermined intervals, and synchronously scans the surface of the recording medium with the plurality of laser beams in the same direction. The scanning unit scans the surface of the recording medium with the plurality of laser beams arranged side-by-side at predetermined intervals in a direction orthogonal or oblique to the scanning direction of the plurality of laser beams.

[0008] In the drawing system according to an embodiment of the present disclosure, the surface of the recording medium is scanned by multiple laser beams, with the illumination spots of multiple laser beams generated by the light source arranged side-by-side at predetermined intervals in a direction orthogonal or oblique to the scanning direction of the multiple laser beams. In this way, thermal crosstalk between adjacent recording layers in the stacking direction can be reduced. As a result, the possibility of accidental writing and erasure can be reduced.

[0009] The drawing method according to embodiments of this disclosure is a method of performing drawing on a recording medium comprising a plurality of stacked recording layers, with a heat-insulating layer interposed between the plurality of recording layers. The plurality of recording layers comprise different color-producing compounds and different photothermal conversion agents. The drawing method includes the following three aspects:

[0010] (1) Generate multiple laser beams with wavelengths that are different from each other and correspond to the absorption wavelength of the photothermal conversion agent;

[0011] (2) The surface of the recording medium is irradiated with multiple laser beams at predetermined intervals, and the surface of the recording medium is simultaneously scanned in the same direction using the multiple laser beams; and

[0012] (3) The surface of the recording medium is scanned by multiple laser beams in a state in which the irradiation spots of multiple laser beams are arranged side by side at a predetermined interval in a direction orthogonal or oblique to the scanning direction of multiple laser beams.

[0013] In the drawing method according to the embodiments of the present disclosure, the surface of the recording medium is scanned by multiple laser beams, with the illumination spots of multiple laser beams generated by the light source arranged side by side at predetermined intervals in a direction orthogonal or oblique to the scanning direction of the multiple laser beams. In this way, thermal crosstalk between adjacent recording layers in the stacking direction can be reduced. As a result, the possibility of accidental writing and erasure can be reduced. Attached Figure Description

[0014] [ Figure 1 [Illustrated diagram] is a schematic diagram illustrating an exemplary configuration of a drawing system according to an embodiment of the present disclosure.

[0015] [ Figure 2 ] is to show Figure 1 A schematic diagram illustrating an exemplary configuration of the drawing section.

[0016] [ Figure 3 ] is to show Figure 2 A schematic diagram of an exemplary cross-sectional configuration of the recording medium.

[0017] [ Figure 4A ] is to show Figure 1 A schematic diagram of the drawing state in the drawing system.

[0018] [ Figure 4B ] is to show Figure 1 A schematic diagram of the drawing state in the drawing system.

[0019] [ Figure 5 [ ] is a schematic diagram illustrating an example of the drawing method based on the comparative example.

[0020] [ Figure 6 [ ] is a schematic diagram illustrating an example of the drawing method based on the comparative example.

[0021] [ Figure 7 ] is to show Figure 1 A schematic diagram illustrating a modified example of the drawing system configuration.

[0022] [ Figure 8 ] is to show Figure 1 A schematic diagram illustrating a modified example of the drawing system configuration.

[0023] [ Figure 9 ] is to show Figure 1 A schematic diagram illustrating a modified example of the drawing system configuration.

[0024] [ Figure 10 ] is to show Figure 1 A schematic diagram illustrating a modified example of the drawing system configuration.

[0025] [ Figure 11 ] is to show Figure 1 A schematic diagram illustrating a modified example of the drawing system configuration.

[0026] [ Figure 12 ] is to show Figure 1 and Figures 7 to 11 A schematic diagram illustrating a modified drawing method in the drawing system.

[0027] [ Figure 13 [Showing] Figure 12 Examples of drawing steps in the drawing method.

[0028] [ Figure 14 [Showing] Figure 12 Examples of drawing steps in the drawing method.

[0029] [ Figure 15 [Showing] Figure 12 Examples of drawing steps in the drawing method.

[0030] [ Figure 16 [Showing the use] Figure 12 Evaluation results of images drawn using the drawing methods described in the document.

[0031] [ Figure 17 ] is to show Figure 12 A schematic diagram illustrating a modified example of the drawing method in the image. Detailed Implementation

[0032] In the following, some embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited thereto.

[0033] <1. Implementation Method>

[0034] [Configuration]

[0035] A drawing system 100 according to an embodiment of the present disclosure will be described. Figure 1 An exemplary schematic configuration of the drawing system 100 according to this embodiment is shown. The drawing system 100 writes (draws) and erases information on the recording medium 10, which will be described later. The drawing system 100, for example, converts externally input image data described in a device-related color space (hereinafter referred to as "input image data") into image data described in the color space of the recording medium 10 (hereinafter referred to as "drawn image data"). Here, the device-related color space is, for example, the RGB color space, such as sRGB or Adobe RGB. The color space of the recording medium 10 is the color space that the recording medium 10 has as a characteristic. The drawing system 100 further converts the drawn image data obtained by conversion into the output setting value of the drawing unit 150, which will be described later, and inputs the output setting value obtained by conversion into the drawing unit 150, thereby drawing on the recording medium 10. Hereinafter, the drawing system 100 will be described first, and then the recording medium 10 will be described.

[0036] (Drawing System 100)

[0037] The rendering system 100 includes, for example, a communication unit 110, an input unit 120, a display unit 130, a memory 140, a rendering unit 150, and an information processor 160. The rendering system 100 is connected to a network, for example, via the communication unit 110. The network is, for example, a communication line such as a LAN or WAN. A terminal device is connected to the network, for example. The rendering system 100 is configured to communicate with the terminal device via the network. The terminal device is, for example, a mobile terminal, and is configured to communicate with the rendering system 100 via the network.

[0038] The communication unit 110 communicates with external devices such as terminal devices. For example, the communication unit 110 sends input image data received from an external device such as a mobile terminal to the information processor 160. The input image data is data describing the grayscale value of each drawing coordinate in a device-related color space. In the input image data, the grayscale value of each drawing coordinate includes, for example, an 8-bit red grayscale value, an 8-bit green grayscale value, and an 8-bit blue grayscale value.

[0039] Input unit 120 accepts input from the user (e.g., execution instructions, data input, etc.). Input unit 120 sends the user-inputted information to information processor 160. Display unit 130 displays the screen based on various screen data created by information processor 160. Display unit 130 includes, for example, a liquid crystal panel, an organic EL (electroluminescent) panel, etc.

[0040] Memory 140 stores, for example, various programs. Memory 140 stores, for example, programs for converting input image data described in a device-related color space into drawing image data described in the color space of recording medium 10. Drawing image data is, for example, data describing the grayscale value of each drawing coordinate in the color space of recording medium 10. If the color space of recording medium 10 is a leuco color space, the grayscale value of each drawing coordinate in the drawing image data includes, for example, 8 bits of magenta grayscale value, 8 bits of cyan grayscale value, and 8 bits of yellow grayscale value. Memory 140 stores, for example, programs for deriving output setting values ​​for the drawing unit 150 based on the grayscale values ​​of the drawing image data obtained through conversion for each drawing coordinate. Figure 1 In this context, these programs are collectively referred to as Program 141.

[0041] Information processor 160 includes, for example, a CPU (central processing unit) and a GPU (graphics processing unit), and executes various programs (e.g., program 141) stored in memory 140. Information processor 160 executes a series of steps described in program 141, for example, by loading program 141.

[0042] Next, the drawing unit 150 will be described. Figure 2 An exemplary schematic configuration of the drawing unit 150 is shown. The drawing unit 150 includes, for example, a signal processing circuit 51, a laser driving circuit 52, a light source unit 53, a scanner driving circuit 54, an X scanner unit 55, a Y stage driving circuit 56, and a Y stage 57. The drawing unit 150 draws on the recording medium 10 by controlling the output of the light source unit 53 based on a voltage value file (a list of command voltage values) input from the information processor 160.

[0043] Signal processing circuit 51 acquires a voltage value file (a list of command voltage values) input from information processor 160 as an image signal Din. Signal processing circuit 51 generates, for example, a pixel signal Dout corresponding to the scanner operation of X-scanner unit 55 from image signal Din. Pixel signal Dout causes light source unit 53 (e.g., each of light sources 53A, 53B, and 53C described below) to output a laser beam with power corresponding to the command voltage value. Signal processing circuit 51, together with laser drive circuit 52, controls the peak value of the current pulse to be applied to light source unit 53 (e.g., each of light sources 53A, 53B, and 53C) based on pixel signal Dout.

[0044] The laser driving circuit 52 drives each of the light sources 53A, 53B, and 53C of the light source unit 53 according to the pixel signal Dout. The laser driving circuit 52 controls, for example, the brightness (brightness) of the laser beam used to draw an image corresponding to the pixel signal Dout. The laser driving circuit 52 includes, for example, a driving circuit 52A for driving light source 53A, a driving circuit 52B for driving light source 53B, and a driving circuit 52C for driving light source 53C. Light sources 53A, 53B, and 53C each output a laser beam with power corresponding to a command voltage value to the recording medium 10, thereby performing drawing on the recording medium 10. Light sources 53A, 53B, and 53C each emit a laser beam in the near-infrared region. Light source 53A is, for example, a semiconductor laser that emits a laser beam La with an emission wavelength λ1. Light source 53B is, for example, a semiconductor laser that emits a laser beam Lb with an emission wavelength λ2. Light source 53C is, for example, a semiconductor laser that emits a laser beam Lc with an emission wavelength λ3.

[0045] The light source unit 53 has multiple light sources (e.g., three light sources 53A, 53B, and 53C) with different light emission wavelengths in the near-infrared region. Each light source (e.g., each of light sources 53A, 53B, and 53C) generates a laser beam with a wavelength corresponding to the absorption wavelength of the photothermal conversion agent (described later) contained in the recording medium 10. The light source unit 53 further includes, for example, an optical system that arranges and outputs multiple laser beams (e.g., three laser beams La, Lb, and Lc) emitted from the multiple light sources (e.g., three light sources 53A, 53B, and 53C) side-by-side in a predetermined direction at predetermined intervals. This optical system outputs, for example, the multiple laser beams La, Lb, and Lc to the X-scanner unit 55, such that multiple illumination spots Pa, Pb, and Pc generated by the multiple laser beams La, Lb, and Lc on the recording medium 10 are arranged side-by-side in the X-axis direction at predetermined intervals on the Y-stage 57. The X-axis direction is orthogonal to the movement direction (Y-axis direction) of the Y-stage 57 and parallel to the scanning direction of the single-axis scanner 55a, which will be described later. The light source unit 63 includes, for example, two reflectors 53a and 53d, and two dichroic mirrors 53b and 53c, as such an optical system.

[0046] Laser beams La and Lb emitted from two light sources 53A and 53B are converted into substantially parallel light (collimated light) by, for example, a collimating lens. Then, for example, laser beam La is reflected by mirror 53a and then by dichroic mirror 53b, while laser beam Lb is transmitted through dichroic mirror 53b. In this way, laser beams La and Lb are output side-by-side in a predetermined direction. Laser beams La and Lb are then transmitted through dichroic mirror 53c.

[0047] The laser beam Lc emitted from the light source 53C is converted into substantially parallel light (collimated light) by a collimating lens. Then, the laser beam Lc is reflected, for example, by a reflecting mirror 53d, and then by a dichroic mirror 53c. In this way, the laser beams La and Lb transmitted through the dichroic mirror 53c are output side-by-side with the laser beam Lc reflected by the dichroic mirror 53c in a predetermined direction. The light source unit 53 outputs, for example, the laser beams La, Lb, and Lc arranged side-by-side in the predetermined direction by the aforementioned optical system to the X-ray scanner unit 55.

[0048] Here, on the dichroic mirror 53b, the spot of the laser beam La reflected and the spot of the laser beam Lb transmitted can overlap. In this case, the optical system is configured such that the optical axis of the laser beam La reflected by the dichroic mirror 53b intersects the optical axis of the laser beam Lb transmitted through the dichroic mirror 53b at a predetermined angle. Alternatively, on the dichroic mirror 53b, the spot of the laser beam La reflected and the spot of the laser beam Lb transmitted can not completely overlap and are offset from each other. Alternatively, on the dichroic mirror 53b, the spot of the laser beam La reflected and the spot of the laser beam Lb transmitted can be separated from each other. In these cases, the optical system can be configured such that the optical axis of the laser beam La reflected by the dichroic mirror 53b intersects the optical axis of the laser beam Lb transmitted through the dichroic mirror 53b at a predetermined angle, or the optical system can be configured such that the optical axis of the laser beam La reflected by the dichroic mirror 53b is parallel to the optical axis of the laser beam Lb transmitted through the dichroic mirror 53b.

[0049] The optical system is configured such that the light spots transmitted by the laser beam La or Lb and the light spots reflected by the laser beam Lc on the dichroic mirror 53c do not completely overlap and are offset from each other. In this configuration, the light spots transmitted by the laser beam La, Lb, and Lc can be arranged side-by-side in a predetermined direction on the dichroic mirror 53c, slightly offset from each other. Furthermore, the light spots transmitted by the laser beam La, Lb, and Lc can be arranged side-by-side at predetermined intervals on the dichroic mirror 53c.

[0050] In these cases, the optical system can be configured such that the optical axes of the laser beam La transmitted through the dichroic mirror 53c, the optical axes of the laser beam Lb transmitted through the dichroic mirror 53c, and the optical axes of the laser beam Lc reflected by the dichroic mirror 53c intersect each other at a predetermined angle. At this time, the light source unit 53 outputs multiple laser beams La, Lb, and Lc to the X-scanner unit 55 with their optical axes offset from each other, and outputs multiple laser beams La, Lb, and Lc to the X-scanner unit 55 such that their optical axes intersect at a predetermined angle.

[0051] Furthermore, the optical system can be configured such that the optical axes of the laser beam La transmitted through the dichroic mirror 53c, the optical axes of the laser beam Lb transmitted through the dichroic mirror 53c, and the optical axes of the laser beam Lc reflected by the dichroic mirror 53c are parallel to each other. In this case, the light source unit 53 outputs multiple laser beams La, Lb, and Lc to the X-scanner unit 55 with their optical axes offset from each other, and outputs the multiple laser beams La, Lb, and Lc to the X-scanner unit 55 such that their optical axes are parallel to each other at predetermined intervals.

[0052] The scanner drive circuit 54 drives the X-scanner unit 55 based on a control signal input from the signal processing circuit 51, for example. Furthermore, for example, when a signal regarding the illumination angle of a single-axis scanner 55a, etc., which will be described later, is input from the X-scanner unit 55, the scanner drive circuit 54 drives the X-scanner unit 55 based on that signal so that the illumination angle becomes the desired illumination angle.

[0053] For example, the X-scanning unit 55 scans the surface of the recording medium 10 in the X-axis direction using multiple laser beams La, Lb, and Lc incident from the light source unit 53. The X-scanning unit 55 includes, for example, a single-axis scanner 55a and an fθ mirror 55b. The single-axis scanner 55a is, for example, a galvanometer mirror that scans the surface of the recording medium 10 in the X-axis direction using laser beams La, Lb, and Lc incident from the light source unit 53 based on a drive signal input from the scanner drive circuit 54. The fθ mirror 55b converts the uniform rotational motion of the single-axis scanner 55a into uniform linear motion of a light spot moving on the focal plane (the surface of the recording medium 10).

[0054] The Y-stage drive circuit 56 drives the Y-stage 57 based on a control signal input from the signal processing circuit 51. By shifting the Y-stage 57 in the Y-axis direction at a predetermined speed, the Y-stage 57 causes the recording medium 10 placed on the Y-stage 57 to move relative to the X-scanner unit 55 in the Y-axis direction at a predetermined speed. Through the coordinated operation of the X-scanner unit 55 and the Y-stage 57, the surface of the recording medium 10 is raster scanned using laser beams La, Lb, and Lc.

[0055] (Recording medium 10)

[0056] Next, the recording medium 10 will be described.

[0057] Figure 3An exemplary configuration of each layer included in the recording medium 10 is shown. The recording medium 10 is, for example, a reversible recording medium on which information can be written (drawn) and erased. The recording medium 10 may also be, for example, an irreversible recording medium on which information can only be written (drawn) once and cannot be erased. The recording medium 10 includes a plurality of recording layers 13, 15, and 17 having different color hues from each other. The recording medium 10 has a structure in which, for example, a base layer 12, a recording layer 13, a heat insulation layer 14, a recording layer 15, a heat insulation layer 16, a recording layer 17, and a protective layer 18 are stacked on a substrate 11 in this order. The protective layer 18 is disposed opposite to the substrate 11, and the base layer 12, the recording layer 13, the heat insulation layer 14, the recording layer 15, the heat insulation layer 16, and the recording layer 17 are interposed between the protective layer 18 and the substrate 11. The protective layer 18 may be disposed on the outermost surface of the recording medium 10, or layers other than the protective layer 18 may be disposed on the outermost surface of the recording medium 10.

[0058] Three recording layers 13, 15, and 17 are arranged in the order of recording layer 13, recording layer 15, and recording layer 17, starting from the substrate 11 side. Two heat insulation layers 14 and 16 are arranged in the order of heat insulation layer 114a and heat insulation layer 16, starting from the substrate 11 side. The base layer 12 is formed to contact the surface of the substrate 11. A protective layer 18 is formed on the outermost surface of the recording medium 10.

[0059] Substrate 11 supports each of the recording layers 13, 15, and 17, and each of the heat insulation layers 14 and 16. Substrate 11 serves as a substrate on which each layer is formed. Substrate 11 may or may not allow light to pass through. In the case where light transmission is not allowed, the surface color of substrate 11 may be, for example, white or a color other than white.

[0060] The substrate 11 may be a card or a film. The substrate 11 may have a main surface on the side where the recording layer 13 is disposed, on which graphics, drawings, photographs, text, or a combination of both are printed. The substrate 11 may include, for example, plastic. Depending on the need, the substrate 11 may include at least one selected from the group consisting of color developers, antistatic agents, flame retardants, surface modifiers, etc.

[0061] The plastic used for the substrate 11 includes at least one selected from, for example, ester-based resins, amide-based resins, olefin-based resins, vinyl-based resins, acrylic-based resins, imide-based resins, styrene-based resins, engineering plastics, etc. When the substrate 11 comprises two or more resins, the two or more resins may be mixed, copolymerized, or stacked.

[0062] The aforementioned ester-based resins include, for example, at least one selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene terephthalate-ethylene isophthalate copolymer, and terephthalic acid-cyclohexanediol-ethylene glycol copolymer. The aforementioned amide-based resins include, for example, at least one selected from the group consisting of nylon 6, nylon 66, and nylon 610. The aforementioned olefin-based resins include, for example, at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), and polymethylpentene (PMP). The aforementioned vinyl resins include, for example, polyvinyl chloride (PVC).

[0063] The aforementioned acrylic resin includes at least one selected from the group consisting of, for example, polyacrylate, polymethacrylate, and polymethyl methacrylate (PMMA). The aforementioned imide resin includes at least one selected from the group consisting of, for example, polyimide (PI), polyamide-imide (PAI), and polyether-imide (PEI). The aforementioned styrene resin includes at least one selected from the group consisting of, for example, polystyrene (PS), high-impact polystyrene, acrylonitrile-styrene resin (AS resin), and acrylonitrile-butadiene-styrene resin (ABS resin). The aforementioned engineering plastic includes at least one selected from the group consisting of, for example, polycarbonate (PC), polyarylate (PAR), polysulfone (PSF), polyethersulfone (PES), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyetherketone (PEK), polyetheretherketone (PEEK), polystyrene oxide (PPO), and polyether sulfite.

[0064] The substrate 12 has the function of improving the adhesion between the recording layer 13 and the substrate 11. The substrate 12 includes, for example, a material that allows light to pass through. It should be noted that a moisture barrier layer or a light barrier layer may be provided above or below the substrate 12 or the substrate 11. In addition, a heat insulation layer may be provided between the substrate 12 and the recording layer 13.

[0065] The three recording layers 13, 15, and 17 are capable of reversibly changing state between a colored state and a decolored state. The three recording layers 13, 15, and 17 may, for example, possess irreversibility, meaning that once they change from a decolored state to a colored state, they will not revert to a decolored state. The three recording layers 13, 15, and 17 are configured such that the colors in the colored states are different from each other. Each of the three recording layers 13, 15, and 17 includes a chromogenic compound, a photothermal conversion agent, and a chromogenic / decolorizing agent. The three recording layers 13, 15, and 17 include different chromogenic compounds and different photothermal conversion agents. In the three recording layers 13, 15, and 17, the chromogenic compound, photothermal conversion agent, and chromogenic / decolorizing agent are dispersed in a polymer material.

[0066] As a color-developing compound, for example, a leuco dye is used. The leuco dye combines with the developer / subtractor upon heating to become a developed color, or separates from the developer / subtractor to become a decolorized color. The color hue of the leuco dye contained in each recording layer 13, 15, and 17 is different for each recording layer 13, 15, and 17. The leuco dye contained in recording layer 13 combines with the developer / subtractor upon heating to develop a magenta color. The leuco dye contained in recording layer 15 combines with the developer / subtractor upon heating to develop a cyan color. The leuco dye contained in recording layer 17 combines with the developer / subtractor upon heating to develop a yellow color. The positional relationship between the three recording layers 13, 15, and 17 is not limited to the example described above. Furthermore, the three recording layers 13, 15, and 17 are transparent in the decolorized state. In this way, the recording medium 10 is capable of recording images using a wide color gamut.

[0067] Photothermal conversion agents, for example, absorb light in a predetermined wavelength region in the near-infrared region and generate heat. It should be noted that, in this specification, the near-infrared region refers to the wavelength range of 700 nm to 2500 nm. Preferably, photothermal conversion agents are selected, for example, those having narrow light absorption bands in the near-infrared region and whose light absorption bands do not overlap in the recording layers 13, 15, and 17.

[0068] The heat insulation layer 14 prevents heat transfer between the recording layers 13 and 15. The heat insulation layer 16 prevents heat transfer between the recording layers 15 and 17. The protective layer 18 protects the surface of the recording medium 10 and acts as an outer coating for the recording medium 10. The heat insulation layers 14 and 16, as well as the protective layer 18, all comprise transparent materials. The recording medium 10 may include, for example, a relatively rigid resin layer (e.g., a PEN resin layer) directly beneath the protective layer 18. It should be noted that the protective layer 18 may include a moisture barrier or a light barrier. Furthermore, the protective layer 18 may include any functional layer.

[0069] Examples of leuco dyes include existing dyes for thermal paper. A specific example is a compound that includes, for example, an electron-donating group within its molecule. This compound is shown in the following chemical formula 1:

[0070] [Chemical Formula 1]

[0071]

[0072] The chromogenic compounds are not particularly limited and can be appropriately selected according to the purpose. Specific examples of chromogenic compounds, in addition to those shown in Formula 1 above, include, for example, fluoralkyl compounds, triphenylmethanephthalyl compounds, azaphthalyl compounds, phenothiazinyl compounds, leucoaluminoamine compounds, indolephthalyl compounds, etc. Examples, besides these materials, include 2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-di(n-butylamino)fluorane, 2-anilino-3-methyl-6-(N-n-propyl-N-methylamino)fluorane, 2-anilino-3-methyl-6-(N-isopropyl-N-methylamino)fluorane, 2-anilino-3-methyl-6-(N-isobutyl-N-methylamino)fluorane, 2-anilino-3-methyl-6-(N-n-pentyl- N-methylamino)fluorane, 2-anilino-3-methyl-6-(N-sec-butyl-N-methylamino)fluorane, 2-anilino-3-methyl-6-(N-n-pentyl-N-ethylamino)fluorane, 2-anilino-3-methyl-6-(N-isopentyl-N-ethylamino)fluorane, 2-anilino-3-methyl-6-(N-n-propyl-N-isopropylamino)fluorane, 2-anilino-3-methyl-6-(N-cyclohexyl-N-methylamino)fluorane, 2-anilino- 3-Methyl-6-(N-ethyl-p-toluidine)fluorane, 2-anilino-3-methyl-6-(N-methyl-p-toluidine)fluorane, 2-(m-trichloromethylanilino)-3-methyl-6-diethylaminofluorane, 2-(m-trifluoromethylanilino)-3-methyl-6-diethylaminofluorane, 2-(m-trichloromethylanilino)-3-methyl-6-(N-cyclohexyl-N-methylamino)fluorane, 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane 2-(N-ethyl-p-toluidine)-3-methyl-6-(N-ethylanilino)fluorane, 2-(N-ethyl-p-toluidine)-3-methyl-6-(N-propyl-p-toluidine)fluorane, 2-anilino-6-(N-n-hexyl-N-ethylamino)fluorane, 2-(o-chloroanilino)-6-diethylaminofluorane, 2-(o-chloroanilino)-6-dibutylaminofluorane, 2-(m-trifluoromethylanilino)-6-diethylaminofluorane, 2,3-Dimethyl-6-dimethylaminofluorane, 3-methyl-6-(N-ethyl-p-toluidine)fluorane, 2-chloro-6-diethylaminofluorane, 2-bromo-6-diethylaminofluorane, 2-chloro-6-dipropylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 3-bromo-6-cyclohexylaminofluorane, 2-chloro-6-(N-ethyl-N-isopentylamino)fluorane, 2-chloro-3-methyl-6-diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, 2-(o-chloroanilino)-3-chloro-6-cyclohexylaminofluorane, 2-(m-trifluoromethylanilino) 1,2-Benzo-6-diethylaminofluorane, 2-(2,3-dichloroanilino)-3-chloro-6-diethylaminofluorane, 1,2-benzo-6-diethylaminofluorane, 3-diethylamino-6-(m-trifluoromethylanilino)fluorane, 3-(1-ethyl-2-methylindole-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindole-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-7-azaphthalide, 3-(1-octyl-2-methylindole-3-yl)-3-(2-ethoxy ... -4-Diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindole-3-yl)-3-(2-methyl-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindole-3-yl)-3-(2-methyl-4-diethylaminophenyl)-7-azaphthalide, 3-(1-ethyl-2-methylindole-3-yl)-3-(4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindole-3-yl)-3-(4-N-n-pentyl-N-methylaminophenyl)-4-azaphthalide, 3-(1 3,3-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-acetanilide)-6-(N-n-pentyl-N-n-butylamino)fluorane, 2-benzylamino-6-(N-ethyl-p-toluidine)fluorane, 2-benzylamino-6-(N-methyl-2,4-dimethylanilide)fluorane, 2-benzylamino-6-(N-ethyl-2,4-dimethylanilide)fluorane, 2-benzylamino-6-(N-ethyl-2,4-dimethylanilide)fluorane,4-Dimethylaniline)fluorane, 2-benzylamino-6-(N-methyl-p-toluidine)fluorane, 2-benzylamino-6-(N-ethyl-p-toluidine)fluorane, 2-(di-p-methylbenzylamino)-6-(N-ethyl-p-toluidine)fluorane, 2-(α-phenylethylamino)-6-(N-ethyl-p-toluidine)fluorane, 2-methylamino-6-(N-methylaniline)fluorane, 2-methylamino-6-(N-ethylaniline)fluorane, 2-methylamino-6-(N-propylaniline)fluorane, 2-ethylamino-6-(N-methyl-p-toluidine)fluorane, 2 2-methylamino-6-(N-methyl-2,4-dimethylaniline)fluorane, 2-ethylamino-6-(N-ethyl-2,4-dimethylaniline)fluorane, 2-dimethylamino-6-(N-methylaniline)fluorane, 2-dimethylamino-6-(N-ethylaniline)fluorane, 2-diethylamino-6-(N-methyl-p-toluidine)fluorane, 2-diethylamino-6-(N-ethyl-p-toluidine)fluorane, 2-dipropylamino-6-(N-methylaniline)fluorane, 2-dipropylamino-6-(N-ethylaniline)fluorane, 2-amino-6-(N-methyl-2,4-dimethylaniline)fluorane, 2-amino-6-(N-methyl-2,4-dimethylaniline)fluorane 2-Amino-6-(N-ethylanilino)fluorane, 2-Amino-6-(N-propylanilino)fluorane, 2-Amino-6-(N-methyl-p-toluidine)fluorane, 2-Amino-6-(N-ethyl-p-toluidine)fluorane, 2-Amino-6-(N-propyl-p-toluidine)fluorane, 2-Amino-6-(N-methyl-p-ethylanilino)fluorane, 2-Amino-6-(N-ethyl-p-ethylanilino)fluorane, 2-Amino-6-(N-propyl-p-ethylanilino)fluorane, 2-Amino-6-(N-methyl-2,4-dimethylanilino)fluorane, 2 The following compounds are used as coloring compounds: 1,2-amino-6-(N-ethyl-2,4-dimethylaniline)fluorane, 2-amino-6-(N-propyl-2,4-dimethylaniline)fluorane, 2-amino-6-(N-methyl-p-chloroaniline)fluorane, 2-amino-6-(N-ethyl-p-chloroaniline)fluorane, 2-amino-6-(N-propyl-p-chloroaniline)fluorane, 1,2-benzo-6-(N-ethyl-N-isoamino)fluorane, 1,2-benzo-6-dibutylaminofluorane, 1,2-benzo-6-(N-methyl-N-cyclohexylamino)fluorane, and 1,2-benzo-6-(N-ethyl-N-tolyl)fluorane. For recording layers 13, 15, and 17, one of the above compounds may be used alone, or two or more of the above compounds may be used in combination as coloring compounds.

[0073] Color developers / subtractives can develop color in colorless chromogenic compounds or decolorize chromogenic compounds that exhibit a predetermined color. Examples of color developers / subtractives include phenol derivatives, salicylic acid derivatives, urea derivatives, etc. Specific examples of color developers / subtractives may include compounds represented by the following chemical formula 2.

[0074] [Chemical Formula 2]

[0075]

[0076] (wherein, in equation (3), X) 0 This indicates a divalent group comprising at least one benzene ring, in X 0 In cases involving at least two benzene rings, the at least two benzene rings may optionally be condensed. Examples include naphthalene, anthracene, etc. 01 and Y 02 Each independently represents a monovalent group. n01 and n02 each independently represent any integer from 0 to 5. When n01 represents any integer from 2 to 5, Y... 01 They can be the same or different from each other, in the case that n02 represents any integer from 2 to 5, Y 02 They can be the same as or different from each other. Z 01 and Z 02 Each group independently represents a hydrogen-bonded group.

[0077] Colorimetric agents may include, for example, compounds represented by the following chemical formula 3:

[0078] [Chemical Formula 3]

[0079]

[0080] (wherein, in chemical formula 3, X) 1 Y represents a divalent group comprising at least one benzene ring. 11 Y 12 Y 13 and Y 14 Each independently represents a monovalent group, Z 11 and Z 12 Each group independently represents a hydrogen-bonded group.

[0081] In the case where both chemical formulas 2 and 4 include a hydrocarbon group, the hydrocarbon group is a general term for groups that include carbon (C) and hydrogen (H), and can be a saturated hydrocarbon group or an unsaturated hydrocarbon group. A saturated hydrocarbon group is an aliphatic hydrocarbon group without carbon-carbon multiple bonds, while an unsaturated hydrocarbon group is an aliphatic hydrocarbon group with carbon-carbon multiple bonds (carbon-carbon double bonds or carbon-carbon triple bonds).

[0082] In cases where both Formula 2 and Formula 3 include a hydrocarbon group, the hydrocarbon group may be a chain hydrocarbon group or a hydrocarbon group comprising one or two or more rings. The chain hydrocarbon group may be a straight-chain hydrocarbon group or a branched hydrocarbon group comprising one or two or more side chains, etc.

[0083] (X containing a benzene ring) 0 and X 1 )

[0084] X in chemical formula 2 0 And X in chemical formula 3 1 For example, both represent divalent groups containing a benzene ring. For example, the divalent group is represented by the following chemical formula 4.

[0085] [Chemical Formula 4]

[0086]

[0087] (wherein, in chemical formula 4, X) 21 The existence of X is optional; if X exists... 21 In the case of X 21 X represents a divalent group. 22 The existence of X is optional; if X exists... 22 In the case of X 22 R represents a divalent group. 21 Let n represent a monovalent group, and n21 represent any integer from 0 to 4. When n21 represents any integer from 2 to 4, R... 21 They can be the same or different from each other. * indicates a bonded portion.

[0088] In chemical formula 4, X 21 and X 22 The bonding position with the benzene ring is unrestricted. In other words, X 21 and X 22 The bonding position with the benzene ring can be any of the ortho, meta, or para positions.

[0089] In terms of improving the high temperature and high humidity storage characteristics, the above-mentioned divalent group containing a benzene ring is preferably represented by the following chemical formula 5.

[0090] [Chemical Formula 5]

[0091]

[0092] (Among them, in chemical formula 5, R) 22 Let n represent a monovalent group, and n22 represent any integer from 0 to 4. When n22 represents any integer from 2 to 4, R... 22 They can be the same or different from each other; the asterisk (*) indicates the bonded portion.

[0093] X in chemical formula 2 0 In the case of a divalent group containing a benzene ring, Z in chemical formula 5 01 and Z 02 The bonding position with the benzene ring is unrestricted. In other words, Z 01 and Z 02 The bonding position with the benzene ring can be any of the ortho, meta, or para positions.

[0094] X in chemical formula 3 1 In the case of a divalent group containing a benzene ring, Z in chemical formula 5 11 and Z 12 The bonding position with the benzene ring is unrestricted. In other words, Z 11 and Z 12 The bonding position with the benzene ring can be any of the ortho, meta, or para positions.

[0095] (X 21 and X 22 )

[0096] X in chemical formula 4 21 and X 22 Each can be represented independently as a divalent group, without particular limitation. One example is a hydrocarbon group that optionally includes substituents. The hydrocarbon group is preferably a chain hydrocarbon group, and particularly preferably a n-alkyl chain.

[0097] Optionally, the number of carbons in the hydrocarbon group that includes the substituent may be, for example, one or more and 15 or fewer, one or more and 13 or fewer, one or more and 12 or fewer, one or more and 10 or fewer, one or more and 6 or fewer, or one or more and 3 or fewer.

[0098] X in chemical formula 21 and X 22 When each refers to an alkyl group, the number of carbon atoms in the alkyl group is preferably 8 or less, more preferably 6 or less, further preferably 5 or less, and particularly preferably 3 or less, from the perspective of high-temperature storage stability. When the number of carbon atoms in the alkyl group is 8 or less, the alkyl group is shorter. Therefore, it is conceivable that this makes it difficult for thermal interference to occur in the color developer during high-temperature storage, and makes it difficult to separate the portion that interacts with chromogenic compounds such as leuco dyes during the color development process. This makes it difficult for chromogenic compounds such as leuco dyes to decolorize during high-temperature storage, thus improving high-temperature storage stability.

[0099] Examples of substituents that optionally include a hydrocarbon group include halogen groups (e.g., fluoro groups), alkyl groups that include halogen groups (e.g., fluoro groups), etc. The hydrocarbon group that optionally includes a substituent can be a hydrocarbon group in which a portion of the carbon atom (e.g., a portion of the carbon atom contained in the main chain of the hydrocarbon group) is replaced by an element such as oxygen.

[0100] (R 21 )

[0101] R in chemical formula 4 21 Simply indicate a monovalent group; there are no particular restrictions. One example is a halogen group or a hydrocarbon group that may optionally include substituents.

[0102] Examples of halogen groups include fluorine (-F), chlorine (-Cl), bromine (-Br), and iodine (-I).

[0103] Optionally, the number of carbons in the hydrocarbon group that includes the substituent may be, for example, one or more and 15 or fewer, one or more and 13 or fewer, one or more and 12 or fewer, one or more and 10 or fewer, one or more and 6 or fewer, or one or more and 3 or fewer.

[0104] Examples of substituents that optionally include a hydrocarbon group include halogen groups (e.g., fluoro groups), alkyl groups that include halogen groups (e.g., fluoro groups), etc. The hydrocarbon group that optionally includes a substituent can be a hydrocarbon group in which a portion of the carbon atom (e.g., a portion of the carbon atom contained in the main chain of the hydrocarbon group) is replaced by an element such as oxygen.

[0105] (R 22 )

[0106] R in chemical formula 5 22 Simply indicate the monovalent group 'Jack'; there are no particular limitations. One example is a halogenated group or a hydrocarbon group that optionally includes substituents. Halogenated groups and hydrocarbon groups that optionally include substituents are respectively similar to the chemical R... 21 The halogen group and optionally the hydrocarbon group including substituents.

[0107] (X containing two benzene rings) 0 and X 1 )

[0108] X in chemical formula 2 0 And X in chemical formula 3 1 For example, these represent divalent groups containing two benzene rings. For example, the divalent group is represented by the following chemical formula 6.

[0109] [Chemical Formula 6]

[0110]

[0111] (Among them, in chemical formula 6, X)31 The existence of X is optional. In the existence of X... 31 In the case of X 31 This indicates a divalent group. X 32 The existence of X is optional. In the existence of X... 32 In the case of X 32 This indicates a divalent group. X 33 The existence of X is optional. In the existence of X... 33 In the case of X 33 R represents a divalent group. 31 and R 32 Each independently represents a monovalent group. n31 and n32 each independently represent any integer from 0 to 4. When n31 represents any integer from 2 to 4, R... 31 They can be the same or different from each other. And when n32 represents any integer from 2 to 4, R 32 They can be the same or different from each other. * indicates a bonded portion.

[0112] In chemical formula 6, X 31 and X 32 The bonding position with the benzene ring is unrestricted. In other words, X 31 and X 32 The bonding position with the benzene ring can be any of the ortho, meta, and para positions. Similarly, in formula 6, X... 32 and X 33 The bonding position with the benzene ring is also unrestricted. In other words, X 32 and X 33 The bonding position with the benzene ring can be any of the ortho, meta, or para positions.

[0113] In terms of improving the high temperature and high humidity storage characteristics, the divalent group containing two benzene rings is preferably represented by the following chemical formula 7.

[0114] [Chemical Formula 7]

[0115]

[0116] (wherein, in chemical formula 7, X) 34 R represents a divalent group. 33 and R 34 Each independently represents a monovalent group. n33 and n34 each independently represent any integer from 0 to 4. When n33 represents any integer from 2 to 4, R... 33 They can be the same or different from each other. In the case where n34 represents any integer from 2 to 4, R... 34 They can be the same or different from each other. * indicates a bonded portion.

[0117] X in chemical formula 2 0 In the case of a divalent group containing two benzene rings, Z in chemical formula 7 01 and X 34 The bonding position with the benzene ring is unrestricted. In other words, Z 01 and X 34 The bonding position with the benzene ring can be any of the ortho, meta, and para positions. Similarly, in formula 7, Z... 02 and X 34 The bonding position with the benzene ring is also unrestricted. In other words, Z 02 and X 34 The bonding position with the benzene ring can be any of the ortho, meta, or para positions.

[0118] X in chemical formula 3 1 In the case of a divalent group containing two benzene rings, Z in Formula 7 11 and X 34 The bonding position with the benzene ring is unrestricted. In other words, Z 11 and X 34 The bonding position with the benzene ring can be any of the ortho, meta, and para positions. Similarly, in Formula 7, Z... 12 and X 34 The bonding position with the benzene ring is also unrestricted. In other words, Z 12 and X 34 The bonding position with the benzene ring can be any of the ortho, meta, or para positions.

[0119] (X 31 X 32 X 33 )

[0120] X in chemical formula 6 31 X 32 X 33 Each divalent group can be represented independently; there are no particular restrictions. One example is a hydrocarbon group that optionally includes a substituent. This hydrocarbon group is related to X in the above chemical formula 4. 21 and X 22 resemblance.

[0121] (X 34 )

[0122] X in chemical formula 7 34 It is sufficient to represent a divalent group; there are no particular restrictions. One example is a hydrocarbon group that optionally includes a substituent. This hydrocarbon group is related to X in the above chemical formula 4. 21 and X 22 resemblance.

[0123] (R 31R 32 )

[0124] R in chemical formula 6 31 R 32 Simply represent the monovalent groups; there are no particular restrictions. One example is a halogenated group or a hydrocarbon group that optionally includes substituents. The halogenated group and the hydrocarbon group that optionally includes substituents are respectively similar to R in the above chemical formula 4. 21 The halogen group and optionally the hydrocarbon group including substituents.

[0125] (R 33 R 34 )

[0126] R in chemical formula 7 33 R 34 Simply represent the monovalent groups; there are no particular restrictions. One example is a halogenated group or a hydrocarbon group that optionally includes substituents. The halogenated group and the hydrocarbon group that optionally includes substituents are respectively similar to R in the above chemical formula 4. 21 The halogen group and optionally the hydrocarbon group including substituents.

[0127] (Y 01 Y 02 )

[0128] Y in chemical formula 2 01 and Y 02 Each can be independently represented, for example, a hydrogen group (-H), a hydroxyl group (-OH), a halogen group (-X), a carboxyl group (-COOH), an ester group (-COOR), or optionally a hydrocarbon group including substituents.

[0129] Examples of halogen groups include fluorine (-F), chlorine (-Cl), bromine (-Br), and iodine (-I).

[0130] Optionally, the number of carbons in the hydrocarbon group that includes the substituent may be, for example, one or more and 15 or fewer, one or more and 13 or fewer, one or more and 12 or fewer, one or more and 10 or fewer, one or more and 6 or fewer, or one or more and 3 or fewer.

[0131] Examples of substituents that optionally include a hydrocarbon group include halogen groups (e.g., fluoro groups), alkyl groups that include halogen groups (e.g., fluoro groups), etc. The hydrocarbon group that optionally includes a substituent can be a hydrocarbon group in which a portion of the carbon atom (e.g., a portion of the carbon atom contained in the main chain of the hydrocarbon group) is replaced by an element such as oxygen.

[0132] In chemical formula 2, (Y 01 ) n01 One of and / or (Y) 02 ) n02One of them preferably represents a hydroxyl group (-OH). (Y) 01 ) n01 One of and / or (Y) 02 ) n02 One of them represents a hydroxyl group (-OH), which can improve display quality and lightfastness.

[0133] (Y 11 Y 12 Y 13 Y 14 )

[0134] In chemical formula 3, Y 11 and Y 12 The bonding position with the benzene ring is not particularly restricted. In other words, Y 11 and Y 12 The bonding position with the benzene ring can be any of the ortho, meta, and para positions. Similarly, in formula 3, Y... 13 and Y 14 The bonding position with the benzene ring is not particularly restricted. In other words, Y 13 and Y 14 The bonding position with the benzene ring can be any of the ortho, meta, and para positions. In formula 3, Y 11 and Y 12 The bonding position with a benzene group and Y 13 and Y 14 The bonding positions with another benzene can be the same or different.

[0135] For example, Y in chemical formula 3 11 Y 12 Y 13 Y 14 Each group independently represents a hydrogen group (-H), a hydroxyl group (-OH), a halogen group, a carboxyl group (-COOH), an ester group (-COOR), or optionally a hydrocarbon group including substituents. The halogen group or the hydrocarbon group optionally including substituents are respectively similar to Y in the above chemical formula 2. 01 and Y 02 The halogen group and optionally the hydrocarbon group including substituents.

[0136] In chemical formula 3, Y 11 and / or Y 13 Preferably, it represents a hydroxyl group (-OH). Y 11 and / or Y 13 The hydroxyl group (-OH) can improve display quality and lightfastness.

[0137] (Z 01 Z 02 )

[0138] Z in chemical formula 2 01Z 02 Each can be independently represented, for example, a urea bond (-NHCONH-), an amide bond (-NHCO- or -OCHN-), or an amide hydrazine bond (-NHCOCONH-). From the perspective of improving high-temperature and high-humidity storage characteristics, Z is preferred. 01 and Z 02 Each represents a urea bond. In Z... 01 In the case of an amide bond, either the nitrogen in the amide bond can be bonded to benzene, or the carbon in the amide bond can be bonded to benzene. In Z... 02 In the case of an amide bond, the nitrogen in the amide bond can be bonded to benzene, or the carbon in the amide bond can be bonded to benzene.

[0139] (Z 11 Z 12 )

[0140] Z in chemical formula 3 11 and Z 12 Each can be independently represented, for example, a urea bond (-NHCONH-), an amide bond (-NHCO- or -OCHN-), or an amide hydrazine bond (-NHCOCONH-). From the perspective of improving high-temperature and high-humidity storage characteristics, Z is preferred. 11 and Z 12 Each represents a urea bond. In Z... 11 In the case of an amide bond, either the nitrogen in the amide bond can bond to benzene, or the carbon in the amide bond can bond to benzene. In Z... 12 In the case of an amide bond, the nitrogen contained in the amide bond may bond with benzene, or the carbon contained in the amide bond may bond with benzene.

[0141] In addition to these materials, examples of color developers / decolorizers include 4,4'-isopropylidene bisphenol, 4,4'-isopropylidene bis(o-methylphenol), 4,4'-sec-butylidene bisphenol, 4,4'-isopropylidene bis(2-tert-butylphenol), zinc p-nitrobenzoate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,2-(3,4'-dihydroxydiphenyl)propane, bis(4-hydroxy-3-methylphenyl)sulfide, 4-{β-(p-methoxyphenoxy)ethoxy}salicylate, 1,7-bis(4-hydroxyphenyl)sulfide 3,5-dioxaheptan, 1,5-bis(4-hydroxyphenylthio)-5-oxapentane, monobenzyl phthalate monocalcium salt, 4,4'-cyclohexyldiphenol, 4,4'-isopropylidene bis(2-chlorophenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-butylidene bis(6-tert-butyl-2-methyl)phenol, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, 4,4-thiobis(6-tert-butyl) 4,4'-diphenyl sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone (4-hydroxy4'-isopropoxydiphenyl sulfone), 4-benzyloxy-4'-hydroxydiphenyl sulfone, 4,4'-diphenol sulfoxide, isopropyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,3-bis(4-hydroxyphenylthio)propane, N,N'-diphenylthiourea, N,N'-di(m-chlorophenyl)thiourea, salicylaniline, methyl bis(4-hydroxyphenyl)acetate, bis(4-hydroxyphenyl)propane, Benzyl phenyl acetate, 1,3-bis(4-hydroxyisopropylphenyl)benzene, 1,4-bis(4-hydroxyisopropylphenyl)benzene, 2,4'-diphenol sulfone, 2,2'-diallyl-4,4'-diphenol sulfone, 3,4-dihydroxyphenyl-4'-methyldiphenyl sulfone, zinc 1-acetoxy-2-naphthoate, zinc 2-acetoxy-1-naphthoate, zinc 2-acetoxy-3-naphthoate, α,α-bis(4-hydroxyphenyl)-α-methyltoluene, antipyrine complex of zinc thiocyanate, tetrabromobisphenol A, tetrabromobisphenol S, 4,4'-thiobis(2-methylphenol), 4,4'-Thiobis(2-chlorophenol), dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, α-hydroxydodecylphosphonic acid, α-hydroxytetradecylphosphonic acid, α-hydroxyhexadecylphosphonic acid, α-hydroxyoctadecylphosphonic acid, α-hydroxyeicosylphosphonic acid, α-hydroxyeicosylphosphonic acid, dihexadecylphosphonic acid, dioctadecylphosphonic acid, dieicosylphosphonic acid, dieicosylphosphonic acid, dieicosylphosphonic acid, monohexadecylphosphonic acid, monooctadecylphosphonic acid, monoeicosylphosphonic acid, monoeicosylphosphonic acid, monoeicosylphosphonic acid, methylhexadecylphosphonic acid, methyloctadecylphosphonic acid, methyleicosylphosphonic acid, methyleicosylphosphonic acid, pentylhexadecylphosphonic acid, octylhexadecylphosphonic acid, laurylhexadecylphosphonic acid, etc. For recording layers 13, 15, and 17, as chromogenic compounds, one of the above-mentioned compounds may be used alone, or two or more of the above-mentioned compounds may be used in combination.

[0142] Photothermal conversion agents, for example, absorb light in a predetermined wavelength region in the near-infrared region and generate heat. Near-infrared absorbing dyes are preferred as photothermal conversion agents, having absorption peaks in the wavelength range of 700 nm or larger and 2500 nm or smaller, and almost no absorption in the visible light region. Specific examples include compounds with a phthalocyanine backbone (phthalocyanine dyes), compounds with a naphtholine backbone (naphtholine dyes), compounds with a squaric acid cyanine backbone (squaric acid cyanine dyes), metal complexes such as dithiocarbides, diammonium salts, ammonium salts, inorganic compounds, etc. Examples of inorganic compounds include metal oxides such as graphite, carbon black, metal powder particles, cobalt tetroxide, iron oxide, chromium oxide, copper oxide, titanium black, ITO, etc.; metal nitrides such as niobium nitride, etc.; metal carbides such as tantalum carbide, etc.; metal sulfides; various magnetic powders, etc. In addition to these materials, compounds with anthocyanin backbones (anthocyanin dyes) with excellent lightfastness and excellent heat resistance can also be used.

[0143] It should be noted that excellent lightfastness means that it does not decompose upon laser irradiation. Excellent heatfastness means, for example, that when formed into a film with a polymer material, the maximum absorption peak in the absorption spectrum does not change by 20% or more after the film is stored at 150°C for 30 minutes, for example. Examples of such compounds with anthocyanin skeletons include those containing an antiion of any one of SbF6, PF6, BF4, ClO4, CF3SO3, and (CF3SO3)2N, or at least one of a methyl chain comprising a five-membered or six-membered ring.

[0144] Anthocyanin-based dyes preferably include any of the aforementioned counterions and both have a cyclic structure such as a five-membered ring and a six-membered ring within the methyl chain; however, sufficient lightfastness and sufficient heat resistance are guaranteed if the anthocyanin-based dye includes at least one of them. As mentioned above, materials with excellent lightfastness and excellent heat resistance do not decompose upon laser irradiation. Examples of methods for confirming lightfastness include measuring the peak change of the absorption spectrum during a xenon lamp irradiation test. Excellent lightfastness can be determined if the rate of change is 20% or less after 30 minutes of irradiation. Examples of methods for confirming heat resistance include measuring the peak change of the absorption spectrum when stored at 150°C. Excellent heat resistance can be determined if the rate of change is 20% or less after 30 minutes of testing.

[0145] As the polymer material, it is preferable that the color-developing compound, colorant / color-reducing agent, and photothermal conversion agent are easily and uniformly dispersed. Furthermore, to obtain high visibility of the information to be written into the recording layer 11, the polymer material preferably has high transparency, for example, it is preferably a polymer material with high solubility in organic solvents. Examples of polymer materials include thermosetting resins and thermoplastic resins. Specific examples include polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene-based copolymers, phenoxy resins, polyesters, aromatic polyesters, polyurethanes, polycarbonate, polyacrylates, polymethacrylates, acrylic copolymers, maleic acid-based polymers, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, etc.

[0146] Each recording layer 13, 15, and 17 includes at least one of the aforementioned colorimetric compounds, at least one of the aforementioned color developers / subtractors, and at least one of the aforementioned photothermal conversion agents. Preferably, the ratio of the colorimetric compound and the color developer / subtractor contained in each recording layer 13, 15, and 17 is, for example, preferably, colorimetric compound: color developer / subtractor = 1:2 (weight ratio). The photothermal conversion agent is varied according to the film thickness of the recording layers 13, 15, and 17. Furthermore, in addition to the materials described above, the recording layers 13, 15, and 17 may include, for example, any various additives, such as sensitizers and ultraviolet absorbers.

[0147] The protective layer 18 may function to inhibit the incorporation of one or both of moisture and oxygen into the recording layers 13, 15, and 17. The protective layer 18 covers the surface of the recording layer 17. The protective layer 18 preferably has a concentration of, for example, 0.001 g / m³. 2 / day or higher and 10g / m 2 / day or lower water vapor permeability. Furthermore, similar to the polymer materials included in recording layers 13, 15, and 17, the protective layer 18 preferably has high transparency to ensure high visibility of the information to be written into recording layers 13, 15, and 17. An example of such a protective layer 18 includes a stacked film in which an inorganic oxide film is disposed on a substrate comprising a plastic film. The protective layer 18, consisting of a stacked film of a plastic film and an inorganic oxide film, covers the recording layer 17 such that the inorganic oxide film is disposed on the side (inner side) of the recording layer 17, while the plastic film is disposed on the outer side.

[0148] The plastic film used as the substrate can be, for example, an industrial plastic film, and can be formed using at least one of, for example, polyethylene terephthalate (PET), polycarbonate (PC), or polymethyl methacrylate (PMMA). The plastic film preferably has a thickness of, for example, 5 μm or more and 100 μm or less.

[0149] Examples of inorganic oxide films include silicon oxide films (SiO2) formed, for example, by sputtering, chemical vapor deposition (CVD), etc. x membrane), alumina membrane (AlO) x (film) or silicon nitride film (SiN) x The protective layer 18 is a single-layer or stacked film of at least one of the following: a film. The protective layer 18 preferably has a thickness of, for example, 10 nm or more and 1 μm or less.

[0150] Next, an example of writing information in the drawing system 100 according to this embodiment will be described.

[0151] [Write]

[0152] First, the user prepares an undeveloped recording medium 10 and places it on the Y stage 57. Next, the user sends the input image data, described in the RGB color space, from the terminal device to the rendering system 100 via a network. After receiving the input image data via the network, the rendering system 100 performs the following rendering process.

[0153] First, after receiving the input image data via the communication unit 110, the information processor 160 converts the input image data described in the RGB color space into laminar image data described in the laminar color space. Next, based on the grayscale values ​​of each color at each drawing coordinate of the converted laminar image data, the information processor 160 exports a voltage value file (a list of command voltage values). The information processor 160 then sends the exported voltage value file (the list of command voltage values) to the drawing unit 150.

[0154] The signal processing circuit 51 of the drawing unit 150 acquires a voltage value file (a list of command voltage values) input from the information processor 160 and uses it as an image signal Din. Synchronously with the scanner operation of the X-scanner unit 55, the signal processing circuit 51 generates an image signal from the image signal Din that corresponds to characteristics such as the wavelength of a laser beam. The signal processing circuit 51 generates a projection image signal that causes a laser beam to be emitted based on the generated image signal. The signal processing circuit 51 outputs the generated projection image signal to the laser drive circuit 52 of the drawing unit 150.

[0155] The laser driving circuit 52 drives each of the light sources 53A, 53B, and 53C of the light source unit 53 according to the projected image signal corresponding to each wavelength. At this time, the laser driving circuit 52, for example, causes a laser beam to be emitted from at least one of the light sources 53A, 53B, and 53C, and scans the recording medium 10.

[0156] For example, when colorizing the recording layer 17, a laser beam La with a light emission wavelength λ1 is used to irradiate the recording layer 17 with energy that brings it to its color development temperature. In this way, the photothermal conversion agent contained in the recording layer 17 generates heat to induce a color reaction (color development reaction) between the colorimetric compound and the color developer / subtractor, thereby displaying, for example, yellow in the irradiated area. Similarly, when colorizing the recording layer 15, a laser beam Lb with a light emission wavelength λ2 is used to irradiate the recording layer 15 with energy that brings it to its color development temperature, thereby displaying, for example, cyan in the irradiated area. When colorizing the recording layer 13, a laser beam Lc with a light emission wavelength λ3 is used to irradiate the recording layer 13 with energy that brings it to its color development temperature, thereby displaying, for example, cyan in the irradiated area. Therefore, it is provided that any part can be irradiated with a laser beam having a corresponding wavelength, making it possible to record graphics, etc. (e.g., full-color graphics, etc.).

[0157] Figure 4 illustrates the state of writing information onto the recording medium 10 by the drawing system 150. Figure 4 illustrates the cross-sectional configuration of the recording medium 10 and further illustrates the state of the laser beams La, Lb, and Lc scanning from the left to the right of the paper at predetermined intervals ΔX1 and ΔX2.

[0158] In this embodiment, a mechanism including a scanner drive circuit 54, an X scanner unit 55, a Y stage drive circuit 56, and a Y stage 57 serves as a scanning unit. This scanning unit uses multiple laser beams La, Lb, and Lc generated by a light source unit 53 to irradiate the surface of the recording medium 10 at predetermined intervals ΔX1 and ΔX2. The mechanism further utilizes the multiple laser beams La, Lb, and Lc to synchronously scan the surface of the recording medium 10 in the same direction. The mechanism scans the surface of the recording medium 10 using multiple laser beams La, Lb, and Lc with multiple irradiation spots Pa, Pb, and Pc arranged side-by-side at predetermined intervals ΔX1 and ΔX2 in the same direction (X-axis direction) as the scanning direction of the multiple laser beams La, Lb, and Lc.

[0159] The interval ΔX1 between the irradiation spot Pa of laser beam La and the irradiation spot Pb of laser beam Lb is preferably such that the high-temperature region Ra generated by laser beam La in and around the recording layer 13 and the high-temperature region Rb generated by laser beam Lb in and around the recording layer 15 do not overlap. Furthermore, the interval ΔX2 between the irradiation spot Pb of laser beam Lb and the irradiation spot Pc of laser beam Lc is preferably such that the high-temperature region Rb generated by laser beam Lb in and around the recording layer 15 and the high-temperature region Rc generated by laser beam Lc in and around the recording layer 17 do not overlap.

[0160] It should be noted that the scanning order of multiple laser beams La, Lb, and Lc on the surface of the recording medium 10, as shown in Figure 4, can be a sequence that allows color development starting from the outermost layer of recording layers 13, 15, and 17 closest to the outermost surface of the recording medium 10. Alternatively, the scanning order of multiple laser beams La, Lb, and Lc on the surface of the recording medium 10 can be a sequence that allows color development starting from the layer of recording layers 13, 15, and 17 closest to the substrate 11 (the layer furthest from the outermost surface of the recording medium 10).

[0161] Next, the effects of the drawing system 100 according to this embodiment will be described by comparing it with a comparative example. Figure 5 and Figure 6 The states of writing information on recording medium 10 in the comparative example are shown respectively.

[0162] exist Figure 5 In the comparative example shown, laser beams La, Lb, and Lc illuminate the same point P1 (the same pixel) of the recording medium 10. Therefore, the high-temperature region Ra partially overlaps with the high-temperature region Rb, and the high-temperature region Rb partially overlaps with the high-temperature region Rc. Therefore, in Figure 5In the comparative example shown, thermal crosstalk occurs between two adjacent recording layers in the stacking direction, leading to accidental writes or erases. Therefore, Figure 5 The comparison example shown has the problem of low rendering quality.

[0163] exist Figure 6 In the comparative example shown, the entire recording medium 10 is sequentially irradiated with laser beams La, Lb, and Lc. In this way, the high-temperature regions Ra and Rb, and also the high-temperature regions Rb and Rc, can be prevented from overlapping. Therefore, in Figure 6 In the comparative examples shown, the drawing quality is good. However, compared to... Figure 5 Compared to the comparative example shown, it takes three times longer to draw.

[0164] On the other hand, in this embodiment, multiple laser beams La, Lb, and Lc generated by the light source unit 53 are used to irradiate the surface of the recording medium 10 at predetermined intervals ΔX1 and ΔX2, and the multiple laser beams La, Lb, and Lc are used to synchronously scan the surface of the recording medium 10 in the same direction. In this way, thermal crosstalk between adjacent recording layers 13 and 15 in the stacking direction and between adjacent recording layers 15 and 17 in the stacking direction can be reduced. As a result, the possibility of accidental writing and erasure can be reduced.

[0165] Furthermore, in this embodiment, the surface of the recording medium 10 is scanned using multiple laser beams La, Lb, and Lc, with the illumination spots Pa, Pb, and Pc arranged side-by-side at predetermined intervals ΔX1 and ΔX2 in the same direction as the scanning direction (X-axis direction) of the multiple laser beams La, Lb, and Lc. In this way, thermal crosstalk between adjacent recording layers 13 and 15 in the stacking direction, and between adjacent recording layers 15 and 17 in the stacking direction, can be reduced. As a result, the possibility of accidental writing and erasure can be reduced.

[0166] Furthermore, this embodiment also includes a mechanism for scanning in the X-axis direction using multiple laser beams La, Lb, and Lc, and a Y-stage 57 for moving the recording medium 10 in the Y-axis direction. In this way, raster scanning can be achieved while reducing thermal crosstalk.

[0167] Furthermore, in this embodiment, grating scanning is performed by scanning in the X-axis direction using multiple laser beams La, Lb, and Lc and moving the Y-stage 57 in the Y-axis direction. In this way, grating scanning can be achieved while reducing thermal crosstalk.

[0168] Furthermore, in this embodiment, multiple laser beams La, Lb, and Lc are output to the X-scanner unit 55 with their optical axes offset from each other. In this way, by irradiating the surface of the recording medium 10 with multiple laser beams La, Lb, and Lc at predetermined intervals ΔX1 and ΔX2, thermal crosstalk between adjacent recording layers 13 and 15 in the stacking direction and between adjacent recording layers 15 and 17 in the stacking direction can be reduced. As a result, the possibility of accidental writing and erasure can be reduced.

[0169] Furthermore, multiple laser beams La, Lb, and Lc are output to the X-scanner unit 55, such that the optical axes of these multiple laser beams La, Lb, and Lc are parallel to each other at predetermined intervals ΔX1 and ΔX2. In this way, by irradiating the surface of the recording medium 10 with multiple laser beams La, Lb, and Lc at predetermined intervals ΔX1 and ΔX2, thermal crosstalk between adjacent recording layers 13 and 15 in the stacking direction, and between adjacent recording layers 15 and 17 in the stacking direction, can be reduced. As a result, the possibility of accidental writing and erasure can be reduced.

[0170] Furthermore, in this embodiment, multiple laser beams La, Lb, and Lc are output to the X-scanner unit 55 such that the optical axes of these multiple laser beams intersect at a predetermined angle. In this way, by irradiating the surface of the recording medium 10 with multiple laser beams La, Lb, and Lc at predetermined intervals ΔX1 and ΔX2, thermal crosstalk between adjacent recording layers 13 and 15 in the stacking direction, and between adjacent recording layers 15 and 17 in the stacking direction, can be reduced. As a result, the possibility of accidental writing and erasure can be reduced.

[0171] <2. Modified Example>

[0172] In the following text, a modified example of the drawing system 100 according to an embodiment of the present disclosure will be described.

[0173] [Modified Example A]

[0174] Figure 7 A modified example of the schematic configuration of the drawing system 100 according to the above embodiment is shown. In the above embodiment, raster scanning is achieved by the X-scanning unit 55 scanning in the X-axis direction using laser beams La, Lb, and Lc, and moving the Y-stage 57 in the Y-axis direction. However, in the above embodiment, for example as Figure 7 As shown, raster scanning can be achieved by using an XY scanner drive circuit 54A, an XY scanner unit 55A, and a stationary stage 57A instead of a scanner drive circuit 54, an X scanner unit 55, a Y stage drive circuit 56, and a Y stage 57.

[0175] The XY scanner drive circuit 54A drives the XY scanner unit 55A based on, for example, a control signal input from the signal processing circuit 51. Furthermore, for example, when a signal regarding the illumination angle of a two-axis scanner 55c, etc., which will be described later, is input from the XY scanner unit 55A, the XY scanner drive circuit 54A drives the XY scanner unit 55A based on this signal, making the illumination angle the desired illumination angle.

[0176] The XY scanner unit 55A, for example, uses laser beams La, Lb, and Lc incident from the light source unit 53 to scan the surface of the recording medium 10 in the X-axis direction, and moves the scan lines of the laser beams La, Lb, and Lc in the Y-axis direction with predetermined steps. The XY scanner unit 55A includes, for example, a two-axis scanner 55c and an fθ mirror 55b. The two-axis scanner 55c is a galvanometer that, based on a drive signal input from the XY scanner drive circuit 54A, uses laser beams La, Lb, and Lc incident from the light source unit 53 to scan the surface of the recording medium 10 in the X-axis direction, and moves the scan lines of the laser beams La, Lb, and Lc in the Y-axis direction with predetermined steps. The fθ mirror 55b converts the constant-speed rotational motion of the two-axis scanner 55c into a constant-speed linear motion of a point moving on the focal plane (the surface of the recording medium 10). The stage 57A is a stage that only supports the recording medium 10.

[0177] In this modified example, an XY scanner unit 55A is provided, which scans in the X-axis direction using multiple laser beams La, Lb, and Lc, and moves the scan lines of the multiple laser beams La, Lb, and Lc in the Y-axis direction at predetermined steps. In this way, raster scanning can be achieved while reducing thermal crosstalk.

[0178] Furthermore, in this embodiment, raster scanning is performed while the recording medium 10 is stationary. This is achieved by scanning along the X-axis using multiple laser beams La, Lb, and Lc, and moving the scan lines of the laser beams La, Lb, and Lc along the Y-axis with predetermined step sizes. In this way, raster scanning can be achieved while reducing thermal crosstalk.

[0179] [Modified Example B]

[0180] Figure 8 A modified example of the schematic configuration of the drawing system 100 according to the above embodiment is shown. In the above embodiment, raster scanning is achieved by the X-scanning unit 55 scanning in the X-axis direction using laser beams La, Lb, and Lc and moving the Y-stage 57 in the Y-axis direction. However, in the above embodiment, for example as Figure 8As shown, raster scanning can be achieved by replacing the light source unit 53 with the light source unit 53D, and replacing the scanner drive circuit 54, X scanner unit 55, Y stage drive circuit 56 and Y stage 57 with the XY stage drive circuit 56A and XY stage 57B.

[0181] The light source unit 53D corresponds to the light source unit 53 which further includes a condenser lens 53e for focusing the laser beams La, Lb, and Lc. The XY stage drive circuit 56A drives the XY stage 57B, for example, based on a control signal input from the signal processing circuit 51. The XY stage 57B moves at a predetermined speed in the X-axis direction and moves in the Y-axis direction by predetermined steps. Through the operation of the XY stage 57B, the surface of the recording medium 10 is raster scanned using the laser beams La, Lb, and Lc.

[0182] In this modified example, an XY stage 57B is provided, which uses multiple laser beams La, Lb, and Lc to scan in the X-axis direction, and moves the scan lines of the multiple laser beams La, Lb, and Lc in the Y-axis direction at predetermined steps. In this way, raster scanning can be achieved while reducing thermal crosstalk.

[0183] [Modified Example C]

[0184] Figure 9 A modified example of the schematic configuration of the drawing system 100 according to the above embodiment is shown. In the above embodiment, an optical system including a dichroic mirror 53b is used to arrange laser beams La, Lb, and Lc side by side in a predetermined direction at predetermined intervals and to output laser beams La, Lb, and Lc. However, in the above embodiment, a light source unit 53E can be used instead of a light source unit 53 to arrange laser beams La, Lb, and Lc side by side in a predetermined direction at predetermined intervals and to output laser beams La, Lb, and Lc.

[0185] like Figure 9 As shown, the light source unit 53E includes, for example, three light sources 53A, 53B and 53C, three optical fibers 53f, 53g and 53h, an optical fiber support 53i and a condenser lens 53j.

[0186] Fiber 53f is coupled to light source 53A, propagating the laser beam La emitted from light source 53A. Fiber 53g is coupled to light source 53B, propagating the laser beam Lb emitted from light source 53B. Fiber 53h is coupled to light source 53C, propagating the laser beam Lc emitted from light source 53C. Fiber optic bracket 53i arranges and fixes the tips of the three fibers 53f, 53g, and 53h side-by-side in a predetermined direction. Concentrating lens 53j focuses the laser beams La, Lb, and Lc emitted from the tips of the three fibers 53f, 53g, and 53h. The laser beams La, Lb, and Lc focused by concentrating lens 53j are output to X-ray scanner 55.

[0187] In this modified example, multiple laser beams La, Lb, and Lc are output to the X-scanner unit 55 via optical fibers 53f, 53g, and 53h, which are respectively provided for the laser beams La, Lb, and Lc. In this way, the surface of the recording medium 10 is irradiated with multiple laser beams La, Lb, and Lc at predetermined intervals ΔX1 and ΔX2, thereby reducing thermal crosstalk between adjacent recording layers 13 and 15 in the stacking direction and between adjacent recording layers 15 and 17 in the stacking direction. As a result, the possibility of accidental writing and erasure can be reduced.

[0188] [Modified Example D]

[0189] Figure 10 A modified example of the schematic configuration of the drawing system 100 according to the above-described modified example A is shown. In the above-described modified example A, an optical system including a dichroic mirror 53b is used to arrange laser beams La, Lb, and Lc side by side in a predetermined direction at predetermined intervals and output laser beams La, Lb, and Lc. However, in the above-described modified example A, a light source unit 53 can be used instead of a light source unit 53 to arrange laser beams La, Lb, and Lc side by side in a predetermined direction at predetermined intervals and output laser beams La, Lb, and Lc. Even in this case, raster scanning can be achieved while reducing the occurrence of thermal crosstalk.

[0190] [Modified Example E]

[0191] Figure 11 A modified example of the schematic configuration of the drawing system 100 according to the above-described modified example B is shown. In the above-described modified example B, an optical system including a dichroic mirror 53b is used to arrange laser beams La, Lb, and Lc side by side in a predetermined direction at predetermined intervals and output laser beams La, Lb, and Lc. However, in the above-described modified example B, a light source unit 53F can be used instead of a light source unit 53 to arrange laser beams La, Lb, and Lc side by side in a predetermined direction at predetermined intervals and output laser beams La, Lb, and Lc. Figure 11As shown, the light source unit 53F includes, for example, three light sources 53A, 53B, and 53C, three optical fibers 53f, 53g, and 53h, an optical fiber support 53i, and a condenser lens 53e. Even in this case, grating scanning can be achieved while reducing thermal crosstalk.

[0192] [Modified Example F]

[0193] Figure 12 A modified example of the drawing method in the drawing system 100 according to the above-described embodiments and their modifications is shown. In the above-described embodiments and their modifications, laser beams La, Lb, and Lc are scanned at predetermined intervals in a direction parallel to the X-axis. However, for example, as Figure 12 As shown, laser beams La, Lb, and Lc can be arranged side-by-side at predetermined intervals in a direction orthogonal to the X-axis (Y-axis direction) to scan the surface of the recording medium 10 using multiple laser beams La, Lb, and Lc, with multiple illumination spots Pa, Pb, and Pc of the multiple laser beams La, Lb, and Lc arranged side-by-side at predetermined intervals in a direction orthogonal to the scanning direction (X-axis direction) of the multiple laser beams La, Lb, and Lc.

[0194] In this modified example, the light source unit 53 includes, for example, an optical system that arranges multiple laser beams (e.g., three laser beams La, Lb, and Lc) emitted from multiple light sources (e.g., three light sources 53A, 53B, and 53C) side-by-side in the Y-axis direction at predetermined intervals, and outputs multiple laser beams. This optical system, for example, outputs the multiple laser beams La, Lb, and Lc to the X-scanner unit 55, such that multiple illumination spots Pa, Pb, and Pc are arranged side-by-side in the Y-axis direction at predetermined intervals in the order of illumination spots Pa, Pb, and Pc on the Y-stage 57.

[0195] Here, the illumination spot Pa moves along line L1 in the recording medium 10 corresponding to a certain pixel row. The illumination spot Pa moves along line L1 in the recording medium 10 corresponding to a certain pixel row. The illumination spot Pb moves along line L2 in the recording medium 10 corresponding to a certain pixel row, the pixel row being located at a predetermined distance from the pixel row in which the illumination spot Pa moves. The illumination spot Pc moves along line L3 in the recording medium 10 corresponding to a certain pixel row, the pixel row being located at a predetermined distance from the pixel row in which the illumination spot Pb moves.

[0196] Figure 13 , Figure 14 and Figure 15 Examples of drawing steps in the drawing system 100 according to this modified example are shown respectively.

[0197] The plotting system 100 first illuminates the recording medium 10 with a laser beam La to scan the illumination spot Pa in the X-axis direction. Then, after completing a scan of one line along the illumination spot Pa, the plotting system 100 temporarily stops illuminating the recording medium 10 with the laser beam La and moves the Y-stage 47 in the Y-axis direction, causing the recording medium 10 to move a predetermined distance in the Y-axis direction. Next, the plotting system 100 illuminates a position at a predetermined distance from the most recently scanned line with the laser beam La to scan the illumination spot Pa in the X-axis direction. In this way, the plotting system 100 scans the recording medium 10 multiple times in the X-axis direction with the laser beam La (see...). Figure 13 At this time, in the recording medium 10, a portion of the recording layer 13 displays a predetermined color (color A) when irradiated by the laser beam La.

[0198] Next, the plotting system 100 illuminates the recording medium 10 with laser beams La and Lb to scan the illumination spots Pa and Pb in the X-axis direction. At this time, the plotting system 100 illuminates the lines in the recording medium 10 scanned by the laser beam La with the laser beam Lb to scan the illumination spot Pb in the X-axis direction. Then, after completing the scanning of one line for each illumination spot Pa and Pb, the plotting system 100 temporarily stops the illumination of the laser beams La and Pb and moves the Y-stage 47 in the Y-axis direction to move the recording medium 10 a predetermined distance in the Y-axis direction.

[0199] Next, the plotting system 100 uses laser beams La and Lb to illuminate a position at a predetermined distance from the most recently scanned line, thereby scanning the illumination spots Pa and Pb in the X-axis direction. At this time, the plotting system 100 also uses laser beam Lb to illuminate the line in the recording medium 10 scanned by laser beam La, thereby scanning the illumination spot Pb in the X-axis direction. In this way, the plotting system 100 uses laser beams La and Lb to scan the recording medium 10 multiple times in the X-axis direction (see...). Figure 14 ).

[0200] At this time, in the recording medium 10, a portion of the recording layer 13 displays a predetermined color (color A) when irradiated by the laser beam La, and a portion of the recording layer 15 displays a predetermined color (color B) when further irradiated by the laser beam Lb. In the recording medium 10, when viewed from the stacking direction, at the position where both recording layers 13 and 15 display color, a combination of color A and color B is displayed.

[0201] Next, the plotting system 100 illuminates the recording medium 10 with laser beams La, Lb, and Lc to scan the illumination spots Pa, Pb, and Pc in the X-axis direction. At this time, the plotting system 100 illuminates the lines in the recording medium 10 scanned by laser beam La with laser beam Lb to scan the illumination spot Pb in the X-axis direction. Furthermore, the plotting system 100 illuminates the lines in the recording medium 10 scanned by laser beam Lb with laser beam Lc to scan the illumination spot Pc in the X-axis direction. Then, after completing the scanning of one line for each illumination spot Pa, Pb, and Pc, the plotting system 100 temporarily stops the illumination with laser beams La, Lb, and Lc, and moves the Y-stage 47 in the Y-axis direction to move the recording medium 10 a predetermined distance in the Y-axis direction.

[0202] Next, the plotting system 100 uses laser beams La, Lb, and Lc to illuminate positions at predetermined distances from the most recently scanned lines, thereby scanning the illumination spots Pa, Pb, and Pc in the X-axis direction. At this time, the plotting system 100 also uses laser beam Lb to illuminate the lines in the recording medium 10 scanned by laser beam La, thereby scanning the illumination spot Pb in the X-axis direction. Furthermore, the plotting system 100 uses laser beam Lc to illuminate the lines in the recording medium 10 scanned by laser beam Lb, thereby scanning the illumination spot Pc in the X-axis direction. In this way, the plotting system 100 uses laser beams La, Lb, and Lc to scan the recording medium 10 multiple times in the X-axis direction (see...). Figure 15 ).

[0203] At this time, in the recording medium 10, a portion of the recording layer 13 displays a predetermined color (color A) when irradiated by the laser beam La, a portion of the recording layer 15 displays a predetermined color (color B) when further irradiated by the laser beam Lb, and a portion of the recording layer 17 displays a predetermined color (color C) when irradiated by the laser beam Lc. In the recording medium 10, when viewed from the stacking direction, the location where all recording layers 13, 15, and 17 are colored is displayed with a combination of colors A, B, and C (e.g., black).

[0204] Incidentally, the distance Δy1 between the illumination spot Pa and the illumination spot Pb is, for example, set such that the time from when the predetermined pixel in the recording medium 10 is illuminated by the laser beam La to when the predetermined pixel is illuminated by the laser beam Lb (the cooling period Δt1 in the predetermined pixel) is 0.2 seconds or longer. Furthermore, the distance Δy2 between the illumination spot Pb and the illumination spot Pcb is, for example, set such that the time from when the predetermined pixel in the recording medium 10 is illuminated by the laser beam Lb to when the predetermined pixel is illuminated by the laser beam Lc (the cooling period Δt2 in the predetermined pixel) is 0.2 seconds or longer. Distances Δy1 and Δy2 may be equal or different. Cooling periods Δt1 and Δt2 may be equal or different.

[0205] When focusing on a predetermined pixel in the recording medium 10, the time points at which that pixel is irradiated by the laser beam La, Lb, and Lc are different from each other. Therefore, cooling periods Δt1 and Δt2 are set for each pixel in the recording medium 10. Then, as described above, the cooling periods Δt1 and Δt2 are 0.2 seconds or longer, which allows the next laser irradiation to be performed while each pixel is sufficiently cooled. As a result, it is possible to prevent… Figure 5 The comparative example shown exhibits thermal crosstalk, but good rendering quality can be achieved. It should be noted that the cooling periods Δt1 and Δt2 do not necessarily have to be 0.2 seconds or longer; they can be set according to the required rendering quality.

[0206] Figure 16 Shown in Figure 5 The comparative examples shown are experimental results from multiple embodiments where various distances Δy1 and Δy2 are set in this modified example. Figure 16 In this context, ΔE_avg represents the average color difference ΔE* of each embodiment relative to the comparative example when drawing a black image on the recording medium 10. Figure 16 In this process, the determination is made regarding whether the average value of the color difference ΔE* is equal to or less than the upper limit of the Class B tolerance, 6.5. When the average value of the color difference ΔE* is equal to or less than the upper limit of the Class B tolerance, 6.5, the average value of the color difference ΔE* is determined to be ○ (acceptable). On the other hand, when the average value of the color difference ΔE* exceeds the upper limit of the Class B tolerance, 6.5, the average value of the color difference ΔE* is determined to be × (unacceptable). Figure 16 In this context, "takt" represents the time required to draw a black image on the recording medium 10. Figure 16 In this context, the beat is represented by a value based on the beat of the comparison example. Figure 16 It can be seen that in Examples 6 to 11, it was determined to be ○ (qualified), and in Examples 1 to 11, the beat was 1 / 3 of the beat of the comparative example.

[0207] It should be noted that in this modified example, raster scanning can be achieved by using XY scanner drive circuit 54A, X scanner unit 55A, and station 57A instead of scanner drive circuit 54, X scanner unit 55, Y station drive circuit 56, and Y station 57.

[0208] [Modified Example G]

[0209] Figure 17 This illustrates a modified example of the drawing method in the drawing system 100 according to the modified example F described above. In the modified example F, the laser beams La, Lb, and Lc are arranged side-by-side at predetermined intervals in a direction orthogonal to the X-axis (Y-axis direction), and scanning is performed in the X-axis direction. However, for example, as Figure 17 As shown, scanning can be performed in the X-axis direction when the laser beams La, Lb, and Lc are arranged side-by-side at predetermined intervals in a direction oblique to both the X-axis and Y-axis directions. That is, the illumination spots Pa, Pb, and Pc do not necessarily have to be arranged in a straight line parallel to the Y-axis; the illumination spots Pb and Pc can deviate from the illumination spot Pa not only in the X-axis direction but also in the Y-axis direction. In this case, the mechanism capable of performing this scanning scans the surface of the recording medium 10 using multiple laser beams La, Lb, and Lc, with multiple illumination spots Pa, Pb, and Pc arranged side-by-side at predetermined intervals in a direction oblique to both the X-axis and Y-axis directions.

[0210] In this modified example, the light source unit 53 includes, for example, an optical system that arranges multiple laser beams (e.g., three laser beams La, Lb, and Lc) emitted from multiple light sources (e.g., three light sources 53A, 53B, and 53C) side-by-side at predetermined intervals in a direction oblique to both the X-axis and Y-axis directions, and outputs the multiple laser beams. For example, the optical system outputs the multiple laser beams La, Lb, and Lc to the X-scanner unit 55, so that multiple illumination spots Pa, Pb, and Pc are arranged side-by-side at predetermined intervals on the Y-stage 57 in the order of illumination spots Pa, Pb, and Pc in a direction oblique to both the X-axis and Y-axis directions. In this case, as in the modified example F described above, it is possible to prevent... Figure 5 The thermal crosstalk that occurred in the comparative example shown can be eliminated, and good rendering quality can be obtained.

[0211] In this modified embodiment, the side-by-side arrangement of the illumination spots Pa, Pb, and Pc is not necessarily a straight line, and the offset of the illumination spots Pa, Pb, and Pc relative to the line segment parallel to the Y-axis can be set to any amount. In this case, the mechanism capable of performing scanning in the drawing system 100 can scan the surface of the recording medium 10 using multiple laser beams La, Lb, and Lc without the lines scanned by each laser beam La, Lb, and Lc overlapping (i.e., without using multiple laser beams La, Lb, and Lc to scan the same line). In this case, similar to the modified example F described above, it is possible to prevent... Figure 5 The thermal crosstalk that occurred in the comparative example shown can be eliminated, and good rendering quality can be obtained.

[0212] In this modified example, the XY scanner drive circuit 54, X scanner unit 55A, and stationary stage 57A can be used instead of the scanner drive circuit 54, X scanner unit 55, Y stage drive circuit 56, and Y stage 57 to achieve raster scanning.

[0213] It should be noted that in the above embodiments and their modifications, the laser driving circuit 52 can, for example, pulse drive the light sources 53A, 53B, and 53C of the light source unit 53, or continuously drive the light sources 53A, 53B, and 53C of the light source unit 53 during scanning a line. When continuously driving the light sources 53A, 53B, and 53C, the laser driving circuit 52 can set the power of at least one of the light sources 53A, 53B, or 53C to zero according to the color to be represented.

[0214] It should be noted that the effects described herein are merely illustrative. The effects of this disclosure are not limited to those described herein. This disclosure may further include any effects other than those described herein.

[0215] Furthermore, this disclosure may have the following configurations, for example: (1)

[0217] A drawing system that draws on a recording medium comprising a plurality of stacked recording layers, with a heat-insulating layer interposed between the plurality of recording layers, the plurality of recording layers comprising different colorimetric compounds and different photothermal conversion agents, the drawing system comprising:

[0218] A light source unit that generates multiple laser beams having wavelengths that are different from each other and correspond to the absorption wavelengths of the photothermal conversion agent; and

[0219] The scanning unit uses multiple laser beams generated by the light source to illuminate the surface of the recording medium at predetermined intervals, and simultaneously scans the surface of the recording medium in the same direction using the multiple laser beams.

[0220] The scanning unit scans the surface of the recording medium using the plurality of laser beams, wherein the irradiation spots of the plurality of laser beams are arranged side by side at predetermined intervals in a direction orthogonal or oblique to the scanning direction of the plurality of laser beams. (2)

[0222] According to the drawing system described in (1), wherein the scanning unit uses a second laser beam, which is different from the first laser beam among the plurality of laser beams, to scan the lines in the recording medium that have been scanned by the first laser beam among the plurality of laser beams. (3)

[0224] According to the drawing system described in (1) or (2), the scanning unit includes an optical system that scans in a first direction using the plurality of laser beams and a stage that moves the recording medium in a second direction orthogonal to the first direction. (4)

[0226] According to the drawing system described in (1) or (2), the scanning unit includes an optical system that uses the plurality of laser beams to scan in a first direction and moves the scan lines of the plurality of laser beams in a second direction orthogonal to the first direction by a predetermined step size. (5)

[0228] According to any one of (1) to (4) of the drawing system, wherein the light source outputs the plurality of laser beams to the scanning unit in a state where the optical axes of the plurality of laser beams are offset from each other. (6)

[0230] According to the drawing system described in (5), the light source outputs the plurality of laser beams to the scanning unit such that the optical axes of the plurality of laser beams are parallel to each other at a predetermined interval. (7)

[0232] According to the drawing system described in (5), the light source outputs the plurality of laser beams to the scanning unit such that the optical axes of the plurality of laser beams intersect at a predetermined angle. (8)

[0234] According to the drawing system described in (5), the light source unit outputs the plurality of laser beams to the scanning unit via optical fibers provided for each of the laser beams. (9)

[0236] A drawing method is a method of drawing on a recording medium comprising a plurality of stacked recording layers, wherein a heat-insulating layer is interposed between the plurality of recording layers, and the plurality of recording layers comprises different color-producing compounds and different photothermal conversion agents, the drawing method comprising:

[0237] Multiple laser beams with wavelengths that are different from each other and correspond to the absorption wavelengths of the photothermal conversion agent are generated;

[0238] The surface of the recording medium is irradiated with multiple laser beams at predetermined intervals, and the surface of the recording medium is simultaneously scanned in the same direction using the multiple laser beams; and

[0239] The surface of the recording medium is scanned by means of the plurality of laser beams, wherein the illumination spots of the plurality of laser beams are arranged side by side at predetermined intervals in a direction orthogonal or oblique to the scanning direction of the plurality of laser beams. (10)

[0241] The drawing method according to (9) includes scanning the lines in the recording medium that have been scanned by the first laser beam among the plurality of laser beams using a second laser beam that is different from the first laser beam among the plurality of laser beams. (11)

[0243] The drawing method according to (9) includes performing raster scanning by scanning in a first direction using the plurality of laser beams and moving the recording medium in a second direction orthogonal to the first direction. (12)

[0245] The drawing method according to (9) includes performing raster scanning by scanning the plurality of laser beams in a first direction with the recording medium in a static state and moving the scan lines of the plurality of laser beams in a second direction orthogonal to the first direction by a predetermined step.

[0246] This application claims priority to Japanese Patent Application No. 2021-061778, filed with the Japan Patent Office on March 31, 2021, the entire contents of which are incorporated herein by reference.

[0247] Those skilled in the art will understand that various modifications, combinations, sub-combinations and alterations may occur based on the design requirements and other factors within the scope of the appended claims or their equivalents.

Claims

1. A drawing system configured to draw on a thermal recording medium, the drawing system comprising: The light source unit (53) is configured to generate multiple laser beams (La, Lb, Lc) having different wavelengths from each other. as well as A scanning unit is configured to illuminate the surface of the recording medium at predetermined intervals using a plurality of laser beams generated by the light source unit, wherein the scanning unit is configured to synchronously scan the surface of the recording medium in the same direction using the plurality of laser beams. The scanning unit is configured to scan the surface of the recording medium using the plurality of laser beams, wherein the illumination spots of the plurality of laser beams are arranged side by side at predetermined intervals in a linear direction oblique to the scanning direction of the plurality of laser beams.

2. The drawing system according to claim 1, wherein the scanning unit is configured to scan lines in the recording medium that have been scanned by the first laser beam among the plurality of laser beams using a second laser beam among the plurality of laser beams, the second laser beam being different from the first laser beam.

3. The drawing system of claim 1, wherein the scanning unit includes an optical system and a stage, the optical system being configured to scan in a first direction using the plurality of laser beams, and the stage being configured to move the recording medium in a second direction orthogonal to the first direction.

4. The drawing system according to claim 1, wherein the scanning unit includes an optical system configured to scan in a first direction using the plurality of laser beams, and configured to move the scan lines of the plurality of laser beams in a second direction orthogonal to the first direction by predetermined steps.

5. The drawing system according to claim 1, wherein the light source unit is configured to output the plurality of laser beams to the scanning unit when the optical axes of the plurality of laser beams are offset from each other.

6. The drawing system according to claim 5, wherein the light source unit is configured to output the plurality of laser beams to the scanning unit such that the optical axes of the plurality of laser beams are parallel to each other at a predetermined interval.

7. The drawing system according to claim 5, wherein the light source is configured to output the plurality of laser beams to the scanning unit such that the optical axes of the plurality of laser beams intersect each other at a predetermined angle.

8. The drawing system according to claim 5, wherein the light source unit is configured to output the plurality of laser beams to the scanning unit via optical fibers respectively provided for each of the plurality of laser beams.

9. A method of drawing, the method being a method of drawing on a recording medium (10), the recording medium comprising a plurality of stacked recording layers (13, 15, 17), with a heat-insulating layer interposed between the plurality of recording layers, the plurality of recording layers comprising different colorimetric compounds and different photothermal conversion agents, the method comprising: Multiple laser beams (La, Lb, Lc) are generated, each having a different wavelength corresponding to the absorption wavelength of the photothermal conversion agent. The surface of the recording medium is irradiated with the generated plurality of laser beams at predetermined intervals, and the surface of the recording medium is scanned synchronously in the same direction with the plurality of laser beams. as well as The surface of the recording medium is scanned by means of the plurality of laser beams, with the illumination spots of the plurality of laser beams arranged side by side at predetermined intervals in a linear direction oblique to the scanning direction of the plurality of laser beams.

10. The drawing method according to claim 9, comprising scanning a line in the recording medium that has been scanned by a first laser beam among the plurality of laser beams using a second laser beam among the plurality of laser beams, wherein the second laser beam is different from the first laser beam.

11. The drawing method of claim 9, comprising performing raster scanning by scanning the recording medium in a first direction using the plurality of laser beams and moving the recording medium in a second direction orthogonal to the first direction.

12. The drawing method according to claim 9, comprising performing raster scanning by scanning in a first direction using the plurality of laser beams while the recording medium is stationary and moving the scan lines of the plurality of laser beams in a second direction orthogonal to the first direction by predetermined steps.

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