Laser recording medium

Abstract

To provide a laser recording medium comprising a plurality of color color-developing layers capable of developing in different colors in which color-developing of a color color-developing layer or a black color-developing layer can be controlled more easily compared with a conventional configuration.SOLUTION: A laser recording medium in which a color information recording part 2 capable of recording information in color and a monochromatic information recording part 3 capable of recording information in black and white are disposed. In the color information recording part 2, a plurality of color color-developing layers capable of developing color in chromatic color having different hue are laminated on a substrate layer, and a black color-developing layer capable of developing color in black is not laminated on the substrate layer. In the monochromatic information recording part, the black color-developing layer is laminated on the substrate layer, and the color color-developing layer is not laminated.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a laser recording medium capable of recording a color image by using a laser beam. [Background technology]

[0002] A laser recording medium is known that has three color-producing layers capable of producing different colors in the three primary colors, and that can record image information in full color by causing each color-producing layer to produce a color individually using laser light and then mixing the recorded images (for example, Patent Document 1).

[0003] The laser recording medium of Patent Document 1 has a black coloring layer under a color coloring layer, which absorbs laser light, carbonizes it, and turns black, and is configured so that when information is recorded in black and white on the laser recording medium, the information is recorded in the black coloring layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-061200 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration of Patent Document 1, a black coloring layer is disposed under three color coloring layers, so that the four coloring layers must be colored separately, necessitating complex control and a highly functional recording device.

[0006] The present invention has been made in consideration of the current situation, and aims to provide a configuration for a laser recording medium having multiple color coloring layers capable of producing different colors, in which the coloring of the color coloring layers and black coloring layer can be more easily controlled than in conventional configurations. [Means for solving the problem]

[0007] The present invention is a sheet-shaped laser recording medium capable of recording information by irradiating laser light, comprising a color information recording section capable of recording information in color and a monochrome information recording section capable of recording information in black and white, wherein the color information recording section has a plurality of color coloring layers capable of producing chromatic colors of different hues laminated on a base layer, and a black coloring layer capable of producing black color is not laminated on the base layer, and the monochrome information recording section has the black coloring layer laminated on the base layer, and the color coloring layer is not laminated.

[0008] Since the color information recording section according to the present invention does not have a black coloring layer, it is easier to control the coloring of the color coloring layer compared to color information recording sections of conventional configurations, and the thickness can be made thinner compared to conventional configurations. As for the monochrome information recording section, since no color coloring layer is provided, it is easier to control the coloring of the black coloring layer, and the thickness can be made thinner compared to conventional configurations. In particular, since no color coloring layer is provided on the black coloring layer in the monochrome information recording section, it is easier to raise the area irradiated with laser light. Effect of the Invention

[0009] As described above, the laser recording medium of the present invention has the advantage that it is easier to control the color development of the color and black color development layers than in the conventional configuration, so that complicated color development control is not required when recording information, and information can be recorded using a simpler laser recording device than in the conventional configuration. [Brief description of the drawings]

[0010] [Figure 1] 1A and 1B are views of the surface of a laser recording medium 1 according to a first embodiment, in which (A) shows a state before a facial image F and the like are recorded, and (B) shows a state after a facial image F and the like have been recorded. [Diagram 2] 1A and 1B are explanatory diagrams showing the layer structure of a laser recording medium 1 in Example 1, in which (A) shows the layer structure of a color information recording section 2 and (B) shows the layer structure of a monochrome information recording section 3. FIG. [Diagram 3] FIG. 1 is an explanatory diagram showing an overview of a laser recording device 10. [Figure 4] 1A is an explanatory diagram showing the layer structure of a color information recording section 2a according to Example 2. FIG. 1B is an explanatory diagram showing the layer structure of a color information recording section 2b according to Example 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Embodiments of the present invention are illustrated by the following examples. EXAMPLES

[0012] The laser recording medium 1 of this embodiment is an identification card paper used for issuing a card-type identification card, as shown in FIG. 1(A). The laser recording medium 1 has a color information recording section 2 in a rectangular area on the left side of the front side. The color information recording section 2 is a plain white area, and when an identification card is issued, as shown in FIG. 1(B), a face image F of the person to be certified is recorded in color by laser light. In addition, a monochrome information recording section 3 for recording and displaying attribute information of the person to be certified is provided in a rectangular area on the right side of the front side of the laser recording medium 1. As shown in FIG. 1(A), only the item names of the attribute information are pre-printed in the plain white area of ​​the monochrome information recording section 3, and when an identification card is issued, the attribute information is recorded in black characters by laser light, as shown in FIG. 1(B).

[0013] FIG. 2 shows the layer structure of the laser recording medium 1. The laser recording medium 1 includes a base layer and a protective layer covering the front side of the base layer (upper side in FIG. 2). As shown in FIG. 2(A), the color information recording section 2 has three color coloring layers and two heat insulating layers between the protective layer and the base layer. The color coloring layers are layers for recording a face image F in color by laser light, and as described later, the three color coloring layers are configured to be capable of developing different chromatic colors by irradiation with laser light. The heat insulating layer is provided between the color coloring layers. On the other hand, as shown in FIG. 2(B), the monochrome information recording section 3 has a black coloring layer between the protective layer and the base layer that can record information in black by laser light. Although not shown, the above pre-printing of the monochrome information recording section 3 is formed on the surface of the base layer (between the base layer and the black coloring layer). Although not shown, the portions other than the color information recording portion 2 and the monochrome information recording portion 3 have a two-layer structure consisting of only a base layer and a protective layer.

[0014] The base layer supports the color developing layer and the black color developing layer from the back side. The thickness of the base layer is not particularly limited, but is preferably about 50 μm to 1000 μm. The base layer may be a single sheet or a laminate of multiple sheets. Specific materials for the base layer include paper, a resin sheet, or a combination of these. The surface of the base layer is desirably a color that does not affect the color of the face image F recorded in the color information recording unit 2. Specific colors include white, light colors, and colorless.

[0015] The protective layer is provided for the purpose of preventing damage or deterioration of the color coloring layer or the black coloring layer, and falsification of recorded information. The protective layer is made of a substantially transparent material that transmits the recording laser light used for recording information and allows the recorded information to be visually recognized. The protective layer may be suitably made of a material that is impermeable to water and air. Desirable film materials constituting the protective layer include polyvinyl chloride (PVC), glycol-modified polyethylene terephthalate (PETG), polyethylene terephthalate (PET), polypropylene (PP), and the like. The thickness of the protective layer is not particularly limited, but is preferably about 1 μm to 100 μm. The protective layer may be made of one or more films. When the protective layer is a film, it is proposed to bond it to the base layer, the color coloring layer, and the like with an adhesive or the like.

[0016] The three color developing layers are substantially transparent before recording the face image F, and are configured to develop chromatic colors of different hues when irradiated with laser light. Each color developing layer contains a photothermal conversion agent that absorbs laser light of a predetermined wavelength and generates heat, a thermosensitive color developing component that develops color when the temperature reaches a predetermined color development threshold temperature or higher, and a binder resin. That is, each color developing layer generates heat when irradiated with laser light of a wavelength that the photothermal conversion agent can absorb, and develops color when the irradiated area rises to the color development threshold temperature. The three color developing layers develop different three primary colors due to the difference in the thermosensitive color developing components they contain. Specifically, as shown in FIG. 2(A), the upper color developing layer of the upper layer (surface side) develops color in yellow (Y), the middle color developing layer of the middle layer develops color in magenta (M), and the lower color developing layer of the lower layer (base layer side) develops color in cyan (C). That is, in this embodiment, a yellow image, a magenta image, and a cyan image are recorded individually on each color developing layer, and then these images are superimposed and mixed, thereby making it possible to record and display a full-color facial image F in the color information recording unit 2.

[0017] The thickness of the color developing layer is not particularly limited, but is preferably about 1 μm to 50 μm. Known materials can be suitably used as the constituent material of the color developing layer. For example, a cyanine dye can be mentioned as a suitable photothermal conversion agent that absorbs laser light in the near infrared region and generates heat. The heat-sensitive color developing component can be a combination of a leuco dye and a developer. The leuco dye and the developer can be selected from known materials according to the color to be developed. The binder resin can be a colorless resin material such as polyvinyl alcohol.

[0018] The photothermal conversion agent contained in each color coloring layer absorbs laser light in a different wavelength range. Thus, the laser recording medium 1 is configured so that the three color coloring layers are selectively heated by selectively irradiating the front side with three types of recording laser light with different wavelengths, thereby individually controlling the color development of each color coloring layer. Specifically, the upper color coloring layer is configured to absorb the recording laser light of the first wavelength to generate heat and develop color, and to transmit the recording laser light of the second wavelength and the third wavelength. The intermediate color coloring layer is configured to absorb the recording laser light of the second wavelength to generate heat and develop color, and to transmit the recording laser light of the third wavelength. The lower color coloring layer is configured to absorb the recording laser light of the third wavelength to generate heat and develop color.

[0019] The three wavelengths of recording laser light used for recording on the laser recording medium 1 are not particularly limited, but it is preferable that all of them are recording laser light in the near infrared region. Specific examples of laser light include YAG laser light, CO2 laser light, YVO4 laser light, fiber laser light, and semiconductor laser light, and it is proposed to use three specific wavelengths, 785 nm, 860 nm, and 1064 nm. In this embodiment, the absorption characteristics of the laser light of each color coloring layer are set so that the first wavelength, which is the shortest wavelength of the three wavelengths, is used as the recording laser light for the upper color coloring layer, and the third wavelength, which is the longest wavelength of the three wavelengths, is used as the recording laser light for the lower color coloring layer.

[0020] The heat insulating layer is disposed between the color developing layers to suppress the thermal conduction between the color developing layers. That is, when the target color developing layer is heated and colored by the recording laser light, the heat of the color developing layer prevents the other color developing layers from rising to the color developing threshold temperature. The heat insulating layer is made of a substantially transparent material that transmits the recording laser light and does not block the information recorded in the color developing layer. Suitable materials for the heat insulating layer include polyvinyl alcohol, polyvinyl acetate, polyacrylic, etc. The thickness of the heat insulating layer is not particularly limited, but a suitable thickness for suppressing the thermal conduction between the color developing layers is 1 μm to 50 μm.

[0021] The color developing layer and heat insulating layer constituting the color information recording section 2 can be formed by applying paint containing the materials of each layer to the front side of the base layer or the back side of the protective layer, drying and laminating them.

[0022] The black coloring layer is substantially transparent before recording, and is configured to develop a black color when irradiated with a laser beam of a predetermined wavelength. The black coloring layer may be a composition consisting of a photothermal conversion agent that absorbs a laser beam of a predetermined wavelength and generates heat, and a resin that is carbonized to black by the heat generated by the photothermal conversion agent. The composition of the black coloring layer may be a widely known composition. The black coloring layer is composed of a material that absorbs all of the recording laser beams of the three wavelengths used for recording the color information recording section 2. The thickness of the black coloring layer is not particularly limited, but is preferably about 1 μm to 200 μm. In addition, when the color information recording section 2 and the monochrome information recording section 3 are adjacent to each other as in this embodiment, it is preferable to set the thickness of the black coloring layer so that the step at the boundary between the color information recording section 2 and the monochrome information recording section 3 is small. The black coloring layer may be suitably formed by coating a material on the front side of the base layer or the back side of the protective layer.

[0023] When issuing an identification card using the laser recording medium 1, as shown in Figures 1(A) to 1(B), a laser recording device capable of emitting the above-mentioned three wavelengths of recording laser light is used to record a facial image F in the color information recording section 2 and to record characters indicating attribute information in the monochrome information recording section 3.

[0024] 3 shows the configuration of a laser recording device 10 capable of recording a face image F and attribute information on the laser recording medium 1 of this embodiment. The laser recording device 10 includes laser oscillators 11a, 11b, and 11c that output recording laser light, a focusing unit 12 that focuses the recording laser light on the laser recording medium 1, an optical fiber 13 that guides the recording laser light from the laser oscillators 11a, 11b, and 11c to the focusing unit 12, a stage 14 that holds the laser recording medium 1, a stage movement mechanism 15 that moves the stage 14, an output control unit 16 that controls the operation of the laser oscillators 11a, 11b, and 11c and the focusing unit 12, a position control unit 17 that controls the operation of the stage movement mechanism 15, and a calculation unit 18 that controls the overall operation of the laser recording device 10.

[0025] The laser recording device 10 can record information using recording laser light of three wavelengths, and the laser oscillators 11a, 11b, and 11c are arranged to output recording laser light of each wavelength. The focusing unit 12 has a single focusing lens 19, and the recording laser light of the three wavelengths output from the laser oscillators 11a, 11b, and 11c and guided by the optical fiber 13 is focused by the same focusing lens 19. The focusing unit 12 also has a height detection mechanism capable of detecting the surface height of the laser recording medium 1, and a lens movement mechanism that moves the focusing lens 19 up and down to adjust the focal position of the recording laser light. The configuration of the laser recording device 10 is known, so a detailed description will be omitted.

[0026] The laser recording device 10 records a face image F and attribute information on the laser recording medium 1 mainly by executing the following steps (1) to (7) in order. (1) The laser recording medium 1 before recording is set at a predetermined position on the stage 14. (2) The height of the surface of the laser recording medium 1 is detected by the height detection mechanism of the light collecting unit 12. (3) Based on the height of the surface of the laser recording medium 1, the condenser lens 19 is moved up and down to adjust the focal position. (4) The face image F to be recorded and attribute information data are input to the calculation unit 18. (5) The facial image F is recorded in the color information recording unit 2. (6) Record the attribute information in the monochrome information recording unit 3. (7) After recording, the laser recording medium 1 is removed from the stage 14.

[0027] In the step of recording the face image F in the color information recording unit 2 (step (5) above), the calculation unit 18 separates the full-color digital data of the face image F into the three primary colors of CMY. Then, the cyan plate image, magenta plate image, and yellow plate image obtained by the color separation are recorded on the three color coloring layers, respectively, using laser light of three wavelengths. Specifically, the calculation unit 18 cooperatively operates the laser oscillator 11c and the stage moving mechanism 15 via the output control unit 16 and the position control unit 17 to irradiate a required position on the laser recording medium 1 with a recording laser light of a third wavelength under required conditions (irradiation time and irradiation intensity), thereby recording the cyan plate image on the lower color coloring layer. Thereafter, in the same manner, the recording laser light of the second wavelength is irradiated to record the magenta plate image on the intermediate color coloring layer, and further, the recording laser light of the first wavelength is irradiated to record the yellow plate image on the upper color coloring layer.

[0028] In this way, the laser recording medium 1 of this embodiment selectively irradiates the front side of the color information recording section 2 with recording laser light of three different wavelengths, records cyan, magenta, and yellow images individually on the three color color-developing layers, and can record a full-color facial image F in the color information recording section 2 by superimposing the images recorded on each color color-developing layer.

[0029] In the step of recording the attribute information in the monochrome information recording unit 3 (step (6) above), The calculation unit 18 cooperatively operates the laser oscillator 11c and the stage movement mechanism 15 to irradiate the required position of the monochrome information recording unit 3 from the front side with the recording laser light under required conditions, thereby carbonizing the required portion of the black coloring layer. At this time, if the energy of the recording laser light irradiated to the monochrome information recording unit 3 is made relatively high, not only can the recorded portion be carbonized to a black color, but also the binder resin can be foamed to cause the recorded portion to protrude to the front side. Since the black coloring layer can absorb the recording laser light of the above three wavelengths, the recording laser light used for recording in the color information recording unit 2 can be used when recording in the monochrome information recording unit 3.

[0030] As described above, in the laser recording medium 1 of this embodiment, three color coloring layers are laminated in the color information recording section 2, no black coloring layer is provided, and a black coloring layer is provided in the monochrome information recording section 3, no color coloring layer is laminated, so that coloring control of the color coloring layers is easier than in the conventional configuration. Specifically, when three color coloring layers and a black coloring layer are laminated, coloring control of four coloring layers is required, and recording laser light of four different wavelengths is required, but if the color coloring layers and the black coloring layer are not laminated as in this embodiment, the recording laser light for the black coloring layer can be shared with the recording laser light for the color coloring layer, so three types of recording laser light are sufficient, and information can be recorded with a relatively simple laser recording device. Furthermore, since the black coloring layer is not formed in the color information recording section 2 according to this embodiment, the color information recording section 2 can be made thinner than in the conventional configuration. Furthermore, since the monochrome information recording section 3 according to this embodiment does not have a color coloring layer laminated on a black coloring layer, it is easier to raise the recording portion of the monochrome information recording section 3 compared to the conventional configuration.

[0031] The following describes Examples 2 and 3. These examples are obtained by partially modifying the configuration of Example 1 described above, and configurations that are not specifically mentioned are common to Example 1, and the same reference numerals as Example 1 are used in the text and drawings to describe these examples. EXAMPLES

[0032] While each color developing layer in the above-mentioned Example 1 is a homogeneous layer containing a photothermal conversion agent and a thermosensitive color developing component, the color information recording section 2a in this embodiment is composed of two layers, a photothermal conversion layer containing a photothermal conversion agent but not a thermosensitive color developing component, and a thermosensitive color developing layer containing a thermosensitive color developing component but not a photothermal conversion agent, as shown in FIG. 4(A). That is, the color developing layer in this embodiment develops a predetermined hue by absorbing the recording laser light, generating heat, and transmitting the heat to the adjacent thermosensitive color developing layer to raise the temperature to a threshold temperature. In this way, the color developing layer according to the present invention may be composed of two layers, a photothermal conversion layer and a thermosensitive color developing layer. EXAMPLES

[0033] In the above-mentioned embodiment 1, three color coloring layers are laminated in the color information recording section 2, whereas in the color information recording section 2b according to this embodiment, two color coloring layers are laminated as shown in FIG. 4(B). Of the two color coloring layers, the upper color coloring layer, which is the upper layer, is configured to develop a reddish hue, and the lower color coloring layer, which is the lower layer, is configured to develop a greenish hue. In this way, the color information recording section according to the present invention can be configured with two color coloring layers. With this configuration, the color information recording section 2b can be made thinner than in embodiment 1, and the manufacturing cost can be reduced. In addition, only two types of recording laser light are required for recording in the color information recording section 2b, so that recording can be performed with a simpler laser recording device, and the time required for recording can be shortened.

[0034] The following describes Examples 2 and 3. These examples are obtained by partially modifying the configuration of Example 1 described above, and configurations that are not specifically mentioned are common to Example 1, and the same reference numerals as Example 1 are used in the text and drawings to describe these examples.

[0035] Although the examples of the present invention have been described above, the embodiment of the present invention is not limited to the configurations of the above examples, and can be appropriately modified within the scope of the present invention. For example, the laser recording medium in the above examples is a card-type identification card, but it may be a booklet-type identification card. Furthermore, the present invention is not limited to identification cards, and can be applied to laser recording media in general that have a color information recording section and a monochrome information recording section.

[0036] The layer configurations of the color information recording section 2 and the monochrome information recording section 3 can also be appropriately changed without departing from the spirit of the present invention. For example, a layer such as a lenticular lens can be further disposed on the protective layer according to the above embodiment. Also, a base layer for improving adhesion with the color coloring layer and the black coloring layer, or a background pattern printing layer can be disposed on the surface of the base layer.

[0037] In addition, while the black coloring layer in the above-mentioned examples is colored black by carbonization of the resin, the black coloring layer of the present invention may contain a thermosensitive coloring component capable of coloring black, and may be colored black by the coloring of the thermosensitive coloring component.

[0038] Furthermore, the multiple color forming layers in the above embodiments have different laser light absorption characteristics and are configured so that their color forming can be individually controlled by recording laser light of different wavelengths, but the multiple color forming layers of the present invention may also be configured so that they have different color forming threshold temperatures and can be individually colored by adjusting the applied energy of the recording laser light.

[0039] Furthermore, in the laser recording medium 1 of the above embodiment, the color information recording unit 2 and the monochrome information recording unit 3 are arranged only on the front side, but a color information recording unit and a monochrome information recording unit may also be arranged on the back side of the laser recording medium 1.

[0040] In addition, the base layer may be made of a material that is transparent to recording laser light, so that the recording laser light can be irradiated from the back side of the laser recording medium 1 to the color information recording section 2 and monochrome information recording section 3 on the front side.

[0041] Furthermore, in the laser recording medium 1 of the above embodiment, the color information recording section 2 and the monochrome information recording section 3 are disposed adjacent to each other, but the color information recording section 2 and the monochrome information recording section 3 do not have to be disposed adjacent to each other.

[0042] In addition, in the laser recording medium 1 of the above-mentioned embodiments, the recording laser light is in the near-infrared region, but the recording laser light according to the present invention may be partially or entirely in the ultraviolet region or in the visible region. [Explanation of symbols]

[0043] 1 Laser recording media 2, 2a, 2b Color information recording section 3. Monochrome information recording section 10 Laser recording device 11a, 11b, 11c Laser oscillator 12 Light collecting section 13. Fiber Optics 14 Stages 15 Stage movement mechanism 16 Output control section 17 Position control section 18 Calculation section 19 Condenser lens F. Face image

Claims

[Claim 1] A sheet-shaped laser recording medium capable of recording information by irradiating a laser beam, The recording medium includes a color information recording section capable of recording information in color, and a monochrome information recording section capable of recording information in black and white, In the color information recording section, a plurality of color coloring layers capable of developing chromatic colors having different hues are laminated on a base layer, and a black coloring layer capable of developing a black color is not laminated on the base layer, 2. A laser recording medium comprising: a substrate layer having a black coloring layer laminated thereon; a color information recording section having a black information recording layer laminated thereon; and a color information recording section having a black information recording layer laminated thereon;

Images