JP7155057B2 - laser recorder - Google Patents

Description

Embodiments of the present invention relate to laser recording apparatus and methods.

Conventional thermal recording methods, including laser recording methods, use raster scanning in which lines or pixels are sequentially recorded in one direction by scanning a laser or a thermal head in the vertical or horizontal direction of an image when recording an image. method was common.
In the raster scan method, adjacent lines or pixels of an input image are recorded continuously in time.

For this reason, the heat remaining after recording a line or pixel recorded earlier in time affects the recording of the next line or pixel, resulting in density disturbance, color mixing, surface destruction, and the like. There is a possibility that unintended image disturbance may occur.

In order to solve this problem, when an image to be recorded is input, it is possible to grasp in advance what kind of recording will be performed before, after, and to the left and right of the pixel of interest, and control the input energy when recording the pixel of interest. , a technique for obtaining a desired image (density) has been proposed.

Japanese Patent No. 3739519 Japanese Patent No. 4386779

In the above conventional method, it is essential to be able to finely control the input energy in order to obtain the desired image (density), and it is necessary to determine the energy input from many parameters by recording the front, rear, left, and right of the pixel of interest. .
In addition, in the case of the control method in which direct heat is applied by a thermal head for drawing, counterfeiting or alteration is easier than laser drawing, and security is low.

On the other hand, in order to perform fine energy control for such recording with a laser, it is necessary to reduce the rated output of the laser. Resulting in. Further, if a laser with a high rated output is used, there is a problem that it is difficult to finely control the energy according to the recording conditions in the front, rear, left, and right of the pixel of interest.

Therefore, the present invention has been made in view of the above, and is capable of suppressing the drawing time while considering the influence of the heat transfer (heat transfer) during image recording, and is capable of recording with high security. It is an object of the present invention to provide a laser recording apparatus and method capable of performing

A laser recording apparatus according to an embodiment is a laser recording apparatus that records an image on a thermosensitive recording medium in which a thermosensitive coloring layer is laminated on a base material, and includes a data conversion unit that converts input image data into color data; parameter setting for setting irradiation parameters of the laser recording light so that the color after image recording corresponds to the input image data in consideration of heat transfer from surrounding pixels to the pixel to be recorded based on The setting of the irradiation parameter includes a case where the irradiation of the recording target pixel with the laser recording light is prohibited and color development is performed only by heat transfer from the peripheral pixels .

FIG. 1 is an external front view of a recording medium (falsification prevention medium) according to the first embodiment in which information is recorded. FIG. 2 is a cross-sectional view of a configuration example of the recording medium of the first embodiment. FIG. 3 is an explanatory diagram of the thickness and thermal conductivity ratio of the recording medium of the first embodiment. FIG. 4 is an explanatory diagram of an example of light absorption characteristics of a photothermal conversion layer. FIG. 5 is a schematic configuration block diagram of the laser recording apparatus of the first embodiment. FIG. 6 is an operation processing flowchart of the laser recording apparatus. FIG. 7 is an explanatory diagram (part 1) of the effect of heat accumulation during laser recording. FIG. 8 is an explanatory diagram (part 2) of the effect of heat accumulation during laser recording. FIG. 9 is an explanatory diagram of a pixel (picture element) arrangement when setting parameters. FIG. 10 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the high-temperature thermosensitive coloring layer is caused to develop color alone. FIG. 11 is an explanatory diagram of the coloring control temperature of the high-temperature thermosensitive coloring layer. FIG. 12 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the medium-temperature thermosensitive coloring layer is caused to develop a color alone. FIG. 13 is an explanatory diagram of the coloring control temperature of the medium-temperature thermosensitive coloring layer. FIG. 14 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the low-temperature thermosensitive color-developing layer alone develops color. FIG. 15 is an explanatory diagram of the coloring control temperature of the low-temperature thermosensitive coloring layer. FIG. 16 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the high temperature thermosensitive coloring layer and the intermediate temperature thermosensitive coloring layer are caused to develop colors in parallel. FIG. 17 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the intermediate temperature thermosensitive coloring layer and the low temperature thermosensitive coloring layer are caused to develop colors in parallel. FIG. 18 is a diagram for explaining the relationship between laser light energy and irradiation time when the high temperature thermosensitive coloring layer, the medium temperature thermosensitive coloring layer and the low temperature thermosensitive coloring layer are caused to develop colors in parallel. FIG. 19 is a processing flowchart of the second embodiment. FIG. 20 is a processing flowchart of color data correction processing. FIG. 21 is a cross-sectional view of a configuration example of a recording medium according to a first alternative embodiment. FIG. 22 is a cross-sectional view of a configuration example of a recording medium of a second alternative mode. FIG. 23 is a cross-sectional view of a configuration example of a recording medium that is a modification of the recording medium of the second alternative mode. FIG. 24 is a cross-sectional view of a configuration example of a recording medium of a third alternative mode. FIG. 25 is an explanatory diagram of a recording medium of a fourth alternative mode. FIG. 26 is an explanatory diagram of a recording medium of a fifth alternative mode. FIG. 27 is an explanatory diagram of a modified example of the recording medium of the fifth other aspect. FIG. 28 is a cross-sectional view of a recording medium of a sixth alternative embodiment. FIG. 29 is an explanatory diagram of a modified example of the recording medium of the sixth alternative mode. FIG. 30 is a cross-sectional view of a recording medium of a seventh alternative mode. FIG. 31 is a cross-sectional view of a recording medium of an eighth alternative. FIG. 32 is a cross-sectional view of a ninth alternative recording medium. FIG. 33 is an explanatory diagram of a card-shaped recording medium of another tenth aspect. FIG. 34 is an explanatory diagram of a card-shaped recording medium of a first modification of the tenth alternative recording medium. FIG. 35 is an explanatory diagram of a card-like recording medium of a second modified example of the tenth alternative recording medium. FIG. 36 is an explanatory diagram of a card-shaped recording medium of a third modification of the tenth alternative recording medium. FIG. 37 is an explanatory diagram of a card-shaped recording medium of a fourth modification of the tenth alternative recording medium.

Embodiments will be described in detail below with reference to the drawings.
[1] First Embodiment First, a recording medium according to a first embodiment will be described.
FIG. 1 is an external front view of a recording medium (falsification prevention medium) according to the first embodiment in which information is recorded.

The recording medium 10 on which information has been recorded is roughly divided into a full-color image forming area ARC for recording a full-color image such as an identification photograph and an image forming area surrounding the full-color image forming area ARC. , and a monochrome image forming area ARM in which specific information such as the issue date is recorded in monochrome.

In FIG. 1, the recording medium 10 has areas other than the full-color image forming area ARC and the monochrome image forming area ARM. good too.

In FIG. 1, the full-color image forming area ARC and the monochrome image forming area ARM are configured so as to be in contact with each other. good.

FIG. 2 is a cross-sectional view of a configuration example of the recording medium of the first embodiment.
FIG. 3 is an explanatory diagram of the thickness and thermal conductivity ratio of the recording medium of the first embodiment.
As shown in FIG. 1, the recording medium 10 comprises a substrate 11, a light absorbing coloring layer 12 as a first coloring layer, a photothermal conversion layer 13, a binder layer 14, and a high-temperature thermosensitive coloring layer 15 as a second coloring layer. , an intermediate layer 16, a medium temperature thermosensitive coloring layer 17 as a second coloring layer, an intermediate layer 18, a low temperature thermosensitive coloring layer 19 as a second coloring layer, and a protective/functional layer 20 are formed in this order.

Here, the high-temperature thermosensitive coloring layer 15, the medium-temperature thermosensitive coloring layer 17, and the low-temperature thermosensitive coloring layer 19 function as thermosensitive recording layers for image recording.
In addition, the intermediate layer 16 and the intermediate layer 18 function as heat insulating layers that adjust the amount of heat transfer and suppress heat transfer.

In addition, the substrate 11 includes a light absorbing coloring layer 12, a photothermal conversion layer 13, a binder layer 14, a high temperature thermosensitive coloring layer 15, an intermediate layer 16, a medium temperature thermosensitive coloring layer 17, an intermediate layer 18, a low temperature thermosensitive coloring layer 19 and a protective/ It retains the functional layer 20 .

Here, the thickness of the base material 11 is, for example, 100 μm, and the thermal conductivity ratio is 0.01 to 5.00 W/m/K.

The light-absorbing color-developing layer 12 is a layer that contains pigment particles and irreversibly develops color when the pigment particles absorb laser light, which is recording light, and carbonize.
Here, the thickness of the light absorbing and coloring layer 12 is, for example, 1 to 50 μm, and the thermal conductivity ratio is 0.01 to 50 W/m/K.

The photothermal conversion layer 13 absorbs recording light (recording laser light) of a predetermined wavelength and performs light/heat conversion to perform at least one of a high-temperature thermosensitive coloring layer 15, a medium-temperature thermosensitive coloring layer 17, and a low-temperature thermosensitive coloring layer 19. It is a layer that generates and transfers heat for coloring the thermosensitive coloring layer.
Here, the thickness of the photothermal conversion layer 15 is, for example, 0.5 to 30 μm, and the thermal conductivity ratio is 0.01 to 1 W/m/K.

The binder layer 14 is a layer that holds the light absorbing and coloring layer 12, the photothermal conversion layer 13 and the high temperature coloring layer 15 in place while binding the light absorbing and coloring layer 12 and the high temperature coloring layer 15 together.
Here, the thickness of the binder layer 14 is, for example, 0.5 to 100 μm, and the thermal conductivity ratio is 0.01 to 50 W/m/K.

The high-temperature thermosensitive coloring layer 15 is a layer containing a temperature-indicating material as a thermosensitive material that develops color when its temperature reaches or exceeds the first threshold temperature T1.
Here, the thickness of the photothermal conversion layer 15 is, for example, 0.5 to 30 μm, and the thermal conductivity ratio is 0.01 to 1 W/m/K.

The intermediate layer 16 is a layer that provides a thermal barrier during color development of the high temperature thermosensitive coloring layer 15 and suppresses heat transfer from the high temperature thermosensitive coloring layer 15 side to the medium temperature thermosensitive coloring layer and the low temperature thermosensitive coloring layer.
Here, the intermediate layer 16 has a thickness of, for example, 7 to 100 μm and a thermal conductivity ratio of 0.01 to 50 W/m/K.

The intermediate temperature thermosensitive coloring layer 17 is a layer containing a temperature indicating material as a thermosensitive material that develops color when its temperature reaches or exceeds the second threshold temperature T2 (<T1).
Here, the thickness of the photothermal conversion layer 17 is, for example, 1 to 10 μm, and the thermal conductivity ratio is 0.1 to 10 W/m/K.

The intermediate layer 18 is a layer that provides a thermal barrier during color development of the intermediate temperature thermosensitive coloring layer 17 and suppresses heat transfer from the intermediate temperature thermosensitive coloring layer 17 side to the low temperature thermosensitive coloring layer.
Here, the intermediate layer 18 has a thickness of, for example, 7 to 100 μm and a thermal conductivity ratio of 0.01 to 50 W/m/K.

The low-temperature thermosensitive coloring layer 19 is a layer containing a temperature-indicating material as a thermosensitive material that develops color when its temperature reaches or exceeds a second threshold temperature T3 (<T2<T1).
Here, the thickness of the low-temperature thermosensitive coloring layer 19 is, for example, 1 to 10 μm, and the thermal conductivity ratio is 0.1 to 10 W/m/K.

The protective/functional layer 20 protects the light absorbing coloring layer 12, the photothermal conversion layer 13, the binder layer 14, the high temperature thermosensitive coloring layer 15, the intermediate layer 16, the intermediate temperature thermosensitive coloring layer 17, the intermediate layer 18, and the low temperature thermosensitive coloring layer 19. In addition, it is a layer provided for placing anti-counterfeiting items such as holograms, lenticular lenses, microarray lenses, and UV-excited fluorescent ink, inserting internal protection items such as UV-blocking layers, or using both functions.
Here, the protective/functional layer 20 has a thickness of, for example, 0.5 to 10 μm and a thermal conductivity ratio of 0.01 to 1 W/m/K.

Here, the light absorption properties of the photothermal conversion layer 13, the binder layer 14, the high-temperature thermosensitive coloring layer 15, the intermediate layer 16, the medium-temperature thermosensitive coloring layer 17, the intermediate layer 18, the low-temperature thermosensitive coloring layer 19, and the protective/functional layer 20 are detailed. explain.

FIG. 4 is an explanatory diagram of an example of light absorption characteristics of a photothermal conversion layer.
As shown in FIG. 4, the photothermal conversion layer 13 has infrared absorption characteristics having an absorption peak at a wavelength λ belonging to near infrared rays (eg, λ=1064 nm).

On the other hand, the binder layer 14, the high-temperature thermosensitive coloring layer 15, the intermediate layer 16, the intermediate-temperature thermosensitive coloring layer 17, the intermediate layer 18, the low-temperature thermosensitive coloring layer 19, and the protective/functional layer 20 are composed of light having a wavelength λ belonging to the near infrared rays (near infrared rays). It is made of a material that transmits infrared light). This is because light (near-infrared light) having a wavelength λ that can be absorbed by the light-absorbing coloring layer 12 or the light-heat converting layer 13 is allowed to reach there.

Therefore, when near-infrared light having a wavelength λ (for example, λ=1064 nm) is incident from the protective/functional layer 20 side, in the full-color image forming region ARC, the protective/functional layer 20→low-temperature thermosensitive coloring layer 19→intermediate layer 18→intermediate temperature thermosensitive coloring layer 17→intermediate layer 16→high temperature thermosensitive coloring layer 15→binder layer 14. Most of the light is absorbed by the photothermal conversion layer 13, photothermal conversion is performed, and high temperature thermosensitive coloring is performed. The layer 15, the medium-temperature thermosensitive coloring layer 17, or the low-temperature thermosensitive coloring layer 19 will be colored.

On the other hand, in the monochrome image forming area ARM, layers are formed in the order of protective/functional layer 20→low temperature thermosensitive coloring layer 19→intermediate layer 18→intermediate temperature thermosensitive coloring layer 17→intermediate layer 16→high temperature thermosensitive coloring layer 15→binder layer 14. It is transmitted and mostly absorbed by the light absorbing and coloring layer 12, causing the light absorbing and coloring layer 12 to develop a color.

Next, materials forming each layer will be described.
First, the base material 11 will be described.
As the base material 11, polyester resin, polyethylene terephthalate (PET), glycol-modified polyester (PET-G), polypropylene (PP), polycarbonate (PP), polychlorinated resin, which are generally used as card, paper, and film materials. Vinyl (PVC), styrene-butadiene copolymer (SBR), polyacrylic resin, polyurethane resin, polystyrene resin, and other resins that can be processed into films or plates can be used.

Furthermore, it is also possible to add silica, titanium oxide, calcium carbonate, alumina, etc. as a filler to the resin described above and use a resin having whiteness, surface smoothness, heat insulating properties, etc. as the base material 11 .

For example, in addition to these, paper (paper) and resin materials described in Japanese Patent No. 3889431, Japanese Patent No. 4215817, Japanese Patent No. 4329744, Japanese Patent No. 4391286, etc. can be used.

Specifically, polyethylene terephthalate (A-PET, PETG), polycyclohexane 1,4-dimethylphthalate (PCT), polystyrene (PS), polymethyl methacrylate (PMMA), transparent ABS (MABS), polypropylene (PP) , polyethylene (PE), polyvinyl alcohol (PVA), styrene-butadiene copolymer (SBR), acrylic resin, acrylic-modified urethane resin, styrene/acrylic resin, ethylene/acrylic resin, urethane resin, rosin-modified maleic acid resin, vinyl chloride/acetic acid Vinyl copolymer, polyvinyl acetal resin, polyamide resin, cellulose resin such as hydroxyethyl cellulose, hydroxypropyl cellulose, nitrocellulose, polyolefin resin, polyamide resin, biodegradable resin, other resin such as cellulose resin, paper A base material, a metal material, etc. can be used.

The above resins and fillers are only examples, and other materials can be used as long as they satisfy processability and functionality.

In the above construction, it is desirable to use a white or transparent resin.
Here, the term “transparent” means that the light transmittance in the visible light region is 30% or more on average in the visible light region.

Next, the photothermal conversion layer 13 will be described.
The light-to-heat conversion layer 13 contains a light absorbing heat generating material that transmits visible light and absorbs infrared light, and a binder resin. Mix in a solvent and apply so that the ratio is 20:99-80.
The film thickness of the photothermal conversion layer 13 when applied is preferably 1 to 10 μm, more preferably 1 to 5 μm.

Examples of the infrared absorbing heat generating agent contained in the photothermal conversion layer 13 include polymethine-based cyanine dyes, polymethine-based dyes, squarylium-based dyes, porphyrin-based dyes, metal dithiol complex-based dyes, phthalocyanine-based dyes, diimmonium-based dyes, and inorganic oxides. As particles, azo dyes, naphthoquinone-based and anthraquinone-based quinone dyes, cerium oxide, indium tin oxide, antimony tin oxide, cesium tungsten oxide, lanthanum hexaboride, and the like can be used.

Binder resins contained in the photothermal conversion layer 13 include nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose propionate, cellulose acetate, cellulose propionate, cellulose palmitate, cellulose myristate, cellulose acetate butyrate, and cellulose. Cellulose esters such as acetate propionate, polyester resins, cellulose resins such as hydroxyethyl cellulose, hydroxypropyl cellulose, ethyl cellulose, methyl cellulose and cellulose acetate can be used.

The binder resin contained in the photothermal conversion layer 13 includes vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, and polyacrylamide; acrylic resins such as polymethyl acrylate and polyacrylic acid; Polyolefins such as polypropylene, polyacrylate resins, epoxy resins, phenolic resins and the like can also be used.

In particular, PET-based resin, PETG, PVC-based resin, PVA-based resin, PC-based resin, PP-based resin, PE-based resin, ABS-based resin, polyamide-based resin, vinyl acetate-based resin and the like are representative. Further, as the light-to-heat conversion layer 13, copolymers based on these resins and additives such as silica, calcium carbonate, titanium oxide and carbon can be used.

As the binder layer 14, the same binder resin as that constituting the photothermal conversion layer 13 is used.

Next, the high temperature thermosensitive coloring layer 15, the medium temperature thermosensitive coloring layer 17 and the low temperature thermosensitive coloring layer 19 will be explained.
The high-temperature thermosensitive coloring layer 15, the medium-temperature thermosensitive coloring layer 17, and the low-temperature thermosensitive coloring layer 19, for example, use highly transparent resins such as polyvinyl alcohol, polyvinyl acetate, and polyacryl as a binder, and the temperature exceeds a certain threshold. A leuco dye, a leuco dye or a temperature indicating material, and a developer are used as the coloring material that sometimes develops color.
Leuco dyes, leuco dyes or temperature indicating materials include 3,3-bis(1-n-butyl-2-methyl-indol-3-yl)phthalide, 7-(1-butyl-2-methyl-1H-indole- 3-yl)-7-(4-diethylamino-2-methyl-phenyl)-7H-furo[3,4-b]pyridin-5-one, 1-(2,4-dichloro-phenylcarbamoyl)-3, 3-dimethyl-2-oxo-1-phenoxy-butyl]-(4-diethylamino-phenyl)-carbamic acid isobutyl ester, 3,3-bis(p-dimethylaminophenyl)phthalide, 3,3-bis(p- dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone = CVL), 3,3-bis(p-dimethylaminophenyl)-6-aminophthalide, 3,3-bis(p-dimethylaminophenyl)- 6-nitrophthalide, 3,3-bis-3-dimethylamino-7-methylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-chloro-7-methylfluorane, 3-diethylamino-7- Anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 2-(2-fluorophenylamino)-6-diethylaminofluorane, 2-(2-fluorophenylamino)-6-di- n-butylaminofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-(N-ethyl-p-toluidino)-7-(N-methylanilino)fluorane, 3-(N-ethyl- p-toluidino)-6-methyl-7-anilinofluorane, 3-N-ethyl-N-isoamylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6 -methyl-7-anilinofluorane, 3-N,N-diethylamino-7-o-chloroanilinofluorane, rhodamine B lactam, 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3- Color-forming dyes such as benzylspironaphthopyran can be used.

Any acidic substance used as an electron acceptor in a heat-sensitive recording medium can be used as a developer.
Examples include inorganic substances such as activated clay and acid clay, inorganic acids, aromatic carboxylic acids, their anhydrides or their metal salts, organic sulfonic acids, other organic acids, and organic color developers such as phenolic compounds. As coloring agents, phenolic compounds are preferred.

Specific examples of color developers include bis-3-allyl-4-hydroxyphenylsulfone, polyhydroxystyrene, zinc salt of 3,5-di-t-butylsalicylic acid, zinc salt of 3-octyl-5-methylsalicylic acid, Phenol, 4-phenylphenol, 4-hydroxyacetophenone, 2,2'-dihydroxydiphenyl, 2,2'-methylenebis(4-chlorophenol), 2,2'-methylenebis(4-methyl-6-t-butylphenol) , 4,4′-isopropylidenediphenol (also known as bisphenol A), 4,4′-isopropylidenebis(2-chlorophenol), 4,4′-isopropylidenebis(2-methylphenol), 4,4′ ethylenebis(2-methylphenol), 4,4'-thiobis(6-t-butyl-3-methylphenol), 1,1-bis(4-hydroxyphenyl)-cyclohexane, 2,2'-bis(4 -Hydroxyphenyl)-n-heptane, 4,4'-cyclohexylidenebis(2-isopropylphenol), phenolic compounds such as 4,4'-sulfonyldiphenol, salts of said phenolic compounds, salicylic acid anilide, novolak type phenol resin, benzyl p-hydroxybenzoate, and the like.

As the intermediate layer 16 and the intermediate layer 18, polypropylene (PP), polyvinyl alcohol (PVA), styrene-butadiene copolymer (SBR), polystyrene, polyacryl, etc. can be used.

The protective/functional layer 20 may be provided as necessary, and specific functions include inserting anti-counterfeiting items such as holograms, lenticular lenses, microarray lenses, ultraviolet-excited fluorescent ink, and ultraviolet-cutting layers. Insertion of protective items, or both, and the like can be used. Colorless and transparent is preferable because it is necessary to visually recognize the color recording or monochrome recording recorded under the protective/functional layer 20 after the recording is completed.

Next, the laser recording apparatus of the first embodiment will be explained.
FIG. 5 is a schematic configuration block diagram of the laser recording apparatus of the first embodiment.
A laser recording apparatus 30 of the first embodiment includes a laser oscillator 31 that outputs a near-infrared laser beam LNIR (=wavelength λ), a beam expander 32 that expands the beam diameter of the near-infrared laser beam LNIR, and a near-infrared A first motor 34 having a first motor 34 drives a first direction scan mirror 33 for reflecting the external laser beam LNIR and for scanning the near infrared laser beam LNIR in the first direction. A direction scanning unit 35 and a second direction scanning mirror 36 that reflects the near-infrared laser beam LNIR are driven to perform a second direction scan to scan the near-infrared laser beam LNIR in a second direction orthogonal to the first direction. A second direction scanning unit 39 having a second motor 38 for driving a mirror 37, and a near infrared laser beam LNIR guided through the first direction scanning unit 35 and the second direction scanning unit 39 onto the recording medium 10. A condensing lens (F·θ lens) 40 for condensing light, a stage 41 for conveying and holding the recording medium 10 to a predetermined position, and irradiation of the far-infrared laser light LFIR based on the inputted input image data GD. A control unit 42 that calculates the position and irradiation intensity and controls the entire laser recording apparatus 30, an output control unit 43 that controls the laser output of the laser oscillator 31 based on the calculation result of the control unit 42, and the control unit 42. and an irradiation position control unit 44 that controls the first motor 34 and the second motor 38 based on the calculation result and controls the irradiation position of the near-infrared laser beam LNIR to the recording medium 10 .

In the above configuration, as the laser oscillator 31, it is possible to use a semiconductor laser, a fiber laser, a YAG laser, a _YVO4 laser, etc., which are lasers in the near-infrared region.

Next, recording processing to the recording medium 10 in the laser recording device 30 will be described.
FIG. 6 is an operation processing flowchart of the laser recording apparatus.
In the following description, the light-absorbing coloring layer 12 is a black (K) coloring layer, the high-temperature thermosensitive coloring layer 15 is a yellow (Y) coloring layer, the medium-temperature thermosensitive coloring layer 17 is a magenta (M) coloring layer, and the low-temperature thermosensitive coloring layer 17 is a magenta (M) coloring layer. Assume that the coloring layer 19 is a cyan (C) coloring layer.

First, the control unit 42 of the laser recording device 30 carries the recording medium 10 to the recording position via a conveying device (not shown) (step S11).

Subsequently, the controller 42 of the laser recording device 30 detects the loaded recording medium 10 with a sensor (not shown) (step S12), and fixes the recording medium 10 at a predetermined loading position with a fixing device (not shown) (step S13). .

Subsequently, when the input image data GD as RGB data is input (step S14), the control unit 42 of the laser recording device 30 analyzes the input image data GD and converts it into color data (CMYK data) for each pixel. (step S15).

By the way, the color data for each pixel (picture element) obtained at this stage does not take into account heat accumulation during laser recording.
Therefore, based on the converted color data for each pixel, the control unit 42 converts the color data into laser irradiation parameter values in consideration of heat accumulation during laser recording (step S16).

Here, the laser irradiation parameter values are specifically a power setting value, a scanning speed setting value, a pulse width setting value, an irradiation repetition number setting value, a scanning pitch setting value, and the like.

Here, the setting of parameters for laser irradiation in laser control in consideration of heat propagation (heat transfer) due to heat storage will be described in detail.
In order to actually draw on the recording medium 10, it is necessary to heat the pixels (places) of the recording medium 10 to be colored at a specific printing temperature for a specific printing time.
However, if the heat accumulation state or the drawing (planned) state of the surrounding pixels is not taken into account in the drawing target pixel, the effective recording temperature will rise due to the heat transfer (heat transfer) due to the heat accumulation, or the effective recording temperature will increase. Recording time is lengthened, and desired color development cannot be performed.

FIG. 7 is an explanatory diagram (part 1) of the effect of heat accumulation during laser recording.
For example, consider the effect on the surrounding pixels when a pixel to be drawn (recorded) shown in FIG. 7 is irradiated with a laser.

Here, for ease of understanding, it is assumed that the pixel to be drawn and the eight pixels surrounding the pixel to be drawn before laser irradiation had the same temperature (for example, room temperature).
Then, the temperature of the pixel to be drawn becomes X1 due to the laser irradiation, and the temperatures of the pixels above, below, to the left and right of the pixel to be drawn among the surrounding pixels are Y1 to Y4 (theoretically, Y1 to Y4 have the same temperature. temperature y1), and the temperatures of the four pixels located diagonally to the target pixel among the surrounding pixels are Y5 to Y8 (theoretically, Y5 to Y8 have the same temperature, so the temperature y2, where y2 < y1).

FIG. 8 is an explanatory diagram (part 2) of the effect of heat accumulation during laser recording.
After that, without waiting for heat dissipation and without considering the effect of heat accumulation, as shown in FIG. The value of the amount of heat received by X2 is (the amount of heat corresponding to temperature y1 - the amount of heat dissipated + the amount of heat obtained by irradiating the pixel X2 with laser), and the temperature assumed by the amount of heat obtained by irradiating the pixel X2 with laser becomes higher than

Also, the pixel X1 is also subjected to a temperature rise Z3 due to the amount of heat caused by the laser irradiation to the pixel X2, and the temperature becomes X1+Z3, which is higher than the assumed temperature X1. Similarly for other surrounding pixels.

In order to avoid this, the power, frequency, irradiation time (pulse width), number of repetitions (number of pulses, passes), and It is necessary to adjust at least one of the inter-irradiation distances (steps).

For example, when drawing on a desired drawing target pixel, all irradiation conditions corresponding to pixels surrounding the drawing target pixel are considered, their heat accumulation state is estimated, and the power of the laser recording light to be irradiated , and the number of pulses should be reduced, and the laser irradiation should be performed so as to achieve the assumed temperature, including the effect of heat propagation (heat transfer) due to heat accumulation.

More specifically, when drawing is performed based on the irradiation parameters of the laser recording light based on the color data of the pixels surrounding the specified pixel, color development or after color development due to heat (heat transfer) propagating to the specified pixel In consideration of the influence on the gradation, the parameter of the laser recording light corresponding to the specified pixel is set to a necessary and sufficient value for color development and desired gradation corresponding to the input image data GD. .

In other words, simply irradiating the specified pixel with the laser recording light based on the parameters of the laser recording light does not develop color, or even if the color develops, the gradation becomes low, but the surrounding pixels are affected. After irradiating the laser recording light, the parameters of the laser recording light are set so that the coloring and desired gradation corresponding to the input image data GD are achieved.

A more specific example will now be described.
In the following explanation, an example of developing a single color is given, but if you want to develop a higher density color, consider the heat transfer (heat transfer) due to heat storage, and set the temperature to a range where color mixing does not occur. Drawing should be performed, and if it is desired to develop a color with a lower density, the drawing should be performed under a low temperature range where color mixture does not occur and the color does not develop, taking heat accumulation into consideration. Although specific examples have been described using the power and the number of pulses, the specific values and methods are not limited to those described because factors such as the number of pulses and steps are also combined.

FIG. 9 is an explanatory diagram of a pixel (picture element) arrangement when setting parameters.
[1.1] First Specific Example The pixel PX13 shown in FIG. 3, the case where the yellow Y color density of the high pixel PX13 is set to 127 and the color density of the yellow Y of the pixel PX14 is set to 127 will be examined.

In this case, both the influence of the heat accumulated during the laser irradiation of the pixel PX13 on the pixel PX14 and the influence of the heat accumulated during the laser irradiation of the pixel PX14 on the pixel PX13 are considered.

Specifically, the color density of the pixel PX13=the color density due to the laser irradiation of the pixel PX13+the color density due to the influence of the laser irradiation of the pixel PX14, and the color density of the pixel PX14=the color due to the laser irradiation of the pixel PX14. Density+coloring density due to influence of laser irradiation to pixel PX13.

More specifically, when the laser is irradiated under the condition that the color density of the pixel PX13 is 110, if the color density of the pixel PX14 due to the laser irradiation of the pixel PX13 is 17, then the color density of the pixel PX13 is 17. The laser is irradiated under the condition that the color density becomes 110. Similarly, the laser is irradiated under the condition that the color density of the pixel PX14 becomes 110.

As a result, the insufficient color density 17 due to the laser irradiation to the pixel PX13 and the laser irradiation to the pixel PX14 is covered by the heat (heat transfer) that propagates from the mutual irradiation points.

The above description is for the case where the number of pixels to be considered is the smallest. If the pixel PX15 and pixels PX17 to PX19 are affected by the laser irradiation, the laser irradiation conditions for the pixel PX13, that is, the color density at the time of irradiation for the pixel PX13, are set in consideration of the influence from all these pixels. do it.

[1.2] Second Specific Example The pixel PX13 shown in FIG. 9 has a color corresponding to the high-temperature thermosensitive coloring layer 15 (=yellow Y, maximum coloring density of 255, minimum coloring density of 1, uncolored density of 0). Pixel PX8, pixel PX12, pixel PX14 and pixel PX18 are set to the color corresponding to the low-temperature thermosensitive coloring layer 19 (=cyan C, maximum coloring density 255, minimum coloring density 1, non-coloring density 0).

In the second specific example, for example, for the pixel PX13, one or both of the laser power and the number of pulses can be set high so that the pixels PX8, PX12, PX14, and the pixel PX18 are not directly drawn. can.

That is, the pixels PX8, PX12, PX14, and the pixel PX18 can be colored by the propagation (heat transfer) of accumulated heat from the laser irradiated to the pixel PX13.
Also, instead of setting the laser power and the number of pulses, the number of passes, the drawing step time can be shortened, and the pulse width can be lengthened.

[1.3] Third Specific Example The pixel PX13 shown in FIG. 9 has a color corresponding to the high-temperature thermosensitive coloring layer 15 (=yellow Y, maximum coloring density of 255, minimum coloring density of 1, uncolored density of 0). , and the pixel PX14 has a color corresponding to the medium-temperature thermosensitive coloring layer 17 (=magenta M, maximum coloring density 255, minimum coloring density 1, uncolored density 0).

In the third specific example, for example, in the pixel PX13, drawing is performed by setting either or both of the laser power and the number of pulses low.
Then, the pixel PX13 and the pixel PX14 can be brought into a final drawing state by direct drawing with the laser irradiated to each and propagation of accumulated heat.

In this case, it is possible to develop colors with lower energy than in the case of laser irradiation alone.
It should be noted that even if the laser power is increased to decrease the number of pulses, or the laser power is decreased to increase the number of pulses, depending on the drawing content of the pixel to be drawn, the same effect can be achieved.

[1.4] Fourth Specific Example The pixel PX13 shown in FIG. 9 has a color corresponding to the low-temperature thermosensitive coloring layer 19 (=cyan C, maximum coloring density of 255, minimum coloring density of 1, uncolored density of 0). and
In the fourth specific example, for example, in the pixel PX13, cyan C is developed by irradiating the pixel PX13 many times under the condition that cyan C is not developed by one laser irradiation in consideration of the influence of heat accumulation. In this case, the number of pulses and the number of passes should be adjusted.

When the setting of the laser irradiation parameters is completed, the control unit 42 controls the output control unit 43 and the irradiation position control unit 44, and emits the near-infrared laser light LNIR based on the laser irradiation parameter values set in step S13. is used to perform image recording on the full-color image forming area ARC in order to cause the high-temperature heat-sensitive coloring layer 15, the medium-temperature heat-sensitive coloring layer 17, and the low-temperature heat-sensitive coloring layer 15 to develop colors (step S17).

Here, color development control in the full-color image forming area ARC will be described.
In the full-color image forming area ARC, the laser recording device 30 uses the high-temperature thermosensitive coloring layer 15, the medium-temperature thermosensitive coloring layer 17, and the low-temperature thermosensitive coloring layer 19 to develop colors.

As described above, the high-temperature thermosensitive coloring layer 15 develops color when its temperature reaches or exceeds the first threshold temperature T1, and the medium-temperature thermosensitive coloring layer 17 develops color when its temperature reaches or exceeds the second threshold temperature T2 (<T1). , the low-temperature thermosensitive coloring layer 19 develops color when its temperature reaches or exceeds the third threshold temperature T3 (<T2<T1).
More specifically, for example, the first threshold temperature T1 corresponding to the high temperature thermosensitive coloring layer 15 = 150 to 270°C, the second threshold temperature T2 corresponding to the medium temperature thermosensitive coloring layer 17 = 100 to 200°C, and the low temperature thermosensitive coloring layer. The third threshold temperature T3 corresponding to No. 19 is in the range of 60 to 140° C., and is set so as to satisfy the above relationship.

First, the coloring control of the high-temperature thermosensitive coloring layer 15 alone will be described.
FIG. 10 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the high-temperature thermosensitive coloring layer is caused to develop color alone.

As shown in FIG. 10, the high temperature thermosensitive coloring layer 15 develops color in the upper right region of the corresponding coloring curve CH (the coloring region of the high temperature thermosensitive coloring layer 15), and the medium temperature thermosensitive coloring layer 17 corresponds to the coloring curve. Color is developed in the upper right region of CM (the coloring region of the medium temperature thermosensitive coloring layer 17), and the low temperature thermosensitive coloring layer 19 is colored in the upper right region of the corresponding coloring curve CL (the coloring region of the low temperature thermosensitive coloring layer 19).

Therefore, when the high-temperature thermosensitive coloring layer 15 is to be colored alone, the coloring area of the high-temperature thermosensitive coloring layer 15 and the non-coloring area of the medium-temperature thermosensitive coloring layer 17, like the hatched area ARH in FIG. And the energy and irradiation time of the laser light may be set so that it belongs to the non-coloring region of the low-temperature thermosensitive coloring layer 19 .

Here, the coloring control of the high-temperature thermosensitive coloring layer 15 will be described in more detail.
FIG. 11 is an explanatory diagram of the coloring control temperature of the high-temperature thermosensitive coloring layer.
When the high-temperature thermosensitive coloring layer 15 is to be colored, it is necessary to generate heat in the photothermal conversion layer 13 and transfer the heat necessary for coloring to the high-temperature thermosensitive coloring layer 15 .

For this purpose, as shown in FIG. 11, the temperature TMH of the high-temperature thermosensitive coloring layer 15 exceeds the first threshold temperature T1, the temperature TMM of the medium-temperature thermosensitive coloring layer 17 does not exceed the second threshold temperature T2, and the low-temperature thermosensitive coloring layer 17 does not exceed the second threshold temperature T2. The temperature TMT of the photothermal conversion layer 13 may be controlled by setting the laser irradiation parameter values so that the temperature TML of the layer 19 does not exceed the third threshold temperature T3 and irradiating the near-infrared laser beam LNIR.

The near-infrared laser beam LNIR passes through the protective/functional layer 20, the low-temperature thermosensitive coloring layer 19, the intermediate layer 18, the medium-temperature thermosensitive coloring layer 17, the intermediate layer 16, the high-temperature thermosensitive coloring layer 15, and the binder layer 14. The conversion layer 13 is reached.

In this case, as shown in FIG. 11, the laser irradiation parameter values are set so that the near-infrared laser light LNIR irradiated to the photothermal conversion layer 13 rapidly increases the heat generation amount and shortens the heat generation time. there is

Therefore, the photothermal conversion layer 13 absorbs the near-infrared laser light LNIR, performs photo-thermal conversion, rapidly generates heat, and the temperature TMT of the photothermal conversion layer 13 changes as shown in FIG.
Along with this, the temperature of the high-temperature thermosensitive coloring layer 15 closer to the photothermal conversion layer 13 rises sharply, exceeding the first threshold temperature T1, and the high-temperature thermosensitive coloring layer 15 develops yellow (Y). .

On the other hand, heat is conducted from the photothermal conversion layer 13 to the intermediate temperature thermosensitive coloring layer 17 via the binder layer 14, the high temperature thermosensitive coloring layer 15 and the intermediate layer 16, and further to the low temperature thermosensitive coloring layer 19 via the intermediate layer 18. However, as shown in FIG. 11, the time for heat conduction is short, and the amount of heat (thermal energy) transferred to the medium temperature thermosensitive coloring layer 17 and the low temperature thermosensitive coloring layer 19 is small. The temperature rise of the temperature TMM of 17 and the temperature TML of the low-temperature thermosensitive coloring layer 19 is small.

Therefore, as shown in FIG. 11, the temperature TMM of the medium-temperature thermosensitive coloring layer 17 does not exceed the second threshold temperature T2, and the medium-temperature thermosensitive coloring layer 17 does not develop color.

Similarly, the temperature TML of the low-temperature thermosensitive coloring layer 19 does not exceed the third threshold temperature T3 as shown in FIG. 11, and the low-temperature thermosensitive coloring layer 17 does not develop color.
Further, since the near-infrared laser light LNIR is absorbed by the photothermal conversion layer 13 and does not reach the light absorbing and coloring layer 12, the light absorbing and coloring layer 12 does not develop color either.

Next, the coloring control of the medium-temperature thermosensitive coloring layer 17 alone will be described.
FIG. 12 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the medium-temperature thermosensitive coloring layer is caused to develop a color alone.

As in the case of the high-temperature thermosensitive coloring layer 15, when the medium-temperature thermosensitive coloring layer 17 is caused to develop color alone, the coloring area of the medium-temperature thermosensitive coloring layer 17, such as the hatched area ARM in FIG. The energy and irradiation time of the laser light may be set so that the laser light belongs to the non-coloring region of the thermosensitive coloring layer 15 and the non-coloring region of the medium temperature thermosensitive coloring layer 17 .

Here, the coloring control of the medium-temperature thermosensitive coloring layer 17 will be described in more detail.
FIG. 13 is an explanatory diagram of the coloring control temperature of the medium-temperature thermosensitive coloring layer.
Even when the intermediate temperature thermosensitive coloring layer 17 is to be colored, heat is generated in the photothermal conversion layer 13, and the intermediate temperature thermosensitive coloring layer 17 is heated through the high temperature thermosensitive coloring layer 15 and the intermediate layer 16 without coloring the high temperature thermosensitive coloring layer 15. It is necessary to transfer the heat necessary for color development.

For this purpose, as shown in FIG. The temperature TMT of the photothermal conversion layer 13 may be controlled by setting a laser irradiation parameter value so that the temperature does not exceed the third threshold temperature T3 and irradiating the near-infrared laser light LNIR.
The near-infrared laser beam LNIR passes through the protective/functional layer 20, the low-temperature thermosensitive coloring layer 19, the intermediate layer 18, the medium-temperature thermosensitive coloring layer 17, the intermediate layer 16, the high-temperature thermosensitive coloring layer 15, and the binder layer 14. The conversion layer 13 is reached.

In this case, the near-infrared laser beam LNIR with which the photothermal conversion layer 13 is irradiated has a gradual increase in heat generation and a longer heat generation time than in the case of causing the high-temperature thermosensitive coloring layer 15 to develop a color. A parameter value is set.

Therefore, the photothermal conversion layer 13 absorbs the near-infrared laser light LNIR, performs light-to-heat conversion, and gradually generates heat, and the temperature TMT of the photothermal conversion layer 13 changes as shown in FIG.
Accompanying this, the temperature of the high-temperature thermosensitive coloring layer 15 closer to the photothermal conversion layer 13 rises, but does not exceed the first threshold temperature T1, and the high-temperature thermosensitive coloring layer 15 does not develop yellow (Y). .

On the other hand, heat is conducted from the photothermal conversion layer 13 to the intermediate temperature thermosensitive coloring layer 17 via the binder layer 14, the high temperature thermosensitive coloring layer 15 and the intermediate layer 16, and further to the low temperature thermosensitive coloring layer 19 via the intermediate layer 18. be done.

At this time, as shown in FIG. 13, the time during which heat is conducted is longer than when the high-temperature thermosensitive coloring layer 15 is colored, and the temperature is also lower. Since the temperature is lower than the threshold temperature T1, energy necessary and sufficient for color development is transmitted to the intermediate temperature thermosensitive coloring layer 17 .

Therefore, the temperature of the medium-temperature thermosensitive coloring layer 17 exceeds the second threshold temperature T2, and the medium-temperature thermosensitive coloring layer 17 develops magenta (M).

At this time, since the low-temperature thermosensitive coloring layer 19 is located far from the photothermal conversion layer 13, the amount of heat (thermal energy) transferred is small, so that the temperature rise of the low-temperature thermosensitive coloring layer 19 is small.
Therefore, the temperature of the low-temperature thermosensitive coloring layer 19 does not exceed the third threshold temperature T3, and the low-temperature thermosensitive coloring layer 17 does not develop color.

Further, since the near-infrared laser light LNIR is absorbed by the photothermal conversion layer 13 and does not reach the light absorbing and coloring layer 12, the light absorbing and coloring layer 12 does not develop color either.

Next, the coloring control of the low-temperature thermosensitive coloring layer 19 alone will be described.
FIG. 14 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the low-temperature thermosensitive color-developing layer alone develops color.

As in the case of the high-temperature thermosensitive coloring layer 15, when the low-temperature thermosensitive coloring layer 19 is to be colored alone, the coloring area of the low-temperature thermosensitive coloring layer 19, such as the hatched area ARL in FIG. The energy and irradiation time of the laser beam may be set so as to belong to the non-coloring region of the thermosensitive coloring layer 15 and the non-coloring region of the medium temperature thermosensitive coloring layer 17 .

Here, the color development control of the low-temperature thermosensitive coloring layer 19 will be described in more detail.
FIG. 15 is an explanatory diagram of the coloring control temperature of the low-temperature thermosensitive coloring layer.
In this case, the near-infrared laser beam LNIR with which the photothermal conversion layer 13 is irradiated has a calorific value that increases more moderately than in the case of causing the medium-temperature thermosensitive coloring layer 17 to develop a color, and a laser beam that emits light for a longer period of time. Irradiation parameter values are set.

Therefore, the photothermal conversion layer 13 absorbs the near-infrared laser light LNIR, performs light-to-heat conversion, and generates heat more slowly. The temperature does not exceed the threshold temperature T1, and the high-temperature thermosensitive coloring layer 15 does not develop yellow (Y).

Further, heat is conducted from the photothermal conversion layer 13 to the intermediate temperature thermosensitive coloring layer 17 via the binder layer 14 , the high temperature thermosensitive coloring layer 15 and the intermediate layer 16 .
At this time, as shown in FIG. 15, the time for which heat is conducted is longer than when the intermediate temperature thermosensitive coloring layer 17 is colored, but the temperature is still lower. T2 is not exceeded, and the high-temperature thermosensitive coloring layer 15 does not develop magenta (M).

Furthermore, heat is conducted from the photothermal conversion layer 13 to the low temperature thermosensitive coloring layer 19 via the binder layer 14, the high temperature thermosensitive coloring layer 15, the intermediate layer 16, the medium temperature thermosensitive coloring layer 17 and the intermediate layer .
At this time, although the low-temperature thermosensitive coloring layer 19 is located far from the photothermal conversion layer 13, as shown in FIG. Although low, the third threshold temperature T3 at which the low-temperature thermosensitive coloring layer 19 develops color is lower.
Therefore, the temperature of the low-temperature thermosensitive coloring layer 19 exceeds the third threshold temperature T3, and the low-temperature thermosensitive coloring layer 19 develops cyan (C) in the full-color image forming area ARC.

In the above description, the high-temperature thermosensitive coloring layer 15, the medium-temperature thermosensitive coloring layer 17, and the low-temperature thermosensitive coloring layer 19 are individually colored, but it is also possible to simultaneously develop two or three colors.
A case in which multiple colors are developed will be described below.

FIG. 16 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the high temperature thermosensitive coloring layer and the intermediate temperature thermosensitive coloring layer are caused to develop colors in parallel.

When the high-temperature thermosensitive coloring layer 15 and the medium-temperature thermosensitive coloring layer 17 are caused to develop colors in parallel, the coloring area of the high-temperature thermosensitive coloring layer 15 and the medium-temperature thermosensitive coloring layer 17 are formed like the hatched area ARHM in FIG. The energy and irradiation time of the laser light may be set so that the laser beam belongs to the non-coloring region of the low-temperature thermosensitive coloring layer 19, which is a coloring region.

By controlling in this manner, yellow (Y) color development corresponding to the high-temperature thermosensitive coloring layer 15 and magenta (M) coloring corresponding to the medium temperature thermosensitive coloring layer 17 occur, and as a result, red color is produced in the full-color image forming area ARC. becomes colored.

FIG. 17 is a diagram for explaining the relationship between the energy of the laser light and the irradiation time when the intermediate temperature thermosensitive coloring layer and the low temperature thermosensitive coloring layer are caused to develop colors in parallel.

When the medium temperature thermosensitive coloring layer 17 and the low temperature thermosensitive coloring layer 19 are caused to develop colors in parallel, the coloring area of the medium temperature thermosensitive coloring layer 17 and the low temperature thermosensitive coloring layer 19 are colored like the hatched area ARML in FIG. The energy of the laser beam and the irradiation time may be set so that it belongs to the coloring region and the non-coloring region of the high-temperature thermosensitive coloring layer 15 .

By controlling in this manner, magenta (M) color development corresponding to the medium temperature thermosensitive coloring layer 17 and cyan (C) color development corresponding to the low temperature thermosensitive coloring layer 19 occur, and as a result, blue color is produced in the full-color image forming area ARC. becomes colored.

FIG. 18 is a diagram for explaining the relationship between laser light energy and irradiation time when the high temperature thermosensitive coloring layer, the medium temperature thermosensitive coloring layer and the low temperature thermosensitive coloring layer are caused to develop colors in parallel.

When the high-temperature thermosensitive coloring layer 15, the medium-temperature thermosensitive coloring layer 17, and the low-temperature thermosensitive coloring layer 19 are caused to develop colors in parallel, the coloring area of the high-temperature thermosensitive coloring layer 15, the medium-temperature thermosensitive coloring area, as shown by the hatched area ARHML in FIG. The energy and irradiation time of the laser light may be set so that the color development region of the color development layer 17 and the color development region of the low-temperature thermosensitive color development layer 19 belong to each other.

By controlling in this way, yellow (Y) corresponding to the high temperature thermosensitive coloring layer 15, magenta (M) coloring corresponding to the medium temperature thermosensitive coloring layer 17, and cyan (C) coloring corresponding to the low temperature thermosensitive coloring layer 19 are obtained. As a result, black (dark gray) develops in the full-color image forming area ARC.

Next, color development control in the monochrome image forming area ARM will be described.
When the recording in the full-color image forming area ARC is completed, the control unit 42 controls the output control unit 43 and the irradiation position control unit 44, and based on the laser irradiation parameter values set in step S13, the near-infrared laser light LNIR is used to record an image in the monochrome image forming area ARM in order to cause the light-absorbing coloring layer 12 to develop a color (step S18).

In this case, the near-infrared laser light LNIR passes through the protective/functional layer 20, the low-temperature thermosensitive coloring layer 19, the intermediate layer 18, the medium-temperature thermosensitive coloring layer 17, the intermediate layer 16, the high-temperature thermosensitive coloring layer 15, and the binder layer . The light reaches the light-absorbing coloring layer 12 without passing through the photothermal conversion layer 13 , that is, without being absorbed by the photothermal conversion layer 13 .

As a result, the pigment particles contained in the light-absorbing color-developing layer 12 absorb the near-infrared laser light LNIR, which is the recording light, and are carbonized, thereby irreversibly developing a black color.
The black color developed in the light absorption color development layer 12 has a higher contrast than the black (dark gray) color developed in the full-color image forming area ARC, and thus images such as characters can be displayed more clearly. ing.

Subsequently, the control unit 42 of the laser recording device 30 releases the fixing of the recording medium 10 by the fixing device (not shown) (step S19), and carries out the recording medium 10 to a predetermined unloading position via the transporting device (not shown) for processing. is terminated (step S20).

As described above, according to the first embodiment, when full-color/monochrome image recording is performed using a single-wavelength laser light source, colors are developed according to the input image data in consideration of the effects of heat accumulation. A high-quality image can be recorded easily and reliably. Furthermore, according to the first embodiment, additional writing cannot be performed using a thermal head or the like, and tampering with the recording medium can be prevented, thereby improving security.

[2] Second Embodiment In the above-described first embodiment, the case of recording an image by controlling laser parameters was described. This is for recording an image by converting it into data.

First, the processing of the second embodiment will be described.
FIG. 19 is a processing flowchart of the second embodiment.
Since steps S11 to S15 are the same as those in the first embodiment, the detailed description thereof is incorporated.

In step S15, when the input image data GD is analyzed and converted into color data (CMYK data) for each pixel, the controller 42 of the laser recording device 30 performs color data correction processing (step S31).
FIG. 20 is a processing flowchart of color data correction processing.
First, the control unit 42 of the laser recording device 30 specifies a pixel at the position to be processed (writing position) (step S41: for example, specifies the pixel PX13 shown in FIG. 13).

Next, the control unit 42 functions as a color data correction unit, and based on the color data of the pixels surrounding the specified pixel, considers the effect of heat on the specified pixel, and determines the color corresponding to the specified pixel. Data is calculated (step S42), and the color data is replaced with the calculated color data.

More specifically, when rendering is performed based on the color data (including corrected color data) of the pixels surrounding the specified pixel, color development or coloring due to heat (heat transfer) propagating to the specified pixel. Taking into consideration the effect on subsequent gradation, the color data of the specified pixel is set to a necessary and sufficient value for achieving the color development and desired gradation corresponding to the input image data GD.

In other words, simply irradiating the laser recording light based on the corrected color data corresponding to the specified pixel does not produce color, or even if the color is produced, the gradation becomes low, but the laser beam is applied to the surrounding pixels. After irradiating the recording light, the color data corresponding to the input image data GD and the desired gradation are replaced with the corrected color data.

Then, the control unit 42 determines whether or not the same color correction processing has been performed for all pixels (step S43).
If it is determined in step S43 that all pixels have not been subjected to the same color correction (step S43; No), the process proceeds to step S41, the pixel at the next position to be processed is specified, and the above-described process.

If it is determined in step S43 that the same color correction processing has been performed for all pixels, the color correction processing is terminated, and the process proceeds to step S16. process.

A specific example will now be described with reference to FIG. 9 again.
[2.1] First Specific Example The pixel PX13 shown in FIG. ), and pixels PX8, PX12, PX14, and pixel PX18 have colors corresponding to the low-temperature thermosensitive coloring layer 19 (=cyan C, maximum coloring density 255, minimum coloring density 1, uncolored density 0).
In the first specific example, for example, the coloring density of the pixel PX13 is replaced with a density higher than the density corresponding to the color data calculated in step S15.
As a result, the temperature of the pixel PX13 becomes higher than the temperature corresponding to the color data calculated in step S15, and the accumulated heat of the pixel PX13 propagates, causing the pixels PX8, PX12, PX14, and the pixel PX18 to develop a cyan color having a desired density. be able to.
[2.2] Second Specific Example The pixel PX13 shown in FIG. ), and the pixel PX14 has a color corresponding to the medium-temperature thermosensitive coloring layer 17 (=magenta M, maximum coloring density 255, minimum coloring density 1, non-coloring density 0).
In the second specific example, for example, the color data is corrected and replaced so as to increase the density of one or both of the pixels PX13 and PX14.
As a result, the pixel PX13 and the pixel PX14 can be brought into a final drawing state by direct drawing by the laser irradiated to each and propagation of accumulated heat.
In this case, it is possible to develop colors with lower energy than in the case of laser irradiation alone.
Depending on the combination of the colors of the pixels PX13 and PX14, the density of the pixel PX13 is increased and the density of the pixel PX14 is decreased, or the density of the pixel PX13 is decreased and the density of the pixel PX14 is increased. It is possible.

According to the second embodiment, by converting the color data corresponding to the input image data into the color data considering the heat accumulation, a high-quality image colored as in the input image data can be easily and reliably printed. can do. Furthermore, according to the first embodiment, additional writing cannot be performed using a thermal head or the like, and tampering with the recording medium can be prevented, thereby improving security.
[3] Configuration of recording medium Next, an example of a recording medium that can be used in each of the above embodiments will be described.
[3.1] Recording Medium of First Alternative Embodiment FIG. 21 is a cross-sectional view of a configuration example of a recording medium of a first alternative embodiment.
The recording medium 10A of the first alternative mode differs from the recording medium 10 of the first embodiment in that the photothermal conversion layer 13 is arranged close to the high-temperature thermosensitive coloring layer 15 side instead of the light absorbing coloring layer 12 side. This is the point.

According to this configuration, in addition to the effects of the first embodiment, the heat transfer loss due to the binder layer 14 can be reduced when the heat generated in the photothermal conversion layer 13 is transferred to the high-temperature thermosensitive coloring layer 15 side, thereby further saving energy. can be realized.

[3.2] Recording Medium of Second Alternative Next, a recording medium of a second alternative will be described.
FIG. 22 is a cross-sectional view of a configuration example of a recording medium of a second alternative mode.
A recording medium 10B of the second alternative mode differs from the recording medium 10 of the embodiment in that the photothermal conversion layer 13 is arranged close to the intermediate layer 16 side of the high-temperature thermosensitive coloring layer 15 .

According to this configuration, in addition to the effects of the first embodiment, heat transfer loss due to the binder layer 14 can be reduced when heat generated in the photothermal conversion layer 13 is transferred to the high-temperature thermosensitive coloring layer 15 side, and photothermal The transmission loss of the near-infrared laser light LNIR to the conversion layer 13 can also be reduced, and more energy saving can be achieved.

[3.2.1] Modification of Recording Medium of Second Other Embodiment Next, a recording medium of a modification of the recording medium of the second other embodiment will be described.
FIG. 23 is a cross-sectional view of a configuration example of a recording medium that is a modification of the recording medium of the second alternative mode.
The recording medium 10C of the modified example of the second alternative mode differs from the recording medium 10B of the third embodiment in that the photothermal conversion layer 13 is arranged in the intermediate layer 16 spaced apart from the high-temperature thermosensitive coloring layer 15 by a predetermined distance. This is the point.

According to this configuration, the same effects as those of the third embodiment can be obtained.

[3.3] Recording Medium According to Third Alternative Next, a recording medium according to a third alternative will be described.
FIG. 24 is a cross-sectional view of a configuration example of a recording medium of a third alternative mode.
In FIG. 24, the same reference numerals are given to the same parts as in the recording medium of the first embodiment in FIG.

As shown in FIG. 24, the recording medium 10D of the third alternative embodiment comprises a base material 11, a light absorbing coloring layer 12 as a first coloring layer, a binder layer 14, and a medium temperature thermosensitive coloring layer as a second coloring layer. Layer 17, intermediate layer 16, high-temperature thermosensitive coloring layer 15 as a second coloring layer, photothermal conversion layer 13 disposed on the side of the high-temperature thermosensitive coloring layer 15 in the intermediate layer 16, intermediate layer 18, low temperature as a second coloring layer A thermosensitive coloring layer 19 and a protective/functional layer 20 are formed in this order.

In this case also, the high-temperature thermosensitive coloring layer 15, the medium-temperature thermosensitive coloring layer 17, and the low-temperature thermosensitive coloring layer 19 function as thermosensitive recording layers for image recording.

In the recording medium of the third alternative embodiment, the thickness of the intermediate layer 16 is set according to the optimum amount of thermal energy transfer to the intermediate temperature thermosensitive coloring layer 17, and the thickness of the intermediate layer 18 is set according to the low temperature thermosensitive coloring layer. 19 through the high temperature thermosensitive coloring layer 15 is set by the optimum amount of thermal energy transfer.
According to the fourth embodiment, in addition to the effect of the first embodiment, it is possible to further improve the thermal energy transfer efficiency and realize energy saving.

[3.4] Recording Medium of Fourth Alternative Embodiment FIG. 25 is an explanatory diagram of a recording medium of a fourth alternative embodiment.
FIG. 25(a) is a plan view, and FIG. 25(b) is a sectional view taken along line AA of FIG. 25(a).

In the above description, the photothermal conversion layer 13 for forming the full-color image forming area ARC has a square shape (rectangular shape in FIG. 20) in plan view like the full-color image forming area ARC1. However, it is possible to have an arbitrary shape like the full-color image forming area ARC2 in the recording medium 10E of the fourth alternative mode shown in FIG.

Arbitrary shapes can be circular, elliptical, polygonal, star-shaped, animal-shaped, map-shaped, human-shaped, and other desired shapes.

In this case, when forming the photothermal conversion layer 13 on the recording medium 10E, it is preferable to use a printing method. As a printing method, it is possible to use general printing methods such as inkjet printing, offset printing, letterpress printing, screen printing, and intaglio printing.

According to the recording medium of another aspect of the fourth aspect, by changing the shape for each issue time of the recording medium, it is possible to facilitate authenticity determination and the like.

[3.5] Recording Medium of Fifth Alternative Embodiment FIG. 26 is an explanatory diagram of a recording medium of the fifth alternative embodiment.
A recording medium 10F of the fifth alternative mode differs from each of the above-described embodiments in that a lenticular lens 50 is provided on the protective/functional layer 20 or integrated with the protective/functional layer 20. FIG.

With this configuration, it is possible to switch the displayed image depending on the viewing angle by performing image formation by changing the irradiation direction of the near-infrared laser beam LNIR when forming an image on the recording medium 10F.

In the example of FIG. 26, since the lenticular lens 50 is provided in the area corresponding to the monochrome image forming area ARM where the photothermal conversion layer 13 is not provided, the recordable image is a monochrome image.

[3.5.1] Modification of Recording Medium of Fifth Other Mode FIG. 27 is an explanatory diagram of a modification of the recording medium of the fifth other mode.
As shown in FIG. 27, it is also possible to form a full-color image by providing the photothermal conversion layer 13 in the recordable area of the lenticular lens 50 .
According to the sixth embodiment, the functionality of the recording medium can be improved, the counterfeiting of the recording medium can be made difficult, and the authenticity determination of the recording medium can be facilitated.

[3.6] Recording Medium of Sixth Alternative Embodiment FIG. 28 is a sectional view of a recording medium of the sixth alternative embodiment.
A recording medium 10G of the sixth aspect differs from each of the above-described embodiments in that a transparent substrate 60 is provided in which a part of the substrate 11 is made of a transparent member.

According to this configuration, it is possible to easily determine authenticity by determining whether the image formed on the recording medium 10G from the base material 11 side is the same as that of the regular recording medium.
FIG. 2 is an external front view of the recording medium (falsification prevention medium) according to the first embodiment in which information is recorded;

[3.6.1] Modification of Recording Medium of Sixth Alternative Embodiment FIG. 29 is an explanatory diagram of a modification of the recording medium of the sixth alternative embodiment.
A modification of the recording medium 10G of the sixth alternative embodiment differs from the recording medium of the sixth alternative embodiment shown in FIG. The point is that the lenticular lens 50 is provided.

With this configuration, it is possible to switch the displayed image depending on the viewing angle by performing image formation by changing the irradiation direction of the near-infrared laser beam LNIR when forming an image on the recording medium 10F.

In the example of FIG. 29, the photothermal conversion layer 13 is provided in the recordable area of the lenticular lens 50, and the dot pattern of the full-color image formed through the lenticular lens 50 has a unique dot pattern depending on the formed image. Since it is formed, the authenticity can be easily determined, and counterfeit products and imitation products can be detected and eliminated.

[3.7] Recording Medium of Seventh Alternative Embodiment FIG. 30 is a sectional view of a recording medium of the seventh alternative embodiment.
The recording medium 10H of the seventh aspect differs from the above embodiments in that the high temperature thermosensitive coloring layer 15 and the medium temperature thermosensitive coloring layer 17 are provided as the thermosensitive coloring layers, and the low temperature thermosensitive coloring layer 19 is not provided. is.

As a result, it is possible to inexpensively construct a recording medium capable of displaying a multicolor image, although full-color display cannot be performed.
In the example of FIG. 30, the low temperature thermosensitive coloring layer 19 was not provided, but it is also possible to provide the low temperature thermosensitive coloring layer 19 and either the high temperature thermosensitive coloring layer 15 or the medium temperature thermosensitive coloring layer 17. be.

[3.8] Recording Medium of Eighth Alternative Embodiment FIG. 31 is a sectional view of a recording medium of an eighth alternative embodiment.
A recording medium 10I according to another aspect of the eighth embodiment differs from each of the above-described embodiments except for the eighth embodiment in that only the high temperature thermosensitive coloring layer 15 is provided as the thermosensitive coloring layer, and the medium temperature thermosensitive coloring layer 17 and the low temperature thermosensitive coloring layer 17 are provided as thermosensitive coloring layers. The difference is that the layer 19 is not provided.

As a result, it is possible to inexpensively configure a recording medium capable of displaying a two-color image, although full-color display cannot be performed.
In the example of FIG. 31, the medium temperature thermosensitive coloring layer 17 and the low temperature thermosensitive coloring layer 19 were not provided, but any two of the high temperature thermosensitive coloring layer 15, the medium temperature thermosensitive coloring layer 17 and the low temperature thermosensitive coloring layer 9 were not provided. It is also possible to configure such that only one of the other is provided.

[3.9] Recording Medium of Ninth Alternative Embodiment FIG. 32 is a sectional view of a recording medium of a ninth alternative embodiment.
The recording medium 10J of the ninth other aspect differs from each of the above-described embodiments in that the thermosensitive coloring layer is provided on the entire surface of the recording medium when viewed from above, but the low-temperature thermosensitive coloring layer 19A is used for full-color image formation. The point is that it is provided only in the portion where the region ARC is formed.

According to the recording medium of the other aspect of the ninth, only a desired area of the recording medium can be used as a full-color image forming area. It is possible to suppress forgery using other recording media.

[3.10] Tenth Other Aspect of Recording Medium In each of the above embodiments, the recording medium was treated as a single unit. It is an embodiment of a card-shaped recording medium having a card-shaped member such as plastic, metal, ceramics, etc.).

In the following description, for ease of understanding, the case where the recording medium 10 is used as the recording medium carried on the carrier will be described as an example.
FIG. 33 is an explanatory diagram of a card-shaped recording medium of another tenth aspect.
FIG. 33(a) is a cross-sectional view, and FIG. 33(b) is a plan view.
Here, FIG. 30(a) is a cross-sectional view taken along the dashed line in FIG. 30(b).

As shown in FIG. 33( a ), the recording medium 10 is carried by a carrier 70 to form a card-like recording medium 71 .
As described above, according to the recording medium of the tenth aspect, since the recording medium 10 is carried by the carrier 70, the durability is improved and the recording medium can be highly reliable over a long period of time. can.

[3.10.1] First Modification of Recording Medium of Tenth Alternative Embodiment FIG. 34 is an explanatory diagram of a card-like recording medium of a first modification of the recording medium of the tenth alternative embodiment.
FIG. 34(a) is a sectional view, and FIG. 34(b) is a plan view.
Here, FIG. 34(a) is a cross-sectional view taken along the dashed line in FIG. 34(b).

The card-like recording medium 71A of the first modification of the recording medium of the tenth other aspect differs from the twelfth embodiment in that two sheets of recording medium 10 are carried on both sides of the carrier 70, respectively. .

By adopting such a configuration, in addition to the effects of the twelfth embodiment, recording can be performed on both sides of the card-like recording medium 71A. Furthermore, the strength of the card-shaped recording medium 71A can be improved and deformation can be prevented.

[3.10.2] Second Modification of Recording Medium of Tenth Alternative Embodiment FIG. 35 is an explanatory diagram of a card-like recording medium of a second modification of the recording medium of the tenth alternative embodiment.
35(a) is a first cross-sectional view, FIG. 35(b) is a plan view, and FIG. 35(c) is a second cross-sectional view.
Here, FIG. 35(a) is a cross-sectional view taken along the broken line x in FIG. 35(b), and FIG. 35(c) is a cross-sectional view taken along the broken line y in FIG. 32(b).

The card-shaped recording medium 71B of the second modified example of the recording medium of the tenth alternative mode differs from the twelfth embodiment in that the recording medium 10 is carried by two carriers 70A and 70B sandwiching a hinge 73. The point is that

In this case, in addition to the effects of the twelfth embodiment, one or more card-shaped recording media 71B can be bound into the booklet at the hinge 73 to make it difficult to remove the card-shaped recording media 71B from the booklet. , tampering and the like can be further suppressed, and security can be improved.

[3.10.3] Third Modification of Recording Medium of Tenth Alternative Embodiment FIG. 36 is an explanatory diagram of a card-like recording medium of the third modification of the recording medium of the tenth alternative embodiment.
The card-shaped recording medium 71C of the third modified example of the recording medium of the tenth aspect differs from the recording medium of the tenth aspect in that the recording medium 10 is configured as a hinge 73 and an IC card. The difference is that the card core 74 is held between two carriers 70A and 70B.

In this case, by incorporating various functions into the card core 74 in addition to the effects of the recording medium of the tenth aspect, a highly functional card-shaped recording medium can be obtained, and recorded data can be digitized. And by applying encryption, it is possible to further improve security.

[3.10.4] Fourth Modification of Recording Medium of Tenth Other Mode FIG. 37 is an explanatory diagram of a card-like recording medium of a fourth modification of the recording medium of the tenth other mode.
A card-like recording medium 71D of the fourth modification of the recording medium of the tenth alternative mode differs from the third modification of the twelfth embodiment shown in FIG. 34 in that a short hinge 73A is provided instead of the hinge 73. is.
According to the fourth modification of the recording medium of the tenth aspect, in addition to the effects of the third modification of the recording medium of the tenth aspect, the thickness of the card-like recording medium is suppressed, and the number of sheets to be bound is reduced. can be increased.

[4] Modifications of the Embodiments In the above description, the case where the number of coloring layers is 2 to 4 is explained, but the case where the number of coloring layers is 5 or more is similarly applicable.

For example, in the above description, the case of CMYK four-color recording was described, but cyan (C), magenta (M), yellow (Y), red (R), green (G), blue (B) and black ( It is also applicable to the case of CMYRGBK 7-color recording having 7-color developing layers of K).

In the above description, near-infrared laser light was used as the laser light, but it is also possible to use near-ultraviolet laser light and far-ultraviolet laser light as the laser light depending on the absorption wavelength of the photothermal conversion layer. .

In the above description, the control unit 42, the output control unit 43, and the irradiation position control unit 44 are described as separate units. And it is also possible to configure it to be executed via various interfaces.

In this case, the program to be executed by the computer is a file in an installable format or an executable format and stored in a computer-readable record such as a semiconductor recording device such as a CD-ROM, a DVD (Digital Versatile Disk), or a USB memory. It may be recorded on a medium and provided.

Alternatively, the program to be executed by the computer may be stored in a computer connected to a network such as the Internet, and provided by being downloaded via the network. Alternatively, the program executed by the control unit 52 may be provided or distributed via a network such as the Internet.

Alternatively, a program to be executed by a computer may be provided by pre-loading it in a ROM or the like.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 10, 10A-10J recording medium 11 base material 12 light absorbing coloring layer 13 photothermal conversion layer 14 binder layer 15 high temperature thermosensitive coloring layer 16 intermediate layer 17 middle temperature thermosensitive coloring layer 18 intermediate layer 19 low temperature thermosensitive coloring layer 20 protective/functional layer 30, 30A laser recording device 42 control unit (data conversion unit, parameter setting unit, color data correction unit)
43 output control unit 44 irradiation position control unit

Claims (7)

A laser recording apparatus for recording an image on a thermosensitive recording medium in which a thermosensitive coloring layer is laminated on a base material,
a data conversion unit that converts input image data into color data;
Based on the color data, the irradiation parameters of the laser recording light are set so that the color after image recording corresponds to the input image data in consideration of the heat transfer from the peripheral pixels to the pixel to be recorded, based on the color data. and a parameter setting unit for
The setting of the irradiation parameter includes a case where the irradiation of the recording target pixel with the laser recording light is prohibited, and coloring is performed only by heat transfer from the surrounding pixels.
Laser recorder. A laser recording apparatus for recording an image on a thermosensitive recording medium in which a thermosensitive coloring layer is laminated on a base material,
a data conversion unit that converts input image data into color data;
Based on the color data, the irradiation parameters of the laser recording light are set so that the color after image recording corresponds to the input image data in consideration of the heat transfer from the peripheral pixels to the pixel to be recorded, based on the color data. and a parameter setting unit for
The thermosensitive coloring layer has a plurality of coloring layers with different coloring threshold temperatures and different colors,
The parameter setting unit sets irradiation parameters of the laser recording light so that the colors of the plurality of coloring layers correspond to the input image data.
Laser recorder. A laser recording apparatus for recording an image on a thermosensitive recording medium in which a thermosensitive coloring layer is laminated on a base material,
a data conversion unit that converts input image data into color data;
Based on the color data, the irradiation parameters of the laser recording light are set so that the color after image recording corresponds to the input image data in consideration of the heat transfer from the peripheral pixels to the pixel to be recorded, based on the color data. and a parameter setting unit for
The thermosensitive coloring layer includes a photothermal conversion layer that absorbs the laser recording light and performs photothermal conversion;
a plurality of coloring layers that transmit the laser recording light, have different coloring threshold temperatures and colored colors, and develop colors due to heat converted by the photothermal conversion layer;
The parameter setting unit sets irradiation parameters of the laser recording light with which the photothermal conversion layer is irradiated so that the colors of the plurality of coloring layers correspond to the input image data.
Laser recorder. The irradiation parameter includes at least one of the power, frequency, irradiation time, number of times of irradiation, and distance between irradiation positions of the laser recording light,
4. The laser recording apparatus according to claim 1 . A laser recording apparatus for recording an image on a thermosensitive recording medium in which a thermosensitive coloring layer is laminated on a base material,
a data conversion unit that converts input image data into color data;
a color data correction unit for correcting the color data of a pixel to be recorded in the image in consideration of heat transfer from surrounding pixels so that the color after image recording corresponds to the input image data;
a parameter setting unit for setting irradiation parameters of the laser recording light based on the corrected color data ;
The correction of the color data includes prohibiting irradiation of the recording target pixel with the laser recording light and causing color development only by heat transfer from surrounding pixels.
Laser recorder. A laser recording apparatus for recording an image on a thermosensitive recording medium in which a thermosensitive coloring layer is laminated on a base material,
a data conversion unit that converts input image data into color data;
a color data correction unit for correcting the color data of a pixel to be recorded in the image in consideration of heat transfer from surrounding pixels so that the color after image recording corresponds to the input image data;
a parameter setting unit for setting irradiation parameters of the laser recording light based on the corrected color data;
The thermosensitive coloring layer has a plurality of coloring layers with different coloring threshold temperatures and different colors,
The color data correction unit corrects the color data so that the colors of the plurality of coloring layers correspond to the colors of the input image data.
Laser recorder. A laser recording apparatus for recording an image on a thermosensitive recording medium in which a thermosensitive coloring layer is laminated on a base material,
a data conversion unit that converts input image data into color data;
a color data correction unit for correcting the color data of a pixel to be recorded in the image in consideration of heat transfer from surrounding pixels so that the color after image recording corresponds to the input image data;
a parameter setting unit for setting irradiation parameters of the laser recording light based on the corrected color data;
The thermosensitive coloring layer includes a photothermal conversion layer that absorbs the laser recording light and performs photothermal conversion;
a plurality of coloring layers that transmit the laser recording light, have different coloring threshold temperatures and colored colors, and develop colors due to heat converted by the photothermal conversion layer;
The parameter setting unit corrects the color data so that the colors of the plurality of coloring layers correspond to the input image data.
Laser recorder.

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