JP3735779B2 - Information rewriting apparatus and method for reversible thermal medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information rewriting apparatus and method for a reversible heat-sensitive medium.
[0002]
[Prior art]
As a reversible thermal paper using a reversible thermal recording material, for example, a leuco rewritable thermal paper using an electron donating dye precursor has been developed. As shown in FIG. 5, the electron-donating dye precursor is colored when the lactone ring in the molecule is opened in an acidic atmosphere, and when the acidic atmosphere is removed, the lactone ring is closed and returns to a colorless state. is there. Leuco-based rewritable thermal paper is a combination of this electron-donating dye precursor and a reversible developer, and the reversible developer reacts with the electron-donating dye precursor and exhibits reversibility of color development and decoloration. To do. As the reversible developer, for example, a phenolic compound having a long-chain alkyl group is used.
[0003]
FIG. 6 is a model diagram of color development / decoloration. As shown in this figure, when the electron-donating dye precursor and the reversible developer in the decolored state (lower left) are heated, both melt and become a colored state (upper), and when rapidly cooled, the state close to the molten state Solidifies and maintains the solid color state (lower right). On the contrary, when it is gradually cooled from the molten state, the electron donating dye precursor and the reversible developer return to the decolored state. Therefore, coloring or decoloring can be performed reversibly by rapid cooling or slow cooling after melting. Moreover, the solid color development state can be changed to the original decoloring state by holding it for a certain period of time in a temperature range slightly lower than the melting temperature.
[0004]
FIG. 7 is a characteristic explanatory diagram of reversible thermal paper. In this figure, the horizontal axis indicates the temperature, and the vertical axis indicates the color density. As shown by the arrows in this figure, when a reversible thermosensitive recording layer (for example, comprising an electron donating dye precursor and a reversible developer) in a decolored state (A) is heated, both melt and become a colored state (B). When this is rapidly cooled, it solidifies in a state close to the molten state and maintains the solid color state (C). On the contrary, when it is gradually cooled from the molten state (B), the electron-donating dye precursor and the reversible developer are phase-separated to return to the original decolored state (A).
Further, in the solid color development state (C), there is a property of transitioning to the original decoloring state (A) when held for a certain time in a temperature region slightly lower than the molten state. This temperature region (a temperature region slightly lower than the melting temperature) is referred to as a “decoloring temperature region”.
[0005]
As information rewriting means of the above-described reversible heat-sensitive medium, for example, Patent Document 1, Patent Document 2, and the like are disclosed.
[0006]
[Patent Document 1]
JP-A-8-267997 [Patent Document 2]
JP 2002-215038 A
As shown in FIG. 8, a “laser recording method and laser recording apparatus” of [Patent Document 1] includes a thermosensitive recording material that changes its optical density depending on temperature and can be recorded and erased reversibly, and exposure. A rewritable thermosensitive recording medium 51 composed of a light absorbing heat converting material that sometimes generates heat or a layer composed of a mixture of the heat sensitive recording material and the light absorbing heat converting material. When erasing, the flash light 52 corresponding to the erasing temperature of the heat-sensitive recording material is irradiated within a predetermined area to erase the image, and during recording, the laser beam 53 formed by intensity modulation corresponding to the recording temperature is scanned and exposed. Recording.
In this figure, 54 is a short arc xenon lamp, 55 is a recording laser beam irradiation means, and 56 is a flash light exposure means.
[0008]
As shown in FIG. 9, the writing apparatus described in “Rewriting method and apparatus for reversible thermal paper with two-dimensional code” in [Patent Document 2] includes a laser temperature controller 61 and an XY stage driver in addition to the control apparatus 60. 62a, an XY stage mechanism 62b, a laser driver 63a, a laser device 63b, galver drivers 64a, 65a, galver mechanisms 64b, 65b, and the like. Is controlled, and the galver mechanisms 64b and 65b are controlled by the galver drivers 64a and 65a, the laser light is controlled two-dimensionally, and a vector scan for writing on the label is performed.
[0009]
[Problems to be solved by the invention]
The reversible heat-sensitive medium described above often has a ground color of white or a light color close to it for the sake of easy viewing. Even if a light spot is applied to write information on the medium in a non-contact manner, the light is reflected and no light-exothermic color reaction occurs. Therefore, in such a case, as described in Patent Document 1, a light-absorbing exothermic substance (light-absorbing heat conversion material) is applied in layers in contact with the coloring layer, or kneaded together with the coloring agent and applied. In general, an absorptive color reaction is caused to occur.
[0010]
However, when information is written on the medium thus created, and then the medium is heated by irradiating with light to erase this information, the surface coated with the light-absorbing exothermic substance has no information (coloring or not). Regardless of (), there is a problem that the entire surface generates heat and the medium becomes hot, which may cause problems such as peeling of the medium and warping.
[0011]
The present invention has been developed to solve such problems. That is, an object of the present invention is to provide information on a reversible heat-sensitive medium that can write and erase information on the reversible heat-sensitive medium, and suppress heat generation of the reversible heat-sensitive medium and suppress inconveniences such as peeling and warping of the medium. It is to provide a rewriting device and method.
[0012]
[Means for Solving the Problems]
According to the present invention, the light-emitting exothermic substance (1) and the reversible thermosensitive agent (2) are included, the background color is white or light, and the color is black or dark at a predetermined recording temperature, and a predetermined erasing temperature is reached. An information rewriting device for a reversible thermosensitive medium (3) that erases to colorless or light color by irradiating the reversible thermosensitive medium with writing light (4) having a wavelength at which the light-absorbing exothermic material absorbs information. And erasing means for erasing information by irradiating the reversible heat-sensitive medium with erase light (5) having a wavelength at which the colored reversible heat-sensitive agent absorbs light and the light-absorbing exothermic substance hardly absorbs ( 14), and an information rewriting device for a reversible heat-sensitive medium.
[0013]
Further, according to the present invention, the light-emitting exothermic substance (1) and the reversible thermosensitive agent (2) are included, the background color is white or light, and the color is black or dark at a predetermined recording temperature. A writing step of writing information by using a reversible thermosensitive medium (3) that erases colorless or light color at an erasing temperature, and irradiating the reversible thermosensitive medium with light (4) having a wavelength at which the light-absorbing exothermic substance absorbs light (4) A) and an erasing step (B) of erasing information by irradiating the erasing light (5) having a wavelength at which the reversible heat-sensitive agent colored on the reversible heat-sensitive medium absorbs light and the light-absorbing exothermic substance hardly absorbs. An information rewriting method for a reversible heat-sensitive medium is provided.
[0014]
According to the above-described apparatus and method of the present invention, the writing light (4) having a wavelength that is absorbed by the light-absorbing exothermic substance is irradiated to write information (characters and figures), so that the writing light is efficiently absorbed in the irradiated portion. It generates heat and can be colored black or dark at a predetermined recording temperature. Further, the information writing area is a small area such as a character or a figure, and the medium is hardly peeled or warped due to this heat generation.
[0015]
In addition, since the information is erased by irradiating the erasing light (5) having a wavelength at which the colored reversible heat-sensitive agent absorbs light and the light-absorbing exothermic substance hardly absorbs, the information can be written even if the erasing light is irradiated on the entire surface. Little heat is generated in uncolored parts that are not rare. Therefore, even if the entire medium is irradiated with erasing light to erase information, only the colored portion where information is written generates heat, so there is little heat generation of the entire medium, and inconveniences such as peeling and warping of the medium occur. Absent.
[0016]
That is, many of the light-absorbing exothermic agents have wavelength dependency in the light-absorbing intensity. In the present invention, when writing information on a medium coated with such a light-absorbing exothermic agent, when writing and erasing with light including the wavelength absorbed by the light-absorbing exothermic agent, the wavelength absorbed by the light-absorbing exothermic agent. Use light that does not contain. As a result, the portion where no information is written (the portion where color is not developed) does not generate heat, and the portion where information is written (the portion where color is generated) does not generate heat due to the light-absorbing agent. Since the agent develops a dark color, the color former itself absorbs light and generates heat, and as a result, information is erased.
[0017]
According to a preferred embodiment of the present invention, the light-absorbing exothermic substance (1) is an organic dye that selectively absorbs light having a wavelength of about 700 nm or more and less than about 900 nm, and the reversible thermosensitive agent (2) is: An electron donating dye precursor that selectively absorbs light having a wavelength of about 400 nm or more and less than about 700 nm in a colored state, and the writing means (12) includes a laser beam having a wavelength of about 700 nm or more and less than about 900 nm. The irradiating means (14) is a light emitting device that irradiates erasing light (5) having a wavelength of about 400 nm or more and less than about 700 nm.
[0018]
The light-absorbing exothermic substance (1) is an organic dye that selectively absorbs writing light (4) having a wavelength of about 700 nm or more and less than about 900 nm, and the reversible thermosensitive agent is about 400 nm in a colored state. The electron donating dye precursor that selectively absorbs the erasing light (5) having a wavelength of less than about 700 nm as described above. In the writing step (A), the laser beam (4) having a wavelength of about 700 nm or more and less than about 900 nm. ) To write information, and in the erasing step (B), erasing light (5) having a wavelength of about 400 nm or more and less than about 700 nm is irradiated to erase the information.
[0019]
By using the apparatus and method with this configuration, the overlapping portion between the absorption wavelength of the light-absorbing exothermic substance (1) and the wavelength of the erasing light (5) is minimized, and the heat generation of the reversible thermosensitive medium during information writing and erasing is suppressed. Thus, peeling of the medium, warping, etc. can be suppressed.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.
[0021]
FIG. 1 is a configuration diagram of an information rewriting device for a reversible heat-sensitive medium according to the present invention. The reversible heat-sensitive medium 3 includes the light-absorbing exothermic substance 1 and the reversible heat-sensitive agent 2, and the background color is white or light, colored black or dark at a predetermined recording temperature, and colorless or light at a predetermined erasing temperature. Has a function to erase colors.
[0022]
That is, as shown in FIG. 1, the reversible thermosensitive medium 3 includes a photothermal conversion layer made of the light-absorbing exothermic substance 1, a reversible thermosensitive recording layer made of the reversible thermosensitive agent 2, a support medium 3a, and a protective film 3b. A reversible thermosensitive recording layer comprising an electron donating dye precursor and a reversible developer is formed on the surface of the support medium 3a by coating or the like. The photothermal conversion layer is a substance that converts light of a specific wavelength into heat, and is usually applied to the surface of the support medium 3a, but may be dispersed in the reversible thermosensitive recording layer. For the photothermal conversion layer, an organic dye that selectively absorbs a specific wavelength is usually used. The protective film 3b is a transparent film that protects the surface of the support medium 3a and the light-to-heat conversion layer. For example, a transparent plastic coating is used.
[0023]
In the present invention, the light-absorbing exothermic substance 1 is preferably an organic dye that selectively absorbs light having a wavelength of about 700 nm or more and less than about 900 nm. The reversible thermosensitive agent 2 is an electron donating dye precursor that selectively absorbs light having a wavelength of about 400 nm or more and less than about 700 nm in a colored state.
[0024]
In FIG. 1, the information rewriting apparatus 10 of the present invention includes a writing means 12 and an erasing means 14.
[0025]
The writing means 12 has a function of writing information on the reversible thermosensitive medium 3 by irradiating the writing light 4 having a wavelength that the light-absorbing exothermic substance 1 absorbs. The writing unit 12 is a laser irradiation apparatus that irradiates laser light 4 having a wavelength of about 700 nm or more and less than about 900 nm, for example. The laser irradiation device 12 includes a scanning mirror 12a. The laser beam 4 is irradiated to a predetermined position of the reversible heat-sensitive medium 3 by swinging the mirror 12 to write information (characters, figures, etc.). . As the laser irradiation device 12, for example, a laser diode that irradiates laser light 4 having a wavelength of 810 nm can be used.
[0026]
The erasing means 14 has a function of erasing information by irradiating the reversible thermosensitive medium 3 with erasing light 5 having a wavelength at which the colored reversible thermosensitive agent 2 absorbs light and the light-absorbing exothermic substance 1 hardly absorbs. The erasing unit 14 is, for example, a light emitting device that irradiates the xenon lamp light 5 having a wavelength of about 400 nm or more and less than about 700 nm. The erasing unit 14 irradiates the entire surface of the reversible thermal medium 3 or a predetermined range with information. It is supposed to be erased.
For example, a YAG laser that emits laser light having a wavelength of 1064 nm can be used as the laser irradiation device 12. In this case, it is preferable to determine a light-absorbing exothermic agent that matches the wavelength of the laser, and to determine the light source for erasure having a wavelength region that is not absorbed by the light-absorbing wavelength characteristics.
[0027]
The information rewriting method of the reversible heat-sensitive medium of the present invention comprises the above-described reversible heat-sensitive medium 3 and includes a writing step (A) for writing information and an erasing step (B) for erasing information.
In the writing step (A), information is written by irradiating writing light 4 having a wavelength that the light-absorbing exothermic substance 1 absorbs. In the erasing step (B), information is erased by irradiating the reversible heat-sensitive medium 3 with erasing light 5 having a wavelength at which the colored reversible heat-sensitive agent 2 absorbs light and the light-absorbing exothermic substance 1 hardly absorbs.
[0028]
2 and 3 are diagrams illustrating an embodiment of the method of the present invention. In these figures, the horizontal axis represents the wavelength of light, and the vertical axis represents the absorption distribution of the light-absorbing and heating substance 1, the wavelength distribution of the writing light 4, and the wavelength distribution of the erasing light 5.
[0029]
As shown in these drawings, in the present invention, the absorption distribution of the light-absorbing exothermic substance 1 and the wavelength distribution of the erasing light 5 are set so that there is almost no overlapping portion.
[0030]
In the first embodiment of FIG. 2, light having a wavelength distribution narrower than the light absorption distribution of the light-absorbing exothermic material 1 is used as the writing light 4, for example, laser light. As a result, the absorption distribution of the light-absorbing exothermic material 1 and the wavelength distribution of the writing light 4 overlap each other, so that the writing light is efficiently absorbed at the irradiated portion to generate heat and colored black or dark at a predetermined recording temperature. Can do.
[0031]
In the second embodiment in FIG. 3, light having a light absorption distribution wider than the light absorption distribution of the light-absorbing exothermic material 1 is used as the writing light 4, for example, white light. Even in this case, the absorption distribution of the light-absorbing exothermic substance 1 and the wavelength distribution of the writing light 4 overlap, so that the writing light is efficiently absorbed at the irradiated portion to generate heat, and is colored black or dark at a predetermined recording temperature. be able to.
[0032]
2 and 3, the information writing area is a small area such as a character or a figure, and other portions are not irradiated with the writing light 4, so that the whole medium generates little heat and the medium peels off due to the heat generation. Almost no warpage occurs.
[0033]
As the erasing light, a light source having a suitable light emission distribution may be used, or only a convenient wavelength may be extracted by operating a filter, a dichroic mirror, or the like on a light source having a wide wavelength distribution. .
Further, by using a light source having a wide wavelength band and turning the filter on and off, one light source can be used for both writing and erasing.
[0034]
FIG. 4 is an embodiment of the method of the present invention. In this figure, the horizontal axis is the wavelength of light, and the vertical axis is the absorption distribution of the light-absorbing and heating substance 1, the wavelength distribution of the writing light 4, and the wavelength distribution of the erasing light 5.
[0035]
In this embodiment, the absorption distribution of the light-absorbing exothermic substance 1 has a maximum value at about 800 nm, and selectively absorbs light having a wavelength of about 700 nm or more and less than about 900 nm, while being about 400 nm or more and less than about 700 nm. The absorbance is low for light of a wavelength.
Further, the wavelength distribution of the erasing light 5 has a high light intensity at a wavelength of about 400 nm or more and less than about 700 nm.
Therefore, in this example, the absorption distribution of the light-absorbing exothermic substance 1 and the wavelength distribution of the erasing light 5 have almost no overlapping portion, and the light of the light-absorbing exothermic substance 1 is absorbed by using about 800 nm laser light as the writing light 4. Since the distribution and the wavelength distribution of the writing light 4 overlap, it can be seen that the irradiation light efficiently absorbs the writing light and generates heat, and can be colored black or dark at a predetermined recording temperature.
[0037]
As described above, according to the apparatus and method of the present invention, the writing light 4 having a wavelength at which the light-absorbing exothermic material absorbs light is written to write information (characters and graphics), so that the writing light is efficiently used at the irradiated portion. It absorbs well and generates heat and can be colored black or dark at a predetermined recording temperature. Further, the information writing area is a small area such as a character or a figure, and the medium is hardly peeled or warped due to this heat generation.
[0038]
In addition, the erased light 5 having a wavelength at which the colored reversible heat-sensitive agent absorbs light and the light-absorbing exothermic substance absorbs little information is erased, so that information is written even if the erased light is irradiated on the entire surface. There is almost no heat generation in non-colored parts. Therefore, even if the entire medium is irradiated with erasing light to erase information, only the colored portion where information is written generates heat, so there is little heat generation of the entire medium, and inconveniences such as peeling and warping of the medium occur. Absent.
[0039]
That is, many of the light-absorbing exothermic agents have wavelength dependency in the light-absorbing intensity. In the present invention, when writing information on a medium coated with such a light-absorbing exothermic agent, when writing and erasing with light including the wavelength absorbed by the light-absorbing exothermic agent, the wavelength absorbed by the light-absorbing exothermic agent. Use light that does not contain. As a result, the portion where no information is written (the portion where color is not developed) does not generate heat, and the portion where information is written (the portion where color is generated) does not generate heat due to the light-absorbing agent. Since the agent develops a dark color, the color former itself absorbs light and generates heat, and as a result, information is erased.
[0040]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.
[0041]
【The invention's effect】
As described above, the information rewriting apparatus and method for a reversible heat-sensitive medium according to the present invention can write and erase information on the reversible heat-sensitive medium, suppress the heat generation of the reversible heat-sensitive medium, and cause inconvenience such as peeling of the medium and warping. Can be suppressed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an information rewriting device for a reversible heat-sensitive medium according to the present invention.
FIG. 2 shows a first embodiment of the method of the present invention.
FIG. 3 shows a second embodiment of the method of the present invention.
FIG. 4 is an embodiment of the method of the present invention.
FIG. 5 is an explanatory diagram of color development / decoloration of a reversible thermosensitive recording material.
FIG. 6 is a model diagram of color development / decoloration of a reversible thermosensitive recording material.
FIG. 7 is a characteristic explanatory diagram of reversible thermal paper.
FIG. 8 is a configuration diagram of information rewriting means of a conventional reversible heat-sensitive medium.
FIG. 9 is a configuration diagram of information rewriting means of another conventional reversible heat-sensitive medium.
[Explanation of symbols]
1 Absorbing exothermic material, 2 Reversible thermosensitive agent,
3 reversible heat sensitive medium, 3a support medium, 3b protective film,
4 writing light, 5 erasing light (xenon lamp light),
10 information rewriting device, 12 writing means (laser irradiation device),
12a scanning mirror, 14 erasing means (light emitting device)

Claims (4)

It contains a light-absorbing exothermic substance (1) and a reversible thermosensitive agent (2), and the ground color is white or light, and it is colored black or dark at a predetermined recording temperature, and colorless or light at a predetermined erasing temperature. An information rewriting device for a reversible thermosensitive medium (3) to be erased,
Writing means (12) for irradiating the reversible heat-sensitive medium with writing light (4) having a wavelength at which the light-absorbing exothermic substance absorbs light, and writing information;
The reversible heat-sensitive medium comprises erasing means (14) for erasing information by irradiating the erase light (5) having a wavelength at which the colored reversible heat-sensitive agent absorbs light and the light-absorbing exothermic substance hardly absorbs. An information rewriting device for a reversible heat-sensitive medium. The light-absorbing exothermic substance (1) is an organic dye that selectively absorbs light having a wavelength of about 700 nm or more and less than about 900 nm, and the reversible heat-sensitive agent (2) is about 400 nm or more and about 700 nm in a colored state. An electron-donating dye precursor that selectively absorbs light having a wavelength of less than
The writing means (12) is a laser irradiation apparatus that irradiates laser light (4) having a wavelength of about 700 nm or more and less than about 900 nm,
2. The information rewriting device for a reversible heat-sensitive medium according to claim 1, wherein the erasing means (14) is a light emitting device that irradiates erasing light (5) having a wavelength of about 400 nm or more and less than about 700 nm. It contains a light-absorbing exothermic substance (1) and a reversible thermosensitive agent (2), and the ground color is white or light, and it is colored black or dark at a predetermined recording temperature, and colorless or light at a predetermined erasing temperature. A writing step (A) of writing information by irradiating the reversible heat-sensitive medium (3) to be erased and irradiating the reversible heat-sensitive medium with light (4) having a wavelength at which the light-absorbing exothermic substance absorbs light;
An erasing step (B) of erasing information by irradiating the erasing light (5) having a wavelength at which the reversible heat-sensitive agent colored on the reversible heat-sensitive medium absorbs light and the light-absorbing exothermic substance hardly absorbs. An information rewriting method for a reversible heat-sensitive medium. The light absorption exothermic substance (1) is an organic dye that selectively absorbs writing light (4) having a wavelength of about 700 nm or more and less than about 900 nm, and the reversible thermosensitive agent is about 400 nm or more in a colored state. An electron donating dye precursor that selectively absorbs erasing light (5) having a wavelength of less than about 700 nm,
In the writing step (A), information is written by irradiating a laser beam (4) having a wavelength of about 700 nm or more and less than about 900 nm,
4. The information rewriting method for a reversible thermosensitive medium according to claim 3, wherein, in the erasing step (B), information is erased by irradiating with erasing light (5) having a wavelength of about 400 nm or more and less than about 700 nm. .

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