JP2007190903A - Recording/erasure system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording/erasure system efficiently erasing characters and images of a massive recording medium. <P>SOLUTION: Ink of which color is changed to a first color at a first color change temperature that is higher than a room temperature and changed to a second color at a second color change temperature that is lower than a room temperature is applied on a recording surface 1A of a card 1 as a recording medium. Characters or images are recorded on the recording surface 1A of the card 1 by a thermal printer 2 which locally heats the surface at a temperature higher than the first color change temperature. Then, in accordance with needs, the recorded card 1 is housed in an inner container 8 of a heat insulating container 4 of an erasure apparatus 3. A Stirling freezing machine 20 serving as a freezing machine generates cold and heat, thereby erasing the recorded characters or images by cooling the space S in the heat insulating container 4 to a temperature equal to or lower than the second color change temperature via a heat transfer means 17 composed of a heat transfer block 26 and a thermo siphon 27. Thus, the characters and images recorded on massive recorded card 1 can be efficiently erased. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording / erasing system capable of recording characters and images on a recording medium (printing medium) such as a card and erasing characters and images recorded on a recording medium.

  Conventionally, a large number of price tags and POPs have been used in relatively large stores such as supermarkets. These price tags and POPs are generally made by writing characters or the like on a card such as paper or synthetic resin with ink or the like. For this reason, if a new price tag or POP is created each time the price of a product changes or a new product arrives, a large number of price tags and POPs that are no longer used are discarded, which is not economical. There was a problem that waste would increase.

On the other hand, on a reversible thermal paper that repeats color development and decoloring due to temperature changes, writing characters and images by applying heat with a writing head, and applying heat to the reversible thermal paper by an erasing unit results in the reversible thermal paper. There is known a thermal printer that can repeatedly print on reversible thermal paper by erasing characters or images printed (recorded) on the thermal paper (see, for example, Patent Document 1). In this thermal printer, when printing a character or an image on the reversible thermal paper on which a character or an image has already been printed, when the reversible thermal paper passes through a conveyance path, After the image is erased, characters and images are printed by the writing head.
Japanese Patent Laid-Open No. 05-345459

  However, in such a thermal printer, although it can be used for reversible thermal paper in which a dye having a color change (coloring or decoloring) temperature of room temperature or higher is used, the color change temperature is lower than room temperature. For such inks, there is a problem that a cooling mechanism must be incorporated in a narrow area near the writing head of the printer, which is not practical. In particular, when it is used as a price tag or POP, a temperature of -20 ° C. or lower is used so that it can be used in a freezer. However, it is difficult to incorporate a mechanism that generates such a low temperature into a printer. Met. In addition, characters and images must be erased in a short time when the reversible thermal paper passes through the conveyance path, and there is a risk that unerased residue may appear as spots on the printing surface of the reversible thermal paper. . In addition, when used in a relatively large store such as a supermarket as described above, in order to distinguish between used ones and unused ones, if you try to erase used price tags or POP prints, There is a problem that it takes time and effort to pass price tags and POPs one by one through the printer.

  An object of the present invention is to solve the above problems and to provide a recording / erasing system capable of efficiently erasing characters and images on a large number of recording media (printing media).

In the recording / erasing system according to claim 1 of the present invention, a reversible thermochromic layer containing a reversible thermochromic composition is formed on the recording surface, and the first color is obtained when the temperature exceeds a predetermined first color change temperature. A recording medium that becomes the second color when the temperature is equal to or lower than a predetermined second discoloration temperature;
A recording apparatus for recording by heating the recording surface of the recording medium to a temperature not lower than the first discoloration temperature;
An erasing device having an insulating container, a refrigerator that generates cold heat, and a heat transfer means that transmits the cold heat generated by the refrigerator into the heat insulating container and cools the heat insulating container to a second color change temperature or lower. ,
It is characterized by having.

The recording / erasing system according to a second aspect of the present invention is the recording / erasing system according to the first aspect, wherein the first color change temperature is higher than normal temperature, and the second color change temperature is lower than normal temperature. There,
The reversible thermochromic layer formed on the recording medium includes a reversible thermochromic composition that decolors at the first color change temperature and develops color at the second color change temperature.

The recording / erasing system according to a third aspect of the present invention is the recording / erasing system according to the first aspect, wherein the first color change temperature is higher than normal temperature, and the second color change temperature is lower than normal temperature. There,
The reversible thermochromic layer formed on the recording medium includes a reversible thermochromic composition that develops color at the first color change temperature and decolors at the second color change temperature.

  According to a fourth aspect of the present invention, there is provided a recording / erasing system according to any one of the first to third aspects, wherein the reversible thermochromic layer contains a non-thermochromic dye or pigment. It is said.

  A recording / erasing system according to a fifth aspect of the present invention is the recording / erasing system according to any one of the first to fourth aspects, wherein the erasing device has a heater and the first discoloration temperature is once set in the heat insulating container. It is characterized by having a control circuit for cooling to the second discoloration temperature or lower after heating as described above.

  The recording / erasing system according to a sixth aspect of the present invention is the recording / erasing system according to the fifth aspect, wherein after the erasing device is cooled down to a second color change temperature or less in the heat insulating container, the heater is the heat insulating container. It is controlled by the control circuit so as to heat the inside to room temperature.

  Furthermore, the recording / erasing system according to claim 7 of the present invention is characterized in that, in any one of claims 1 to 6, the refrigerator is a Stirling refrigerator.

  The recording / erasing system according to claim 1 of the present invention is configured as described above, and when recording on a recording medium, a part of the surface on which the reversible thermochromic layer of the recording medium is formed by the recording apparatus. Is heated to the first discoloration temperature or higher so that characters and images are recorded on the recording medium, and when the characters and images on the recorded recording medium are erased, the recorded recording medium is used as a heat insulating container of the erasing device. The inside of the heat insulating container is cooled to the second discoloration temperature or lower by the refrigerator and the characters and images of the recording medium stored in the heat insulating container are erased. And by putting a large amount of recorded recording media in the heat insulating container of the erasing device, there is an effect that it is possible to erase characters and images of a large amount of recording media collectively and efficiently.

  The recording / erasing system according to claim 2 of the present invention is configured as described above, and when recording on a recording medium, a part of the surface on which the reversible thermochromic layer of the recording medium is formed by the recording apparatus. Is heated to a temperature higher than the first discoloration temperature, the color of the reversible thermochromic composition contained in the reversible thermochromic layer is decolored (discolored to the first color), whereby characters and images are recorded on the recording medium. When recording and erasing characters and images on a recorded recording medium, the recorded recording medium is accommodated in a heat insulating container of the erasing device, and the inside of the heat insulating container is cooled to the second discoloration temperature or lower by a refrigerator. By doing so, the color of the reversible thermochromic composition develops color (discolored state to the second color), thereby erasing characters and images on the recording medium accommodated in the heat insulating container. And by putting a large amount of recorded recording media in the heat insulating container of the erasing device, there is an effect that it is possible to erase characters and images of a large amount of recording media collectively and efficiently.

  The recording / erasing system according to claim 3 of the present invention is configured as described above, and when recording on a recording medium, a part of the surface on which the reversible thermochromic layer of the recording medium is formed by the recording apparatus. Is heated to the first discoloration temperature or higher to develop the color of the reversible thermochromic composition contained in the reversible thermochromic layer (discolored to the first color), thereby recording characters and images on the recording medium. At the same time, when erasing characters and images on the recorded recording medium, the recorded recording medium is accommodated in a heat insulating container of the erasing device, and the inside of the heat insulating container is cooled to the second discoloration temperature or lower by a refrigerator. As a result, the color of the reversible thermochromic composition is decolored (discolored to the second color), thereby erasing characters and images on the recording medium contained in the heat insulating container. And by putting a large amount of recorded recording media in the heat insulating container of the erasing device, there is an effect that it is possible to erase characters and images of a large amount of recording media collectively and efficiently.

The recording / erasing system according to claim 4 of the present invention is configured as described above,
By heating a part of the surface on which the reversible thermochromic layer is formed to a temperature higher than the first color change temperature, only the heated part of the reversible thermochromic layer containing the non-thermochromic dye or pigment is changed to the first color. Then, characters and images are recorded on the recording medium. In addition, by cooling the recorded recording medium to the second color change temperature or lower, the entire reversible thermochromic layer is changed to the second color, and characters and images recorded on the recording medium are erased. As described above, there is an effect that recording on the recording medium and erasing of the recorded characters and the like can be performed by simple means.

  Further, the recording / erasing system according to claim 5 of the present invention is configured as described above, so that the control circuit once heats the inside of the heat insulating container to the first discoloration temperature or higher by the heater and records on the recording medium. After the entire surface is once changed to the first color, the inside of the heat insulating container is cooled to the second color change temperature or lower by a refrigerator and the entire recording surface of the recording medium is changed to the second color, thereby recording on the recording medium. There is an effect that it can be erased without spots so as not to leave traces of printed characters and images.

  In addition, the recording / erasing system according to claim 6 of the present invention is configured as described above, so that the recording / erasing recording medium accommodated in the erasing device can be brought to room temperature. There is an effect that it is possible to prevent condensation when the medium is taken out.

  Furthermore, the recording / erasing system according to claim 7 of the present invention is configured as described above, and is recorded on a recording medium using ink having a very low second discoloration temperature during recording / erasing. Even in the case of erasing characters and images, it is possible to efficiently erase the recorded characters and images by efficiently cooling the inside of the heat insulating container of the erasing device to the second color change temperature.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 14. Reference numeral 1 denotes a card as a recording medium (printing medium). Reference numeral 2 denotes a thermal printer (thermal printer) as a recording device for recording (printing) on the recording surface (printing surface) 1A of the card 1. Further, 3 is an erasing device for erasing characters and images recorded on the recording surface 1A of the card 1. The card 1, the thermal printer 2 and the erasing device 3 constitute a recording / erasing system.

The card 1 as the recording medium is formed by molding a sheet-like synthetic resin or the like into an appropriate size. The recording surface 1A of the card 1 is coated with temperature discolorable ink (a reversible thermochromic layer is formed) on the entire surface.
FIG. 2 shows a card 1 using a heat-colorable reversible thermochromic composition (as will be described later, the first color is colored blue, the second color is colorless, etc.) FIG. 10 shows an example of a recording medium in which the entire recording surface 1A is decolored to the second color and the ground color (eg, white) of the card 1 can be seen before recording. Card 1 using the reversible thermochromic composition (as will be described later, the second color is a colored state such as blue, the first color is colorless and erased, and before recording, the recording surface 1A Is an example of a recording medium in which the entire surface is colored in a second color (for example, blue).
Hereinafter, the configuration of the card 1 as a recording medium will be described in detail.

As the card 1, for example, a recording material described in JP-A-2006-15726 is preferably used, and a reversible thermochromic composition containing a reversible thermochromic composition on a support such as paper, synthetic paper, or plastic film. Obtained by forming a layer.
The reversible thermochromic layer is prepared by dispersing a reversible thermochromic composition in a vehicle to prepare a liquid composition such as paint or printing ink, and conventionally known methods such as screen printing, offset printing, and gravure printing. It can be formed by printing means such as coater, tampo printing, transfer, brush painting, spray coating, flow coating, roller coating, dip coating and the like.
The liquid composition contains a general dye or pigment (non-thermochromic) and exhibits a color change behavior from colored (1) (first color) to colored (2) (second color). You can also.
Further, the card 1 can be obtained by molding the reversible thermochromic composition in various thermoplastic resins or thermosetting resins and then molding the dispersion.
The card 1 may have a three-dimensional shape, but preferably has a planar shape. Also, the size may be from a small card form to a large one used for a display.
By providing a protective layer on the uppermost layer of the card 1, the scratch resistance can be improved. Furthermore, the light resistance of the reversible thermochromic composition can be improved by incorporating a light stabilizer in the protective layer.

  The reversible thermochromic composition comprises at least three components of (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction of both occurs. A reversible thermochromic composition, such as disclosed in JP 2005-1369 A, JP 2006-188660 A, which exhibits a large hysteresis characteristic and changes color, that is, temperature. The shape of the curve plotting the change in color density due to the change shows a path that differs greatly depending on whether the temperature is raised from the lower temperature side than the color change temperature range or vice versa. It is a type of composition that changes color by tracing, and in the normal temperature range between the low temperature side color change point (second color change temperature) and the high temperature side color change point (first color change temperature), it is below the low temperature side color change point or high temperature side color change. Reversible thermochromic composition of the heat-decolorizable to hold stores the state of changing the above temperature is effective.

The hysteresis characteristics in the color density-temperature curve of the heat-decolorable reversible thermochromic composition will be described with reference to the graph of FIG.
In FIG. 13, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change proceeds along the arrow.
Here, the decolored state means that the reversible thermochromic layer containing the reversible thermochromic composition is colorless (in the case of the heat decoloring type, “first color”) and is the background of the support of the recording medium. The color is visible, and the colored state is a state in which the reversible thermochromic layer containing the reversible thermochromic composition is colored (in the case of a heat decoloring type, “second color”). In FIG. 13, A is a point indicating a density at a temperature T ₄ (hereinafter referred to as a complete decoloring temperature) reaching a completely decolored state, and B is a temperature T ₃ (hereinafter referred to as a decoloring) at which decoloring is started. C is a point indicating a concentration at a temperature T ₂ at which color development starts (hereinafter referred to as a color development start temperature), and D is a temperature T ₁ (at which a complete color development state is reached). Hereinafter, it is a point indicating the density at the complete coloring temperature).
Discoloration temperature region is a temperature region between the T ₁ and T _4, both phases of the colored state and the decolored state can coexist, the temperature range between T ₂ and T ₃ is a large area of the difference in color density substantially Discoloration temperature range (two-phase holding temperature range).
The length of the line segment EF is a temperature width indicating the degree of hysteresis (hereinafter referred to as hysteresis width ΔH). The larger the ΔH value, the easier it is to hold each state before and after the color change.
Here, _{T E} is the temperature of the midpoint of _{T 1} and _{T 2, T F} is the temperature of the midpoint of _{T 3} and _{T 4.}
The ΔH value that can be maintained before and after the color change of the reversible thermochromic composition suitably used in the present invention is in the range of 40 ° C to 70 ° C, preferably 50 to 70 ° C, more preferably 60 to 70 ° C. is there.
Further, in the two-phase color development state and decolorization state is substantially retained, practical use test by the temperature, i.e., temperature range between of T ₃ and T ₂ including T _A is 20 ° C. or higher 60 ° C. A range of less than is valid.
Furthermore, in order to allow only one specific state to exist in the room temperature range before and after the color change, the complete decoloring temperature (T ₄ ) is 40 ° C. or higher, preferably 45 ° C. or higher, more preferably 50 ° C. or higher. And the minimum holding temperature (T ₂ ) is 20 ° C. or lower, preferably 0 ° C. or lower, more preferably −5 ° C. or lower.

Hereinafter, the components (a), (b), and (c) of the reversible thermochromic composition will be specifically described.
As the component (a), that is, the electron donating color-forming organic compound, conventionally known diphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, phenyl indolyl aza Examples thereof include phthalides, fluorans, styrinoquinolines, diazarhodamine lactones and the like.

As the electron-accepting compound of the component (b), a compound group having active protons, a pseudo-acidic compound group (a compound group that is not an acid but acts as an acid in the composition to cause the component (I) to develop color), There is a group of compounds having electron vacancies.
Examples of compounds having active protons include monophenols to polyphenols as compounds having phenolic hydroxyl groups, and alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, carboxy groups and esters thereof as substituents. Or what has an amide group, a halogen group, etc., phenol-aldehyde condensation resin etc., such as a bis type and a tris type phenol, are mentioned. Moreover, the metal salt of the compound which has the said phenolic hydroxyl group may be sufficient.

Examples of the component (c) include esters, ketones, and ethers.
Examples of the esters include octanoic acid-4-benzyloxyphenylethyl, nonanoic acid-4-benzyloxyphenylethyl, decanoic acid-4-benzyloxyphenylethyl, undecanoic acid-4-benzyloxyphenylethyl, and dodecanoic acid-4. -Benzyloxyphenylethyl, tridecanoic acid-4-benzyloxyphenylethyl, tetradecanoic acid-4-benzyloxyphenylethyl, pentadecanoic acid-4-benzyloxyphenylethyl, hexadecanoic acid-4-benzyloxyphenylethyl, heptadecanoic acid-4 -Benzyloxyphenylethyl, octadecanoic acid-4-benzyloxyphenylethyl, 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1 undecanoic acid -Diphenylmethyl, dodecanoic acid 1,1-diphenylmethyl, tridecanoic acid 1,1-diphenylmethyl, tetradecanoic acid 1,1-diphenylmethyl, pentadecanoic acid 1,1-diphenylmethyl, hexadecanoic acid 1,1-diphenylmethyl, heptadecane Examples include acid 1,1-diphenylmethyl and octadecanoic acid 1,1-diphenylmethyl.

Furthermore, (b) an electron donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reversible thermochromic composition comprising at least three components of a reaction medium that determines the temperature at which the color reaction of both occurs. As a heat-colorable reversible thermochromic composition using gallic acid ester as an electron-accepting compound (see, for example, JP-A-2003-253149) can be applied.
In this case, the reversible thermochromic layer containing the reversible thermochromic composition at a temperature equal to or lower than the second color change temperature is colorless (second color) and the background color of the support of the recording medium can be seen (decolored). State), and the reversible thermochromic layer containing the reversible thermochromic composition is colored (first color) at a temperature equal to or higher than the first color change temperature (color development state). In this case, the room temperature region between the low temperature side color change point (second color change temperature) and the high temperature side color change point (first color change temperature) is the same as in the case of the heat erasable reversible thermochromic composition. The state changed at a temperature below the low temperature side discoloration point or above the high temperature side discoloration point can be stored and retained.

In the present invention, the proportions of the three components (A), (B), and (C) depend on the concentration, the color change temperature, the color change form, and the type of each component, but in general, components that provide desired characteristics. The ratio is in the range of (b) component 1 to (b) component 0.1 to 50, preferably 0.5 to 20, (c) component 1 to 800, preferably 5 to 200 (the ratio). Are all parts by mass).
Each component may be a mixture of two or more, and an antioxidant, ultraviolet absorber, infrared absorber, dissolution aid, light stabilizer, etc. can be added as long as the function is not hindered. .

The reversible thermochromic composition is preferably used by being encapsulated in microcapsules. This means that even if it comes into contact with a chemically active substance such as an acidic substance, a basic substance or a peroxide, or other solvent components, its function is not deteriorated, and heat resistance stability can be maintained. This is because the temperature-sensitive color-changing color memory composition can be maintained in the same composition and exhibit the same effects under various use conditions.
The microcapsules satisfy the practicality in the range of an average particle size of 1.0 to 20 μm, preferably 1.5 to 15 μm, more preferably 1.5 to 10 μm.
The microcapsule is effective in the range of inclusion / wall membrane = 7/1 to 1/1 (mass ratio), and preferably 6/1 to 1/1 (mass ratio).
Microencapsulation includes conventionally known interfacial polymerization method, in situ polymerization method, in-liquid curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melt dispersion cooling method, air suspension coating method There are spray drying methods and the like, which are appropriately selected according to the application. Further, a secondary resin film may be provided on the surface of the microcapsule according to the purpose to impart durability, or the surface characteristics may be modified for practical use.

  Here, a production example of a recording medium (card 1) applicable to the present embodiment is specifically shown.

  First, production of a recording medium in the case of a recording medium using a heat decoloring type reversible thermochromic composition is performed as follows.

For example, a microcapsule pigment encapsulating a heat decolorable reversible thermochromic composition that changes color from black to colorless with temperature change [complete color developing temperature 0 ° C., complete decoloring temperature 41 ° C., hysteresis width (ΔH) 30 ° C. ] Is dispersed in a vehicle and coated on the surface of white synthetic paper (thickness: 200 μm) as a support to produce a recording medium.
In the case of the recording medium thus produced, by cooling to 0 ° C. or less as the second color change temperature, the black color (second color) is developed and heated to 41 ° C. or more as the first color change temperature. As a result, the color changes to colorless (first color).

Also, for example, a microcapsule pigment encapsulating a heat decolorable reversible thermochromic composition that changes color from blue to colorless with temperature change [complete color development temperature -20 ° C, complete color erase temperature 60 ° C, hysteresis width (ΔH ) 64 ° C.] is dispersed in a vehicle and coated on the surface of a white polyester film (thickness: 188 μm) as a support to produce a recording medium.
In the case of the recording medium thus produced, by cooling to −20 ° C. or less as the second color change temperature, the blue color (second color) is developed and heated to 60 ° C. or more as the first color change temperature. As a result, the color changes to colorless (first color).

Also, for example, a microcapsule pigment encapsulating a heat decolorable reversible thermochromic composition that changes color from blue to colorless with temperature change [complete color development temperature -20 ° C, complete color erase temperature 60 ° C, hysteresis width (ΔH ) 64 ° C.] and a non-thermochromic pink pigment are dispersed in a vehicle and coated on the surface of a white polyester film (thickness: 188 μm) as a support to produce a recording medium.
In the case of the recording medium thus produced, by cooling to −20 ° C. or less as the second color change temperature, the blue color (second color) is developed and heated to 60 ° C. or more as the first color change temperature. By changing the color to colorless (first color), the color changes from purple to pink with a change in temperature.

Further, for example, a microcapsule pigment encapsulating a heat decolorable reversible thermochromic composition that changes from pink to colorless with temperature change [complete color developing temperature—14 ° C., complete decoloring temperature 58 ° C., hysteresis width (Δ H) 55 ° C.] is dispersed in a vehicle, and screen-printed on the surface of a white polyester film (thickness: 188 μm) as a support to produce a recording medium.
In the case of the recording medium thus produced, by cooling to −14 ° C. or less as the second color change temperature, the pink color (second color) is developed and heated to 58 ° C. or more as the first color change temperature. By doing so, the color changes to colorless (first color).

On the other hand, production of a recording medium in the case of a recording medium using a heat-colorable reversible thermochromic composition is performed as follows.
For example, a microcapsule pigment encapsulating a heat-developable reversible thermochromic composition that changes color from colorless to pink with temperature change [complete color developing temperature 41 ° C., complete color erasing temperature 8 ° C., hysteresis width (ΔH 23 ° C.) is dispersed in a vehicle, and the surface of a white polyester film (thickness: 188 μm) as a support is coated to produce a recording medium.
In the case of the recording medium produced in this way, the first color change temperature is heated to 41 ° C. or higher, whereby a pink color (first color) is developed and the second color change temperature is cooled to 8 ° C. or lower. As a result, the color changes to colorless (second color).

  In the present embodiment, in the following, by cooling to −20 ° C. or lower as the second color change temperature, the second color (for example, blue) is developed, and by heating to 70 ° C. or higher as the first color change temperature. The case where the color is changed (decolored) to the first color (colorless) will be described as an example.

Next, as shown in FIG. 14, the thermal printer 2 includes a platen 51 that supports the card 1 that is a recording medium from the non-recording surface side, and a print head 52 that is disposed to face the platen 51. In addition, the image forming apparatus includes a transport mechanism 53 that transports the card 1 that is a recording medium and includes a plurality of rollers in a predetermined transport direction. The print head 52 is a thermal head that is heated to a predetermined temperature or higher by a heating mechanism (not shown), and the thermal printer 2 locally changes the color change temperature (reversible) of the recording surface 1A by the print head 52. A first discoloration temperature at which the thermochromic layer changes to the first color (in this embodiment, about 70 ° C.) or higher, so that characters and images are recorded on the recording surface 1A of the card 1. is there.
For example, on the recording surface 1A of the card 1, when the temperature is less than 70 ° C. which is the first color change temperature, the color is blue (second color), and when the temperature is 70 ° C. which is the first color change temperature or more, the color is changed to colorless (first color) If the recording surface 1A is locally heated to 70 ° C. or higher by the print head 52 of the thermal printer 2, the color of the heated portion is blue. When the color is changed from (second color) to colorless (first color) (decolored from blue to colorless) and the background color of the card 1 is white, it is recorded in a so-called white state.
The thermal printer 2 is not limited to the configuration shown here, and a known printer can be applied.

The erasing device 3 has a heat insulating container 4 and a machine room 5. The heat insulating container 4 and the machine room 5 are provided in the outer shell body 6. The heat insulating container 4 includes the outer shell body 6, a heat insulating material 7 provided on the inner side of the outer shell body 6, an inner container 8 provided on the inner side of the heat insulating material 7, and an inner container 8. And a lid body 9 that opens and closes the upper opening. The inner container 8 is made of a metal having high thermal conductivity such as aluminum.
A plurality of vertical partition plates 10 (seven in this example) are provided in parallel to the lower side in the inner container 8, and the space S in the inner container 8 is provided by these partition plates 10. Small spaces S1 to S8 that are open to each other are formed. The partition plate 10 is made of a metal having a high thermal conductivity such as aluminum, and is attached to the inner surface of the inner container 8 integrally and thermally like the inner container 8. It has been. The inner container 8 only needs to be configured to prevent the cards 1 from interfering with each other when the card 1 is accommodated therein, and the partition plate 10 is perpendicular to the interior. It is not limited to the structure which provides. For example, the partition plate 10 may be provided obliquely and the card 1 may be stood diagonally, or the partition plate 10 may be provided horizontally and the card 1 may be accommodated sideways in the inner container 8. .
In addition, a pipe 27A of a thermosiphon 27, which will be described later, is wound around the outer surface of the inner container 8 in heat transfer, and the thermistor 11 is provided in heat transfer contact. A heater 12 is provided on the outer bottom surface of the inner container 8 so as to be in heat transfer. The lid body 9 includes an outer shell body 13, a heat insulating material 14 provided inside the outer shell body 13, and an inner lid 15 provided inside the heat insulating material 14. At the same time, the outer shell 6 is pivotally supported via a hinge mechanism (not shown).

The machine room 5 is provided in a space in the outer shell body 6 and is adjacent to the heat insulating container 4. In the machine room 5, a refrigerator unit 16, heat transfer means 17 for moving the cold generated by the refrigerator unit 16 to the inner container 8 of the heat insulating container 4, and a circuit board 18 are provided. ing.
The refrigerator unit 16 includes a substantially cylindrical casing 19, a free piston type Stirling refrigerator 20 accommodated in the casing 19 in a substantially coaxial shape, and an exhaust heat fan 21. Yes. The casing 19 has an inlet opening 22 formed at the upper end thereof, an outlet opening 23 formed in the lower side surface thereof, and a lower portion of the casing 19 with respect to the fixed portion 6A provided at the bottom of the outer shell body 6. Fixed. Then, the cylindrical portion 20A of the Stirling refrigerator 20 protrudes from the inlet opening 22, and is provided in a heat transfer portion 20B located on the base end side of the cylindrical portion 20A of the Stirling refrigerator 20. The Stirling refrigerator 20 is disposed in the casing 19 so that the exhaust heat fins 24 thus positioned are located at the inlet opening 22. A sealing member 25 for sealing these gaps is provided in the gap between the outer peripheral portion of the exhaust heat fin 24 and the inner surface of the inlet opening 22.
Further, a heat transfer block 26 is attached in the vicinity of the heat absorbing portion 20C located on the distal end side of the cylindrical portion 20A of the Stirling refrigerator 20, and the heat transfer block 26 is connected to the pipe 27A of the thermosiphon 27. Is kept in heat transfer. The heat transfer means 17 is configured by the heat transfer block 26 and the thermosiphon 27. The periphery of the Stirling refrigerator 20 in the vicinity of the heat absorbing portion 20C, the periphery of the heat transfer block 26, and the periphery of the pipe 27A of the thermosiphon 27 are covered with a heat insulating material 28. Further, the exhaust heat fan 21 is attached to the outlet opening 23, and the exhaust heat fan 21 is attached to the outer shell body 6 in a state where the refrigerator unit 16 is attached to the fixed portion 6A. It is provided facing the formed exhaust port 29.

  The circuit board 18 is provided with a control circuit 30 for controlling the Stirling refrigerator 20, the cooling fan 21 and the heater 12, and a drive circuit 31 for driving the Stirling refrigerator 20. The circuit board 18 is provided with an operation switch 32, and an operation portion 33 is provided on the upper surface of the outer shell 6 corresponding to the operation switch 32. Further, power is supplied to the circuit board 18 from an external 100V AC power supply via an AC adapter 34.

Next, the operation of this embodiment will be described.
First, the card 1 is a recording medium using a heat-colorable reversible thermochromic composition (recording medium in which the first color is colored blue and the second color is colorless). In this case, a case where characters or images are recorded (printed) on the card 1 will be described.
First, the user sets the card 1 in the thermal printer 2 so that the print head 52 of the thermal printer 2 is in contact with the recording surface 1A of the card 1. Then, the thermal printer 2 is operated by a personal computer (not shown) to prepare a recording surface 1A of the card 1 that is colorless, and the recording surface 1A of the card 1 is locally applied to the temperature-color-changing ink. The above-mentioned discoloration temperature (the first discoloration temperature at which the reversible thermochromic layer discolors to the first color (for example, develops blue). In this embodiment, about 70 ° C.) The color changes to a color (for example, blue), and arbitrary characters and images are recorded on the recording surface 1A of the card 1 as shown in FIG. Note that the characters and images recorded on the card 1 do not fall below a predetermined second discoloration temperature (in this embodiment, about −20 ° C.), the first color discoloration state (as described above, the first discoloration state). When the color is blue, and the second color is in a state where the blue color has disappeared and becomes colorless, only characters and images are in a blue state). In the freezing temperature range of a freezer generally called an open showcase or the like, the discoloration state of the first color is maintained, and characters and images recorded on the card 1 are lost in general use. There is no.

Next, the case of erasing characters and images recorded on the card 1 will be described.
First, the user collects the card 1 on which characters and images are recorded. The recovered card 1 is accommodated in a space S surrounded by the heat insulating container 4 and the inner lid 15 of the erasing device 3. At this time, the card 1 is accommodated in the space S by being inserted vertically between the small open spaces S1 to S8 partitioned by the partition plates 10 provided in the inner container 8. Is done. When there are a plurality of the cards 1, they are accommodated vertically in the small spaces S <b> 1 to S <b> 8 between the partition plates 10 almost evenly. And after closing the said cover body 9 and sealing the inside of the said heat insulation container 4, the said erasing apparatus 3 will act | operate by operating the said operation part 33 and pressing the said operation switch 32. FIG.

  First, the space S in the heat insulating container 4 of the erasing device 3 is heated by the heater 12. That is, the heater 12 is energized by the control circuit 30 when the operation switch 32 is pressed. The heat generated from the heater 12 is conducted to the inner container 8 and the partition plate 10 formed of aluminum or the like, and is discharged from the inner container 8 and the partition plate 10 into the space S. The inside will be heated. The control circuit 30 controls energization of the heater 12 based on temperature information obtained from the thermistor 11. In this way, the space S of the heat insulating container 4 is heated to 70 ° C., which is the color change temperature of the ink (the first color change temperature at which the reversible thermochromic layer changes to the first color), as shown in FIG. Will be. As described above, once the space S of the heat insulating container 4 is heated to the first color change temperature, the recording surface 1A of the card 1 is temporarily changed to the first color as shown in FIG. As described above, when the first color is blue and the second color is in a state where the blue color has disappeared and becomes colorless, the entire surface of the card 1 becomes a single blue color). Become. Further, since the card 1 is accommodated vertically in the small spaces S1 to S8 opened between the partition plates 10, not only the heat released from the inner container 8 but also the partition plate Therefore, the card 1 can be efficiently heated to change the color of the ink on the recording surface 1A (change to the first color (for example, blue)). Further, even when a plurality of the cards 1 are accommodated in the space S, the inner container can be accommodated by accommodating the cards 1 in the small spaces S1 to S8 opened between the partition plates 10 almost equally. 8 and a plurality of the partition plates 10 are heated by the heat, so that the plurality of cards 1 are efficiently heated to change the color of the recording surface 1A (change to the first color). Can do. Further, when a plurality of the cards 1 are accommodated in each of the small spaces S1 to S8, for example, even when four cards are accommodated in each small space, for example, a total of 32 cards, the cards 1 are oriented vertically. By being accommodated, the plurality of cards 1 accommodated in the small spaces S1 to S8 are difficult to adhere to each other, so that the recording surface 1A of the overlapping portion of the cards 1 does not change color (discolor to the first color). This can reduce the risk. (That is, if a plurality of cards 1 are horizontally or vertically overlapped even if they are vertically oriented, the cards 1 are brought into close contact with each other due to their own weight or atmospheric pressure. Although there is a possibility that the temperature of the overlapped portion does not rise sufficiently, as described above, when it is accommodated vertically in a state of being divided into small spaces S1 to S8 between the partition plates 10, as shown in FIG. Thus, since the cards 1 are difficult to adhere to each other due to their own weight or atmospheric pressure, the temperature of the entire card 1 can be sufficiently raised.)

Then, based on the temperature information obtained from the thermistor 11, the control circuit 30 increases the temperature in the space S to about 70 ° C., which is the first color change temperature of the ink (the temperature at which the first color is developed). When it is detected, the heater 12 is stopped, the Stirling refrigerator 20 is operated via the drive circuit 31, and the exhaust heat fan 21 is further operated. The cold heat generated in the heat absorption part 20C of the Stirling refrigerator 20 passes through the heat transfer block 26 and the thermosiphon 27 constituting the heat transfer means 17, and the inner container 8 and the partition plate 10 formed of aluminum or the like. Then, the space S is cooled by being discharged from the inner container 8 and the partition plate 10 into the space S. (In other words, the heat in the space S moves from the inner container 8 and the partition plate 10 to the heat absorption part 20C of the Stirling refrigerator 20 through the thermosiphon 27 and the heat transfer block 26). 30 controls the drive circuit 31 based on temperature information obtained from the thermistor 11, and the Stirling refrigerator 20 is driven and controlled by the drive circuit 31. The heat generated in the exhaust heat section 20B of the Stirling refrigerator 20 is generated by the exhaust heat fan 24 by the exhaust heat fin 24 and discharged into an airflow passing through the inlet opening 22 of the casing 19. . Further, the airflow that has taken heat from the exhaust heat fins 24 is discharged out of the erasing device 3 through the outlet opening 23 of the casing 19 and the exhaust port 29 of the outer shell 6.
In this way, the space S of the heat insulating container 4 is cooled. The Stirling refrigerator 20 can be cooled to a very low temperature, for example, about −50 ° C. with a relatively small amount of electric power. Therefore, as shown in FIG. Can be sufficiently cooled to about −20 ° C., which is the second color change temperature (the temperature at which the second color changes). And the space 1 of the said heat insulation container 4 is cooled to the 2nd color change temperature (temperature which changes to a 2nd color) in this way, As shown in FIG. The entire surface changes color to the second color (for example, when the first color is blue and the second color is colorless as described above, the first color blue is decolored to become colorless. ). In addition, since the card 1 is accommodated vertically in the small spaces S1 to S8 opened between the partition plates 10, not only the cold heat that the card 1 is released from the inner container 8 but also the partition plates. Therefore, the card 1 can be efficiently cooled to change the color of the ink on the recording surface 1A. Further, even when a plurality of the cards 1 are accommodated in the space S, the inner container can be accommodated by accommodating the cards 1 in the small spaces S1 to S8 opened between the partition plates 10 almost equally. Since the cooling is performed by the cold heat emitted from the eight and the plurality of partition plates 10, the plurality of cards 1 can be efficiently cooled to change the color of the ink on the recording surface 1A. Further, when a plurality of the cards 1 are accommodated in each of the small spaces S1 to S8, for example, even when four cards are accommodated in each small space, for example, a total of 32 cards, the cards 1 are oriented vertically. By being accommodated, the plurality of cards 1 accommodated in the small spaces S1 to S8 are less likely to be in close contact with each other, thereby reducing the possibility that the recording surface 1A of the overlapping portion of the cards 1 will not be discolored. it can. (That is, if a plurality of cards 1 are horizontally or vertically overlapped even if they are vertically stacked, the cards 1 are in close contact with each other due to their own weight or atmospheric pressure. Although there is a possibility that the temperature of the overlapped portion does not drop sufficiently, as described above, when it is accommodated vertically in a state of being divided into small spaces S1 to S8 between the partition plates 10, as shown in FIG. Thus, since the cards 1 are difficult to adhere to each other due to their own weight or atmospheric pressure, the temperature of the entire card 1 can be lowered sufficiently.)

Then, based on the temperature information obtained from the thermistor 11, the control circuit 30 decreases the temperature in the space S to about −20 ° C., which is the second color change temperature (the temperature at which the ink changes to the second color). When it is detected, the Stirling refrigerator 20 is stopped via the drive circuit 31, the exhaust heat fan 21 is stopped, and the heater 12 is energized. The heat generated from the heater 12 is conducted to the inner container 8 and the partition plate 10 formed of aluminum or the like, and is discharged from the inner container 8 and the partition plate 10 into the space S. The inside will be heated again. The control circuit 30 controls energization of the heater 12 based on temperature information obtained from the thermistor 11.
In this way, the space S of the heat insulating container 4 is heated to room temperature, for example, 20 ° C., as shown in FIG. Then, when the space S rises to 20 ° C., which is normal temperature, the erasing process of characters and images recorded on the recording surface 1A of the card 1 is completed.
The card 1 regenerated in this way is taken out from the space S of the heat insulating container 4 of the erasing device 3 by opening the lid 9. At this time, since the card 1 is warmed to 20 ° C. which is normal temperature in the erasing device 3, dew condensation on the surface of the card 1 by taking out the card 1 from the erasing device 3 in a normal environment. There is no fear. Therefore, it is possible to record on the recording surface 1A using the thermal printer 2 immediately after the card 1 is taken out from the erasing device 3.

  When the card 1 on which characters or the like are recorded is cooled to the second color change temperature without heating to the first color change temperature, the characters and images recorded on the recording surface 1A of the card 1 are erased, Although the entire recording surface 1A changes to the second color (for example, when the second color is colorless, the entire surface of the card 1 is colorless), the erased characters and image traces remain for a while. It will be in a state that can be seen slightly. However, as described above, once the card 1 is heated to the first color change temperature, the entire recording surface 1A is changed to the first color (for example, the entire surface of the card 1 is blue which is the first color). After that, the recording surface 1A is cooled to the second color change temperature and the entire recording surface 1A is changed to the second color (for example, the first color blue is decolored and becomes colorless, and the entire surface of the card 1 becomes the ground of the card 1). In other words, when the recording surface 1A is changed to the first color (for example, coloring from colorless to blue), not the traces of characters and images. The entire recording surface 1A is uniformly discolored.

Next, the card 1 is a recording medium using a heat-erasable reversible thermochromic composition (a recording medium in which the second color is a colored state such as blue and the first color is colorlessly erased). ), The case of recording (printing) characters and images on the card 1 will be described.
In this case, as shown in FIG. 10, the user prepares the recording surface 1A of the card 1 that is colored blue or the like, and the recording surface 1A of the card 1 is locally applied to the recording surface 1A by the thermal printer 2. The temperature is changed to a color change temperature of the temperature-changeable ink (a first color change temperature at which the reversible thermochromic layer changes to the first color. In this embodiment, about 70 ° C.). As a result, the heated area changes color to the first color (for example, a state in which the color is erased from blue to colorless), and arbitrary characters and images are recorded on the recording surface 1A of the card 1 as shown in FIG. The Note that the characters and images recorded on the card 1 do not fall below a predetermined second discoloration temperature (in this embodiment, about −20 ° C.), the first color discoloration state (the second color as described above). When the color is blue and the first color is in a state where the blue color has disappeared and becomes colorless, the blue color of the character or image portion is erased and the white color that is the background color of the card 1 is The visible white state) is maintained.

Next, the case of erasing characters and images recorded on the card 1 will be described.
First, the user collects the card 1 on which characters and images are recorded, accommodates the collected card 1 in the space S in the heat insulating container 4 of the erasing device 3, and operates the erasing device 3. .

  First, the space S in the heat insulating container 4 of the erasing device 3 is heated by the heater 12 to change the color change temperature of the ink (the reversible thermochromic layer changes to the first color as shown in FIG. 7). It is heated to 70 ° C., which is 1 discoloration temperature. In this way, once the space S of the heat insulating container 4 is heated to the first color change temperature, the recording surface 1A of the card 1 is temporarily changed to the first color as shown in FIG. As described above, when the second color is blue and the first color is in a state where the blue color disappears and becomes colorless, the blue color is erased on the entire surface of the card 1 and the background color of the card In a state of white one color).

Then, based on the temperature information obtained from the thermistor 11, the control circuit 30 has a temperature in the space S up to about 70 ° C., which is the first color change temperature of the ink (the temperature at which the second color is erased). When it is detected that the heater has risen, the heater 12 is stopped, the Stirling refrigerator 20 is operated, and the exhaust heat fan 21 is further operated. As a result, the space S of the heat insulating container 4 is cooled.
Then, by cooling the space S of the heat insulating container 4 to the second color change temperature (temperature changing to the second color), the entire recording surface 1A of the card 1 is changed in color as shown in FIG. (For example, when the second color is blue as described above, the second color is changed to blue).

Then, based on the temperature information obtained from the thermistor 11, the control circuit 30 decreases the temperature in the space S to about −20 ° C., which is the second color change temperature (the temperature at which the ink changes to the second color). When it is detected, the Stirling refrigerator 20 is stopped, the exhaust heat fan 21 is stopped, and the heater 12 is energized. Thereby, the inside of the space S is heated again. The control circuit 30 controls energization of the heater 12 based on temperature information obtained from the thermistor 11.
In this way, the space S of the heat insulating container 4 is heated to room temperature, for example, 20 ° C., as shown in FIG. Then, when the space S rises to 20 ° C., which is normal temperature, the erasing process of characters and images recorded on the recording surface 1A of the card 1 is completed.

  As in the case of using a recording medium using a heat-developable reversible thermochromic composition, the card 1 on which characters and the like are recorded is cooled to the second color change temperature without being heated to the first color change temperature. In this case, the characters and images recorded on the recording surface 1A of the card 1 are erased, and the entire recording surface 1A is changed to the second color (for example, when the second color is blue, the card 1 However, for a while, the erased characters and traces of the image will be slightly visible. However, as described above, once the card 1 is heated to the first color change temperature, the entire recording surface 1A is changed to the first color (for example, the second color blue is decolored to become colorless and the entire surface of the card 1 is changed). Is changed to a white color which is the background color of the card 1, and then cooled to the second color change temperature to change the entire recording surface 1A to the second color (for example, from colorless to blue) ), But the trace of the entire recording surface 1A changes to the first color (for example, the color disappears from blue to colorless), not the traces of characters or images, so the entire recording surface 1A is uniform. Will be discolored.

  As described above, according to the present invention, the reversible thermochromic layer is formed on the recording surface 1A, and becomes the first color when the temperature is equal to or higher than a predetermined first color change temperature (for example, 70 ° C.). 20 [deg.] C. or lower) on the card 1 as the recording medium that becomes the second color at a temperature below, the thermal printer 2 that records by heating an arbitrary area of the recording surface 1A of the card 1 to the first discoloration temperature or higher. After the image is recorded, the recorded card 1 is accommodated in the inner container 8 of the heat insulating container 4 of the erasing device 3 as necessary, and cold heat is generated by the Stirling refrigerator 20 to generate the heat transfer block 26 and the thermosiphon. The space S in the heat insulating container 4 is cooled to the second color change temperature or lower through the heat transfer means 17 comprising 27, whereby the entire surface of the card 1 is changed to the second color, and the recorded characters and images are displayed. to erase. Thereby, by putting a large amount of the recorded card 1 in the space S of the heat insulating container 4 of the erasing device 3, it is possible to efficiently erase a large number of characters and images recorded on the card 1. It can be done. By using the Stirling refrigerator 20 as a refrigerator, even if the recording surface 1A of the card 1 is coated with ink having a very low second color change temperature, the space S of the heat insulating container 4 of the erasing device 3 is used. The inside can be efficiently cooled to the second discoloration temperature to reliably erase the recorded characters and images.

  Further, in the present invention, before the space S of the heat insulating container 4 of the erasing apparatus 3 is cooled by the Stirling refrigerator 20, the control circuit 30 once heats the space S by the heater 12 to the first discoloration temperature or higher. The entire recording surface 1A of the card 1 is once changed to the first color, and then the space S is cooled to a second color change temperature or lower by the Stirling refrigerator 20 to change the entire recording surface 1A of the card 1 to the first color. By changing the color to two colors, the characters and images recorded on the card 1 can be erased without leaving marks.

  Further, in the present invention, after the space S in the heat insulating container 4 is cooled to the second discoloration temperature or lower by the Stirling refrigerator 20, the space S in the heat insulating container 4 is heated to room temperature by the heater 12. As described above, since the reproduced card 1 accommodated in the erasing device 3 can be brought to room temperature by being controlled by the control circuit 30 as described above, when the card 1 is taken out, It is possible to prevent condensation on the surface.

  Further, according to the present invention, the heat insulating container 4 of the erasing apparatus 3 has an inner container 8 made of metal such as aluminum having a high thermal conductivity, and a metal having a high thermal conductivity such as aluminum in the inner container 8. By providing a plurality of partition plates 10 made of heat with respect to the inner container 8, the recorded card 1 is placed in the inner container 8 of the heat insulating container 4 of the erasing device 3. After being accommodated in the small spaces S1 to S8 opened between the plates 10 and heating the space S in the heat insulating container 4 to the first discoloration temperature or higher by the heater 12, the Stirling refrigerator 20 can When the space S is cooled to the second color change temperature or lower, the partition plate 10 also releases and absorbs heat, so that the space S in the inner container 8 is made to be the first color change temperature or higher and the second color change temperature or lower without blur. And this makes heavy Suits the first color change temperature or more and the following second color change temperature to the inside of the card 1, it can be erased reliably characters and images recorded on the card 1.

In addition, this invention is not limited to the above embodiment, A various deformation | transformation implementation is possible within the range of the summary of invention.
For example, in the above-described embodiment, the case where the card 1 formed of a synthetic resin sheet is used as a recording medium (printing medium) has been described as an example. However, the recording medium is not limited thereto, and may be paper or the like. Good. Furthermore, the recording medium is not limited to a sheet shape, and may be a three-dimensional shape such as various containers such as trays and cups, a pen shaft, and the like.
Moreover, in the said embodiment, although the thermosiphon was used as a heat-transfer means, the said heat-transfer means may be only a heat-transfer block, and you may make it cool an inner container by the heat conduction through a heat-transfer block.
In the above embodiment, when the recording medium is taken out from the erasing apparatus, the room temperature is set to 20 ° C. In short, when the recording medium is taken out from the erasing apparatus, moisture in the air is not condensed on the surface of the recording medium. The temperature may be about 20 ° C., for example, about 10 to 30 ° C.
Furthermore, in the above embodiment, eight open small spaces are formed in the inner container by seven partition walls, but the number of the partition walls can be arbitrarily set. In addition, the present invention is not limited to the case where a small space is formed in the inner container by the partition wall. For example, the recording medium is accommodated in a bag or rack so as not to interfere with each other, and the entire bag or rack is recorded. You may make it accommodate a medium in an inner container. With such a configuration, the recording medium can be easily accommodated and taken out from the inner container.
In the above embodiment, the case where characters and images are recorded (printed) on the recording medium by the thermal printer 2 has been described as an example. However, the method of recording on the recording medium can heat the recording medium locally. It may be sufficient and it is not limited to what was illustrated here. For example, a method of heating a recording medium with a laser or the like may be used, or a user can manually write an object (recording medium) with the pen using a pen that can generate heat at the tip. Techniques other than printing, such as recording characters and images, can also be used.
In the above embodiment, the case where the color of the ink is developed and the case where the color is erased (colorless) is described as an example of the color change. However, the color change is not limited to this. It also includes the case where the color changes.

1 is an overall view of a recording / erasing system showing an embodiment of the present invention. FIG. 2 is an external view of a recording medium using a heat-colorable reversible thermochromic composition. FIG. 2 is an external view of the erasing device. It is sectional drawing of an erasing apparatus same as the above. It is an expanded sectional view which shows the state which accommodated the card | curd in the erasing apparatus same as the above. It is a block diagram of the circuit of an erasing apparatus same as the above. It is a graph which shows the outline of the temperature change in an erasing apparatus same as the above. It is explanatory drawing which shows the process recorded on the recording medium using a heating coloring type reversible thermochromic composition same as the above. FIG. 4 is an explanatory diagram showing a process of erasing the recording on the recording medium using the heat-colorable reversible thermochromic composition. FIG. 2 is an external view of a recording medium using a heat erasing type reversible thermochromic composition. It is explanatory drawing which shows the process recorded on the recording medium using a heat decoloring type reversible thermochromic composition same as the above. It is explanatory drawing which shows the process in which the recording of the recording medium using the heat decoloring type reversible thermochromic composition same as the above is erased. It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the heat decoloring type reversible thermochromic composition used in the present invention. 1 is a schematic diagram illustrating a main configuration of a thermal printer according to an embodiment of the present invention.

Explanation of symbols

1 card (recording medium)
1A Recording surface 2 Thermal printer (recording device)
DESCRIPTION OF SYMBOLS 3 Eraser 4 Thermal insulation container 8 Inner container 10 Partition plate 12 Heater 17 Heat transfer means 20 Stirling refrigerator (refrigerator)
30 control circuit 52 print head T ₁ complete color development temperature T ₂ color erasure retention temperature T ₃ color development retention temperature T ₄ complete color erasure temperature ΔH hysteresis width

Claims (7)

A reversible thermochromic layer containing a reversible thermochromic composition is formed on the recording surface and becomes the first color when the temperature is not lower than a predetermined first color change temperature, and the second color is not higher than a predetermined second color change temperature. A recording medium;
A recording apparatus for recording by heating the recording surface of the recording medium to a temperature not lower than the first discoloration temperature;
An erasing device having an insulating container, a refrigerator that generates cold heat, and a heat transfer means that transmits the cold heat generated by the refrigerator into the heat insulating container and cools the heat insulating container to a second color change temperature or lower. ,
Recording / erasing system. The first color change temperature is a temperature higher than normal temperature, and the second color change temperature is a temperature lower than normal temperature,
The reversible thermochromic layer formed on the recording medium includes a reversible thermochromic composition that is decolored at the first color change temperature and develops color at the second color change temperature. Record / erase system. The first color change temperature is a temperature higher than normal temperature, and the second color change temperature is a temperature lower than normal temperature,
The reversible thermochromic layer formed on the recording medium includes a reversible thermochromic composition that develops color at the first color change temperature and decolors at the second color change temperature. Record / erase system.   The recording / erasing system according to any one of claims 1 to 3, wherein the reversible thermochromic layer contains a non-thermochromic dye or pigment.   5. The apparatus according to claim 1, wherein the erasing device includes a heater, and further includes a control circuit that heats the inside of the heat insulating container to a temperature not lower than a first color change temperature and then cools the temperature to a temperature lower than a second color change temperature. The recording / erasing system according to any one of the above.   The erasing device is controlled by the control circuit to heat the inside of the heat insulation container to room temperature after the inside of the heat insulation container is cooled to a second discoloration temperature or lower. 5. The recording / erasing system according to 5.   7. The recording / erasing system according to claim 1, wherein the refrigerator is a Stirling refrigerator.

Images