JP2001341429A - Initializing method of reversible heat sensitive recording medium, rewriting method and rewriting and initializing device. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an initializing method and a rewriting method, by which a favorable recorded image having no afterimage (which emerges as ununiform coloring) is obtained at the rewriting of the image of a reversible heat sensitive recording medium and its device. SOLUTION: This initializing method is that of the reversible heat sensitive recording medium, which develops color or decolorizes due to the change of a heating temperature or of a cooling speed after heating. In this method, an operation for uniformalizing a recording layer by heating the whole surface or the recording region of the reversible heat sensitive recording medium with a thermal head up to its coloring temperature for developing color in the medium is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversible thermosensitive coloring composition utilizing a coloring reaction between an electron-donating color-forming compound and an electron-accepting compound. The present invention relates to an initialization method, a rewriting method, and a rewriting device for a reversible thermosensitive recording medium capable of forming and erasing information.

[0002]

2. Description of the Related Art Conventionally, an electron-donating color-forming compound (hereinafter, referred to as an electron-donating color-forming compound)
Thermosensitive recording media utilizing a color-forming reaction between a color former or a leuco dye) and an electron-accepting compound (hereinafter also referred to as a developer) are widely known. Used in printers. However, these conventional recording media that have been put into practical use all have irreversible color development, and it has not been possible to erase recorded images once and use them repeatedly.

On the other hand, in recent years, a recording medium capable of reversibly developing and decoloring has been proposed.
Japanese Patent Application Laid-Open No. 1936991 discloses a composition using a combination of gallic acid and phloroglucinol as a color developing agent. Japanese Patent Application Laid-Open Nos. 62-138556, 62-138568, and 62-140
JP-A-881 discloses a recording layer containing a homogeneous solution of a color former, a developer and a carboxylic acid ester in a recording layer, and JP-A-63-173684 uses an ascorbic acid derivative as a developer. Is disclosed in Japanese Patent Laid-Open No.
JP-A-93-93 and JP-A-2-188294 disclose proposals in which bis (hydroxyphenyl) acetic acid or a salt of gallic acid and a higher aliphatic amine is used as a developer.

Further, in Japanese Patent Application Laid-Open No. 5-124360, an organic phosphoric acid compound, an aliphatic carboxylic acid compound or a phenol compound having a long-chain aliphatic hydrocarbon group is used as a color developing agent. By combining with a certain leuco dye, color development and decoloration can be easily performed by heating and cooling conditions, and furthermore, it is possible to stably maintain the color development state and the color decoloration state at room temperature, and furthermore, to develop and decolor A reversible thermosensitive coloring composition capable of repeating colors and a reversible thermosensitive recording medium using the same in a recording layer have been proposed. Thereafter, the use of a specific structure for a phenol compound having a long-chain aliphatic hydrocarbon group has been proposed (Japanese Patent Application Laid-Open No. 6-210954).

As a method of rewriting these recording media, image formation using a thermal head is generally widely used as a printing method. On the other hand, a hot stamp or a ceramic heater is used as an erasing method.
Rewriting devices using these printing and erasing methods are used as card printers and the like.

In order to reduce the size and cost of the apparatus, there has been proposed a method of performing printing and erasing by using a thermal head. For example, Japanese Patent Application Laid-Open No. Hei 7-52421 discloses a method of applying a voltage to a thermal head during printing. A rewritable card processing device having an applied voltage control means for increasing the voltage and setting the applied voltage low during erasing is disclosed in
In Japanese Patent Publication No. 0, a preheating area is provided before the recording area of the recording medium as an overwriting method, and preheating of the thermal head is performed in the preheating area, thereby reducing printing and erasing defects in the recording area. It has been proposed to. These proposals all use a transparent / opaque reversible thermosensitive recording medium. However, after erasing by the thermal head, when reprinting is performed, the image pattern before erasing, that is, an afterimage remains, and there is a disadvantage that an afterimage is easily generated particularly in a halftone color developing portion.

Further, the present inventors have proposed a method of heating or heating / erasing a medium of Muku once as a pre-treatment at the time of producing a raw material or before shipment from a factory. But,
These were only the first time, ie, initialization, for the medium of Muku (unused medium), and did not perform the heating step in each recording step. Further, the heating means used in practice has been almost limited to heating by an oven or the like which can heat a large amount of medium at once.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an initialization method and a rewriting method for obtaining a good recorded image free from afterimages (appearing as color unevenness) when rewriting an image on a reversible thermosensitive recording medium. It is to provide a method and an apparatus therefor.

[0009]

According to the present invention, a reversible thermosensitive recording medium that develops or decolors depending on a difference in a heating temperature or a cooling rate after heating uses a developer having a long-chain alkyl group and a leuco dye. After examining the residual image on the thermosensitive recording medium, an operation (step) of heating the entire surface to a temperature equal to or higher than the color development temperature of the reversible thermosensitive recording medium was added before the erasing operation (step) prior to the printing operation (step). It has been found that the rewriting method can obtain a clear rewritten image without being affected by the print pattern before erasure, that is, without a residual image (image unevenness). In addition, it was also found that a clear rewritten image free from afterimages (color unevenness) at the time of rewriting can be obtained by similarly initializing an unrecorded recording medium by heating the entire surface.

Also, a practical rewriting device suitable for performing such an excellent rewriting method has been created.

That is, the basic rewriting method of the reversible thermosensitive recording medium of the present invention is to apply energy to the entire surface or the recording area of the recording medium at the beginning of each rewriting step (operation) so as to bring about a coloring state (coloring). Heating to a temperature or heating to develop color over the entire surface). Further, rewriting is performed by simultaneously or independently performing an erasing operation (step) and a printing operation (step) as needed. Also,
It is characterized in that the recording head is initialized by applying an energy which is a coloring condition to the unrecorded recording medium by a thermal head.

In the basic rewriting method for a reversible thermosensitive recording medium according to the present invention, in each rewriting step, first, an energy which is a coloring condition is applied to the entire surface or the recording region of the recording medium (heating is performed to color the entire surface). The heating means is adjusted, or the heating time of the reversible thermosensitive recording medium is adjusted. Or it is more preferable to adjust both.
The same applies to erasing / printing. The adjustment of the heating unit / erasing unit / printing unit includes the output intensity and / or output time of each unit, or the exercise timing of each unit. For example, rewriting is performed by simultaneously or independently performing the erasing step and the printing step as needed. In addition, an energy which is a coloring condition is applied to an unrecorded recording medium by a thermal head to initialize the medium. These operations can be performed well using the rewriting device of the present invention. For the sake of explanation, the rewriting method and rewriting device have been described assuming a medium on which an image has already been printed on a medium, but the rewriting method of the present invention can be applied to an unused medium, and By heating the entire surface even before printing, the effect of the present invention can be strictly exhibited. This is the initialization method according to the present invention.

[0013] Therefore, the above object is achieved by (1) the present invention.
"This is a method for initializing a reversible thermosensitive recording medium that develops or decolors depending on the difference in heating temperature or cooling rate after heating. A method of initializing a reversible thermosensitive recording medium, characterized by performing an operation of heating the medium to a color development temperature to develop a color to make the recording layer uniform, and (2) “the color development by the color development operation is performed. The method for initializing a reversible thermosensitive recording medium according to the above item (1), wherein the color is erased by slow cooling. (4) The initialization method for a reversible thermosensitive recording medium according to (2), wherein the method is performed using one of a roller, laser light irradiation, and a sheet heater. Coloring operation But the first (1) initialization method of the reversible thermosensitive recording medium according to claim, characterized in that it is erased by heating ", color development due to (5)" the color operation,
(4) The method for initializing a reversible thermosensitive recording medium according to the above (4), wherein the color is erased by heating and cooling operations after the color forming operation. (7) The method for initializing a reversible thermosensitive recording medium according to the above (4) or (5), which is performed by a thermal head or laser beam irradiation. The reversible thermosensitive material according to any one of the above items (1) to (6), wherein the color forming operation of the entire region is performed by heating to a temperature at which the color is colored to the maximum density. Initialization method of recording medium ",
(8) The method for initializing a reversible thermosensitive recording medium according to any one of the above items (1) to (7), wherein the color development start temperature substantially coincides with the melting point of the developer. Is achieved preferably. The operation referred to here means an operation step or operation step, and may be simply referred to as “step” hereinafter. Further, the heat block in the present invention includes a heat stamp.

Another object of the present invention is to provide (9) a method for rewriting a reversible thermosensitive recording medium which develops or decolors depending on a difference in a heating temperature or a cooling rate after heating. An operation of heating the entire surface or the recording area to the coloring temperature of the reversible thermosensitive recording medium to form a color, an operation of erasing the entire surface or the recording area of the entire color, and a step of printing again on the entire surface or the recording area and printing on the printing unit A rewriting method for a reversible thermosensitive recording medium characterized by sequentially performing an operation of re-forming a color-formed image ”, (10)“ Reversible thermosensitive material that develops or decolors depending on the difference in heating temperature or cooling rate after heating. A method for rewriting a recording medium, the method comprising: heating the entire surface or a recording area of a reversible thermosensitive recording medium to a coloring temperature of the reversible thermosensitive recording medium to form a color; and coloring the entire surface or the recording area. A method of rewriting a reversible thermosensitive recording medium, characterized by sequentially performing operations of re-printing and re-forming a color image on a printed portion following the entire erasure, and (11) “heating temperature or cooling rate after heating”. A method for rewriting a reversible thermosensitive recording medium that develops or decolors due to the difference between the reversible thermosensitive recording medium and the entire surface or the recording area is heated to the coloring temperature of the reversible thermosensitive recording medium to develop a color. (A) rewriting a reversible thermosensitive recording medium, which sequentially performs the operation of erasing the color development of the entire surface or the recording area in an image-wise manner, (12) "color development due to difference in heating temperature or cooling rate after heating. Or a method for rewriting a reversible thermosensitive recording medium to be decolored, wherein the entire surface or recording area of the reversible thermosensitive recording medium is heated to the coloring temperature of the reversible thermosensitive recording medium to form a color, and Rewriting method of the reversible thermosensitive recording medium, characterized by performing the operation for erasing the color of the recording area imagewise simultaneously or sequentially with the "(13)
"A rewriting method for a reversible thermosensitive recording medium that develops or decolors depending on a difference in heating temperature or a cooling rate after heating, wherein the entire surface or recording area of the reversible thermosensitive recording medium is colored with the coloring temperature of the reversible thermosensitive recording medium. Reversible thermosensitive recording medium characterized by sequentially performing an operation of erasing the entire surface of the color following the heating and coloring, and an operation of printing again on the entire surface or the recording area and re-forming a color image on a printing unit. (14) "A rewriting method for a reversible thermosensitive recording medium that develops or decolors depending on a difference in a heating temperature or a cooling rate after heating. The reversible thermosensitive recording medium is characterized in that heating and coloring to the coloring temperature of the reversible thermosensitive recording medium, and erasing and re-printing the entire coloring and re-forming a colored image in a printing portion are continuously performed. book It is achieved by the method ".

The object of the present invention is also described in (15) of the present invention, wherein the coloring by the coloring operation of the entire surface or the entire recording area is erased by slow cooling.
The item (10), the item (13) or the item (1)
(4) The method for rewriting a reversible thermosensitive recording medium according to any one of the items (1) to (4), wherein the color developing operation on the entire surface or the entire recording area is performed by heating the reversible thermosensitive recording medium to a color developing temperature or higher. Being executed.
Rewriting method for reversible thermosensitive recording medium described in item 5) ”(1)
7) “(11) wherein the color forming operation of the entire surface or the entire recording area is performed using one of a thermal head, a heat block, a heat roller, laser irradiation, and a planar heater. Item, the item (12), the method for rewriting a reversible thermosensitive recording medium according to any one of the items (15) and (16) ”.

Still another object of the present invention is to provide (18) the present invention.
"The color development by the color development operation on the entire surface or the entire recording area is erased by heating, wherein the item (9), the item (10), the item (13) or the item (14) is removed. Item 19. The rewriting method for a reversible thermosensitive recording medium according to any one of the paragraphs, and (19) "the coloring by the coloring operation on the entire surface or the entire recording area is erased by the heating and cooling operations after the coloring operation." The method for rewriting a reversible thermosensitive recording medium according to the above (18), "
(20) Any of the above items (9) to (19), wherein the color forming operation of the entire surface or the entire recording area is performed by heating to a temperature at which the color is colored to the maximum density. (21) A method for rewriting a reversible thermosensitive recording medium according to (1), (21), wherein the coloring operation of the entire surface or the entire recording area is performed by using a thermal head or laser irradiation. (22) "The method for rewriting a reversible thermosensitive recording medium according to the above item", (22) "(9) to (21), wherein the color development start temperature substantially coincides with the melting point of the color developer. The rewriting method for a reversible thermosensitive recording medium according to any one of "1."

Another object of the present invention is to provide (23) a reversible thermosensitive recording composition comprising a reversible thermosensitive recording composition which is colored or decolored depending on a difference in heating temperature or cooling rate after heating and which can repeatedly record and erase images. A rewriting device for a reversible thermosensitive recording medium having a layer, the rewriting device having a heating unit, an erasing unit, and a printing unit for heating a recording area of the reversible thermosensitive recording layer, wherein the heating unit, the erasing unit And / or the printing unit includes a pulse energizing unit that is controllable between an energizing period and a non-energizing period, and the amount of energization during the energizing period is controlled. (24) "A reversible thermosensitive recording layer having a reversible thermosensitive recording layer made of a reversible thermosensitive recording composition which is colored or decolored depending on the heating temperature or the cooling rate after heating and which can repeatedly record and erase images. A recording medium rewriting device, wherein the rewriting device has a heating means for heating the recording area of the reversible thermosensitive recording layer therein, an erasing means, a printing means, and a conveyance means for the reversible thermosensitive recording medium, The transporting means changes the transporting speed of the reversible thermosensitive recording medium in the apparatus so that the operation period of the reversible thermosensitive recording medium by at least one of the heating means, the erasing means, and the printing means is controlled by the other two means. A rewriting device for a reversible thermosensitive recording medium, characterized by controlling the temperature and / or rate of heating and / or cooling in each of the means by differentiating the operation period from the above.
(25) "A rewriting device for a reversible thermosensitive recording medium having a reversible thermosensitive recording layer made of a reversible thermosensitive recording composition which is colored or erased depending on the heating temperature or the cooling rate after heating and which can repeatedly record and erase images. Wherein the rewriting device has a heating unit, an erasing unit, and a printing unit for heating a recording area of the reversible thermosensitive recording layer, and the heating unit and / or the erasing unit is a thermal head, a sheet heater, or a heating unit. The rewriting device for reversible thermosensitive recording medium according to the above item (23) or (24), which is one of a roller and a heating temperature or a cooling rate after heating. A reversible thermosensitive recording medium having a reversible thermosensitive recording layer composed of a reversible thermosensitive recording composition which is colored or erased depending on the difference and which can repeatedly record and erase images. But heating means for heating the recording area of the reversible thermosensitive recording layer has a deletion means, and printing means,
The rewriting device for a reversible thermosensitive recording medium according to the item (23) or (24), wherein the heating unit, the erasing unit, and / or the printing unit are a thermal head. You.

Hereinafter, the present invention will be described in detail. The reversible recording layer in the present invention may be on the entire surface of the medium or on a part thereof. When it is located in a part, the heating region may be the whole surface or a part, but it is preferable that part of the heating region does not consume extra heat and does not cause extra damage. In the case of the entire surface, the heating region naturally becomes the entire surface. Even when the recording area is located on the entire surface, there are cases where the recording area is used only partially and where the entire area is used. In the case of the entire surface, the heating region is naturally the entire surface, but in the case of a part, the heating region may be the entire surface or a part.

The rewriting method of separating printing from heating and erasing by pixels uses a thermal head, and in a device that prints one pixel line at a time, the medium is fed stepwise (stopped during printing) or continuous printing. This is suitable when the feeding speed is slower than the time. The reason is that the medium advances if the feed is continuous and the feed is faster than the printing time.
This is because even if the slow cooling pulse is added, the slow cooling effect is not obtained, and the color is developed.

The color development and decoloration in the present invention do not mean a change between a cloudy state and a transparent state due to a change in light scattering but a difference between a colorless or light color and a colored or dark color. In other words, the present invention relates to a heat-sensitive recording medium utilizing a color development reaction between an electron-donating color-forming compound and an electron-accepting compound. The color development start temperature of the present invention usually almost coincides with the melting point of the color developer.

The energy for the color-forming condition means the energy for heating to the color-forming temperature or the energy for heating to color the entire surface. The inside of the recording layer is heated by a thermal head, a heat roller, a sheet heater, or the like. This is a condition at which the melting point is substantially equal to or higher than the melting point of the developer. Coloring is confirmed by rapid cooling after heating, but the color may also be erased depending on the cooling conditions, and the degree of coloring varies depending on the characteristics of the material used for the recording medium. But,
In the present invention, by applying energy equal to or higher than the coloring condition by heating the entire surface to a temperature equal to or higher than the coloring temperature, there is substantially no difference in the state of the inside of the recording layer between the recording area portion and the non-recording area, and the uniformity is achieved. This solves the problem. Therefore, it does not matter whether the state after the processing is the colored state or the erased state.

The reversible thermosensitive recording medium used in the rewriting method of the present invention is capable of forming a relatively colored state and a decolored state depending on the heating temperature and / or the cooling rate after heating. Hereinafter, as an example of a recording medium used in the present invention, a basic color developing / decoloring phenomenon of a composition including a color former and a developer will be described. FIG. 1 shows the relationship between the color density and the temperature of the recording medium. When the temperature of the recording medium in the decolored state (A) is raised at _{first, the} temperature T ₁ at which the recording medium starts to melt.
And a color is formed (B). When rapidly cooled from the molten coloring state (B), the temperature can be lowered to room temperature while maintaining the coloring state, and the solidified coloring state (C) is obtained. Whether this color-developed state is obtained depends on the rate of temperature decrease from the melted state. In the case of slow cooling, decoloration occurs in the process of temperature decrease, and the same decolored state (A) or rapidly-colored state (C) as at the beginning. A) is formed with a relatively lower concentration. On the other hand, rapidly cooled colored state (C) is again raised gradually and decoloration occurs with a color temperature lower than temperature T ₂ and (E from D), returns the beginning when the temperature decreases from here to the same decolored state (A). Actual color temperature,
The decoloring temperature varies depending on the combination of the color developer and the color former used, and can be selected according to the purpose. Further, the density in the molten color-developing state and the color density after quenching are not always the same and may differ.

In this recording medium, the color-developed state (C) obtained by quenching from the molten state is a state in which the developer and the color-developing agent are mixed in a state in which molecules can contact and react with each other. Often formed. This state is a state in which the color developer and the color forming agent aggregate to maintain the color development, and it is considered that the color formation is stabilized by the formation of the aggregate structure. On the other hand, the decolored state is a state where both are separated. Separation involves phase separation of both. Alternatively, it is considered that the separation of the two is probably caused by the contraction of the resin binder dispersed therein during the cooling mode and the binding force of the two molecules by the resin binder upon contraction. This state is a state in which molecules of at least one compound are aggregated to form a domain or crystallized, and it is considered that the color former and the developer are separated and stabilized by aggregation or crystallization. Can be In many cases, the present invention causes more complete decoloration due to phase separation of the two and crystallization of the color developer. In the decoloring by slow cooling from the molten state and the decoloring by raising the temperature from the colored state shown in FIG. 1, the cohesive structure changes at this temperature, and phase separation and crystallization of the developer occur.

Considering the mechanism of color development and decoloration described above, it is considered that in the decoloration process, phase separation between the color developer and the color former occurs, and single color crystallization of the color developer occurs. At this time, when the heating to the decoloring temperature region is performed for a long time, the color developer and the color developing agent can be sufficiently separated from each other. It is believed that the color former separates but exists relatively close. In addition, it is considered that there is a great difference in the degree of separation between the color former and the developer between the part that was the image part before erasing and the part that was the background part. Depending on the degree of the separation, a difference occurs in the coloring characteristics. In a state where the coloring agent and the developing agent are present relatively close to each other (for example, a portion which was an image portion before rewriting),
It is easier to develop a color than a part where the color former and the developer are sufficiently separated (such as a background part before rewriting).

Further, when the recording layer of the reversible thermosensitive recording medium is heated to a temperature lower than the temperature at which melting starts (that is, the temperature T ₁ in FIG. ₁ ), a slight color development is observed. by heating to above T _1, i.e. by cooling after heating to a temperature above T _1, it can be decolored. And, as you can see from these results,
In the present invention, not only a monotone print image but also a halftone print image can be obtained by combining a controlled heating temperature or a cooling rate after heating.

As described above, the color development characteristics of the color developer and the color developer after erasure differ depending on the state before erasure. As a result, the density of the image pattern portion before erasure is different from that of the other portions (that is, afterimage). ). In addition, when erasing is performed by a thermal head, the above effect is considered to be particularly large because the heating time is very short. In the rewriting method of the present invention, at each time of each rewriting, the energy of coloring is applied to the entire surface or the recording area, and in order to make the state of the developer and the coloring agent present in the area uniform,
When the necessary rewritten image portion is printed after erasure, good rewriting can be repeated without causing a partial sensitivity difference.

As described above, in the present invention, in the rewriting process, it is important to first make the state of the color developer and the color former uniform over the entire surface. The uniformity of the state can be achieved by applying a condition in which the developer is melted and the dye diffuses, that is, an entire heating step at a temperature equal to or higher than the color development temperature (application of thermal energy for complete color development conditions) to the entire surface or the recording area at the beginning of each rewriting. Good. Further, the color forming step, the decoloring step, and the rewriting image printing step for uniformity may be performed independently, or a plurality of steps may be performed simultaneously.

When each step is performed independently,
The above steps may be performed sequentially. That is, a heat roller,
The sheet is heated to a color-developing condition by a sheet heater, a thermal head, or the like, and then a decoloring step and a printing step are performed. However, when the cooling condition after heating is gradually cooled in the first step, depending on the characteristics of the recording medium, the color may not be able to be maintained and the color may be erased to all or a certain density. In this case, the decoloring step is not required, and the printing step can be performed.

There are the following cases depending on the difference in cooling rate after the entire surface is heated. With rapid cooling, there is no erasure, and the concentration decreases as the cooling rate decreases.
Finally, it is completely erased.

When a plurality of steps are performed, the following six steps can be given as basic aspects. There is no particular problem in performing any of these rewriting methods. (I) After the heating (entire surface heating) step, a step of erasing the once colored image is performed, and then a reprinting step is performed. (Ii) After the heating (overall heating) step, a reprinting step is performed which is continuous with the slow cooling step. (Iii) After the heating (entire surface heating) step, a reprinting step is performed (negative image formation). (IV) A reprinting step is performed simultaneously with the heating (entire surface heating) step or continuously with the heating step (negative image formation). (V) A gradual cooling step following the heating (entire surface heating) step is performed to perform an erasing step of the once-colored image, and then a reprinting step. (Vi) The heating (entire surface heating) step, the slow cooling step, and the reprinting step are continuously performed.

However, in the present invention, in addition to these six basic aspects, other secondary operations (steps) can be appropriately combined as described above. Thermal properties of the reversible thermosensitive recording medium, for example, thermal sensitivity, the difference in the properties of the recording layer used, namely the thermal conductivity between each raw material used for the recording layer, melting point, volume change rate due to solid-liquid change,
Naturally, the thermal expansion coefficient, the reaction rate, etc., will differ depending on the difference in various chemical properties, so the reversible thermosensitive recording medium having a different thermal property from the previously used reversible thermosensitive recording medium will be used next time in the present invention. Is, for example, whether the heating (full surface heating) is sufficient as in the previous case, ie whether the heating is in a state where the developer and the color former are separated from each other and are relatively close to each other. Depending on this, it is preferred that no additional heating step be performed or performed. Here, whether or not the heating is sufficient depends, of course, on the heating temperature and the heating time, for example, whether or not an additional heating step is required, and depending on the temperature at which the developer in the recording layer starts melting. T ₁ (i.e. temperatures T ₁ in FIG. 1) whether it is heating to a lower temperature can be prospect.

Therefore, in the present invention, the color forming step
The decoloring step and the printing step can be performed in the following manner. (Vii) The coloring step and the decoloring step for uniformity are successively performed as the same step, and then the rewriting image printing step is performed. (Viii) After the color forming step for uniformity is performed, the decoloring step and the printing step of the rewritten image are performed simultaneously. (iX) Perform three steps simultaneously.

When the color forming step is performed by using a heat roller or a planar heater, it is difficult to simultaneously perform the color forming step and other steps at the same time. However, when the step is performed by a thermal head, a plurality of steps are performed simultaneously. It is possible.
The method of applying energy from the thermal head in these steps may be a single pulse or a plurality of pulses,
In particular, when a plurality of steps are performed simultaneously, processing can be performed by applying a plurality of pulses under different conditions.
(However, depending on the type of recording medium, decoloring may occur due to cooling conditions after heat treatment with a heat roller or sheet heater,
The coloring step and the decoloring step can be performed simultaneously. )

In the case where the color forming step and the decoloring step in the embodiment (Vii) are performed as the same step, for example, as a method of applying the energy by the thermal head, the energy for forming the color and the energy for forming the decoloring condition are determined. What is necessary is just to apply continuously. Specifically, the rewriting method shown in (Vii) will be described. For example, first, the voltage and / or the number of pulses and the frequency are controlled so as to satisfy the color-developing condition, and the voltage and / or the frequency and / or the frequency are controlled so as to continuously satisfy the decoloring condition. Energy is applied by controlling the number of pulses and the frequency. After that, there is a method of applying energy which is a coloring condition for printing a rewritten image. In the case where the decoloring step and the printing step in the mode (Viii) are performed as the same step, the energy which is the decoloring condition is applied to the entire thermal head, and the energy which is the decoloring condition is applied to the portion for forming the rewritten image. What is necessary is just to apply. (Vii
Specifically, the embodiment shown in (i) and the embodiment shown in (Vii) are described.For example, first, the recording medium is colored by applying energy which is a coloring condition, and then a voltage is set so as to be in a decoloring condition. There is a method of applying energy as a coloring condition to a portion where rewriting image printing is performed while applying energy while controlling the number and frequency of pulses.
In the case of performing the three modes of (iX), the energy for the coloring condition is applied to the entire thermal head, and the energy for the decoloring condition is continuously applied to the entire thermal head. Energy may be applied. Specifically, the mode shown in (iX) is as follows. First, the pulse intensity (voltage and current) and / or the pulse width, the number of pulses and the pulse frequency are controlled so as to satisfy the coloring conditions over the entire thermal head. Pulse strength, such as voltage and / or pulse width, so as to be the erase condition;
Applying energy by controlling the number of pulses and pulse frequency,
There is a method of applying energy which is a coloring condition to a portion where a rewriting image is printed while applying energy which is a coloring condition for printing a rewritten image.

Further, in the present invention, after the color forming step for uniforming, the rewriting may be performed by erasing only the background portion (erased portion) of the rewritten image. It is also within the scope of the present invention to make the developer and the color former uniform. These include the following two embodiments. (X) After performing the color forming step for uniformity, a step of erasing only the background portion (the portion other than the image) after rewriting is performed. (Xi) The color development step for uniformity and the step of decoloring only the background portion (other than the image) after rewriting are performed simultaneously.

In the step (X), the energy for the coloring condition is applied to the entire thermal head, and then the energy for the decoloring condition is applied to the background portion of the rewritten image.
When the method shown in (X) is specifically shown, for example, first, after applying the energy which is the coloring condition, the recording medium is colored, and then the partial erasing condition corresponding to the background portion of the rewritten image is obtained. For example, there is a method of applying energy by controlling the voltage and / or the pulse width, the number of pulses, and the frequency. In the step (Xi), the energy for the color development condition may be applied to the entire thermal head, and the energy for the color erasure condition may be continuously applied to the background portion of the rewritten image. (X
When the method shown in i) is specifically shown, for example, first, the recording medium is colored by first applying the energy that is the coloring condition so that the partial erasing condition corresponding to the background portion of the rewritten image is continuously obtained. For example, there is a method of applying energy by controlling the voltage and / or the pulse width, the number of pulses, and the frequency.

In the non-colored portion of the reversible thermosensitive recording medium used in the present invention, in which color has never been formed, the dispersed particles composed of crystals of the developer alone are usually well separated from the color former. I have. On the other hand, in the color-developed portion, since the color developer is melted and erased after being mixed well with the color developer, the color developer and the color developer are separated but exist relatively close to each other. it is conceivable that. As described above, since the difference between the state of the color developer and the state of the color developing agent is the largest between the uncolored portion where the color has never been formed and the portion where the color has been formed one or more times, the coloring process of the entire surface or the recorded portion is performed as the initialization of the recording medium. Performing the process once first has a great effect of making the inside of the recording layer uniform. However, in a normal case, since the coloring temperature is considerably high, the influence on the support and the like is large. For example, there is a problem that the curl is largely generated by heating with a heat roller or the like. Therefore, by performing the coloring step with a thermal head, the recording layer can be heated to a high temperature for a short time, and the influence on the support and the like is reduced.

As a method for uniformizing and initializing the recording layer using a thermal head, it is sufficient to apply the energy for coloring once to the entire surface or the recording area of the unrecorded recording medium. There are two embodiments. (Xii) After performing a coloring step for uniformizing the uncolored recording layer with a thermal head, a decoloring step is performed using a heat roller, a sheet heater, hot air or a thermal head to initialize. (Xiii) A coloring step for making the uncolored recording layer uniform is performed by a thermal head, and at the same time, energy is applied as an erasing condition to initialize the recording layer. Further, rewriting is performed a plurality of times, and when a problem occurs in the image, by performing the coloring process on the entire surface or the recording area as described above, the state inside the recording layer is uniformed, and the rewritten image is in a good state. Become.

As the reversible thermosensitive recording medium used in the present invention, for example, a developer having a long-chain alkyl group and a leuco dye are used. The basic configuration of the reversible thermosensitive recording medium is shown below.
As the developer having a long-chain alkyl group, a compound having an alkyl chain having 8 or more carbon atoms is preferable, and a compound having a phenolic hydroxyl group is particularly preferably used. The compounds shown are preferably used.

[0040]

Embedded image In the formula, X ₁ represents a divalent group containing a hetero atom or a direct bond, and X ₂ represents a divalent group containing a hetero atom. R ₁
Represents a divalent hydrocarbon group, and R ₂ has 1 to 22 carbon atoms.
Represents a hydrocarbon group. Further, m represents an integer of 0 to 4, and when m is 2 to 4, R ₁ and X ₂ repeated may be the same or different. N represents 1 to 3.

Specifically, R ₁ and R ₂ each represent a hydrocarbon group which may have a substituent, which may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. It may be a hydrocarbon group constituted. Further, the aliphatic hydrocarbon group may be linear or branched, and may have an unsaturated bond. Examples of the substituent attached to the hydrocarbon group include a hydroxyl group, a halogen, and an alkoxy group. Note that R ₁ may be a direct bond. When the sum of the number of carbon atoms of R ₁ and R ₂ is 7 or less, the stability of color development and the decoloring property decrease, so that the number of carbon atoms is preferably 8 or more, more preferably 11 or more. X ₁ and X ₂ each represent a divalent group containing a hetero atom, preferably a divalent group having at least one of the groups shown in Table 1.

[0042]

[Table 1] Examples are shown in Table 2.

[0043]

[Table 2] Particularly preferred examples of the phenol compound used in the present invention include a compound represented by the following formula.

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

[0048]

Embedded image In the formula, w, w ', and y each independently represent an integer that satisfies the carbon number of R ₁ or R ₂ .

In the present invention, another developer can be used in combination with the phenolic compound. As the developer used in combination, as disclosed in JP-A-5-124360, together with typical examples of a phosphoric acid compound, a fatty acid compound and a phenol compound having a long-chain hydrocarbon group, a coloring agent is present in the molecule. Can be used in combination with a structure having a color-developing ability capable of developing a compound and a structure having a structure for controlling cohesion between molecules.

Hereinafter, the color developer used in the present invention will be specifically exemplified. Examples of the organic phosphoric acid developer include the following compounds. Dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, docosylphosphonic acid, tetracosylphosphonic acid, ditetradecyl phosphate, dihexadecyl phosphate, phosphoric acid Dioctadecyl ester, dieicosyl phosphate, dibehenyl phosphate, and the like.

The following compounds can be exemplified as the aliphatic carboxylic compound. 2-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 2-hydroxyoctadecanoic acid, 2-hydroxyeicosanoic acid, 2-hydroxydocosanoic acid, 2-bromohexadecanoic acid, 2-bromooctadecanoic acid, 2-bromoeicosanoic acid 2-bromodocosanoic acid, 3-bromooctadecanoic acid, 3-bromodocosanoic acid, 2,3-dibromooctadecanoic acid,
Fluorododecanoic acid, 2-fluorotetradecanoic acid, 2
-Fluorohexadecanoic acid, 2-fluorooctadecanoic acid, 2-fluoroeicosanoic acid, 2-fluorodocosanoic acid, 2-iodohexadecanoic acid, 2-iodooctadecanoic acid, 3-iodohexadecanoic acid, 3-iodooctadecanoic acid, par Fluorooctadecanoic acid and the like.

As the aliphatic dicarboxylic acid and tricarboxylic acid compounds, the following compounds can be exemplified. 2-
Dodecyloxysuccinic acid, 2-tetradecyloxysuccinic acid, 2-hexadecyloxysuccinic acid, 2-octadecyloxysuccinic acid, 2-eicosyloxysuccinic acid,
2-dodecyloxysuccinic acid, 2-dodecylthiosuccinic acid, 2-tetradecylthiosuccinic acid, 2-hexadecylthiosuccinic acid, 2-octadecylthiosuccinic acid, 2-eicosylthiosuccinic acid, 2-docosylthiosuccinic acid, 2
-Tetracosylthiosuccinic acid, 2-hexadecyldithiosuccinic acid, 2-octadecyldithiosuccinic acid, 2-eicosyldithiosuccinic acid, dodecylsuccinic acid, tetradecylsuccinic acid, pentadecylsuccinic acid, hexadecylsuccinic acid, octadecylsuccinic acid, eicosylsuccinic Acid, docosylsuccinic acid, 2,3-dihexadecylsuccinic acid,
2,3-dioctadecylsuccinic acid, 2-methyl-3-hexadecylsuccinic acid, 2-methyl-3-octadecylsuccinic acid, 2-octadecyl-3-hexadecylsuccinic acid, hexadecylmalonic acid, octadecylmalonic acid, eicosyl Malonic acid, docosylmalonic acid, dihexadecylmalonic acid, dioctadecylmalonic acid, didocosylmalonic acid, methyloctadecylmalonic acid, 2-hexadecylglutaric acid, 2-octadecylglutaric acid, 2-eicosylglutaric acid, docosylglutaric acid, 2-pentadecyl adipic acid, 2-octadecyl adipic acid, 2-eicosyl adipic acid, 2-docosyl adipic acid, 2-hexadecanoyloxypropane-1,2,3-tricarboxylic acid, 2-octadecanoyloxy Propane-1,2,3
-Tricarboxylic acids and the like.

As the leuco dye, conventionally known leuco dyes can be arbitrarily used, and are used alone or in combination. Examples of the leuco dye used in the present invention are described below, but the present invention is not limited to these. 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-di (n-
Butylamino) fluoran, 2-anilino-3-methyl-6- (Nn-propyl-N-methylamino) fluoran, 2-anilino-3-methyl-6- (N-isopropyl-N-methylamino) fluoran , 2-anilino-
3-methyl-6- (N-isobutyl-N-methylamino) fluoran, 2-anilino-3-methyl-6- (N
-N-amyl-N-methylamino) fluoran, 2-anilino-3-methyl-6- (N-sec-butyl-N-
Methylamino) fluoran, 2-anilino-3-methyl-6- (Nn-amyl-N-ethylamino) fluoran, 2-anilino-3-methyl-6- (N-iso-amyl-N-ethylamino ) Fluoran, 2-anilino-
3-methyl-6- (Nn-propyl-N-isopropylamino) fluoran, 2-anilino-3-methyl-6
-(N-cyclohexyl-N-methylamino) fluoran, 2-anilino-3-methyl-6- (N-ethyl-p
-Toluidino) fluoran, 2-anilino-3-methyl-6- (N-methyl-p-toluidino) fluoran, 2
-(M-trifluoromethylanilino) -3-methyl-6
-Diethylaminofluoran, 2- (m-trifluoromethylanilino) -3-methyl-6-diethylaminofluoran, 2- (m-trichloromethylanilino) -3-
Methyl-6- (N-cyclohexyl-N-methylamino) fluoran, 2- (2,4-dimethylanilino)-
3-methyl-6-diethylaminofluoran, 2- (N
-Ethyl-p-toluidino) -3-methyl-6- (N-
Ethylanilino) fluoran, 2- (N-ethyl-p-
Toluidino) -3-methyl-6- (N-propyl-p-
Toluidino) fluoran, 2-anilino-6- (N-n
-Hexyl-N-ethylamino) fluoran, 2- (o
-Chloroanilino) -6-diethylaminofluoran,
2- (o-chloroanilino) -6-dibutylaminofluoran, 2- (m-trifluoromethylanilino) -6
Diethylaminofluoran, 2,3-dimethyl-6-dimethylaminofluoran, 3-methyl-6- (N-ethyl-p-toluidino) fluoran, 2-chloro-6-diethylaminofluoran, 2-bromo-6 -Diethylaminofluoran, 2-chloro-6-dipropylaminofluoran, 3-chloro-6-cyclohexylaminofluoran, 3-bromo-6-cyclohexylaminofluoran, 2-chloro-6- (N-ethyl- N-isoamylamino) fluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-chloro-
6-diethylaminofluoran, 2- (o-chloroanilino) -3-chloro-6-cyclohexylaminofluoran, 2- (m-trifluoromethylanilino) -3-chloro-6-diethylaminofluoran, 2- ( 2,3-
Dichloroanilino) -3-chloro-6-diethylaminofluoran, 1,2-benzo-6-diethylaminofluoran, 3-diethylamino-6- (m-trifluoromethylanilino) fluoran, 3- (1-ethyl -2-methylindol-3-yl) -3- (2-ethoxy-4
-Diethylaminophenyl) -4-azaphthalide, 3-
(1-ethyl-2-methylindol-3-yl) -3
-(2-ethoxy-4-diethylaminophenyl) -7
-Azaphthalide, 3- (1-octyl-2-methylindol-3-yl) -3- (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-methylindole-3 -Yl) -3- (2-
Methyl-4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-methylindole-3-
Yl) -3- (2-methyl-4-diethylaminophenyl) -7-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2
-Methylindol-3-yl) -3- (4-N-n-
Amyl-N-methylaminophenyl) -4-azaphthalide, 3- (1-methyl-2-methylindol-3-yl) -3- (2-hexyloxy-4-diethylaminophenyl) -4-azaphthalide, 3, 3-bis (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis (2-ethoxy-4-diethylaminophenyl) -7-azaphthalide and the like.

As the color former used in the present invention, in addition to the above-mentioned fluoran compound and azaphthalide compound, conventionally known leuco dyes can be used alone or in combination. The coloring agent is shown below. 2- (p-acetylanilino)-
6- (Nn-amyl-Nn-butylamino) fluoran, 2-benzylamino-6- (N-ethyl-p-toluidino) fluoran, 2-benzylamino-6- (N
-Methyl-2,4-dimethylanilino) fluoran, 2
-Benzylamino-6- (N-ethyl-2,4-dimethylanilino) fluoran, 2-benzylamino-6-
(N-methyl-p-toluidino) fluoran, 2-benzylamino-6- (N-ethyl-p-toluidino) fluoran, 2- (di-p-methylbenzylamino) -6
(N-ethyl-p-toluidino) fluoran, 2- (α
-Phenylethylamino) -6- (N-ethyl-p-toluidino) fluoran, 2-methylamino-6- (N-
Methylanilino) fluoran, 2-methylamino-6-
(N-ethylanilino) fluoran, 2-methylamino-6- (N-propylanilino) fluoran, 2-ethylamino-6- (N-methyl-p-toluidino) fluoran, 2-methylamino-6- (N -Methyl-2,4-
Dimethylanilino) fluoran, 2-ethylamino-6
-(N-ethyl-2,4-dimethylanilino) fluoran, 2-dimethylamino-6- (N-methylanilino)
Fluoran, 2-dimethylamino-6- (N-ethylanilino) fluoran, 2-diethylamino-6- (N-
Methyl-p-toluidino) fluoran, 2-diethylamino-6- (N-ethyl-p-toluidino) fluoran, 2-dipropylamino-6- (N-methylanilino) fluoran, 2-dipropylamino-6- (N -Ethylanilino) fluoran, 2-amino-6- (N-methylanilino) fluoran, 2-amino-6- (N-ethylanilino) fluoran, 2-amino-6- (N-propylanilino) fluoran, 2-amino- 6- (N-
Methyl-p-toluidino) fluoran, 2-amino-6
-(N-ethyl-p-toluidino) fluoran, 2-amino-6- (N-propyl-p-toluidino) fluoran, 2-amino-6- (N-methyl-p-ethylanilino) fluoran, 2-amino- 6- (N-ethyl-p-
Ethylanilino) fluoran, 2-amino-6- (N-
Propyl-p-ethylanilino) fluoran, 2-amino-6- (N-methyl-2,4-dimethylanilino) fluoran, 2-amino-6- (N-ethyl-2,4-dimethylanilino) fluoran, 2-amino-6- (N-
Propyl-2,4-dimethylanilino) fluoran, 2
-Amino-6- (N-methyl-p-chloroanilino) fluoran, 2-amino-6- (N-ethyl-p-chloroanilino) fluoran, 2-amino-6- (N-propyl-p-chloroanilino) fluoran, 1,2-benzo-6- (N-ethyl-N-isoamylamino) fluoran, 1,2-benzo-6-dibutylaminofluoran,
1,2-benzo-6- (N-methyl-N-cyclohexylamino) fluoran, 1,2-benzo-6- (N-ethyl-N-toluidino) fluoran, and others.

Specific examples of other color formers preferably used in the present invention are as follows. 2-anilino-3-methyl-6- (N-2-ethoxypropyl-N
-Ethylamino) fluoran, 2- (p-chloroanilino) -6- (Nn-octylamino) fluoran, 2
-(P-chloroanilino) -6- (Nn-palmitylamino) fluoran, 2- (p-chloroanilino) -6
-(Di-n-octylamino) fluoran, 2-benzoylamino-6- (N-ethyl-p-toluidino) fluoran, 2- (o-methoxybenzoylamino) -6
(N-methyl-p-toluidino) fluoran, 2-dibenzylamino-4-methyl-6-diethylaminofluoran, 2-dibenzylamino-4-methoxy-6- (N
-Methyl-p-toluidino) fluoran, 2-dibenzylamino-4-methyl-6- (N-ethyl-p-toluidino) fluoran, 2- (α-phenylethylamino)
-4-methyl-6-diethylaminofluoran, 2-
(P-Toluidino) -3- (t-butyl) -6- (N-
Methyl-p-toluidino) fluoran, 2- (o-methoxycarbonylamino) -6-diethylaminofluoran, 2-acetylamino-6- (N-methyl-p-toluidino) fluoran, 4-methoxy-6- (N -Ethyl-p-toluidino) fluoran, 2-ethoxyethylamino-3-chloro-6-dibutylaminofluoran, 2
-Dibenzylamino-4-chloro-6- (N-ethyl-
p-Toluidino) fluoran, 2- (α-phenylethylamino) -4-chloro-6-diethylaminofluoran, 2- (N-benzyl-p-trifluoromethylanilino) -4-chloro-6-diethylaminofluor Oran, 2
-Anilino-3-methyl-6-pyrrolidinofluoran,
2-anilino-3-chloro-6-pyrrolidinofluoran, 2-anilino-3-methyl-6- (N-ethyl-N
-Tetrahydrofurfurylamino) fluoran, 2-mesidino-4 ', 5'-benzo-6-diethylaminofluoran, 2- (m-trifluoromethylanilino) -3-
Methyl-6-pyrrolidinofluoran, 2- (α-naphthylamino) -3,4benzo-4′-bromo-6- (N-
Benzyl-N-cyclohexylamino) fluoran, 2
-Piperidino-6-diethylaminofluoran, 2-
(Nn-propyl-p-trifluoromethylanilino)
-6-morpholinofluoran, 2- (di-Np-chlorophenyl-methylamino) -6-pyrrolidinofluoran, 2- (Nn-propyl-m-trifluoromethylanilino) -6 Morpholinofluoran, 1,2-benzo-6- (N-ethyl-Nn-octylamino) fluoran, 1,2-benzo-6-diallylaminofluoran, 1,2-benzo-6- (N -Ethoxyethyl-N
-Ethylamino) fluoran, benzoleucomethylene blue, 2- [3,6-bis (diethylamino) -7-
(O-chloroanilino) xanthyl] lactam benzoate, 2- [3,6-diethylamino) -9- (o-chloroanilino) xanthyl] lactam benzoate, 3,3-
Bis (p-dimethylaminophenyl) -phthalide, 3,
3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis- (p-dimethylaminophenyl)
-6-diethylaminophthalide, 3,3-bis- (p-
Dimethylaminophenyl) -6-chlorophthalide, 3,
3-bis- (p-dibutylaminophenyl) phthalide,
3- (2-methoxy-4-dimethylaminophenyl)-
3- (2-hydroxy-4,5-dichlorophenyl) phthalide, 3- (2-hydroxy-4-dimethylaminophenyl) -3- (2-methoxy-5-chlorophenyl)
Phthalide, 3- (2-hydroxy-4-dimethoxyaminophenyl) -3- (2-methoxy-5-chlorophenyl) phthalide, 3- (2-hydroxy-4-dimethylaminophenyl) -3- (2-methoxy- 5-nitrophenyl) phthalide, 3- (2-hydroxy-4-diethylaminophenyl) -3- (2-methoxy-5-methylphenyl) phthalide, 3- (2-methoxy-4-dimethylaminophenyl) -3- (2-hydroxy-4-chloro-5-methoxyphenyl) phthalide, 3,6-bis (dimethylamino) fluorenespiro (9,3 ')-6'-
Dimethylaminophthalide, 6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6'-bromo-
2'-methoxy-benzoindolino-spiropyran, and others.

The ratio of the color former and the color developer varies in an appropriate range depending on the combination of the compounds used. Preferably it is in the range of 0.2 to 10. If the amount of the developer is smaller or larger than this range, the density of the color-developed state is reduced, which is problematic. The ratio of the decoloring accelerator and the coloring / decoloring control agent is preferably from 0.1% by weight to 300% by weight, more preferably from 3% by weight to 100% by weight, based on the color developer. Further, the color former and the developer can be used by being encapsulated in microcapsules. The ratio of the color-forming component and the resin in the recording layer is preferably 0.1 to 10 with respect to the color-forming component 1, and if the ratio is less than this, the heat intensity of the recording layer is insufficient. Problem.

In the recording layer, the above-described color developer, color former, and if necessary, the decoloring accelerator can be used.
For the formation of the recording layer, a coating liquid prepared by uniformly mixing and dispersing a mixture of these materials, a binder resin and a coating liquid solvent is used. As the binder resin used in the recording layer, conventionally known water-based and solvent-based resins are widely used. From the viewpoint of water resistance of the image area, a solvent-based resin is preferably used, and more preferably a crosslinked resin is used. As these resins, for example, a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or the like used when dissolving the above-mentioned ultraviolet absorbent is used.

As can be understood from the above description, coloring,
Decolorization, of course, depends on the bond-breakage between the color-forming component compound and the developer compound in the resin binder, or at least the proximity of the tubular portion to increase or decrease the effective electron density at the color-forming site. Therefore, in that sense, not only both component molecules but also the resin binder becomes important. In other words, the color development depends on how close the functional parts of the two component molecules are in the resin binder, and how easily they come into contact with each other. Along with this, under a sufficiently restrained state of at least a part of both component molecules by the resin binder, thermal contraction of the resin binder progresses to apply tension to a functional portion of both component molecules, thereby cutting or at least coloring component. A mode is needed to isolate the developer compound in a state that would prevent the compound from changing to a color system.
The cured resin, even though the main chain conformational change and relaxation-contraction due to the difference in temperature are small, when the resin contracts by cooling, at least the long-chain alkyl group portion of the developer having a long-chain alkyl group. The force of contraction in a state where is restricted is large. Similarly, it is preferable that the leuco dye as a color-forming component has a bulk diameter firmly constrained in a binder resin that expands and contracts, for example, at the 3rd and 6th positions.
For this reason, in the present invention, the curing of the resin binder may be performed after the initialization treatment according to the present invention.

In addition to the recording layer, the reversible thermosensitive recording medium used in the present invention may further include an ultraviolet absorbing agent for improving durability, printability, storage stability (light fastness, water fastness, etc.), etc.
A protective layer containing a filler, a curable resin, etc., an intermediate layer, an undercoat layer, etc. may be provided. Further, the support of the reversible thermosensitive recording medium used in the present invention may be paper, a film or a composite thereof. There is no particular limitation as long as the recording layer can be provided, and processing such as attaching the produced reversible thermosensitive recording medium to another support may be used.

[0060]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, as a heating means for a recording layer of a reversible thermosensitive recording medium, a thermal head, a heat block including a heat stamp, a heat roller, laser irradiation, flash irradiation with a halo lamp, and a xenon lamp are used. Various direct (contact) heat sources and indirect (non-contact) heat sources such as flash irradiation, infrared lamps, planar heaters, and infrared lamps can be used.

As described above, whether or not heating is sufficient depends on the heating temperature and heating time, including the case of additional heating, and the cooling mode in the cooling step is also important. And this cooling mode is also affected by the heating mode. In any case, it is preferable that the desired region can be surely heated uniformly and can be uniformly cooled in a desired mode, and it is more preferable that the desired region can be surely heated to a desired temperature and can be surely cooled in a desired mode. The desired region in particular, if sufficiently heated to the temperature above T _1, and in the case of slow cooling the heat already in the area, it is preferred to note the uniform heating and uniform cooling, the desired degree of the desired area When heating and cooling rapidly,
Further, it is important to execute a controlled heating mode. Therefore, in the former case, a thermal head, a heat block including a heat stamp, a heat roller, laser irradiation,
It is preferably performed by using one of the planar heaters, and in the latter case, it is preferably performed by a thermal head or laser beam irradiation based on a pulse current that is easily controlled. In the present invention, the control of the heating intensity, particularly the heating time, is performed not only by controlling the heating source, but also by controlling the transport speed of the reversible thermosensitive recording medium, which is the medium to be heated, to the heating source. Can be achieved.

Hereinafter, an example of the rewriting device of the present invention having such controlled heating means will be described with reference to the drawings. In the rewriting device shown in FIG.
The reversible thermosensitive recording medium (1) inserted from 0) travels along the transport path (30) shown by a dashed line, or travels in the apparatus along the transport path (30) in the reverse direction. . The reversible thermosensitive recording medium (1) inserted from the entrance (10) is transported by the transport roller (11) and the guide roller (1).
When the sheet is conveyed in the recording apparatus by the method (2) and reaches a predetermined position on the conveyance path (30), the sensor (13) controls the control means (1).
4c), the presence of which is recognized and may be omitted. The magnetic recording layer is magnetically applied between the magnetic head (14) and the platen roller (15) of the magnetic recording apparatus for magnetic recording on the magnetic recording layer area. It is recorded or erased, passes between the guide roller (16) and the transport roller (17), passes between the guide roller (19) and the transport roller (20), and may be omitted by the position sensor (23). Heat treatment for image erasing is performed between a serial type S thermal head (18) and a platen roller (24) which operate by recognizing the presence thereof through a thermal head energizing control means (18c), and a rotation control not shown. Roller (25) (2) controlled by means (control of rotation speed and rotation direction including stop)
6) The dot L is conveyed in the conveyance path (30) by (27) and recognized at a predetermined position by the position sensor (31) through the thermal head control means (33c) to recognize its presence and operate. An image is formed between the thermal head (33) and the platen roller (32), and an outlet (from a conveying path (36a)) is conveyed by a conveying roller (39) (controlled by rotation control means not shown) and a guide roller (40). 4
It is carried out of the apparatus via 1).

In the drawing, reference numeral (18a) indicates a temperature sensor for the S thermal head (18), and reference numeral (33a) indicates a temperature sensor for the L thermal head (33). Here, the set temperature of the S thermal head (18) is, for example, 1
The temperature is preferably 00 ° C. or higher, more preferably 105 ° C. or higher. However, in the rewriting device of the present invention, the control of energization to the thermal head for heating can be reliably performed. Is carried on the L thermal head (33), so that the S thermal head (18) can be omitted.

Then, if desired, the transport path switching means (3
5a), the guide is guided to the transport path (36b), and moves in a direction opposite to the operation of the limit switch (37a) input by pressing the reversible thermosensitive recording medium (1). The heat-reversible recording medium (1) is again heat-treated between the L thermal head (33) and the platen roller (32) by the conveyance belt (38) whose is controlled, and then the conveyance path switching means (35b).
Is transported in the forward direction via a transport path (29b), a limit switch (37b), and a transport belt (28) whose rotation speed is controlled by control means (not shown). Conveyance roller (39)
And it can be carried out of the apparatus via the outlet (41) by the guide roller (40). Further, such a branched transport path and transport switching means are provided by the S thermal head (1).
8), the sensor (23a) may be connected to the platen roller (24) and the transport roller (2).
It is desirable to provide between 5). In addition, in order to prevent the magnetic recording layer and the like from being affected by the heat from the thermal head, the thermal head (33) and / or
Or (18) A heat insulating cover can be provided around the periphery.

FIG. 3 relates to the apparatus example of the present invention shown in FIG.
One example of a control circuit for one thermal head is shown. In this example, the transistor (TR11) and the transistor (TR12) form a first self-propelled multivibrator for the first thermal head (18), and alternately conduct (TR11) and (TR12). Let
A high-voltage secondary inductive output corresponding to the alternating input to the primary coil (L11) of the transformer is obtained in the secondary coil (L21), and this is used as the load (R1) and the resistances (R1) and (R1) are obtained.
The power supply for the first thermal head (18) having the above (1) is used to carry out the pulsed heating, and the self-propelled multivibrator circuit is controlled by a transistor (TR1), a resistor (Rx) and a resistor (Rx). 2 and the thermistor (SM1) of the temperature sensor (18a),
This is performed by a feedback circuit in which a negative input / output relationship is established with respect to a load change of the self-running multivibrator circuit. As for the self-propelled multivibrator, when one of the transistors, for example, (TR11) is turned on, the primary coil (L11) of the transformer is energized. A secondary induction output is obtained and used as a heater source, and at the same time, a secondary induction output is generated in the coil (L11) after some time by the secondary output. The next output is fed back to the other transistor (TR12) to make it conductive, so that the same operation as that of the transistor (TR11) is performed in the case of the transistor (TR12), and this operation is alternately repeated. And a multivibrator. The capacitor (C1) cooperates with the coil (L11) in the circuit to determine the conduction time constant of both transistors (that is, the frequency of pulse conduction). ) Is applied.

The same applies to the second thermal head (33) and the second self-propelled multivibrator including the thermistor (SM2) of the temperature sensor (33a) in FIG. The switch (SW) can switch the first thermal head (18) between a high calorific value (R1 + R11) and a low calorific value (only R1), and can set the second thermal head (33) to a high calorific value (R2 + R12). It is possible to switch to a low heat value (only R2). In addition, circuit elements
Conventionally known means for protecting against di-voltages can be combined, for example with a resistor (R) for a rectifier (D).
3) In order to protect the rectifier (D) from a sudden overvoltage current, a Zener diode that conducts when the Zener breakdown voltage is reached is arranged in parallel with the resistor (R3) and the rectifier (D), so that an overcurrent bypass path is provided. Can be provided. In the case of this circuit device, there is an advantage that not only a pulse output but also a general counter electromotive force absorption circuit having a high time constant such as a diode and a resistor is not included.

FIG. 4 shows still another example of the means for finely adjusting the amount of energization in the apparatus according to the present invention. 4 is an input means (44) for inputting information for controlling the rewriting device of the present invention;
Judgment for controlling the first thermal head (18)
Comparing means (45), determining / comparing means (46) for controlling the second thermal head (33), a thermistor (SM1) of the first temperature sensor (18a), and a second temperature sensor (33a) Thermistor (SM2), rewriting device control means (47) for controlling the device of the present invention, the first thermal head (18) and the second thermal head (3).
The timer input means (48) for generating a reference clock for the integration time of (3) and the integration time of the first thermal head (18) and the second thermal head (33) are counted, and zero payment is performed and counting is performed again. Data memory (49), first temperature sensor (SM1) and second temperature sensor (SM2)
A controller (50) that controls the entire heating system of the apparatus in a certain sequence based on information from the data memory and information from the data memory (49), and a memory (51) storing the sequence.

The clock signal input by the timer input means (48) is taken into the controller (50), and the clock signal and the heating data in the first thermal head (18) by the judgment / comparison means (45) are taken in. Is taken in as the output temperature signal of the judging / comparing means (45), and the clock signal and the judging / comparing means (46)
Is taken as an output temperature signal of the judging / comparing means (46). Then, by a signal from the memory (51) that stores a certain sequence,
The controller (50) is activated, and the controller (5) is operated.
According to 0), the rewriting device control means (47) allows the first thermal head relay (CR1) for pulse conduction to the first thermal head (18) and the pulse conduction to the second thermal head (33). The second thermal head relay (CR2) is ON-OFF controlled, for example. Specifically, the controller (50) is realized by a one-chip microcomputer which also contains a memory (51) and a data memory (49), and the input means (44) is a control input switch (53a) (53b). To input an input signal to the microcomputer. In addition, the first thermal head (1
The determination / comparison means (45) of 8) includes an intermediate input voltage of a series circuit including the temperature-sensitive resistance element (SM1) and the thermovolume (54) and an intermediate voltage of a series connection of the resistance (55) and the resistance (56). Is determined and compared by a comparator (57) that performs comparison detection of the reference voltage, and the microcomputer (65) determines whether the current temperature of the first thermal head (18) is "H" or "L". Is input as a digital output signal. The resistance (58) is a resistance for a thermo differential value for providing an ON point and an OFF point in the thermo volume (54) for setting a temperature.

As shown in FIG. 5, the power supply circuit of this control circuit is composed of an AC power supply (66), a rectifier (D), a capacitor (69) and the like, and a timer control circuit (70) This is for controlling the timer circuit inside the microcomputer (65). In the figure, the microcomputer (6
5) includes a power supply terminal (VD) and an input switch (53a).
And an output terminal for an output for operating the judgment / comparison means (45) via the input switch (53b).
There is an output terminal for an output for operating the comparing means (46), and an input port (AΦ) for inputting an output of the comparator (57) and an input port for inputting an output of the comparator (63). Input port (B
Φ), an input port (CΦ) for inputting an output of the timer control circuit (70), an output port (DΦ) for outputting to a base electrode of the transistor (TR1) as an output port, and a base of the transistor (TR2). There is an output port (EΦ) for outputting to the electrodes. Microcomputer (6
5) starts operation with a DC power supply from the power supply terminal (VD), and turns ON / OFF the control input switches (53a) and (53b).
The operation control mode is selected by the FF signal.

Referring to FIG. 5, a description will be given of a case in which the control input switch (53a) is ON and the control input switch (53b) is OFF with reference to FIG. ) Is heated and reaches the OFF point of the thermo differential (Δt), the output of the comparator (57) is output, that is, the “L” signal is output to the Aφ port of the microcomputer (65). At the same time, an L (low) signal is output to the output terminal Dφ port to disconnect the relay (CR1), and count the clock signal from the timer input means (48) in the data memory (51).
When the value counted in the data memory (21), that is, the energization stop time elapses a predetermined initial setting time (t1), an H (high) signal is output to the Dφ port to force O.
N to start energization. At the same time, the data memory (4
The integration time in 9) is set to zero and the integration of the next energization time is started. When the energization time elapses a predetermined period (t0), an L (low) signal is output to the Dφ port to forcibly disconnect the relay (CR1) to stop energization. With this apparatus, the power supply time (t0) and the power supply stop time (t1) can be adjusted and set in advance, respectively, and the “offset point” and the ON point of the thermo differential (Δt) can be set according to “this adjustment setting”. A point can be defined, and the width of the thermo differential (Δt) can also be pre-selected as the difference between the OFF point and the ON point.

In this apparatus, the judgment / comparison means (45) and (46) and the comparators (57) and (63) have been described as being separate to facilitate understanding of the present invention. By making the control input switch (53a) ON / OFF by the microcomputer through the means (44), the judgment / comparison means (45) and the comparator (5) are controlled.
7) and the judgment / comparison means (46) and the comparator (6)
3) can also be used.

FIG. 6 shows the state of the energizing pulse and the temperature change of the first thermal head (18). First, before the reversible thermosensitive recording medium (1) reaches the first thermal head (18) for coloring and heating, in synchronization with the heating timing based on the output signal of the position detection sensor (23). The recording medium (1) is energized to a temperature (T1) to rapidly heat the first thermal head (18). The first thermal head (18) heats the recording medium to a temperature (T1) when the recording medium reaches the temperature (T1), so that the first thermal head (18) generates a continuous constant energizing pulse thereafter. The temperature is maintained by applying to (18), and the recording medium is colored.

In this example, the cycle (C) of the energizing pulse is
Is set to 10 ms, and the energizing time P is set to 9 at the time of temperature rise.
When a predetermined number of energizing pulses are applied as ms, the temperature of the first thermal head (18) for full-color heating is rapidly increased, and when the temperature of the thermal head (18) reaches a temperature at which the entire recording medium can be colored. Then, heating is performed so as to maintain the temperature by setting the energization time to 2 ms, and the energization is terminated after applying a number of energization pulses corresponding to the length of the recording medium (1).

FIG. 7 is a diagram showing the processing contents of the energizing pulse by the controller (50). The number of pulses of a series of energizing pulses is Nn, the energizing cycle is Cn, and the energizing time is Pn. These data (Nn, Cn, Pn) are stored in ROM
(Read only memory) (101), the data (Nn, Cn, Pn) are read out by the address signal being supplied from the controller (50) to the ROM, and the register section (103) and the data latch section (104). This register section (10
3) The data latch section (104) is controlled by the controller (50), the data Nn is sent to the N pulse counter section (105), and the data (Cn, Pn) is sent to the energization time creation counter section (106). Sent.

This energization time creation counter unit (106)
Determines the energizing time for one pulse from the data (Cj, Pk) and inputs the output data to the driver unit (107). The driver unit (107) outputs an energizing pulse corresponding to the energizing time data to drive the erasing thermal head (18). At the same time, the N-pulse counter unit (105) counts the number of outputs of the energizing pulse, and when the data Ni is counted, the controller (5).
Send a signal to 0).

Thus, the controller (50) outputs an address signal in the next cycle and controls the register section (103) and the data latch section (104). For example, in the present invention, Cn can be kept constant at 10 ms, P ₀ = 9 ms and N ₀ = 30 when the temperature rises, and P ₁ = 2 ms and N ₁ = 213 to 215 during constant temperature control. The energization time and the number of pulses in each mode are set based on data collected in advance.

FIG. 8 shows the first state of the controller (50).
It is a block diagram showing an example of actual energization pulse control which applies an energization pulse to a thermal head (18). that's all,
Although the case of the first thermal head (18) has been described, the same applies to the case of the second thermal head (33).

[0078]

(Preparation of reversible thermosensitive recording medium)

1) 2-anilino-3-methyl-6-dibutylaminofluorane 2 parts 2) Color developer having the following structure 8 parts 3) 15% solution of acrylic polyol resin in 15% tetrahydrofuran (THF) 150 parts 0.1 to 3μ average particle size
m. 20 parts of Coronate HL (adduct type hexamethylene diisocyanate 75% ethyl acetate solution) manufactured by Nippon Polyurethane Co., Ltd. was added to the obtained dispersion,
The mixture was stirred well to prepare a recording layer coating solution.

A recording layer coating solution having the above composition was applied to a thickness of 188 μm.
m on a white polyester film using a wire bar, dried at 100 ° C. for 2 minutes, and then heated at 60 ° C. for 24 hours to produce a reversible thermosensitive recording medium provided with a recording layer having a thickness of about 8.0 μm. did. The prepared reversible thermosensitive recording medium is
Rewriting was performed using a thermal printing simulator manufactured by Yashiro Seisakusho using an EUX-ET8A9AS1 end face type thermal head (resistance 1152Ω) manufactured by Matsushita Electronic Components.
(Conditions: pulse width 2 ms, line cycle 2.86 ms, printing speed 43.10 mm / s, sub-search density 8 dot / m
m)

Example 1 A voltage of 1 was applied to a reversible thermosensitive recording medium.
A character pattern was printed under the condition of 5 V, and a clear character image was recorded on the reversible thermosensitive recording medium. For a reversible thermosensitive recording medium having a character image,
A solid pattern was applied at a voltage of 5 V to color the entire surface.
Next, a solid pattern was printed on the entire surface at a voltage of 11 V serving as a decoloring condition, and the entire surface was erased. Furthermore, from 10V to 0.5
When a fixed area was printed in gradations up to 17.5 V in V increments, the printed image was in a state of good uniformity at each gradation.

Example 2 A voltage of 1 was applied to a reversible thermosensitive recording medium.
After a solid pattern was printed under the condition of 5V and the entire surface was colored, the color was erased in a 110 ° C constant temperature bath. Thereafter, a character pattern was printed under the condition of a voltage of 15 V, and a solid pattern was printed over the entire surface at a voltage of 11 V serving as an erasing condition, and the entire surface was erased. Next, from 10V to 0.5V every 1V
When a fixed area was printed in gradations up to 7.5 V, the printed image was in a state of good uniformity at each gradation. Thereafter, rewriting was performed by repeatedly erasing the entire surface and printing various character patterns. The rewritten character patterns had no partial shading and had good image quality.

(Comparative Example 1) A reversible thermosensitive recording medium was prepared in the same manner as in Example 1, except that in the step of rewriting the character pattern printed in the same manner as in Example 1, the entire color developing step with the solid pattern was not performed. Rewritten. As a result, the gradation print density after rewriting was affected by the character pattern before rewriting at each density, and especially in the halftone color developing portion, the uniformity was very poor.

(Comparative Example 2) A reversible thermosensitive recording medium of 180
The mixture was heated on a hot plate at ℃ ° C., pressed against an aluminum plate at room temperature, cooled, and the entire surface was colored. The recording medium was greatly deformed by heat, and the uniformity of contact with the thermal head during erasing / printing by the thermal printing simulator using the thermal head was poor, resulting in poor image quality.

[0084]

As is apparent from the detailed and concrete description, the rewriting method and the initializing method of the reversible thermosensitive recording medium of the present invention have excellent image quality without unevenness in image density after rewriting. In which an excellent effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing color development / decoloration characteristics of a reversible thermosensitive recording medium of the present invention.

FIG. 2 is a diagram showing one example of a reversible heating recording medium rewriting device of the present invention.

FIG. 3 is a diagram showing an example of an energization control unit in the rewriting device of the present invention.

FIG. 4 is a diagram showing another example of the power supply control means in the rewriting device of the present invention.

FIG. 5 is a diagram showing a power supply circuit of an energization control unit in the rewriting device of the present invention.

FIG. 6 is a diagram showing a state of an energizing pulse and a temperature change of a thermal head according to the present invention.

FIG. 7 is a diagram showing processing contents of an energizing pulse in the present invention.

FIG. 8 is a block diagram showing an example of actual energizing pulse control in which an energizing pulse is applied to a first thermal head (18) by a controller (50) in the apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reversible thermosensitive recording medium 10 Doorway 11 Transport roller 12 Guide roller 13 Sensor 14 Magnetic head 14c Control means 15 Platen roller 16 Guide roller 17 Transport roller 18 Thermal head 18a Temperature sensor 18c Thermal head energization control means 19 Guide roller 20 Transport roller 21 Data memory 23 Temperature sensor 24 Platen roller 25 Transport roller 26 Transport roller 27 Transport roller 28 Transport belt 29b Transport path 30 Transport path 31 Position sensor 32 Platen roller 33 Thermal head 33a Temperature sensor 33c Thermal head control means 35a Transport path switching means 35b Conveying path switching means 36a Conveying path 36b Conveying path 37a Limit switch 38 Conveying belt 39 Conveying roller 40 Guide roller 41 Exit 43 Power supply adjustment Means 44 Input means 45 Judgment / comparison means 46 Judgment / comparison means 47 Rewriting device control means 48 Timer input means 49 Data memory 50 Controller 51 Memory 53a Control input switch 53b Control input switch 54 Thermo volume 55 Resistance 56 Resistance 57 Comparator 58 Resistance 63 Comparator 65 Microcomputer 66 AC power supply 69 Capacitor 70 After passing through the timer control circuit, 101 ROM (read only memory) 103 register section 104 data latch section 105 N pulse counter section 106 energization time creation counter section 107 driver section AΦ input port B power supply BΦ Input port C Energizing pulse period CΦ Input port DΦ Output port EΦ Output port C1 Capacitor CR1 Relay D Rectifier L11 Primary coil L21 Secondary Side coil R1 Load R3 Resistance R11 Resistance R12 Resistance Rx Resistance sensor SM1 Thermistor SM2 Thermistor TR1 Transistor TR2 Transistor TR11 Transistor TR12 Transistor VD Power supply terminal

Continued on the front page (72) Inventor Kyoji Tsutsui 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2C065 AF01 CJ01 CJ03 2H026 AA07 AA09 AA24 AA28 BB02 BB24 FF01

Claims (26)

[Claims] 1. A method for initializing a reversible thermosensitive recording medium that develops or decolors according to a difference in a heating temperature or a cooling rate after heating, wherein the entire surface or the recording area of the reversible thermosensitive recording medium is subjected to the reversible thermal recording by a thermal head. A method for initializing a reversible thermosensitive recording medium, which comprises performing an operation of heating the color to a color development temperature of the thermosensitive recording medium to form a color, thereby making the recording layer uniform. 2. The method for initializing a reversible thermosensitive recording medium according to claim 1, wherein the coloring by the coloring operation is erased by slow cooling. 3. The reversible method according to claim 2, wherein the coloring by the coloring operation is performed using one of a thermal head, a heat block, a heat roller, laser irradiation, and a planar heater. Initializing method for thermosensitive recording medium. 4. The method for initializing a reversible thermosensitive recording medium according to claim 1, wherein the coloring by the coloring operation is erased by heating. 5. The method for initializing a reversible thermosensitive recording medium according to claim 4, wherein the coloring by the coloring operation is erased by a heating and cooling operation after the coloring operation. 6. The method for initializing a reversible thermosensitive recording medium according to claim 4, wherein the coloring by the coloring operation is performed by a thermal head or laser beam irradiation. 7. The color image forming apparatus according to claim 1, wherein the color forming operation for the entire surface or the entire recording area is performed by heating to a temperature at which the color is colored to a maximum density. A method for initializing a reversible thermosensitive recording medium. 8. The method for initializing a reversible thermosensitive recording medium according to claim 1, wherein the color development start temperature substantially coincides with the melting point of the color developer. 9. A rewriting method for a reversible thermosensitive recording medium which develops or decolors according to a difference in heating temperature or a cooling rate after heating, wherein the entire surface or recording area of the reversible thermosensitive recording medium is subjected to the reversible thermosensitive recording. The operation of heating the medium to the coloring temperature to form a color, the operation of erasing the entire surface or the recording area of the entire color, and the operation of printing again on the entire surface or the recording area and re-forming a color image on a printing unit are sequentially performed. Rewriting a reversible thermosensitive recording medium. 10. A rewriting method for a reversible thermosensitive recording medium which develops or decolors depending on a difference in a heating temperature or a cooling rate after heating, wherein the reversible thermosensitive recording medium is entirely or in a recording area. A reversible process characterized by sequentially performing operations of heating the medium to the color-forming temperature to form a color and erasing the entire surface or the entire color of the recording area, and then performing an operation of printing again and re-forming a color image on a printing portion. Rewriting method for thermosensitive recording media. 11. A rewriting method for a reversible thermosensitive recording medium which develops or decolors depending on a difference in a heating temperature or a cooling rate after heating, wherein the entire surface or a recording area of the reversible thermosensitive recording medium is subjected to the reversible thermosensitive recording. A rewriting method for a reversible thermosensitive recording medium, comprising sequentially performing an operation of heating the medium to a color development temperature to form a color and an operation of image-wise erasing the color development of the entire surface or the recording area. 12. A rewriting method for a reversible thermosensitive recording medium that develops or decolors depending on a difference in a heating temperature or a cooling rate after heating, wherein the entire surface or a recording area of the reversible thermosensitive recording medium is subjected to the reversible thermosensitive recording. A rewriting method for a reversible thermosensitive recording medium, wherein an operation of heating the medium to a color development temperature to form a color and an operation of erasing the color of the entire surface or the recording area imagewise are performed simultaneously or continuously. 13. A rewriting method for a reversible thermosensitive recording medium which develops or decolors depending on a difference in a heating temperature or a cooling rate after heating, wherein the reversible thermosensitive recording medium is entirely or in a recording area. A reversible method characterized by sequentially performing an operation of erasing the entire surface of the color following the heating and coloring to the color temperature of the medium and an operation of printing again on the entire surface or the recording area and re-forming a color image on a printing unit. Rewriting method for thermosensitive recording media. 14. A rewriting method for a reversible thermosensitive recording medium which develops or decolors depending on a difference in a heating temperature or a cooling rate after heating, wherein the entire surface or a recording area of the reversible thermosensitive recording medium is subjected to the reversible thermosensitive recording. A rewriting method for a reversible thermosensitive recording medium, comprising continuously performing color development by heating to a color development temperature of a medium, erasing the entire surface of the color development, performing printing again, and re-forming a color development image on a printing portion. 15. The color processing according to claim 9, wherein the color development by the color development operation on the entire surface or the entire recording area is erased by slow cooling.
The method for rewriting a reversible thermosensitive recording medium according to any one of the above items. 16. The reversible thermosensitive recording medium according to claim 15, wherein the coloring operation of the entire surface or the entire recording area is performed by heating the recording medium to a color developing temperature of the reversible thermosensitive recording medium or higher. Rewriting method. 17. The color forming operation for the entire surface or the entire recording area includes a thermal head, a heat block, a heat roller,
The laser irradiation is performed using one of the planar heaters, and the laser irradiation is performed using one of the planar heaters.
A method for rewriting a reversible thermosensitive recording medium according to claim 5 or claim 16. 18. The printing method according to claim 9, wherein the coloring by the coloring operation on the entire surface or the entire recording area is erased by heating.
The method for rewriting a reversible thermosensitive recording medium according to any one of the above items. 19. The reversible thermosensitive recording medium according to claim 18, wherein the coloring by the coloring operation on the entire surface or the entire recording area is erased by a heating and cooling operation after the coloring operation. Rewriting method. 20. The image forming apparatus according to claim 9, wherein the color forming operation of the entire surface or the entire recording area is performed by heating to a temperature at which the color is colored to a maximum density.
The method for rewriting a reversible thermosensitive recording medium according to any one of the above items. 21. The rewriting method for a reversible thermosensitive recording medium according to claim 20, wherein the coloring operation of the entire surface or the entire recording area is performed by using a thermal head or laser irradiation. 22. The rewriting method for a reversible thermosensitive recording medium according to claim 9, wherein the color development start temperature substantially coincides with the melting point of the color developer. 23. Rewriting of a reversible thermosensitive recording medium having a reversible thermosensitive recording layer made of a reversible thermosensitive recording composition which is colored or erased depending on the heating temperature or the cooling rate after heating and which can repeatedly record and erase images. An apparatus, wherein the rewriting device has a heating unit, an erasing unit, and a printing unit for heating a recording area of the reversible thermosensitive recording layer, and the heating unit, the erasing unit, and / or the printing unit are configured to perform an energization period and A rewriting device for a reversible thermosensitive recording medium, comprising: a pulse energizing means that can be controlled during a non-energization period, wherein an energization amount is controlled during the energization period. 24. Rewriting of a reversible thermosensitive recording medium having a reversible thermosensitive recording layer made of a reversible thermosensitive recording composition which is colored or erased depending on a heating temperature or a cooling rate after heating and can repeatedly record and erase images. An apparatus, wherein the rewriting device has a heating unit for heating a recording area of the reversible thermosensitive recording layer, an erasing unit, a printing unit, and a conveying unit for the reversible thermosensitive recording medium, wherein the conveying unit is By changing the conveyance speed of the reversible thermosensitive recording medium in the apparatus, the operation period of the reversible thermosensitive recording medium by at least one of the heating unit, the erasing unit, and the printing unit is set to the operation period of the other two units. A rewriting device for a reversible thermosensitive recording medium, characterized in that the temperature and / or the speed of heating and / or cooling in each of the means are controlled by making them different. 25. Rewriting of a reversible thermosensitive recording medium having a reversible thermosensitive recording layer made of a reversible thermosensitive recording composition which is colored or erased depending on a heating temperature or a cooling rate after heating and which can repeatedly record and erase images. An apparatus, wherein the rewriting device has a heating unit, an erasing unit, and a printing unit for heating a recording area of the reversible thermosensitive recording layer, wherein the heating unit and / or the erasing unit is a thermal head, a sheet heater or 25. The reversible thermosensitive recording medium rewriting device according to claim 23, wherein the rewriting device is any one of a heat roller. 26. Rewriting of a reversible thermosensitive recording medium having a reversible thermosensitive recording layer made of a reversible thermosensitive recording composition which is colored or decolored depending on the heating temperature or the cooling rate after heating and which can repeatedly record and erase images. An apparatus, wherein the rewriting device has a heating unit, an erasing unit, and a printing unit for heating a recording area of the reversible thermosensitive recording layer, and the heating unit, the erasing unit, and / or the printing unit are a thermal head. The rewriting device for a reversible thermosensitive recording medium according to claim 23 or claim 24.