JP3076453B2 - Recording device heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for writing or erasing information on a sheet-like or card-like recording material made of a heat-sensitive material whose visible state changes reversibly by heating. The present invention relates to a recording medium heating apparatus that is used repeatedly and is applied to a printer, a digital copying machine, a facsimile, and the like.

[0002]

2. Description of the Related Art Conventionally, as a heating device for a recording medium of this kind,
A sheet-shaped or card-shaped recording body is made of a heat-sensitive material whose visible state is reversibly changed by heating, and a recording unit having a writing member for writing information to the recording body; It is known to provide an erasing section having an erasing member for uniformly heating a recording medium to erase written information.

[0003]

However, in such a heating apparatus for a recording medium, a sheet made of a heat-sensitive material having a wide range of sizes from B5 to A3 and whose visible state is reversibly changed by heating is used. There has not yet been proposed a device capable of writing and erasing information according to its characteristics on a recording medium in the form of a card or a card. This is because there is a difference in the temperature condition, and since the recording medium can be reused, the operation is not easy when returning the collected recording medium to a device for writing or erasing information. There is a problem that these heating devices cannot solve these problems.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional recording medium heating apparatus and to provide a reliable erasing property by optimizing the temperature required for erasing information on the recording medium. Another object of the present invention is to provide a heating device for a recording medium capable of shortening the time required for erasing, improving operability, and smoothly performing repeated reuse of the recording medium to reduce running costs. .

[0005]

According to the present invention, in order to achieve the above object, the invention according to claim 1 is characterized in that the visible state of a sheet-like or card-like recording medium is reversibly changed by heating. A recording unit having a writing member for writing information to the recording medium, and an erasing member heating the recording body to erase the information written by the recording unit. In the heating device for a recording medium having a portion, the erasing member has a plurality of planar heating elements capable of heating the recording medium from above and below, so that these heating elements do not press against the recording medium, It is characterized in that the heating elements are arranged at intervals larger than the thickness of the recording medium, and the temperatures of these heating elements can be adjusted independently. According to a second aspect of the present invention, in the first aspect of the present invention, between the electrodes of the heating elements arranged vertically, an interval between the heating elements is maintained, and an insulating property for insulating the electrodes is provided. A heat-resistant spacer is provided.

[0006]

In the present invention as described above, the erasing member is set to a temperature characteristic of the background of the recording medium, the recording medium passes over the entire length thereof, and the temperature condition is satisfied immediately before the exit of the erasing member. When the recording body enters from one side of the heating element and moves to the other side, the recording body at room temperature takes a lot of heat from the entrance side heating element and discharges Since the temperature approaches the temperature at the heating element, a plurality of heating elements are provided, and the heating temperature of each of these heating elements is independently controlled, and the heating temperature at the side where the recording medium enters is discharged. The heating temperature on the side to be heated, that is, a temperature higher than the set temperature of the recording medium is controlled. Further, when the linear velocity or heat capacity of the recording medium, that is, the thickness of the support layer of the recording medium is different, and the linear velocity is increased or the heat capacity is increased, that is, the thickness of the support layer of the recording medium is increased, the heating elements of The temperature is controlled accordingly.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In each embodiment of the present invention shown in the drawings, common portions are denoted by the same reference numerals, and description of already described portions is omitted, and different portions are mainly described. 1 to 4 show a first embodiment of the present invention. Reference numeral 1 denotes a storage unit, on which an erasing unit 5 is provided on one side and a recording unit 6 is provided on the other side. The storage unit 1 has an upper storage unit 2 for storing a recording body before erasure, and a lower storage unit 3 for storing a recording body after erasure. A tray 7 pivotally supported by the unit 5 is disposed, and a recording body receiver 8 having a recording unit 6 opened at the base end of the tray 7.
3 is provided near the erasing section 5 of the bottom plate 10 of the front storage section 2.
As shown in the figure, the base end of the lifting plate 11 is pivotally supported, and its free end is constantly given a rising tendency by a spring 12 provided on the bottom plate 10, and a discharge roller 13 is provided above the free end. ,
A display unit 9 is provided on a side plate of the recording unit 6, and a temperature detecting member 14 is provided on a back surface of the lifting plate 11.

An erasing section entrance 16 is provided at an intermediate position between the lifting plate 11 and the discharge roller 13 of the inner plate 15 of the erasing section 5, and a storage section entrance 17 is provided at a position corresponding to the rear storage section 3. A passage 18 communicating between the two inlets 16 and 17 is provided inside the section 5, and the passage 18 has an erasing member 21 near the erasing section entrance 16.
A temperature detecting member 22 is provided, a pair of feed rollers 19 is provided downstream thereof, and an air cooling fan 20 is provided below the passage 18 in order. The temperature detecting member 22 is attached at a position that does not interfere with the running of the recording body 45 to detect the temperature of the heating element 56, and is a thermistor type, a thermocouple type, a contact type temperature detector such as a side temperature resistor type, or Any of a non-contact type temperature detector and the like may be used.

A storage outlet 26 is provided at a position corresponding to the rear storage unit 3 of the inner plate 25 of the recording unit 6, and a discharge roller 27 is provided at the bottom of the rear storage unit 3 just before the storage outlet 26, and a discharge roller 27 is provided. At the upper part, pressure contact members 30 are provided, each of which is suspended from the back surface of the bottom part 10 by a spring 29. A guide plate below the inside of the recording unit 6
A thermal head 35 and a pressure contact plate 36 are provided on the upper portion of the thermal head 35 and a guide roller 34 so as to face each other. The lower end of the thermal head 35 is pivotally supported by the recording section 6, and a pair of A discharge roller 37 is provided with a discharge port 38 on a top plate above the discharge roller 37, and a discharge port cover 39 is further provided thereon.

FIG. 4 shows details of the erasing section 5.
The material of the erasing member 21 is a material obtained by electrodepositing nickel chromium or stainless steel metal, a metal foil, a conductive polymer, a trace amount of rare earth element or an additive for lowering the resistance, and a ceramic semiconductor baked in a furnace. Indium oxide (ITO) or the like can be used, and a ceramic can be applied to a substrate by a screen printing method or the like. be able to. Figures 5 and 6 show ceramic substrates
55, an example of the erasing member 21 in which the metal oxide is a planar heating element 56-1 to 3 is shown, and the ceramic substrate 55 has an insulating property and is divided into a plurality of bases 58 by slits 57. Heating elements 56-1 to 5-3 are mounted on each base 58, and electrode portions 59 provided on the heating elements 56-1 to 3 are located at connecting portions of the base 58. Is covered with a protective layer 60 as shown in FIG. 6, and this protective layer 60 does not cover the electrode portion 59. Electrodes 63 covered with an electrode cover 62 are connected to the electrode portions 59, respectively.
61, energization is controlled by the CPU 65 via the heating element driver 64, and this energization control is performed according to programmed conditions and erasing members.
The determination is performed based on the feedback information of the 21 detected temperatures.

FIG. 7 shows an example of a sheet-like or card-like recording body 45 used for the above-mentioned recording medium. This recording body 45 is made of a heat-sensitive material made of a visible and reversible heat-sensitive material. The layer 46 is coated on a resin support layer 47 of 20 μm to 0.5 mm by 2 μm to 2 μm.
On the heat-sensitive layer 46, a laminate layer 48 is formed, and the laminate layer 48 is composed of an adhesive layer 49 and a resin layer 50 such as polyethylene terephthalate from the bottom. The layer 51 is formed, and the total thickness of the laminate layer 48 and the heat-resistant layer 51 is 5 μm or less. Then, between the support layer 47 and the heat-sensitive layer 46, a coloring layer such as ink, a metal layer such as Al, or a light absorbing layer is provided according to the heating method and purpose for writing the characteristics and information of the heat-sensitive material. Thus, characters and patterns can be printed on the heat-resistant layer 51 by screen printing.

The characteristics of such a recording medium 45 are shown in FIGS. The vertical axis in FIG. 8 shows the transparent and cloudy state, and the horizontal axis shows the temperature for heating the heat-sensitive material.
When the temperature of the recording material 45 is increased from room temperature to the temperature T1 in the recording material 45, the heat-sensitive material is in the transparent state B. When the temperature of the heat-sensitive material at the temperature T1 is lowered to room temperature, the transparent state B is maintained. When the temperature T1 is further raised to the temperature T2 and then lowered to around room temperature, the temperature becomes lower than the temperature T0, the state changes to the cloudy state A, and the cloudy state A is maintained at room temperature. After raising the temperature of the heat-sensitive material to the temperature T1 or T2, the temperature of the heat-sensitive material returns to room temperature, and two visible states can be secured.
The vertical axis in FIG. 9 shows the decoloring and coloring states, and the horizontal axis shows the temperature at which the heat-sensitive material is heated.
From the room temperature to the temperature T2 'after passing through the temperature T1', the heat-sensitive material changes to the coloring state C. And the temperature T2 '
When the temperature of the heat-sensitive material is lowered to room temperature, the coloring state C is maintained during that time. The heat-sensitive material in the color development state C at room temperature or lower at the temperature T0 'or lower passes through the temperature T0' to the temperature T1 '.
When the temperature is increased to the above, the density decreases as shown by the dotted line to be in the decolored state D, and when the temperature of the heat-sensitive material is again lowered to room temperature, the decolored state D is maintained. The temperature of the thermosensitive material is set to temperature T
When the temperature is further increased from 1 'to T2', the heat-sensitive material changes to the colored state C, and the colored state C is maintained even when the temperature is lowered to room temperature. The heat-sensitive material forms a heat-sensitive material layer using a polymer / small molecule as a dispersed film, and the low-molecular material is formed into particles having a particle size of 0.1 to 5 μm.
If the crystal state of the particles is polycrystal, the incident light is scattered by the polycrystal and becomes cloudy state A. In addition, when the crystal state of the particles becomes a relatively large crystal, the light enters the transparent state B without being scattered by the crystal. Repetition of the decoloring and coloring state with another heat-sensitive material is composed of a coloring agent, a developing / decoloring agent, and a binder.

The operation of the above-described heating device in the erasing section 5 will be described first. As shown in FIG. 2, a recording medium 45 for opening the tray 7 and erasing information or a new recording medium 45 is used. The recording medium 45 is set in the front storage unit 2, and is sequentially sent from the upper recording medium to the passage 18 of the erasing unit 5 by the discharge roller 13, and is heated by the erasing member 21 of the passage 18. The erasing member 21 is set at the temperatures T1, T2, T1 'and T2' which are characteristic of the background of the recording medium 45 having the characteristics shown in FIGS. The recording body 45 passes and the erasing member
These temperature conditions are set immediately before the exit of 21. The temperature can be set within a range of ± 5 ° C. to ± 10 ° C., and the temperatures T1 and T1 ′ are different depending on the heat-sensitive material, but may be 50 ° C.
C. to 100.degree. C., and temperatures T2 and T2 'are 80.degree.
° C range. Taking the heating at the temperatures T1 and T1 'as an example, it is difficult to control the temperature of the recording body 45 by rapid heating in this temperature range, and the heating elements 56-1 to 3-1 are heated to the temperatures T1 and T1'. The method of heating at this temperature over a relatively long time is optimal. However, the recording body 45 is a heating element 56
When entering from the -1 side and moving to the heating element 56-3 side,
The recording medium 45 in the room temperature state takes a lot of heat from the heating element 56-1, approaches the temperature of the heating element 56-3 at the heating element 56-3, and changes the temperature state of the heating elements 56-1 to 3 in this case. FIG. 10 shows this.

In FIG. 10, the abscissa indicates the distance between the heating elements 56-1 to 3-3, the ordinate indicates the temperature of the heating elements 56-1 to 3-3, and the solid line B and the dotted line A indicate the line of the recording body 45, respectively. Speed or heat capacity, that is, a temperature state when the thickness of the support layer 47 of the recording body 45 is different, and when the linear velocity increases or the heat capacity increases, that is, when the thickness of the support layer 47 of the recording body 45 increases, the temperature state becomes From the dotted line a to the solid line b. The temperature condition of the heating elements 56-1 to 3-3 is as shown by a solid line B, as shown by a dotted line A,
Providing a margin for the heating state is a necessary condition for ensuring the erasure of the recording medium 45. In order to do so, the heating temperature of each of the plurality of heating elements 56-1 to 3 is controlled independently, and the heating temperature on the side where the recording body 45 enters is the heating temperature on the side where the recording medium 45 is discharged. The temperature is controlled to be higher than the set temperature of the recording body 45. FIG. 11 shows an example of the temperature conditions of the heating elements 56-1 to 3-3 at that time.
Are set as temperatures Ta, Tb, Tc, but may be set as temperatures Ta, Tc, Tc.
The upper limit temperature of the temperature Ta is determined by the heat-sensitive layer 46 constituting the recording medium 45.
Alternatively, the temperature at which one of the support layers 47 undergoes thermal deformation, that is, the glass transition temperature is set to a low temperature or lower, and when the temperature exceeds these temperatures, streaks or scratches due to thermal deformation occur in the recording body 45, and recording is performed. The durability of the body 45 will be impaired.
In the above case, the feed roller 19 in the passage 18 of the erasing section 13 comes into contact with the recording medium and runs the recording medium.
The temperature of the recording body 45 approaches the temperature of the heating elements 56-1 to 3-3 when the recording medium is continuously run, and the recording body 45 thus formed is stored in the rear storage unit. 3, the temperature of the storage unit 1 is also increased by the heat stored in the recording body 45. Therefore, in order to prevent such a phenomenon from occurring and lower the temperature to near room temperature, an air cooling fan 20 and a radiation fin 23 are provided in the passage 18 as shown in FIG. Means may be provided such as passing a heat pipe or mounting a Peltier element inside.

FIG. 12 shows that the heating element 56-1 to 3 can be heated from above and below, so that the heating element can be heated from above and below. 56-
There is shown a second embodiment of the present invention in which 1-3 are arranged. In such a case, the upper and lower heating elements 56-1 to 56-1
Reference numeral 3 is provided at an interval y equal to or greater than the thickness x of the recording body 45 so as not to be pressed against the recording body 45. Then, a guide plate 67 is attached to the base body 58 on the entry side of the recording body 45,
The recording body 45 is guided by the guide plate 69 and smoothly inserted between the upper and lower heating elements 56-1 to 56-3. As a method of smoothly inserting the recording body 45 between the upper and lower heating elements 56-1 to 3-3, the interval between the upper and lower heating elements 56-1 to 3 may be set such that the entrance side is wide and the discharge side is narrow. Although it is good, the heat conduction to the recording body 45 at the longer interval is reduced, so that the temperature of the heating element 56-1 on that side is set higher than the temperature of the heating element 56-3 on the narrow side.

FIG. 13 shows a third embodiment obtained by partially modifying the second embodiment.
An embodiment is shown, in which the upper and lower heating elements 56
In order to maintain an interval between -1 to -3, spacers 69 having insulation and heat resistance are interposed between the electrodes 63 of the upper and lower heating elements 56-1 to 56-3. In this embodiment, since the upper and lower electrodes 63 are insulated by the spacer 69, they can be controlled separately, and the upper and lower heating elements can be controlled.
56-1 to 3-3 and the electrode 63 are pressed and adhered by a spring plate 71 provided on the electrode cover 62, thereby forming the upper and lower heating elements 56.
The interval between -1 to -3 is kept constant, and the electrode cover 62 is attached to an apparatus main body (not shown) by the fixture 72. As another modified example of this embodiment, the width or the number of the heating elements 56-1 to 56-3 is different from that shown in the drawing, or the lower heating element according to the configuration and other conditions of the recording body 45. 56-1
The temperature of all the heating elements 56-
Examples in which the temperatures of 1 to 3 are different from each other can be given.

FIGS. 14 and 15 show a fourth embodiment in which the heating element 56 is in the form of a roller. The heating element 56 is made of the same material as the planar heating element 56 described above. Can be
Extrusion molding is performed by adding an additive to lower the resistance to the ceramic and then sintering in a furnace. The shape is 2-5 mm in thickness, 10-20 mm in outer diameter, and the resistance value is 50-200Ω. I have. Two such heating elements 56 are juxtaposed, and the recording body 45 passes around it in an S-shape. Gears 75 having the same diameter as the heating element 56 meshing with each other are attached to one end faces of these heating elements 56, and both end faces and the gear 75 of the heating element 56 are rotatably supported by a positioning member 76 attached to the heating device main body. Have been. Then, the brushes 77-1, 78-1, 78-1 and 2 are pressed against the outer peripheral surfaces near both ends of each heating element 56, and voltage is applied between the brushes 77-1 and 78-1 and between the brushes 78-1 and 78-1. This voltage is different from each of the above embodiments. However, since the surface resistance of both heating elements 56 is low, both heating elements 56 should not be leaked between them.
In order to make the 56 non-contact, a spacer belt made of an insulator (not shown) is provided at both ends of one of the heating elements 56, and the thickness of the spacer belt does not slip on the surface of the recording body 45 and the heating element 56, thereby preventing leakage. The function can be performed. FIG. 15 shows such a heating element 56 with a recording body 45.
The guide / cover 79, which also serves as a passage guide, is shown, and the guide / cover 79 may cover the heating element 56 entirely or partially. In consideration of the above, it can be said that a partially coated one is more preferable.

In the above embodiment, the temperature control of the heating elements 56-1 to 3-3 needs to be performed in the longitudinal direction of the heating elements 56-1 to 3-3. The temperature of the heating elements 56-1 to 3 through which the body 45 has passed decreases, and the heating element 56-1 at the point where the body 45 does not pass.
-3 are maintained, whereby the heating elements 56-1 to 36-1 are maintained.
This causes temperature unevenness in the longitudinal direction.
When such temperature unevenness occurs, the visual state changes in the longitudinal direction of the recording medium 45 when passing through the wide recording medium 45 immediately after passing through the narrow recording medium 45 due to the temperature variation. Will occur. As a method of preventing the occurrence of such temperature unevenness, a once-heating element 56
After turning off the power to -1 to 3 to reduce the temperature to a temperature at which the temperature unevenness decreases, the method of restarting the power supply and the heating element 56-1 to
There is a method of providing a contact member for removing heat from the surface of the third recording body 45 that does not contact, and lowering the temperature by the contact of the contact member. In this case, as the contact member, for example, a metal plate such as aluminum is used, and if necessary, a smooth resin coating is applied to the surface thereof, and a rough surface having a large surface area is provided to prevent heat storage of the contact member. Surface or hollow shape. The length of the contact member is
After the recording medium 45 having a certain width passes, the divided contact member is brought into contact with a portion other than the width of the recording medium 45 to lower the temperature. Such a series of movements in which the contact member comes into contact with the heating elements 56-1 to 3 can be performed by operating a crank mechanism with a motor or a solenoid as a driving source.

In each of the above embodiments, the heating element 56
The energization to -1 to 3 is started after the power switch of the heating device is turned on, and when the erasing of the recording body 45 is performed immediately,
The temperature is raised to that temperature condition. Even when the erasing of the recording body 45 is not necessary, the heating elements 56-1 to 3-3 are energized, and the temperature outside the range where the heat-sensitive layer 46 of the recording body 45 causes a visible change, that is, the temperatures T0 and T0 in FIGS. ′, And stands by so that the time required to raise the temperature when the erasing of the recording medium 45 becomes necessary can be shortened. The temperature control of the heating elements 56-1 to 3
The temperature of the heating elements 56-1 to 3 is estimated from the power supply to the heating elements 56-1 to 3 based on the conditions such as the heat capacity and power density of the heating elements 6-1 to 3-3, the heat capacity and the linear velocity of the recording medium 45, and the power This power supply is performed by controlling the supply, and the power supply is performed by controlling the number of pulses by making a constant voltage into a pulse shape. At this time, the heating element 56
The temperatures of -1 to -3 are detected by the temperature detecting member 22 shown in FIG. 4, and a measuring circuit (not shown) is connected to the temperature detecting member 22, and the temperature is controlled from the CPU 65 through the heating element driver 64 through the measuring circuit. You can also.

Next, the operation in the recording section 6 will be described. The recording medium 45 which has been subjected to the erasing operation in the erasing section 5 as described above is fed through the passage 18 by the feed roller.
Through the inlet 17 of the storage unit 1, the paper is sent to the rear storage unit 3 through the entrance 17, and is stocked from below to above.
Is sent from the lower recording medium 45 to the thermal head 35 of the recording unit 6 via the storage unit outlet 26 sequentially, where information is written to the recording medium 45. If the recording medium 45 on which the information is to be written has the characteristics shown in FIG. 8, the temperature is raised by the thermal head 35 in order to change the cloudy state to the background state and to make the information transparent. The temperature is the temperature T1, and the temperature at which the temperature is raised by the thermal head 35 is the temperature T2 in order to set the transparent state to the background state and to make the information cloudy. When the recording medium 45 has the characteristics shown in FIG. 9, the temperature at which the temperature is raised by the thermal head 35 is set to the temperature T2 'in order to set the decolored state to the background state so that the information is colored. Becomes In this case, the voltage applied to the thermal head 35 is a single pulse voltage or a plurality of single pulse voltages for forming one dot. It is advantageous from the viewpoint of thermal efficiency that the surface of the recording body 45 in contact with the thermal head 35 at the time of writing is on the laminate layer 48 side in FIG. 7. Is also determined. The recording body 45 can be printed on the heat-resistant layer 51, but since the surface of the recording body 45 can be clearly specified by a marker by printing, the surface in contact with the thermal head 35 is heat-resistant of the recording body 45. Whether the layer 51 side or the support layer 47 side is detected by a recording body detector (not shown), the voltage applied to the thermal head 35 can be set correspondingly.

[0021] The recording medium for which writing has been completed as described above.
45 is sent to the tray 7 by the discharge roller 37 via the outlet 38 of the recording unit 6 and the outlet cover 39, and is stocked there. At this time, since there is a step between the surface of the recording section exit 38 and the surface of the tray 7, even if a large number of recording bodies are stocked in the tray 7, the recording medium 45 coming out of the recording section exit 38 is disturbed. Nothing. In this case, the recording body 45 is checked at the time of recording by a detector (not shown) which is provided near the storage unit outlet 26 and detects the presence or absence of the recording body 45, and when the recording body 45 is absent, the display unit 9 is displayed. This is displayed, and the operator replenishes the storage unit 1 with the recording medium 45.

[0022]

The present invention is as described above. According to the first aspect of the present invention, a sheet-like or card-like recording medium is made of a heat-sensitive material whose visible state is reversibly changed by heating. A recording unit having a recording unit having a writing member for writing information to the recording unit, and an erasing unit having an erasing member for heating the recording unit to erase the information written by the recording unit. In the heating device, the erasing member has a plurality of planar heating elements capable of heating the recording body from above and below, and the heating elements are spaced apart from each other by a distance equal to or greater than the thickness of the recording body so as not to be pressed against the recording body. And the temperature of these heating elements can be adjusted independently of each other, so that each heating element is adjusted to the temperature required for erasing the recording body, thereby making the recording body as a whole Erased uniformly, then When writing the information to the body, it becomes uniform background of the image quality, there is an effect that occurrence of an abnormal image quality due to non-uniform image quality can be improved by preventing. According to a second aspect of the present invention, in the first aspect of the present invention, between the electrodes of the heating elements arranged above and below, an interval between these heating elements is maintained, and insulation and heat resistance for insulating the electrodes are provided. Since the recording body is not pressed against the upper and lower planar heating elements because the spacers are provided, this prevents the surfaces of the heating element and the recording body from rubbing each other, thereby suppressing the occurrence of damage to the recording body. This has the effect of improving durability, enabling repeated reuse, and reducing running costs.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention when a tray is closed.

FIG. 2 is a perspective view when the tray is opened.

FIG. 3 is a vertical sectional front view taken along line 3-3 in FIG. 1;

FIG. 4 is an enlarged view of a main part of the above.

FIG. 5 is an enlarged perspective view of the same erasing member.

FIG. 6 is an enlarged view of a portion surrounded by a line 6 in the same.

FIG. 7 is an end view of the recording medium according to the first embodiment.

FIG. 8 is a correlation diagram between the temperature of the recording medium and transparency and cloudiness.

FIG. 9 is a correlation diagram between the temperature of the recording medium and coloring and decoloring.

FIG. 10 is a non-adjusted set temperature diagram of the heating element according to the first embodiment.

FIG. 11 is an adjustment set temperature diagram of the heating element according to the first embodiment.

FIG. 12 is a front view of a main part of a second embodiment of the present invention.

FIG. 13 is a perspective view of a main part of a third embodiment of the present invention.

FIG. 14 is a perspective view of a main part according to a fourth embodiment of the present invention.

FIG. 15 is a perspective view showing a state where the heating element is covered with a cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage part 5 Erasing part 6 Recording part 16 Erasing part entrance 17 Storage part entrance 18 Passage 21 Erasing member 22 Temperature detecting member 26 Storage part exit 35 Thermal head 38 Recording part exit 45 Recording medium 46 Thermal layer 56 Heating element 57 Slit 58 Substrate 59 Electrode part 63 Electrode 67 Guide plate 69 Spacer

Claims (2)

(57) [Claims] 1. A recording unit comprising: a sheet-shaped or card-shaped recording body made of a heat-sensitive material whose visible state changes reversibly by heating; and a recording unit having a writing member for writing information to the recording body. An erasing section having an erasing member for heating a recording body to erase information written by the recording section, wherein the erasing member is a recording medium.
Multiple planar heating elements that can heat
These heating elements are recorded so that they do not press against the recording medium.
Are placed at an interval of at least the thickness of the body, and
That the temperature each of these heating elements independently has become adjustable heating device for a recording material according to claim. 2. Electrodes of a heating element arranged respectively above and below
While maintaining the space between these heating elements,
Spacer with insulation and heat resistance to insulate between them is provided
The heating device for a recording medium according to claim 1, wherein: