JPH09123488A - Thermal head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sustain the temperature within a specified narrow range at the time of waiting even for an object corresponding to image recording of A4 size or larger by providing means for heating a thermal head, and means for cooling thermal head. SOLUTION: At the time of image recording using a thermal head 10, a control means 80 detects the measured temperature T of a thermal head body 64 (glaze 70). If the temperature T is between an objective temperature TA at the time of waiting image recording and an appropriate temperature TB being set higher than TA, a decision is made that the temperature of glaze 70 is appropriate and a sign is delivered indicating that the recording can be started before transfer of a thermal material is started through a regulation roller. If the temperature T is lower than the objective temperature TA, a planar heater 78 is actuated and if the temperature T is higher than the objective temperature TA, a cooling fan 76 is actuated until TA<T<TB is satisfied and then the image recording is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of image recording using a heat-sensitive recording material, and more specifically, temperature adjustment can be suitably performed even with a large size corresponding to image recording of A4 size or more. The present invention relates to a thermal head device.

[0002]

2. Description of the Related Art Image recording using a heat-sensitive recording material (hereinafter referred to as a heat-sensitive material) is used for image recording such as ultrasonic diagnosis. In recent years, wet development processing is unnecessary,
Image recording using thermal materials (hereinafter also referred to as thermal image recording) because of its advantages such as easy handling
Is not only a small image record such as ultrasonic diagnosis, but also M
Utilization for medical diagnosis that requires large images such as RI diagnosis and X-ray diagnosis is also being studied.

As is well known, in thermal image recording, a thermal head is used in which heating recording points (recording dots) for heating the thermal material to record an image are arranged in one direction, and the thermal head and the thermal material are dots. Image recording is performed by moving relatively in a direction orthogonal to the arrangement direction of the thermal head. In thermal image recording, high accuracy is required for temperature adjustment of the thermal head (especially the glaze as the recording portion). It

In thermal image recording, image recording is performed by supplying energy to the recording dots of the thermal head to heat the recording dots to heat the heat sensitive material.
This energy amount affects the life of the thermal head, and it is preferable that the energy be small. Furthermore, the smaller the temperature rise during recording, the better the recording sensitivity. Therefore, in this respect, it is preferable that the temperature of the thermal head in standby is high. On the other hand, if the temperature of the thermal head is too high, thermal recording will be performed at unnecessary positions during image recording. Therefore, the temperature of the thermal head in standby must be kept lower than the recording temperature. That is, the temperature of the thermal head is preferably kept at a limit temperature at which recording of the heat-sensitive material is not performed during standby. In addition, during recording, unnecessary recording is not performed, so that it is necessary to quickly cool the recording dots below the recording temperature after recording at the non-recording points.

However, since the shape of the thermal head is greatly restricted by the control of recording, the structure of the thermal recording device in which the thermal head is mounted, etc., it is very difficult to make the structure suitable for temperature adjustment. Therefore, it is difficult to suitably heat and cool the thermal head in the standby state and maintain it at a predetermined temperature. Above all, it is more difficult to control the temperature of a thermal head corresponding to a large image recording of A4 size or more, particularly B4 size or more, as compared with a conventional small thermal head, and it is necessary to solve the problem.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. Even if the apparatus is capable of recording a large image of A4 size or more, the temperature during standby is It is an object of the present invention to provide a thermal head device which can preferably maintain a predetermined temperature range in a narrow range.

[0007]

In order to achieve the above object, the present invention provides a thermal head for recording an image on a thermosensitive recording material, a heating means for heating the thermal head, and a cooling for the thermal head. The present invention provides a thermal head device characterized by having a cooling means for operating the thermal head device.

Further, it is preferable that the heating means is a control means and / or a heater for heating the thermal head, and the cooling means is a cooling means composed of a cooling fan and a heat sink.

Further, it is preferable that the heat sink is directly fixed to the substrate of the thermal head on which the glaze is formed.

Further, in the thermal head device,
Furthermore, it is preferable to have a ventilation path that is isolated from the inside of the apparatus, from the intake port of the apparatus in which the thermal head device is installed to the cooling fan.

Further, in the thermal head device,
Furthermore, when the temperature measuring means of the thermal head is provided and the target temperature during recording standby is TA and the measured temperature of the thermal head is T, the temperature T is equal to the temperature "TA" during recording standby.
When the temperature T exceeds a temperature "Ta + b" which is higher than "TA + a", the operation of the heating means is stopped, and the temperature T is the temperature "Ta +".
When the temperature becomes "TA + d" which is higher than "b", the cooling means is operated, and when the temperature T becomes the temperature "Ta + c" between the temperatures "TA + b" and "TA + d", the operation of the cooling means is stopped,
On the other hand, at the time of recording, it is preferable to have control means for controlling the heating means and the cooling means so that the cooling means operates continuously and the heating means does not operate (however, a and b may be minus). ).

Further, when the temperature T of the thermal head is not the predetermined temperature at the start of recording, it is preferable to wait for the recording until the temperature of the thermal head reaches the predetermined temperature.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a thermal head device according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 is a schematic view of a thermal image recording apparatus using the thermal head device of the present invention. The thermal image recording device 12 (hereinafter referred to as recording device 12) shown in FIG. 1 uses a thermal recording material of a predetermined size such as B4 (hereinafter referred to as thermal material), that is, a so-called cut sheet thermal material A. The thermal head device 10 of the present invention performs thermal image recording on the thermosensitive material A. The loading part 14, the feeding / conveying part 16, the recording / conveying part 18, the recording part 20 using the thermal head device 10 of the present invention, and the discharging. Part 2
2.

In this recording device 12, the heat-sensitive material A
Are stacked and stored in the magazine 24 with the heat-sensitive recording layer as the lower surface. The magazine 24 is a housing having a lid 26 and is loaded in the loading section 14 of the recording device 12.
The loading unit 14 includes an insertion opening 30 formed in the housing 28 of the recording device 12, a guide plate 32, and guide rolls 34, 3.
4. The magazine 24 is inserted into the recording device 12 from the insertion opening 30 with the lid 26 first, and is guided by the guide plate 32 and the guide roll 34, while the stop member 36 is provided. The recording device 12 is loaded at a predetermined position by being pushed to a position where the recording device 12 comes into contact.

The supply / conveyance means 16 has a sheet-fed mechanism using a suction cup 40, a conveyance means 42 and a conveyance guide 44. The heat-sensitive material A is taken out from the magazine 24,
The sheet is transported to the recording transport section 18 downstream in the transport direction. Conveying means 4
2 includes a transport roller 46, a pulley 47a coaxial with the transport roller 46, a pulley 47b connected to a rotary drive source, a tension pulley 47c, an endless belt 48 stretched over the three pulleys, And a nip roller 50 pressed against the
The transporting roller 46 and the nip roller 50 hold the leading end of the heat-sensitive sheet A that has been sheet-fed by zero, and transport the heat-sensitive sheet A downstream.

In the recording device 12, when a recording start instruction is issued, the lid 26 is opened by an opening / closing mechanism (not shown), and the sheet-fed mechanism using the suction cup 40 conveys the leading end of the heat-sensitive material A to the conveying means 42 (conveyance). Roller 46 and nip roller 5
0). The supplied heat-sensitive material A is transported to the recording transport unit 18 by the transport unit 42 while being guided by the transport guide 44. At the time when the heat-sensitive material A is nipped by the transport roller 46 and the nip roller 50,
The suction by the suction cup 30 is released, and when the heat-sensitive material A to be used for recording is completely discharged from the magazine 24, the lid 26 is closed by the opening / closing means.

The recording / conveying section 18 has a regulating roller pair 52, a conveying roller pair 56 and a guide 58.
First, the tip of the heat-sensitive material A reaches the regulating roller pair 52. Therefore, the distance from the conveying means 42 defined by the conveying guide 44 to the regulating roller pair 52 is equal to the heat-sensitive material A.
Is set to be slightly shorter than the length in the transport direction. The regulation roller pair 52 is initially stopped, and when the tip of the heat-sensitive material A reaches the regulation roller pair 52, the temperature of the thermal head main body 64 is confirmed. The conveyance of the heat-sensitive material A by the roller pair 52 is started (this point will be described later in detail), and is conveyed to the recording unit 20 while being guided by the guide 58.

The recording unit 20 has the thermal head device 10 of the present invention, a platen roller 60 and a guide 62. Thermal head body 64 of thermal head device 10
(See FIG. 2) and the heat sink 66 has a fulcrum 68a.
Is supported by a support member 68 which is rotatable in the direction of arrow a and in the opposite direction. Before the heat-sensitive material A is transported,
The support member 68 is rotated upward (in the direction opposite to the arrow a direction), and the thermal head main body 64 and the platen roller 60 are not in contact with each other. The heat-sensitive material A by the recording and transporting section
When the leading end of the sheet is conveyed to the recording start position (the position corresponding to the glaze 70 of the thermal head body 64), the supporting member 6
8 rotates in the direction of arrow a, and the heat sensitive material A is sandwiched between the thermal head main body 64 and the platen roller 60, and the heat sensitive material A is held at a predetermined position by the platen roller 60 and conveyed downstream. Meanwhile, a thermal image is recorded by the thermal head main body 64. The thermal head device 10 will be described later in detail.

The heat-sensitive material A on which the heat-sensitive image recording has been completed is guided by the guide 62 and is conveyed to the platen roller 60 and the pair of conveying rollers 63 and is ejected to the tray 72 of the ejecting section 22. The tray 72 protrudes outside the recording device 12 through a discharge port 74 formed in the housing 28, and the heat-sensitive material A on which an image has been recorded is discharged to the outside through the discharge port 74 and is taken out.

FIG. 2 is a schematic perspective view of the thermal head device 10. The thermal head device 10 is capable of recording an image up to a maximum B4 size, for example, about 300 mm.
The thermal head main body 64, which is an (electrical) substrate for performing thermal image recording with a recording (pixel) density of dpi, on which the glaze 70 that is a portion for performing thermal image recording on the thermal sensitive material A is formed, A heat sink 66 as a cooling means that is directly fixed to the head body 64, and three cooling fans 7 that form a cooling means together with the heat sink 66.
6. Sheet heater 78 and cooling fan 76 as heating means
And a control means 80 for controlling the drive of the planar heater 78.

In the illustrated example, the heat sink 6
The fin 66a of 6 is 5 at the portion corresponding to the glaze 70.
There are notches 66c, 66c ... at the locations, and a thermistor is arranged at the base portion 66b of the heat sink 66 at this portion. In the thermal head device 10, the temperature of the thermal head main body 64 (glaze 70) is detected by measuring the temperature of the base 66b at the upper part of the glaze 70, and the control unit 80 as a result, more specifically, (That is, the thermistor corresponding to the wiring 80a), the driving of the cooling fan 76 and the sheet heater 78 during the recording standby is controlled. The thermistors other than the center are mainly used for disconnection. The method for detecting the temperature of the thermal head main body 64 is not limited to this, and various known methods can be used.

In the illustrated thermal head device 10, a (flexible) planar heater 78 attached to the base 66b of the heat sink 66 is used as a heating means. The sheet heater 78 is formed by using a metal such as stainless steel as a heating element and sandwiching the same with an insulator such as polyimide. For example, the sheet heater 78 is commercially available from Mitsui Toatsu Fine under the trade name of a flexible sheet heating element. Have been. Similar products are also commercially available from Kurabe Co., Ltd. This planar heater 78 can be designed and manufactured in an arbitrary shape according to the application. Therefore, the thermal head body 64
The heating means can have any shape depending on the shape of the heat sink 66 or the shape of the heat sink 66, or in consideration of a more preferable heating portion. For example, the heat sink 66 is designed to have a suitable shape in which the cooling efficiency is prioritized. After that, the heating means, that is, the planar heater 78 can be designed according to the shape of the heat sink 66. Moreover, since it is planar, no space is required. Therefore, by using the planar heater 78, it is possible to achieve both suitable cooling efficiency and heating efficiency, and the thermal head main body 64 (more specifically, the glaze 70) is preferably used within a narrow temperature range. It becomes possible to control, and it is possible to realize a thermal head having a high sensitivity and a long life even if the thermal head is capable of recording a large image of B4 size or more.

In the thermal head device 10 of the present invention, the heating means is not limited to this, and a mode in which the glaze 70 is heated to such an extent that the thermal recording is not performed on the thermal material A, that is, the so-called blanking is used as the cooling means is also suitable. Is exemplified. According to this blanking, since a separate heating member is not required, the above-described planar heater 78 can be replaced with a heat sink 66.
Therefore, the thermal head main body 64 can be suitably controlled within a narrow temperature range. In the case of performing the blank shot, the driving of the head main body 64 may be controlled so that the blank shot is always performed during a standby time other than the recording time, or the driving of the head main body 64 may be controlled according to the temperature measurement result by the thermistor. It may be controlled. The driving control of the head main body 64 in this idling is as follows.
A control unit for image recording may be performed, or a control unit for idling may be separately provided.

As described above, in the illustrated thermal head device 10, the heat sink 66 and the cooling fan 76 constitute a cooling means. Here, in the embodiment shown in FIG. 2, as a preferred embodiment, the thermal head main body 64 which is an (electrical) substrate on which the glaze 70 is formed.
The base 66b of the heat sink 66 is directly fixed to the.

As in another embodiment of the present invention shown in FIG. 3, a normal thermal head is constructed by adhering a base 82 made of a metal plate or the like to a thermal head main body 64 and attaching a heat sink 66 thereto. In this case, the base portion 66b of the heat sink 66 is fixed to the base 82. On the other hand, the thermal head device 10 in the illustrated example has a heat sink
By directly fixing the base 66b, the cooling effect can be improved and a more suitable cooling effect can be obtained. The present invention can be preferably applied to the normal thermal head having the base 82 shown in FIG.

In the thermal head device 10 of the present invention, the shape of the heat sink 66 is not limited to the illustrated example.
Of course, for example, it may not have a notch for attaching a thermistor as shown in FIG. Further, it is of course preferable that the temperature of the glaze 70 is uniform in the extending direction thereof, but FIG.
As shown in FIG. 6, if the fins 66a are partially cut out, the cooling effect may be uneven, and the temperature distribution may be formed in the extending direction of the glaze 70. Therefore, when mounting the thermistor, as shown in FIG.
The fins 66a in the portion corresponding to the glaze 70 may be entirely cut out. Furthermore, in order to make the temperature of the glaze 70 uniform, the distribution and size of the fins of the heat sink 66 may be adjusted to partially adjust the cooling effect. For example, since the central portion of the thermal head main body 64 usually tends to have a high temperature, as shown in FIG. 5, the fins in the central portion are large and the formation density is high, and the fins are smaller toward both ends. Further, the formation density may be roughened to improve the cooling effect toward the central portion.

Three cooling fans 76, which form a cooling means together with the heat sink 66, are arranged in the extending direction of the glaze 70, and mainly apply cooling air to the fins 66a.
By cooling a, the thermal head body 64 (glaze 70) is cooled.

In the illustrated example of the thermal head device 10, the cooling fan 76 is disposed in a fan box 84 as a preferred embodiment. As shown in FIG.
The fan box 84 forms a ventilation path from an intake port 86 formed in the housing 28 to the cooling fan 76 and substantially isolates the ventilation path from other areas in the recording device 12. In the recording device 12 that performs thermal image recording, the temperature inside the apparatus increases greatly. Therefore, by having the fan box 84 forming the duct as shown in the illustrated example, it is possible to cool the heat sink 66 and the like by taking in the air outside the device, and to obtain more excellent cooling efficiency. Note that the present invention is not limited to an embodiment having such a fan box 84.

In the illustrated example, the cooling fan 76
Is disposed in a state of being slightly inclined with respect to the heat sink 66, but the present invention is not limited to this, and the cooling fan 76 may be disposed at a larger angle, or the cooling fan may be cooled vertically. The fan 76 may be arranged. That is, according to the present invention, the cooling fan 76 is preferably provided with the heat sink 66 in accordance with the design of the recording device 12 or the like.
What is necessary is just to arrange | position the cooling fan 76 in the position and angle which can cool etc.

Hereinafter, the planar heater 78 by the control means 80 will be described.
The drive control of the cooling fan 76 will be described. In the following description, T is the temperature measured by the thermistor in the center of the thermal head body 64 (glaze 70), and TA
Indicates the target temperature during image recording standby. Also, a <b <c <d, and a and b may be negative. First, in the initial state in which the recording device 12 is powered on, when T <TA + a, the control means 80 starts heating by the planar heater 78 (or performs the blanking), and T> TA + d. In some cases, cooling by the cooling fan 76 is started. In other states, both the planar heater 78 and the cooling fan 76 remain stopped.

When the power is on and the image recording is on standby, the control means 80 controls T> TA + a to T <T.
When it becomes A + a, heating by the planar heater 78 is started, and when T> TA + b becomes T> TA + b,
When the heating by the planar heater 78 is stopped and the temperature T> TA + c becomes T <TA + c, the cooling by the cooling fan 76 is stopped, and when the temperature T <TA + d becomes T> TA + d, the cooling by the cooling fan 76 is performed. To start.

On the other hand, during image recording by the thermal head device 10, the control means 80 detects the temperature T,
When the temperature T is between the TA and a temperature TB that is appropriately set higher than the TA (that is, TA <T <TB, which is appropriately set as a suitable temperature range during standby), glaze is performed. Assuming that the temperature of 70 is appropriate, a sign indicating that recording can be started is issued to the control unit of the recording device 12, the conveyance of the heat-sensitive material A by the regulation roller pair 52 is started, and image recording is started. On the other hand, when T is equal to or lower than TA, heating is performed by the planar heater 78 (stopped if the cooling fan 76 is driven), and conversely, when T is equal to or higher than TB, cooling is performed. Cooling is performed by the fan 76 (stopped if the sheet heater 78 is driven), TA <T <TB
Image recording is started after waiting for.

When image recording is started, the planar heater 78 is stopped during the recording regardless of the temperature T of the glaze 70 detected by the thermistor, and the cooling fan 76 continuously cools the image. That is, in the thermal head device 10, the planar heater 78 is used in any case.
And the cooling fan 76 are not driven at the same time. Even during recording, the planar heater 7 is operated according to the detection result of the thermistor.
8 or the cooling fan 76 may be controlled. However, in the thermal head device 10, in order to perform high-quality image recording, the temperature of the glaze 70 is detected by the central thermistor even during recording, and the energy applied for recording is predicted according to the result. Determining and supplying energy for recording. Therefore, if the planar heater 78 and the cooling fan 76 are repeatedly turned on / off during recording, the rate of temperature increase and the rate of temperature decrease change, making it very difficult to predict the required energy. Moreover, the glaze is 70 during recording.
Generates heat according to the recorded image. Therefore, during the image recording, as described above, the planar heater 7 does not depend on the temperature T.
It is preferable that 8 is stopped and cooling by the cooling fan 76 is continuously performed. In order to make the above prediction more suitable, a temperature detecting means for the air guided to the cooling fan 76 may be provided.

Further, in the thermal head device 10 shown in FIG. 2, a thermal protector 88 is installed on the fin 66a of the heat sink 66. The thermal protector 88 detects abnormal heating of the thermal head device 10 by measuring the temperature of the fins 66a. When the temperature detected by the thermal protector 88 exceeds a predetermined value, at least the thermal head 88 is used. The energy supply to the main body 64 is stopped, and the recording device 12
At, a message indicating that the thermal head device 10 has abnormally heated is displayed.

Although the thermal head device of the present invention has been described above in detail, the present invention is not limited to the above examples, and various improvements and changes may be made without departing from the scope of the present invention. Of course.

[0037]

As described above in detail, according to the thermal head device of the present invention, even in the case of a thermal head compatible with recording a large image of A4 size or more, the temperature during standby can be controlled within a narrow range. It is possible to suitably maintain the temperature in a predetermined temperature range, and it is possible to realize a thermal head having high sensitivity and long life.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a thermal image recording apparatus using a thermal head device of the present invention.

FIG. 2 is a schematic perspective view of an example of a thermal head device of the present invention.

FIG. 3 is a schematic perspective view of another example of the thermal head device of the present invention.

FIG. 4 is a schematic perspective view of another example of the thermal head device of the present invention.

FIG. 5 is a schematic perspective view of another example of the thermal head device of the present invention.

[Explanation of symbols]

 10 Thermal Head Device 12 (Thermal Image) Recording Device 14 Loading Section 16 Supply Conveying Section 18 Recording Conveying Section 20 Recording Section 22 Ejecting Section 24 Magazine 26 Lid 28 Housing 30 Insertion Port 32 Guide Plate 34 Guide Roll 36 Stopping Member 40 Sucker 42 Conveying means 44 Conveying guide 46 Conveying roller 48 Endless belt 50 Nip roller 52 Restricting roller pair 56,63 Conveying roller pair 58,62 Guide 60 Platen roller 64 (Thermal) head body 66 Heat sink 68 Supporting member 70 Glaze 72 Tray 74 Discharge port 76 Cooling Fan 78 Sheet heater 80 Control means 82 Base 84 Fan box 86 Intake port 88 Thermal protector

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[Procedure amendment]

[Submission date] November 30, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

Further, in the thermal head device,
Furthermore, when the temperature measuring means of the thermal head is provided and the target temperature during recording standby is TA and the measured temperature of the thermal head is T, the temperature T is equal to the temperature "TA" during recording standby.
When the temperature T exceeds a temperature "TA + b" which is higher than the above "TA + a", the operation of the heating means is stopped, and the temperature T is the temperature "TA +".
When the temperature becomes "TA + d" which is higher than "b", the cooling means is operated, and when the temperature T becomes the temperature "TA + c" between the temperatures "TA + b" and "TA + d", the operation of the cooling means is stopped,
On the other hand, at the time of recording, it is preferable to have control means for controlling the heating means and the cooling means so that the cooling means operates continuously and the heating means does not operate (however, a and b may be minus). ).

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction contents]

In the thermal head device 10 of the present invention, the heating means is not limited to this, and a mode in which the glaze 70 is heated to the extent that heat-sensitive recording is not performed on the heat-sensitive material A, that is, so-called blanking is used as the heating means is also preferable. It is illustrated in. According to this blanking, since a separate heating member is not required, the above-described planar heater 78 can be replaced with a heat sink 66.
Therefore, the thermal head main body 64 can be suitably controlled within a narrow temperature range. In the case of performing the blank shot, the driving of the head main body 64 may be controlled so that the blank shot is always performed during a standby time other than the recording time, or the driving of the head main body 64 may be controlled according to the temperature measurement result by the thermistor. It may be controlled. The driving control of the head main body 64 in this idling is as follows.
A control unit for image recording may be performed, or a control unit for idling may be separately provided.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction contents]

Although the thermal head device of the present invention has been described in detail above, the present invention is not limited to the above examples, and various improvements and changes may be made without departing from the scope of the present invention. Of course.

Claims (6)

[Claims] 1. A thermal head device comprising: a thermal head for recording an image on a heat-sensitive recording material; a heating means for heating the thermal head; and a cooling means for cooling the thermal head. . 2. The thermal unit according to claim 1, wherein the heating unit is a control unit and / or a heater for heating the thermal head in an idle state, and the cooling unit is an air cooling unit including a cooling fan and a heat sink. Head device. 3. The thermal head device according to claim 2, wherein the heat sink is directly fixed to the substrate of the thermal head on which glaze is formed. 4. The thermal head device according to claim 2, further comprising: an inside of the device, which extends from an intake port of the device in which the thermal head device is installed to the cooling fan. A thermal head device having a ventilation path. 5. The thermal head device according to claim 1, further comprising temperature measuring means for the thermal head, wherein a target temperature during recording standby is TA and a measured temperature of the thermal head. When T is set to T, the heating means is activated when the temperature T becomes lower than the temperature “TA + a”, and the heating means is activated when the temperature T exceeds the temperature “Ta + b” higher than the “TA + a”. When the temperature T becomes “TA + d”, which is higher than the temperature “Ta + b”, the cooling means is activated and the temperature T becomes the temperature “TA + d”.
When the temperature "Ta + c" between "b" and "TA + d" is reached, the operation of the cooling means is stopped, while at the time of recording, the cooling means and the cooling means are operated continuously so that the heating means does not operate. A thermal head device having control means for controlling the means (provided that a and b may be minus). 6. The temperature T of the thermal head at the start of recording.
If the temperature is not a predetermined temperature, the thermal head device according to claim 5, which waits for recording until the temperature of the thermal head reaches a predetermined temperature.