JPH0615922A - Thermal recording device - Google Patents

Abstract

PURPOSE:To provide a thermal recording device which can keep the cooling condition uniform regardless of the pressing or non-pressing condition between a thermal head and platen roller, and can perform cooling efficiently. CONSTITUTION:A plurality of heating elements are arranged in parallel on a thermal head 1, and a protective cover 2 is attached on the lower surface of the thermal head 1. A heat sink 3 (radiation member) made of aluminum fixes the thermal head 1, and at the same time, has an action to radiate heat which is accumulated on the thermal head 1, and rotatably holds a fan 5 (blowing member) by a bearing. On the heat sink 3, a blowing guide 3a is provided while placing a gap to one part of the outer periphery of the fan 5, and the fan 5 sucks air from the direction shown by arrow C by rotating in the direction shown by arrow B, and discharges air in the direction shown by arrow D. By this method, the relative locations between the heat sink 3 and fan 5 are formed to be always uniform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording device for recording characters and images on a recording paper by using a thermal head.

[0002]

2. Description of the Related Art The schematic structure of a conventional thermal recording apparatus is shown in, for example, Japanese Patent Laid-Open No. 1-280568. In a conventional thermal recording apparatus of this type, as shown in FIGS. 7 and 8, a heating element 102 is fixed to a thermal head 101, and an ink sheet 103 coated with ink transferred by heat is heated by the thermal head 101. The ink from the ink sheet 103 is configured to be transferred to the recording paper 104 by heat from the body 102.
Are configured to be sandwiched and pressed by the platen 105. In the figure, 106 is the thermal head 10.
1 is a head pressing lever that moves 1 to the platen 105 from a pressed state to a separated state, and 107 is a head pressing lever 106.
A head pressing lever shaft provided at the center of rotation of the thermal head 101, a heat sink 108 fixed to the thermal head 101, and a fan for radiating the accumulated heat of the thermal head 101 accumulated by the heat generation of the heating element 102. 109 is a cooling fan provided in the vicinity of the head pressing lever 106.
0a and 110b are the head pressing lever shaft 107 and the platen 105.
A side plate that supports the side plate, and 111 is a top plate that fixes the side plate. 112
Is a heat sink cover fixed to the heat sink 108, and the front end portion A extends near the top plate 111 above the extension of the head pressing lever 107 and guides the wind of the cooling fan 109 to the fins of the heat sink 108.

The operation of the conventional thermal recording apparatus configured as described above will be described with reference to FIG. 7. In the recording state, first, the head pressing lever 106 rotates about the head pressing lever shaft 107. Thermal head
The heating element 102 fixed to 101 sandwiches the ink sheet 103 and the recording paper 104 and presses it against the platen 105, and the ink of the ink sheet 103 is transferred from the heating element 102 to the recording paper 104 coated with the dyeing layer. The thermal head 101 accumulates heat when continuously transferred to the recording paper 104, but the tip A of the heat sink cover 112 is provided near the top plate 111 above the extension of the head pressing lever shaft 107. Is a circular arc about the axis of the head pressing lever 107, which is almost in contact with the top plate. Even if the A part is rotated from the pressing force state to the separated state by a certain angle, the arc shape of the A part with respect to the top plate 111. The inclination of the rotation locus is minimized, and the wind sent from the cooling fan 109 can be guided to the heat sink 108 even when the thermal head 101 is in a pressed state.

[0004]

However, in the structure of such a conventional thermal recording apparatus, the thermal head 101 is used.
The ventilation resistance is different between the case where is separated from the case where is separated from the case where the case is pressed. Therefore, the cooling state differs depending on whether the thermal head 101 and the platen 105 are in the separated state or in the pressed state, and the heat sink 108, the cooling fan 109, and the heat sink cover 112 that can perform efficient cooling in one state.
With respect to the positional relationship, shape, and the like, the efficiency was reduced in the other state. For this reason, it cannot be said that efficient cooling can always be performed, the cooling is insufficient, and the heat generated by the heating element 102 is accumulated in the thermal head 101, and the number of sheets that can be continuously recorded is small. I had a problem.

According to the first aspect of the present invention, which solves the above-mentioned problems of the prior art, heat can be efficiently maintained by keeping the cooling state constant regardless of whether the thermal head and the platen roller are pressed or not pressed. It is an object to provide a recording device. Further, according to claim 2 of the present invention, the cooling condition for each device is reduced by blocking the heat dissipating member and the air blowing member, improving the accuracy of the relative positional relationship between the heat dissipating member and the air blowing member, and reducing the variation among the devices. An object of the present invention is to provide a thermal recording device which is made constant and whose productivity is improved by blocking. According to a third aspect of the present invention, the thermal recording device is capable of normally transmitting the driving force even if the precision of the parts is lowered by giving the positional relationship of the gear transmitting the drive to the blower member a degree of freedom. It is intended to provide.

[0006]

In order to achieve the above object, the present invention according to claim 1 provides a thermal head, a platen, a heat radiating member fixed to the thermal head, and a blower for blowing air to the heat radiating member. A member and a holding means for rotatably holding the blower member, wherein the thermal head and the platen have a pressed state of pressing through the recording paper and the ink sheet, and a separated state where the pressing is released, The thermal recording device is characterized in that the holding means is provided such that its relative position to the heat dissipation member remains unchanged.

The present invention according to claim 2 is the same as claim 1 above.
In the thermal recording apparatus, the heat radiation member also serves as the heat radiation member. Further, according to the present invention of claim 3, a thermal head, a heat radiating member fixed to the thermal head, a blower member for blowing air to the heat radiating member by being held by the heat radiating member and rotating, and the blower member. A first gear attached to one end in the rotation axis direction, a second gear for transmitting a driving force from a drive source, and a concentric circle of either one of the first gear and the second gear are moved. The thermal recording device is characterized in that the driving force is transmitted from the second gear to the first gear through the planetary gears.

[0008]

Therefore, according to the thermal recording apparatus of the first aspect of the present invention, since the blower member is held by the holding means whose relative position does not change with respect to the heat radiating member fixed to the thermal head, the thermal head serves as the platen. The positional relationship between the blower member and the heat radiating member is constant regardless of the pressed state or the separated state.
As a result, the ventilation resistance and the ventilation path are also constant, so that the cooling state is also constant. Further, according to the structure of the thermal recording apparatus of the second aspect of the present invention, since the air radiating path is held by the heat radiating member, the relative position accuracy of both is determined only by the accuracy of the heat radiating member. The accuracy is improved, and the variation among devices is extremely small. Further, the thermal head, the heat radiating member, and the blowing member can be handled as a block. Further, according to the thermal recording apparatus of claim 3 of the present invention,
Since the planetary gear is provided in the drive force transmission path from the drive source to the blower member, the positional relationship between the first gear and the second gear can be arbitrarily selected within a certain range. .

This certain range is a range in which the first gear, the planet gears, and the second gear can normally mesh with each other.
Although the specific numerical value depends on the design, it is usually several millimeters to ten and several millimeters. On the other hand, since the positional relationship between the heating element provided on the thermal head and the platen has a great influence on recording, a jig or the like is used to position the relative position of the two. Since the mounting position varies in the range of 0.3 to 0.5 mm, if the relative position of the heating element and the platen is adjusted to the design value, the relative position of the platen and the thermal head should vary in the range of 0.3 to 0.5 mm. become. Usually, since the thermal head is moved with the platen as a reference and the relative position of the platen and the heating element is aligned, the position of the thermal head varies about 0.3 to 0.5 mm in the entire thermal recording apparatus. Therefore, the position of the first gear attached to one end of the blower member held by the heat radiating member fixed to the thermal head varies about 0.3 to 0.5 mm in the entire thermal recording apparatus. It can be absorbed by the above structure.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 to 5 show a thermal recording apparatus according to a first embodiment of the present invention, FIG. 1 is a front sectional view of a main part of the thermal recording apparatus, FIG. 2 is a plan view of the main section, and FIG. FIG. 4 is an exploded perspective view showing the structure of the blower member and the heat radiating member, and FIG. 5 is a front sectional view of the main part in the recording state. The thermal head 1 has a plurality of heating elements (not shown).
Are arranged side by side in parallel, and the protective cover 2 is attached to the lower surface. The protective cover 2 is attached to protect the circuit for selectively energizing the heating element attached to the thermal head 1, and also serves as a guide for the recording paper 29 and the ink sheet 8. The heat sink 3 (heat dissipation member) made of aluminum has a function of fixing the thermal head 1 and radiating heat accumulated in the thermal head 1, and can rotate the fan 5 (blower member) via the bearings 6a and 6b. Hold on. The heat sink 3 is provided with a blower guide 3a at a part of the outer periphery of the fan 5 and is rotated. Discharge in the direction. The fan 5 and the air guide 3a form a cross flow fan. The side plates 4a and 4b fix the heat sink 3 with screws 7a, 7b, 7c and 7d. The ink sheet 8 is a film-like sheet on which inks of three colors of yellow, magenta, and cyan are repeatedly applied. The unused ink sheet 8 is wound around the supply reel 9, and the take-up reel 10 winds the ink sheet 8 that has been used. The supply reel 9 and the take-up reel 10 are contained in the ink cassette 11.

A roller platen 12 whose periphery is covered with rubber is provided to face the heating element on the thermal head 1. The platen 12 is rotatably supported at its shaft ends by pressing arms 13a and 13b. There is. Pressing arms 13a and 13b
Are support shafts 14 provided on the side plates 4a and 4b, respectively.
It is supported by a and 14b. Capstan 15 is side plate 4
It is supported by a and 4b and rotated by a paper transport motor (not shown). The pinch roller 16 whose surface is covered with rubber has both shaft ends rotatably supported by the pressing arms 17a and 17b, and the pressing arms 17a and 17b have side plates 4a and 4b.
It is rotatably supported by support arms 18a and 18b provided on b.

The motor 19 is a DC motor and is attached to the side plate 4b, and a motor pulley 20 is attached on the motor shaft. The motor pulley 20 meshes with a second gear 21 rotatable about a gear shaft 22 provided on the side plate 4b. The idler arm 23 is made of an L-shaped metal plate and is rotatable around a gear shaft 22. An idler gear shaft 25 that rotatably holds an idler gear (planetary gear) 24 at one end is provided.
Is provided, and one hook of the tension spring 26 is hooked at the other end. The other hook of the tension spring 26 is hooked on a spring shaft 27 provided on the side plate 4b to urge the idler arm 23 in the direction of arrow E. First gear 28
Is press-fitted and attached to the shaft end of the fan 5 on the bearing 6b side, and rotates together with the fan 5. The idler gear 24 is rotatable about the gear shaft 22 while meshing with the second gear 21, and is urged by the tension spring 26 in the arrow E direction to mesh with the first gear 28. Further, the recording paper 29 is conveyed while being sandwiched between the capstan 15 and the pinch roller 16 with the recording surface facing up.

The operation of the thermal recording apparatus of the present embodiment constructed as above will be described. At the time of recording, as shown in FIG. 5, the pinch roller 16 is pressed against the capstan 15 via the recording paper 29, and the platen 12 is also pressed against the thermal head 1 via the recording paper 29 and the ink sheet 8. By energizing the heating element on the thermal head 1 while rotating the capstan 15 counterclockwise, the ink on the ink sheet 8 is heated and the ink is transferred onto the recording paper 29. At the same time, a sheet (not shown) is rotated by a winding means to rotate the take-up reel 10 in a clockwise direction to take up the used ink sheet 8. The heat generated from the heating element travels through the thermal head 1 and reaches the heat sink 3, but the fan 5
It is cooled by the air sent from.

In order to obtain a color image, three colors of yellow, magenta and cyan are sequentially recorded and superposed, and when the recording of yellow is completed, the pressing arm 13a and the pressing arm 13a for recording magenta are next. The platen 12 and the thermal head 1 are separated by rotating 13b clockwise.
Further, the capstan 15 is rotated clockwise to convey the recording paper 29 to the recording start position. At this time, pinch roller 16
Remains pressed against the capstan 15 via the recording paper 29. The fan 5 also keeps rotating in the direction of arrow B, and blows air to the heat sink 3 in the same manner as during recording. After the recording paper 29 is conveyed to the recording start position, the pressing arms 13a and 13b are rotated again in the counterclockwise direction and the platen 12 is moved.
Is pressed against the thermal head 1 via the recording paper 29 and the ink sheet 8, and magenta recording is performed in the same manner as in yellow recording.

In the same manner, after the recording of magenta is completed, the recording paper 29 is conveyed to the recording start position and then the recording of cyan is performed. After the recording of cyan is completed, the recording paper 29 is ejected to a predetermined position. During this time, the fan 5 continues to rotate in the direction of arrow B and continues to blow air to the heat sink 3 in a constant state. As described above, according to the present embodiment, the relative positional relationship between the heat sink 3 and the fan 5 is constant and the cooling state is constant regardless of whether the thermal head 1 and the platen 12 are pressed or separated. It is possible to perform efficient cooling. Further, since the heat-dissipating member holds the blower member, the relative position accuracy between them is determined only by the accuracy of the heat-dissipating member. It will be constant.
Further, since the thermal head, the heat radiating member, and the blowing member are made into blocks, the productivity is improved. Further, since the planetary gear is provided in the drive force transmission path from the drive source to the blower member, the first gear in the thermal recording device due to the variation in the positional accuracy of the heating element in the thermal head is not provided. Variations can be absorbed.

FIG. 6 is an exploded perspective view showing the structure of the air blowing member and the heat radiating member of the thermal recording apparatus showing the second embodiment of the present invention. In the second embodiment, the heat sink 3, the air guide 3a and the bearings 6a and 6b of the first embodiment are replaced with the following configuration. The heat sink 30 has openings 30
a and 30b are provided to fix the thermal head 1. The bearing block 31 is an elastically deformable hook.
31a, 31b, 31c, 31d and elastically deformable bearings 31e,
It consists of 31f and a blower guide 31g. Hooks 31a and 31b are provided in the opening 30a, and hooks 31c are provided in the opening 30b.
The bearing block 31 is fixed to the heat sink 30 by fitting and 31d respectively. Also, the bearing 31e
By fitting the shaft of the fan 5 to and 31f, the fan 5 is rotatably held by the heat sink 3 via the bearing block 31. The blower guide 31g is provided apart from a part of the outer circumference of the fan 5 and forms a cross flow fan together with the fan 5. Even with such a configuration, the same effects as in the first embodiment can be obtained, the number of parts is reduced, and the method of attaching the fan 5 to the bearing block 31 is simple, so that the productivity is improved. To do.

Although the thermal head is fixed to the side plate and the platen moves in the first embodiment of the present invention, in claim 1 of the present invention, the thermal head moves and the platen rotates to the side plate. The structure may be freely fixed. In this case, the fan may be attached to the heat sink or the head pressing lever of the conventional example described above. Although the fan of the embodiment has a cross-flow fan structure, an axial fan may be used. Further, in the case of the present embodiment, the rotation direction of the second gear 21, which is the sun gear of the idler gear 24, is the same as the arrow E. Therefore, the rotation force of the second gear 21 causes the idler gear 24 to move to the first direction.
The tension spring 26 may be omitted because it is urged to the gear 28 of FIG.

[0018]

As described above, the thermal recording apparatus according to claim 1 of the present invention comprises a thermal head, a platen, a heat radiating member fixed to the thermal head, and a blowing member for blowing air to the heat radiating member. The thermal head and the platen have a pressed state in which the thermal head and the platen are pressed through the recording paper and the ink sheet, and a separated state in which the pressing is released. However, since the thermal head and the heat radiating member are configured so that their relative positions do not change, the thermal head is in a pressed state against the platen,
In any of the separated states, the positional relationship between the blower member and the heat radiating member is constant. As a result, the ventilation resistance and the air flow path are constant and the cooling state is also constant, so that efficient cooling can be performed, so that the heat accumulated in the thermal head is reduced and the number of continuously recorded sheets is increased.

The thermal recording apparatus according to claim 2 of the present invention is
Since the heat dissipating member of the thermal recording apparatus according to claim 1 also functions as a heat dissipating member, the relative position accuracy of the heat dissipating member and the blower means is determined only by the accuracy of the heat dissipating member, so that the relative position accuracy is improved, The variation among the devices is extremely small, the cooling state between the devices is almost constant, and the thermal head, the heat radiating member, and the air blowing member are blocked, so that the productivity is improved.

The thermal recording apparatus according to claim 3 of the present invention is
A thermal head, a heat dissipation member fixed to the thermal head, a blower member that is held by the heat dissipation member and blows air to the heat dissipation member, and a first member attached to one end of the blower member in the rotation axis direction. A first gear, a second gear that transmits a driving force from a driving source, and a planetary gear that can move on a concentric circle of either one of the first gear and the second gear. Since the driving force is transmitted from the second gear to the first gear via the planetary gear, the positional relationship between the first gear and the second gear can be arbitrarily selected within a certain range. As a result, it is possible to absorb the variation in the first gear in the thermal recording device due to the variation in the positional accuracy of the heating element in the thermal head. As a result, it is not necessary to strictly set and control the positional accuracy of the heating element in the thermal head with high accuracy, and efficient cooling can be performed without increasing the cost of the thermal head. That is, as a method of absorbing the variation of the first gear in the thermal recording device, 0.5 or at most 1.0 is used for the gear module, so that the position of the first gear is about 0.3 to 0.5 mm. If there are variations, the meshing cannot be performed normally, but if the module is set to 5 or 10, for example, the influence of such a variation on the meshing of the gears cannot be practically neglected. However, since the gear inevitably becomes large, there is a problem that the thermal transfer recording apparatus becomes large in size, which is not suitable in reality.

[Brief description of drawings]

FIG. 1 is a front sectional view of a thermal recording apparatus according to a first embodiment of the present invention,

FIG. 2 is a plan view of the thermal recording apparatus according to the first embodiment of the present invention,

FIG. 3 is an explanatory diagram of a gear configuration showing a driving force transmission path of the thermal recording device in the first embodiment of the present invention;

FIG. 4 is an exploded perspective view showing a heat radiating member and a blowing member of the thermal recording apparatus according to the first embodiment of the present invention,

FIG. 5 is a front sectional view of the thermal recording apparatus according to the first embodiment of the present invention during recording,

FIG. 6 is an exploded perspective view showing a heat radiating member and a blowing member of the thermal recording apparatus according to the second embodiment of the present invention,

FIG. 7 is a front view of a conventional thermal recording device,

FIG. 8 is a plan view of a conventional thermal recording device.

[Explanation of symbols]

 1 Thermal Head 3 Heat Sink (Heat Dissipating Member) 5 Fan (Blower Member) 8 Ink Sheet 21 Second Gear 24 Idler Gear (Planetary Gear) 28 First Gear 29 Recording Paper

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location 8907-2C B41J 3/20 117 A (72) Inventor Hirofumi Iwakawa 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Denki Sangyo Co., Ltd.

Claims (3)

[Claims] 1. A thermal head, a platen, a heat radiating member fixed to the thermal head, an air blowing member for blowing air to the heat radiating member, and a holding means for rotatably holding the air blowing member. The head and the platen have a pressed state in which they are pressed via the recording paper and the ink sheet, and a separated state in which the pressing is released, and the holding means is provided so that the relative position to the heat dissipation member does not change. A thermal recording device characterized by the above. 2. The thermal recording apparatus according to claim 1, wherein the heat dissipation member also serves as the heat dissipation member. 3. A thermal head, a heat radiating member fixed to the thermal head, a blower member which is held by the heat radiating member and blows air to the heat radiating member, and one end of the blower member in a rotation axis direction. A first gear attached to the first gear, a second gear that transmits a driving force from a driving source, and a planetary gear that can move on a concentric circle of either one of the first gear and the second gear. And a driving force is transmitted from the second gear to the first gear via the planetary gear.