JPH08216471A - Thermal transfer printer - Google Patents

Abstract

PURPOSE: To obtain a thermal transfer printer which is operated in the state that the tension of an ink sheet conveying is always stable despite the change in a roll diameter form the start of using the ink sheet to the end of the use. CONSTITUTION: The thermal transfer printer comprises pressing means 14 for pressing a supply guide roller 13 to the position for drawing an ink sheet 4 at a corner Ca for setting the supply side roll 6 of the ink sheet 4, a supply holding roller 12 to the predetermined relative position to the roller 13 and the supply side roll 6 to the position opposed to the roller 12 at the roller 13, and a torque limiter for generating predetermined tension at the ink sheet 4 to any of the rollers in contact with the rollers 12, 13 and 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus in which an ink sheet pulled out from a rolled state and a recording sheet fed from a sheet feeding device are superposed and thermally transferred. It is about.

[0002]

2. Description of the Related Art FIG. 9 shows, for example, JP-A-61-12078.
FIG. 10 is a schematic configuration diagram of a conventional thermal transfer printing apparatus disclosed in Japanese Patent Laid-Open No. 2 publication, and FIG. In the figure, reference numeral 1 is a main body of a thermal transfer printing apparatus, 2 is a platen, 3 is a thermal head, which is supported by a head driving mechanism (not shown) so as to be pressed or released from the platen 2. ing. Reference numeral 4 denotes an ink sheet pulled out from a state of being wound in a roll, and is a sheet in which heat-melting or heat-subliming ink is applied on a base film in the order of yellow, magenta, and cyan, for example. 5
Is a recording paper, and 6 is a supply-side roll formed by the ink sheet 4 wound in a roll shape, which is set at a predetermined corner of the main body 1. 7 is a winding-side roll in which the heat-transferred ink sheet is wound into a roll,
It is driven by a winding drive device (electric motor). Figure 10
8 is a holder for a shaft support fitted to one end of the supply-side roll 6, 9 is a holder for a shaft support with a gear fitted to the other end of the supply-side roll 6, and 10 is a holder 8 for a shaft support and a gear. A shaft holder holder receiver that supports the shaft holder 9 is provided, and 11 is a torque limiter that meshes with the gear of the gear shaft holder 9 and applies tension so that the ink sheet 4 is pulled out with a predetermined tension. For example, it has a friction clutch inside.

The take-up roll 7 side is also provided with the same components (not shown) as the shaft support holder 8, the geared shaft support holder 9 and the shaft support holder receiver 10 in the supply side roll 6. ing. Further, a winding drive device (not shown) is connected to the one corresponding to the torque limiter 11 so that the winding drive device slips when the winding tension exceeds a predetermined tension. ing.

The conventional thermal transfer printing apparatus is constructed as described above, so that tension is applied to the ink sheet 4 to print by thermal transfer. That is, the recording paper 5 and the ink sheet 4 are superposed on the platen 2, the thermal head 3 is pressed, and a predetermined electric signal is applied to the thermal head 3 to transfer the ink of the ink sheet 4 to the recording paper 5. The platen 2 is rotated to sequentially perform transfer recording. At this time, it is necessary to apply tension, that is, back tension B / T to the ink sheet 4 so as not to cause wrinkles on the ink sheet 4 that is pulled out by the rotation of the platen 2. The back tension B / T is configured to have a tension set in advance by a friction clutch built in the torque limiter 11. Winding side roll 7
On the side, when the winding tension (hereinafter referred to as front tension F / T) becomes equal to or higher than a predetermined tension, the torque limiter causes the winding drive device to slip.

[0005]

In the conventional thermal transfer printing apparatus as described above, a torque serving as a back tension B / T is applied to the supply-side roll 6 via the geared shaft support holder 9 to wind it. Similarly, the side roll 7 is also provided with a torque as a front tension F / T through the geared shaft support holder. In this case, a constant torque is applied to both rolls 6 and 7 by the torque limiter, but both the back tension B / T and the front tension F / T acting on the ink sheet 4 change as transfer recording is performed. That is, the roll diameter of the ink sheet 4 on the supply side roll 6 becomes smaller as the transfer recording is performed, and the roll diameter of the ink sheet 4 at the winding side roll 7 becomes larger as the transfer recording is performed. Since the back tension B / T and the front tension F / T acting on the ink sheet 4 have a relationship of “tension = torque / roll diameter”, when the torque is constant as described above, transfer recording as shown in FIG. The front tension F / T becomes smaller and the back tension B / T becomes larger as it goes.

Therefore, when the number of ink sheets 4 per roll is large, the degree of change in roll diameter is large, and the ink sheet 4
Front tension F / T
There is a problem that the back tension B / T becomes larger than that and a state in which winding cannot be performed occurs. For this reason,
In some cases, it was necessary to provide a back tension B / T switching mechanism as shown in JP-A-61-72570. Further, the setting of the supply-side roll 6 and the winding-side roll 7 requires a shaft support holder such as a shaft support holder 8 and a geared shaft support holder 9, which causes inconvenience in setting. There was also.

The present invention has been made in order to solve the above-mentioned problems, and a first object of the present invention is to always maintain the back tension B regardless of the change of the roll diameter from the start to the end of use of the ink sheet. The purpose of the present invention is to obtain a thermal transfer printing apparatus in which the front tension F / T is larger than / T and the winding can be performed with a stable tension. A second object of the present invention is to provide a thermal transfer printing apparatus which can be wound with a stable tension and has a simple structure and can easily set the supply-side roll and the winding-side roll.

[0008]

In a thermal transfer printing apparatus according to the present invention, a supply guide roller is provided at a position where a roll-shaped ink sheet is drawn out, and a supply holding roller is provided at a predetermined relation position with respect to the supply guide roller. A pressing means for pressing the ink sheet wound in a roll shape is arranged at a position facing the supply guide roller and the supply holding roller, and the ink is applied to any one of the rollers abutting the roll ink sheet. A torque limiter for generating a predetermined back tension on the seat is provided.

Further, in the above construction, the winding guide roller is arranged at a position where the heat-transferred ink sheet is wound up in a roll, and the winding holding roller is arranged at a predetermined position relative to the winding guide roller. A pressing means for pressing the ink sheet wound in a roll shape is arranged at a position facing the guide roller and the holding roller for winding, and any one of the rollers abutting the ink sheet wound in a roll shape is disposed. The roller is provided with a winding drive device having a torque limiter for generating a predetermined winding torque with respect to the ink sheet.

Further, in the above-mentioned structure, the pressing means for pressing the ink sheet wound in a roll shape is composed of a plate-shaped supporting member biased by a spring.

Further, the winding drive device is provided with speed switching means for switching the winding speed, so that the speed is slightly faster than the peripheral speed of the platen when the thermal transfer is performed, and the speed is slow when the thermal transfer is performed when the ink sheet is idly conveyed. On the other hand, it is designed so that it can be rapidly switched and wound.

Further, a corner for mounting the roll-shaped ink sheet and a corner for winding the heat-transferred ink sheet in a roll are arranged on the base side of the thermal transfer printing apparatus, and supply guide roller, winding guide roller and thermal head. Is disposed on the cover side.

[0013]

In the thermal transfer printing apparatus configured as described above, the ink sheet wound in a roll shape by the supply guide roller, the supply holding roller, and the pressing means provided at a position facing both rollers. And set
Since a torque limiter that generates a predetermined back tension is provided on the roller that contacts the roll-shaped ink sheet,
The torque limiter works to apply a stable tension regardless of the roll diameter of the ink sheet.

An ink sheet wound into a roll is set by a winding guide roller, a winding holding roller, and a pressing means provided at a position facing both rollers, and is wound into a roll. The roller that comes into contact with the ink sheet is provided with a winding drive device having a torque limiter that generates a predetermined winding torque for the ink sheet, regardless of the roll diameter of the ink sheet on which the torque limiter is wound. It works to give a stable tension.

Further, the pressing means constituted by the plate-shaped supporting member urged by the spring works so that the constitution can be simplified and provided at a low cost.

Further, the winding drive device is provided with speed control means for controlling the winding speed, so that the speed is slightly faster than the peripheral speed of the platen when the thermal transfer is performed, and the speed when the thermal transfer is performed is idle when the ink sheet is idly conveyed. In the case where the speed is rapidly switched to the speed of winding, the speed control means works to speed up the cue at the time of color printing and speed up the color printing.

Further, a corner for setting the roll-shaped ink sheet and a corner for winding the heat-transferred ink sheet in a roll are provided on the base side of the thermal transfer printing apparatus, and a supply guide roller, a winding guide roller and a thermal head are provided. With the cover disposed on the cover side, setting of the roll-shaped ink sheet becomes easy.

[0018]

【Example】

Example 1. FIG. 1 is a schematic configuration diagram showing a thermal transfer printing apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part. In the figure, 1 to 7 are the same as the above-mentioned conventional device, and the description thereof is omitted. Ca is the supply side roll 6
Although not shown in the figure, it is a corner for setting the inner side mechanism and is divided from a portion for accommodating the internal mechanism, and is provided with an opening so that the supply side roll 6 can be set. Cb is a corner for setting the winding-side roll 7, and although not shown, it is separated from the part for housing the internal mechanism and has an opening so that the winding-side roll 7 can be set. Reference numeral 12 is a supply holding roller, 13 is a supply guide roller, and 14 is a pressing roller. The rollers 12, 13, 14 are parallel to each other,
Each of them is arranged in a corner Ca for setting so as to be located around the supply-side roll 6 formed by the ink sheet 4.

In this arrangement, the supply guide roller 1
3 is provided at a position convenient for drawing out the ink sheet with respect to the platen 2. Supply holding roller 12
Is close to the supply guide roller 13, and both rollers 12,
The size of the gap formed by 13 is arranged to be smaller than the outer size of the winding core of the supply-side roll 6. The pressing roller 14 is always in a position to press the set supply side roll 6 against both rollers 12 and 13, and is biased by a pressing spring 19a. And it is arrange | positioned so that it can move to the arrow A direction of FIG. 11
Is a torque limiter connected to the supply holding roller 12 by a gear, and is provided with a friction clutch inside, like the torque limiter 11 of the conventional example.

As for the take-up roll 7 as well, the supply roll 6
The ink sheet 4 is wound while holding the winding-side roll 7 in the same structure as in (1). That is, in FIG. 3, 15 is a winding holding roller, 16 is a winding guide roller, and 17 is a pressing roller. The rollers 15, 16 and 17 are parallel to each other and are arranged in a corner Cb for setting so as to be located around the winding side roll 7 around which the ink sheet 4 is wound. In this arrangement,
The winding guide roller 16 is provided at a position convenient for winding the ink sheet 4 conveyed through the platen 2. The take-up holding roller 15 is arranged close to the take-up guide roller 16, and the gap between the rollers 15 and 16 is arranged to be smaller than the outer size of the winding core of the take-up roll 7. .

The pressing roller 17 is in a position to constantly press the set winding side roll 7 against both rollers 15 and 16, and is biased by a pressing spring 19b. And it is arranged so that it can move in the direction of arrow B in FIG. Reference numeral 22 denotes a torque limiter connected to the winding holding roller 15 by a gear, and like the torque limiter 11 on the supply side, has a friction clutch inside. Reference numeral 23 denotes a winding drive device using a small electric motor, which winds the ink sheet 4 by rotating the winding side roll 7 via the torque limiter 22 and the winding holding roller 15. In this case, the torque limiter 22 is configured to slip when the winding tension exceeds a predetermined tension.

In the above structure, the supply holding roller 12 and the take-up holding roller 15 are made of a material having a high friction coefficient with respect to the ink sheet 4 forming the supply side roll 6 and the winding side roll 7, for example, It is made of silicone rubber, polyurethane rubber, or CR rubber. Further, the supply guide roller 13 is located at a position where the ink sheet 4 can be easily pulled out to the position of the platen 2, but when the supply side roll 6 is set, it can be opened and retracted to a position where it does not interfere. Similarly, when the winding-side roll 7 is set, it can be opened and retracted to a position where it does not interfere. Further, as shown in FIG. 2, the pressing roller 14 is a lever 1 whose one end is pivotally supported.
8a is attached to the movable side, and the lever 1 is attached by the push spring 19a.
8a may be biased in the direction of the arrow to press the supply-side roll 6. A stopper 20a prevents the pressing roller 14 from unnecessarily approaching the supply holding roller 12 or the supply guide roller 13. Furthermore, as shown in FIG. 3, the pressing roller 17 is mounted on the movable side of a lever 18b whose one end is axially supported,
The lever 18b may be biased in the direction of the arrow by the pressing spring 19b to press the winding-side roll 7. Two
A stopper 0b prevents the pressing roller 17 from unnecessarily approaching the winding holding roller 15 or the winding guide roller 16.

In the thermal transfer printing apparatus configured as described above, the back tension B / T during the feeding and feeding of the ink sheet 4 is outside the feeding holding roller 12 and the feeding side roller 6 which are generated by the torque limiter 11. It is obtained by friction with the surface. That is, the friction between the supply holding roller 12 and the outer surface of the supply side roll 6 always acts as back tension B / T regardless of the outer diameter of the supply side roll 6.
In the above configuration, the torque limiter 11 is provided on the supply holding roller 12, but it may be provided on the supply guide roller 13 or the pressing roller 14. Further, the front tension F / T at the time of winding the ink sheet 4 is obtained by the friction between the winding holding roller 15 and the outer surface of the winding side roll 7 caused by the torque limiter 22. . That is,
The friction between the take-up holding roller 15 and the outer surface of the take-up roll 7 always acts as a front tension F / T regardless of the outer diameter of the take-up roll 7. In the above configuration, the torque limiter 22 is shown as being provided on the winding holding roller 15, but the winding guide roller 1
6 or the pressing roller 17 may be provided. The front tension F / T of the take-up roll 7 can be obtained by a conventional device. In any case, the front tension F / T is the back tension B /
It is set so that the tension is always higher than T.

Embodiment 2 FIG. Although the pressing rollers 14 and 17 are provided as the pressing means for the supply-side roll 6 and the winding-side roll 7 in the first embodiment, the plate-shaped supporting member may be used for pressing. That is, FIG. 4, FIG. 5, FIG.
21 is a plate-like support member for the supply-side roll 6, one end of which is rotatably supported so that the push spring 1 can be rotated.
9a is configured to urge the supply side roll 6 by urging it in the direction of the arrow. Reference numeral 24 denotes a plate-like support member for the winding-side roll 7, one end of which is pivotally supported so as to be rotatable, and is configured to press the winding-side roll 7 by urging it in the direction of the arrow by a pressing spring 19b. There is. The portions of the plate-like support members 21 and 24 that come into contact with the supply-side roll 6 or the winding-side roll 7 are coated with a fluffy resin film or have a mirror finish in order to improve sliding. Is desirable.

In the case where the plate-like support members 21 and 24 are used for pressing as described above, the rollers are present at the portions which are pressed by following the change in the outer diameter of the supply-side roll 6 or the winding-side roll 7. Since it does not, the structure is simple and the device is inexpensive. Further, since the sliding friction between the supply-side roll 6 and the plate-like support member 21 is added to the back tension B / T of the ink sheet 4 when the ink sheet 4 is conveyed, the load on the torque limiter 11 can be reduced accordingly.

Example 3. Although not described in the first and second embodiments, the torque required to wind up the ink sheet 4 is different when the thermal transfer is performed and when the ink sheet 4 is idly fed. This is because speeding up is particularly required when the ink sheet 4 is cued up at the time of color printing. That is, since the rotational force of the platen 2 is stronger than the back tension B / T of the supply-side roll 6 during the thermal transfer, the winding-up roll 7 winds the ink sheet 4 delivered from the platen 2 without slack. And torque. However, during idling of the ink sheet 4, a torque that exceeds the back tension B / T of the supply-side roll 6 and high-speed conveyance for speeding up printing are required. If this is executed by one torque limiter, for example, the winding speed of the winding-side roll 7 is set to a high-speed conveyance for cueing, and when the thermal transfer is executed, the torque limiter is slipped to match the printing speed. Become. Therefore, when thermal transfer is executed, the slip ratio of the torque limiter becomes large and the life of the torque limiter becomes short.

The embodiment shown in FIG. 7 is designed to solve this problem. In the figure, 2-7, 15, 1
Reference numerals 6 and 19b to 24 are the same as those of the devices of the first and second embodiments, and the description thereof will be omitted. Reference numeral 25 is a speed control unit of the winding drive device (for example, electric motor) 23. The speed control unit 25 controls the winding drive device 23 in response to a signal related to pressing and opening of the thermal head 3 from a control unit (not shown) of the main body 1. This control sets the speed of the winding drive device 23 so that when the thermal head 3 is pressed against the platen 2, the winding speed of the winding-side roll 7 is slightly higher than the peripheral speed of the platen 2. To do. Further, when the thermal head 3 is separated from the platen 2, the speed of the winding drive device 23 is switched so as to increase the transport speed of the ink sheet 4.

In the above embodiment, the structure in which the speed of the winding drive device 23 is switched has been described, but the same effect can be obtained even in the structure in which the gear train is switched by the clutch.

Example 4. FIG. 8 shows the construction of a thermal transfer printing apparatus which is Embodiment 4 of the present invention. In the figure, 2-7, 11-13, 15, 16, 19b-24
Is the same as the device of Embodiments 1 and 2, and the description thereof is omitted. Reference numeral 1a is a cover of the main body 1 and 1b is a base, which is joined by a hinge 1c so that the cover 1a can be opened and closed. Ca is a corner for setting the supply side roll 6, and Cb is a corner for setting the winding side roll 7. Inside the cover 1a, a thermal head 3, a head driving mechanism (not shown) of the thermal head 3, a supply guide roller 13, a winding guide roller 16 and the like are installed. Torque limiter 1
1, the supply holding roller 12, the pressing means 21, and the like are arranged at the setting corner Ca of the base 1b. The torque limiter 22, the winding holding roller 15, the pressing means 24, etc. are arranged at the setting corner Cb of the base 1b.

According to the above construction, the setting of the supply side roll 6 and the winding side roll 7 can be easily performed. That is, in the configuration of the first embodiment, the supply-side roll 6 and the winding-side roll 7
At the time of setting, the feeding guide roller 13 and the winding guide roller 16 can be opened and retracted to a position where they do not get in the way. According to the above configuration, the feeding guide roller 13 and the winding guide roller are arranged. It is possible to set the supply-side roll 6 and the winding-side roll 7 without retracting 16. When the cover 1a is closed with respect to the base 1b, the supply guide roller 13 and the winding guide roller 16 come into contact with the supply-side roll 6 and the winding-side roll 7 during the closing process, and the movement until the cover 1a is closed. The supply side roll 6 and the winding side roll 7 are set by compressing the pressing springs 19a and 19b of the pressing means.

[0031]

Since the present invention is constructed as described above, it has the following effects.

An ink sheet wound in a roll is set by a guide roller, a holding roller, and a pressing means provided at a position opposed to both rollers, and a predetermined back tension is applied to the roller contacting the roll-shaped ink sheet. Alternatively, since the torque limiter for generating the front tension is provided, it is possible to operate with a stable tension regardless of the roll diameter of the ink sheet.

When the pressing means is composed of a plate-shaped supporting member which is biased by a spring, the structure is simple and the apparatus becomes inexpensive.

Further, the winding drive device is provided with a speed control means for controlling the winding speed, so that the speed is slightly faster than the peripheral speed of the platen when the thermal transfer is performed, and the speed when the thermal transfer is performed is idle when the ink sheet is unloaded. The one in which the speed is rapidly switched to the speed for winding can speed up the cueing in the color printing and speed up the color printing. The durability of the torque limiter is also improved.

A corner for setting the roll-shaped ink sheet and a corner for winding the heat-transferred ink sheet in a roll are arranged on the base side of the thermal transfer printing apparatus to cover the supply guide roller, the winding guide roller and the thermal head. Since it is disposed on the side, setting of the supply side roll and the winding side roll becomes easy.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a thermal transfer printing apparatus that is an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part showing the first embodiment of the present invention.

FIG. 3 is an enlarged view of a main part showing the first embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of an apparatus showing Embodiment 2 of the present invention.

FIG. 5 is an enlarged view of a main part showing a second embodiment of the present invention.

FIG. 6 is an enlarged view of a main part showing a second embodiment of the present invention.

FIG. 7 is an enlarged view of a main part showing a third embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of an apparatus showing Embodiment 4 of the present invention.

FIG. 9 is a schematic configuration diagram showing a conventional thermal transfer printing apparatus.

FIG. 10 is an enlarged perspective view of a main part showing a conventional thermal transfer printing apparatus.

FIG. 11 is an explanatory diagram showing a relationship between tensions of ink sheets.

[Explanation of symbols]

1 device body, 1a cover, 1b base, 2 platen, 3 thermal head, 4 ink sheet, 6
Supply side roll, 7 Winding side roll 11,12 Torque limiter, 12 Supply holding roller, 13 Supply guide roller, 14 Pressing roller, 15 Winding holding roller, 16 Winding guide roller, 17 Pressing roller, 1
9a, 19b push spring, 20a, 20b stopper, 2
1, 24 plate-like support member, 23 winding drive device, 25
Speed control unit.

Claims (5)

[Claims] 1. A thermal head for selectively heating a heating element, and the ink so that the thermal head can press an overlapping portion of an ink sheet and a recording paper pulled out from a rolled state. In a thermal transfer printing apparatus having a platen arranged on the back side of the sheet and the recording paper, and a head drive mechanism for pressing or separating the thermal head from the platen, for supplying to the drawing position of the roll-shaped ink sheet The guide roller is pressed against the supply guide roller in a predetermined relationship with the supply holding roller, and the supply guide roller and the supply holding roller are opposed to each other by pressing the ink sheet wound into a roll. Means for arranging the means, and at least one of the rollers contacting the roll-shaped ink sheet has the above-mentioned A thermal transfer printing apparatus comprising a torque limiter for generating a predetermined back tension on the sheet. 2. A winding guide roller is provided at a position where the heat-transferred ink sheet is wound into a roll, a winding holding roller is provided at a predetermined relationship with the winding guide roller, and the winding guide roller is provided. And a pressing means for pressing the rolled-up ink sheet at a position opposed to the winding-holding roller, and at least one of the rollers abutting the rolled-up ink sheet. 2. The thermal transfer printing apparatus according to claim 1, wherein the roller is provided with a winding drive device having a torque limiter for generating a predetermined front tension with respect to the ink sheet. 3. The thermal transfer printing apparatus according to claim 1, wherein the pressing means for pressing the ink sheet wound in a roll shape is composed of a plate-shaped support member biased by a spring. 4. A take-up drive device is provided with speed control means for controlling a take-up speed so that the take-up speed is slightly faster than the peripheral speed of the platen when the thermal transfer is performed and the slow speed when the thermal transfer is performed when the ink sheet is idly conveyed. 4. The thermal transfer printing apparatus according to claim 2 or 3, wherein the thermal transfer printing apparatus is configured to be rapidly switched and wound. 5. A corner for mounting a roll-shaped ink sheet and a corner for winding a thermally transferred ink sheet in a roll are provided on the base side of a thermal transfer printing apparatus, and supply guide rollers, winding guide rollers and a thermal head are provided. To
The thermal transfer printing apparatus according to any one of claims 2 to 4, wherein the thermal transfer printing apparatus is arranged on a cover side that is openably and closably attached to the base.