JP2728543B2 - Thermal transfer printing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention performs printing by selectively melting an ink layer of an ink ribbon and transferring it to paper by selective heat generation of heat generating dots of a thermal head. The present invention relates to a thermal transfer printing method, and more particularly to a thermal transfer printing method capable of always obtaining a good transfer image without being affected by the smoothness of the surface of a sheet.

[Conventional technology]

A general ink ribbon used in a thermal transfer printer for performing the thermal transfer printing method described above is an ink layer formed by mixing a face material such as carbon black in a vehicle as a coloring material on a base layer such as polyethylene terephthalate. Were laminated. Here, the vehicle is a wax such as paraffin wax or carnauba wax as a main binder material, a thermoplastic resin such as ethylene vinyl acetate copolymer or polyamide, a terpene resin or the like as an auxiliary material, and further, if necessary, silicon. It was configured by adding a softener such as oil.

However, in the thermal transfer printing using the conventional ink ribbon configured as described above, since the ink cohesion is weak, if the smoothness of the paper is low, bubbles and bleeding may occur, and the printing quality may be degraded. Was.

In order to improve such deterioration of print quality, it is conceivable to increase the amount of a thermoplastic resin which strengthens the ink cohesion, and the ink cohesion increases with the increase, so-called ink bridging becomes possible. Although it is expected to reduce bubbles and bleeding, increasing the amount of thermoplastic resin actually increases the affinity with the base layer and hinders ink peeling, so increase the amount of thermoplastic resin so much Could not.

As a countermeasure, there has been proposed an ink ribbon 32 having a release layer 34 interposed between a base layer 33 and an ink layer 35 as shown in FIG.

The ink ribbon 32 has a release layer 34 formed by adding a softener such as silicone oil to a wax such as amide wax, if necessary, on a base layer 33 such as polyethylene terephthalate. On top, thermoplastic resins such as ethylene vinyl acetate copolymer and polyamide are used as the main binder material, waxes such as amide wax and carnauba wax, terpene resins, etc. are used as auxiliary materials, and if necessary, silicone oil etc. The ink layer 35 is formed by laminating a face material such as carbon black as a coloring material on a vehicle to which a softener or the like is added.

Then, the thermal head 31 is pressed against the base layer 33 of the ink ribbon 32 and the ink layer 35 of the ink ribbon 32 is pressed.
The release layer 34 and the ink layer 35 are melted by the heat generated by the thermal head 31 and the affinity of the ink layer 35 with the paper P is melted and the ink ribbon 32 is removed from the paper P in a state where the affinity is high. Ink layer by peeling
35 was thermally transferred to paper P.

[Problems to be solved by the invention]

However, in the conventional thermal transfer printing method described above, as shown in an enlarged view in FIG. 4, the transferred ink layer 35B is pulled by the ink layer 35B that is melted and transferred to the non-transferred ink layer 35A. Of the transfer image was blurred, and the outline of the transferred image was blurred, and there was a possibility that high quality printing could not be performed due to chipping or bubbles.

Further, when the paper P is a so-called rough paper having a rough surface such as bond paper, in the above-described conventional one, the non-transferred ink layer 35A is pressed against the paper P in the same manner as the transferred ink layer 35B. As a result, the adhesiveness of the transferred ink layer 35B to the paper P is poor, resulting in deterioration of print quality.

The present invention solves the above-described problems of the conventional art, and can obtain a high-quality transfer image without any curling up at the end of the transferred ink layer and even on rough paper. It is an object of the present invention to provide a thermal transfer printing method which can be performed.

[Means for solving the problem]

In order to achieve the above-mentioned object, a thermal transfer printing method according to the present invention is a method for stopping a movable transfer belt, running a thermal head, and transferring the ink of an ink ribbon to the surface of the transfer belt by the thermal head. When printing on one line of the transfer belt by the above is completed, the transfer belt is run to oppose a portion of the transfer belt where ink is attached to the paper, and then the transfer roller and the thermal head are run synchronously. In addition, the transfer roller transfers ink on the transfer belt to paper, and the thermal head transfers ink on the ink ribbon to the surface of the transfer belt.

(Operation)

According to the thermal transfer printing method of the present invention having the above-described configuration, first, in order to perform printing for the first line (which does not necessarily coincide with one line of printing itself) in the thermal head, the transfer belt is used. When the thermal head is stopped, the thermal head is pressed into contact with the transfer belt via the ink ribbon. Is transferred to the transfer belt.
At this time, the transfer image by the ink transferred to the transfer belt is a reverse pattern of the final transfer image on the paper.

When a transfer image of one line is first formed on the transfer belt in this manner, the transfer belt is driven by a driving unit,
The part of the transfer belt where the transfer image is formed is opposed to the sheet facing the front of the platen. Then, the transfer belt of a portion where there is no transfer image faces the traveling range of the thermal head.

Next, the transfer roller and the thermal head run synchronously, and the transfer image on the transfer belt is transferred to the sheet by the transfer roller, and at the same time, the ink of the ink ribbon is transferred to the transfer belt by the thermal head. As a result, the last one line is printed on the paper.

After the first one line of printing is performed on the paper in this way, the transfer belt is again driven by the driving means so that the portion of the transfer belt on which the transfer image is formed is opposed to the paper, and the paper is printed. The sheet is fed by a small amount so that a portion adjacent to the portion where the transfer image of the sheet is formed faces the transfer belt.

Thereafter, the transfer roller and the thermal head run again synchronously, and the transfer image on the transfer belt is transferred to the paper by the transfer roller, and the ink on the ink ribbon is transferred to the transfer belt by the thermal head.

As described above, by performing the transfer of the image by the synchronous movement of the transfer roller and the thermal head and the conveyance of the transfer belt and the paper alternately, printing can be performed on the entire surface of the paper.

Moreover, printing is not performed directly on the paper from the ink ribbon, but is performed by transferring the transfer image once formed on the transfer belt to the paper again. Even if the edge of the transferred image is turned up, the transferred image is transferred from the transfer belt to the paper so that the turned up side comes in contact with the paper, and good quality printing is performed. Can be.

Even if the paper is so-called rough paper, only the image to be transferred to the paper exists on the transfer belt, and since this image protrudes from the surface of the transfer belt, only the image to be transferred is transferred. The transfer is performed by strongly pressing the paper onto the paper, so that the transfer image has good adhesion to the paper, and therefore, it is possible to perform good quality printing even on rough paper.

〔Example〕

 Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.

1 and 2 show an embodiment of a thermal transfer printer for carrying out a thermal transfer printing method according to the present invention. A flat platen extending in the left-right direction is provided on the rear portion of the printer main body 1. 2 are erected. Above the printer main body 1 behind the latin 2, a plurality of paper feed rollers 3 for supplying paper from below to the front of the platen 2 are supported and supported by a rotating shaft 4 extending in the horizontal direction. . A large gear 5 is fitted to one end of the rotary shaft 4, and a paper conveying motor 6 disposed near the large gear 5
A small gear 8 meshed with the large gear 5 is fitted to the output shaft 7. Therefore, each paper feed roller 3 is rotated by the driving of the paper transport motor 6 to transport the paper P.

A carriage support shaft 9 extending in parallel with the platen 2 is provided on the printer main body 1 in front of the platen 2, and the carriage support shaft 9 allows a carriage 10 to reciprocate. It is supported by. The carriage 10 is dimensioned to reach from the front end of the printer body 1 to the vicinity of the platen 2 in the front-rear direction of the printer body 1.

The carriage 10 at the front of the printer body 1
A drive pulley 11A and a driven pulley 11B whose axes extend in the vertical direction are rotatably supported on both sides of the movement range of the drive pulley 11A and the driven pulley 11B. The drive belt 12 attached to is wound around. A large gear 13 is connected to the driving pulley 11A, and an output shaft 15 of a carriage traveling motor 14 arranged near the large gear 13 has
A small gear 16 meshed with the large gear 13 is fitted. Therefore, the drive pulley 11A rotates by driving the carriage traveling motor 14, and the carriage 10 is rotated.

On a substantially central portion of the carriage 10, a thermal head 17 slightly inclined in the left-right direction is provided.
A plurality of heat generating dots (not shown) are vertically arranged on the side facing the platen 2 on the thermal head 17. The number of heating dots of the thermal head 17 is set so that at least one line can be printed on the paper P.

Also, the carriage 10 ahead of the thermal head 17
An ink ribbon 18 accommodated in a ribbon cassette (not shown) is mounted on the upper portion, and an intermediate portion of the ink ribbon 18 is wrapped around the heating dots of the thermal head 17. Further, on the carriage 10 at the back of the thermal head 17, there is provided a backup roller 19 on which the heating dots of the thermal head 17 can be pressed.

A drive pulley 20A and a driven pulley 20B whose axes extend in the vertical direction are rotatably supported on both sides of the movement range of the carriage 10 at an intermediate portion in the front-rear direction of the printer body 1. An endless transfer belt 21 is wound around 20A and the driven pulley 20B. A large gear 22 is connected to the drive pulley 20A, and a small gear meshed with the large gear 22 is connected to an output shaft 24 of a belt drive motor 23 disposed near the large gear 22. 25 are fitted. Therefore, the transfer belt 21 runs by the drive of the belt drive motor 23.

The heat generating portions of the platen 2 and the thermal head 17 are set at the same height in the vertical direction, and the transfer belt 21 located between the platen 2 and the thermal head 17 is also set at the same height. I have.

The transfer belt 21 has a base layer made of a metal, a resin, or the like on the inside in contact with the driving pulley 20A and the driven pulley 20B, and a fluorine resin such as polytetrafluoroethylene or silicon on the outside of the base layer. The ink transfer layer is formed by laminating an ink transfer layer formed of a material such as rubber which can easily remove ink. One side of the transfer belt 21, which is located substantially at the center in the front-rear direction of the carriage 10, can be sandwiched between the thermal head 17 and the backup roller 19. The side is
It can come near the platen 2.

On the rear end of the carriage 10, the transfer belt 21
A transfer roller 26 for pressing the sheet from the back to the platen 2 is movably provided in the front-rear direction of the carriage 10. The pressure (linear pressure) of the transfer roller 26 against the platen 2 is suitably in the range of 2 to 5 kg / cm, for example. Also,
Inside the transfer roller 26, a heater (not shown) is housed for softening the transfer image formed on the transfer belt 21 to a certain extent and pressing the transfer image onto the sheet P. The outer peripheral surface of 26 is heated to about 60 ° C. Further, the transfer roller
A small-diameter belt peeling roller 27 is erected on the carriage 10 so as to be adjacent to the carriage 26, and the belt peeling roller 27 is moved by the transfer roller 26 via the sheet P to the platen 2.
The transfer belt 21 pressed against the platen 2 is separated from the platen 2.

The paper transport motor 6, the carriage travel motor
14, the thermal head 17, the belt drive motor 23, and the like are electrically connected to control means of a printer (not shown),
A predetermined operation for printing is performed at a predetermined timing.

Next, the operation of the present embodiment having the above-described configuration will be described.

First, in order to print the first one line in the thermal head 17, the paper transport motor 6 is driven to position a predetermined position of the paper P in front of the platen 2, and the transfer belt 21 is stopped. In the state, the thermal head 17
Is pressed against the transfer belt 21 via the ink ribbon 18. At this time, since the transfer belt 21 is supported by the ink ribbon from the back, the thermal head 17 is reliably pressed against the transfer belt 21.

Then, the carriage traveling motor 14 is driven to move the carriage 10 at the initial position in one direction, and the thermal head 17 mounted on the carriage 10 is moved along the transfer belt 21 via the ink ribbon 18. At this time, while the thermal head 17 is running, each heating dot of the thermal head 17 is selectively heated according to the print information to partially melt the ink of the ink ribbon 18 and transfer the melted ink to the transfer belt 21. I do. At this time, the transfer image formed by the ink transferred to the transfer belt 21 is a reverse pattern of the final transfer image on the paper P.

In this way, once the transfer image of the first line on the transfer belt 21 is formed by the forward movement of the carriage 10 once, the transfer belt 21 is driven by the driving of the belt driving motor 23 as a driving means. Then, the portion where the transfer image of the transfer belt 21 is formed is opposed to the sheet P facing the front of the platen 2 and then stopped. Then, the transfer belt 21 at a portion where there is no transfer image faces the traveling range of the thermal head 17. At this time, the carriage traveling motor 14 is simultaneously driven to return the carriage 10 to the initial position.

Next, the carriage 10 travels in a state where the transfer roller 26 is moved and the transfer roller 26 is pressed against the platen 2 via the transfer belt 21 and the paper P, and the transfer and transfer are performed by the pressure and heat of the transfer roller 26 and the belt separation roller 27. The transfer image on the belt 21 is transferred to the sheet P, and the ink on the ink ribbon 18 is transferred by the thermal head 17 to the transfer belt 21.
Transfer to As a result, printing of the first line is performed on the paper P.

After the first line of printing is performed on the paper P in this manner, the transfer belt 21 is driven again by the drive of the belt drive motor 23, and the portion of the transfer belt 21 where the transfer image is formed is printed on the paper P. At the same time, the sheet P is driven slightly by driving the sheet conveying motor 6 so that the portion adjacent to the portion where the transfer image of the sheet P is formed faces the platen 2 and the transfer belt 21.

Thereafter, the carriage 10 returned to the initial position is again driven by the drive of the carriage traveling motor 14 to synchronously travel the transfer belt 21 and the thermal head 17,
The transfer image on the transfer belt 21 is transferred to the paper P by the transfer roller 26 and the belt peeling roller 27, and the ink on the ink ribbon 18 is transferred by the thermal head 17 to the transfer belt 21.
Transfer to

Thus, the transfer roller accompanying the movement of the carriage 10
26, the transfer of the image from the transfer belt 21 to the paper P and from the ink ribbon 18 to the transfer belt 21 by the synchronous movement of the belt peeling roller 27 and the thermal head 17, the traveling of the transfer belt 21 and the conveyance of the paper P By alternately performing printing, printing can be performed on the entire surface of the paper P.

According to the present embodiment, printing is performed on the ink ribbon 18.
Is not performed directly on the paper P, but is performed by transferring the transfer image once formed on the transfer belt 21 to the paper P again, so that the ink on the ink ribbon 18 is partially When the transfer to the transfer belt 21 is performed, the cut of the ink between the non-transferred ink and the end of the transfer image formed on the transfer belt 21 is turned up. Paper P again
The transferred image is transferred from the transfer belt 21 to the paper P such that the turned up side comes into contact with the paper P, so that good quality printing can be performed on the paper P. it can.

Even if the paper P is a so-called rough paper having a rough surface, only an image to be transferred onto the paper P exists on the transfer belt 21, and this image moves outward from the surface of the transfer belt 21. Since it is protruded, only the image to be transferred is strongly pressed against the sheet P by the transfer roller 26 and is transferred onto the sheet P together with the heat of the transfer roller 26, so that the transfer image has good adhesion to the sheet P. Good quality printing can be performed on rough paper.

〔The invention's effect〕

As described above, according to the present invention, it is possible to obtain an excellent effect that a good quality transfer image can be formed on a sheet and good printing can be performed regardless of the type of the sheet.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a thermal transfer printer for carrying out the thermal transfer printing method according to the present invention, FIG. 2 is an enlarged perspective view of a main part of FIG. 1, and FIGS. FIG. 4 is a process chart of a typical thermal transfer printing method. 1 Printer main body 2 Platen 6 Paper transport motor 10 Carriage 14 Carriage running motor 17 Thermal head 18 Ink ribbon 19
... backup roller, 21 ... transfer belt, 23 ... belt drive motor, 26 ... transfer roller, 27 ... belt peeling roller, P ... paper.

Claims (1)

(57) [Claims] An ink jet printer according to claim 1, wherein the movable transfer belt is stopped, the thermal head is moved, and the ink on the ink ribbon is transferred to the surface of the transfer belt by the thermal head. When the transfer is completed, the transfer belt runs to oppose the portion of the transfer belt where the ink adheres to the paper, and then the transfer roller and the thermal head run synchronously, and the transfer roller transfers the transfer belt ink to the paper. A thermal transfer printing method, wherein the transfer is performed and the ink of the ink ribbon is transferred to the surface of a transfer belt by a thermal head.