JPH05139004A - Inking device for thermal transfer printer - Google Patents

Abstract

PURPOSE:To solve the problem in the inking quality when an ink film is regenerated by applying an ink film evenly on an ink film of a thermal transfer printer. CONSTITUTION:The residual ink is molten and scraped off by bringing a rotating cleaning roll 101 into contact with a running ink film 100 after a transfer. Then, an even ink film is applied by transferring the ink on the ink film 100 while an applicator roll 106, on the surface of which a specified quantity of an ink film has been applied by a pick-up roll 107, is being rotated in the opposite direction to the running direction of the ink film 100. Also, an excessive ink is prevented from adhering to both end parts of an ink film 103a on the ink film 100 by a wiper roll 124 and wiper block 122 which are respectively brought into contact with the cleaning roll 101 and applicator roll 106.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inking device for repeatedly reproducing an ink film in a printer using a thermal transfer recording system.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 11, the basic construction of a thermal transfer recording type line printer capable of recording on plain paper by using a thermal head is as follows. Ink ribbon 401 coated with an ink having a relatively low melting point, such as one obtained by adding a colorant such as a pigment to a binder material such as ester wax
A plurality of heating resistors are wound from the reel A 402 which has been wound in advance through the guide roller 404 between the thermal head 418 and the paper 421 arranged in series, and an appropriate pressure is applied between the platen 420 and the thermal head 418. Meanwhile, the heating resistor is heated in response to the print signal applied by the thermal head 418, the ink of the ink ribbon 401 is melted, transferred and recorded, and the recorded ink ribbon is wound on the reel B403. Further, such a thermal transfer recording system is characterized in that it can print not only on plain paper but also on a resin material such as polyester such as an OHP film as a recording medium.

However, the ink ribbon 401 after transferring the ink to the recording medium has a drawback that it cannot be used again. Furthermore, there is an uneconomical aspect in that the ink is left in the ink ribbon 401 other than the heat-transferred portion and is discarded without being used. This is a very expensive usage price when using this type of printer. There was a problem to do. Further, a reel B 403 for winding the ink ribbon 401 is required, and therefore a space for providing the reels 402 and 403 is required inside the apparatus, which causes a problem of increasing the size of the printer. Further, the characters output on the used ink ribbon remain in an inverted form, which can be easily discriminated by a third party, which is a problem for confidentiality. These problems have been a problem in that the cost of using the thermal transfer printer is extremely high when it is used.

On the other hand, the ink ribbon is replaced with a belt-shaped ink holder having heat resistance and durability, the ink is supplied to the ink ribbon, and the thermal head transfers the ink to a recording medium. After the transfer, the ink is again held on the ink holder. By storing the ink, the above problem can be solved. As a means for solving this problem, as shown in FIG. 6, a plurality of guide rollers 202 and return rollers 105, 203 are provided.
Thickness of heat-resistant polyimide etc. stretched by
On the endless ink film 100 of about 0 μm,
The hot-melt ink having a film thickness of 5 to 10 μm is uniformly applied to the surface of the ink film 100 by the preheated inking device 111. Then, the ink film 100 containing the solidified ink film is attached to the thermal head 1.
The ink is melted and transferred to the paper 121 that is sandwiched by the platen 120 by using the No. 18. Then, the transferred ink film 100 is returned to the inking device 111 and reproduced. By repeating this process, the running cost can be reduced to 1/5 or less as compared with the conventional thermal transfer printer in which the ink film is disposable. An example of the inking device 111 will be described with reference to FIG. A cleaning roll 101 that rotates at the same frequency as the running speed of the ink film 100 or at a higher peripheral speed is applied to the running transferred ink film 100 in the forward direction with respect to the running direction of the ink film 100 to melt the residual ink and perform cleaning. It is collected on the roll 101 or scraped off. In addition, from the ink tank 102 to the cleaning roll 101
Since the ink 103 attached to the ink is regulated by the doctor roll 104, the ink 103 is not applied to the ink film 100. Next, the ink 103 is transferred to the ink film 100 while rotating the applicator roll 106 coated with a predetermined amount of ink film on the surface by the pick-up roll 107 in the direction opposite to the running direction of the ink film 100, and at the position of the thermal head. By the time the ink is sent, the ink is naturally cooled and solidified to form a uniform ink film 103a. According to an experiment by the inventor, ± 1 μm is obtained in an ink film thickness range of 5 to 10 μm.
The ink could be uniformly applied to the ink film 100 with an accuracy within the range. In the figure, 108 is a heater and 109 is an ink pellet.

[0005]

However, when the ink film 100 comes into contact with the cleaning roll 101 and the applicator roll 106, the ink 103 spreads in the width direction of the ink film 100, and each of the rollers 101,1.
8A along the running direction of the ink film 100 at both ends of the ink application area 103a determined by the width of the applicator roll 106 on the ink film 100 as shown in FIG. 8A. 8 (b) which is a sectional view taken along line AA of FIG. 8), a ridge-shaped ink rising 103b occurs. When this height is large, it reaches 0.5 to 1 mm. Normal ink film thickness 5-10μ
In the case of m, the ink film is not peeled from the ink film 100 unless the ink film 100 is subjected to considerable bending deformation, but in the case of the ink swell 103b described above, the ink film 100 is easily peeled from the ink film 100 even with a slight bending deformation. To do. Therefore, there is a problem that only the ink swell 103b falls off inside the printer and the inside of the device is soiled.

As a means for solving this problem, Japanese Patent Laid-Open No. 61-61
There is a thermal transfer recording device disclosed in Japanese Patent No. 41562/1992. As shown in FIGS. 9 and 10, the ink film 1 made of a polyimide resin has an ink film 1 with a thickness of about 2.5 μm on the surface.
Polytetrafluoroethylene-6, which has poor wettability and adhesion with 3
Fluorinated propylene copolymer resin layer (hereinafter abbreviated as FEP layer)
Is used and only the ink application range W is subjected to the sputter etching treatment to improve the wettability and adhesion of 13 with the ink. Further, in the inking device, as shown in FIGS. 9 and 10, a roller composed of rubber rollers 15a and 15b called a counter roller is rotated in a direction opposite to the traveling direction of the ink film 1 as indicated by an arrow D, so that the ink film 1 Unnecessary ink 13c that overflows and adheres to both sides of the ink roller 14 is removed by adhering it to the rubber roller portions 15a and 15b, and is scraped off by the front edge portion 14a of the ink tank 14 that is in contact with the rubber roller portions 15a and 15b. I am taking a way to put it back inside. Further, the blade 16 is arranged at a position opposite to the counter roller 15 so as to come into contact with both ends of the ink applying roller 12. Is sucked up and wraps around from the both side edges of the ink film 1 to the back surface so as not to adhere.

However, in the configuration of this conventional inking device, the rubber roller portions 15a and 15b are arranged in the ink tank 1.
It is heated because it is in contact with the No. 4 ink 13
c is melted or ink 1 in this position
Since 3 is not sufficiently solidified, the ink 13 overflows from both ends of both rubber rollers 15a and 15b as in the case of the above-mentioned ink applying roller 12, and unnecessary ink 13d
Is made. Further, when the rubber rollers 15a and 15b are out of the ink film 1, there is a problem that the ink 13 goes around to the back surface of the ink film 1 and deteriorates the recording quality.

It is an object of the present invention to provide an inking device for a thermal transfer printer which solves the above problems.

[0009]

SUMMARY OF THE INVENTION The present invention relates to an inking device of a thermal transfer printer in which an endless ink film coated with a heat-meltable ink is repeatedly regenerated and used, and the heat-melting property is preliminarily heated and melted by a heating means. On the ink tank that stores the ink, a cleaning roll that rotates to remove the ink on the ink film, a doctor roll that removes the ink on the surface of the cleaning roll, and an ink film that rotates in the opposite direction to the running direction of the ink film An applicator roll that applies the ink, a pickup roll that supplies ink from the ink tank and regulates the height of the ink film on the surface of the applicator roll, and both ends of the doctor roll that are in close contact with both side surfaces and both ends of the cleaning roll. And both side parts of the cleaning roll and both end shaft parts Installed between the wiper roll that removes the adhered ink and regulates the adherence of the ink, and both ends of the applicator roll and the pickup roll, and adheres closely to both side surfaces and both end shafts of the applicator roll. It is composed of both side surface portions of the roll and wiper blocks that remove the ink adhering to the shaft portions at both ends and regulate the adhering of the ink.

The wiper block may be replaced with a cylindrical wiper roll which is press-fitted into both ends of the pickup roll.

[0011]

According to the present invention, the ink film, which has been transferred by the thermal head and has the transfer missing portion of the ink film, is brought into contact with the cleaning roll to dissolve and remove the ink in the transfer missing portion of the surface, and then the applicator. By re-applying a predetermined amount of ink film on the entire surface of the ink film with a roll, an ink film with a smooth ink film surface and a uniform ink film thickness is reproduced, and there is no rise of ink by the wiper roll and wiper block. A regenerated ink film is obtained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

A cross-sectional view of an embodiment of the inking device of the present invention is shown in FIG. First, in the ink tank 102 in the inking device 111 that is heated by a heater (not shown) that is a heat generating unit, a heat-melting material that is solid at room temperature, for example, a binder material such as ester wax and a coloring agent such as a pigment. The ink 103 having a relatively low melting point of about 80 ° C. is melted by the heat of the heater, and the ink 103 is stored in the bottom portion of the ink tank 102. Then, on the upper part of the ink tank 102,
For example, a rotatable cylindrical cleaning roll 1 made of a material having a relatively high thermal conductivity such as aluminum.
01 is provided, and its length is smaller than the width of the ink film 100 and equal to or larger than the recording width.
Further, the surface of the cleaning roll 101 is subjected to sandblasting, etching, or the like to have a satin finish. Further, as another example, a linear thin groove or a spiral thin groove may be formed along the length direction over the entire outer peripheral surface of the cleaning roll 101. Then, at the position shown in the figure, the cleaning roll 101
And a doctor roll 104 having the same length as the cleaning roll 101 is provided. The doctor roll 104 removes excess ink adhering to the surface of the cleaning roll 101.

Now, the ink film 1 which is pretensioned
00 is brought into contact with the cleaning roll 101 as shown in FIG. 1, but the ink on the ink film 100 is melted and at the same time scraped off by the irregularities or grooves on the surface of the cleaning roll 101, or the ink 1
It is removed by a surface tension of 03. However, since this operation is regarded as a pretreatment stage of inking, it is not always necessary to remove all the ink on the ink film 100. Then, the ink 103 attached to the cleaning roll 101 is collected in the ink tank 102.

Next, the ink film 100 from which the ink 103 has been removed is brought into contact with the applicator roll 106 by the return roller 105. The applicator roll 106 is made of a stainless material, an aluminum material, or a metal material thereof by chrome plating so as to have a relatively durable surface and good ink wettability. It rotates in the direction opposite to the running direction, and the number of rotations is a parameter such as the viscosity of the ink 103, the surface tension, the running speed of the ink film 100 with respect to the target thickness of the coating film on the ink film 100 (5 to 10 μm). Defined by Further, the applicator roll 106 is pressed and brought into contact with the surface of the applicator roll 106 at a position shown in the drawing below the applicator roll 106,
The pick-up roll 107 to be supplied is the ink tank 10.
It is provided above 2. The ink 103 uniformly applied to the surface of the applicator roll 106 by the pickup roll 107 is transferred to the ink film 100 by coming into contact with the ink film 100. Further, since the applicator roll 106 is rotated in the direction opposite to that of the ink film 100, the ink coating film can be smoothed, and an ink film having a uniform and uniform thickness is formed along the surface of the ink film 100. It Therefore, uneven transfer due to unevenness of the ink film does not occur during recording.

In the ink swell 103b, which has been a problem in the prior art, an ink reservoir 103c is formed on the side corner portion 106d of the applicator roll 106 by the surface tension of the ink itself, as shown in FIG. The ink swell 103b remains on the ink film 100. Therefore, in this embodiment, a wiper made of a material such as tetrafluoroethylene-6-propylene propylene copolymer resin having poor wettability and adhesion to ink and provided with the grooves 122a and 122b shown in FIG. 3 (a). Block 122
2 applicator rolls 1 as shown in FIG.
06 and the notch shaft 106a provided between the flange portions 106b provided at both ends thereof, and the pickup roll 1
Notch shaft 1 provided between 07 and the flange portion 107b
It is attached so that it is sandwiched between 07a. Each surface of the wiper block 122 has a side surface 106c of the applicator roll 106 and a side surface 107 of the pickup roll 107.
c. The dimensions of the wiper block 122 are determined so as to make surface contact with the surfaces of the respective cutout shafts 106a and 107a.

As another embodiment, as shown in FIG. 4 (a), two cylindrical wiper rolls 123 are press-fitted into both ends 107e of the pickup roll 107 as shown in FIG. The wiper roll 123 has a side surface on the side surface 106c of the applicator roll 106 and a cylindrical surface on which the notch shaft 106a is sandwiched by the notch shaft 106a between the troll 106 and the flange portion 106b.
Make a surface contact with a.

The wiper roll 12 shown in FIG.
2 of the doctor rolls 104 as shown in FIG.
When the doctor roll 104 and the cleaning roll 101 come into contact with each other, the wiper roll 124 causes the step portion 101a of the cleaning roll 101 and the side surface 10 to contact each other.
Make a surface contact with 1b.

First, the effect of the wiper block 122 will be described with reference to FIG. Since the wiper block 122 sandwiched between the applicator roll 106 and the flange 106b is constantly in contact with the cutout shaft 106a and the side surface 106c, the ink does not adhere to the corner portion 106d and the surface of the applicator roll 106 is eliminated. Only the ink 103a is applied. Applicator roll 10
6 rotates and its surface comes into contact with the ink film 100, and the surplus ink is absorbed by the notch shaft 106a side due to the surface tension. As a result, the ink swell 103b as shown in FIG. 2A is not formed. Therefore, it is desirable that the roll shaft material has a good ink wettability. Then, the cutout shaft 106
The ink sucked by a is applied to the applicator roll 106.
Since it is rotating, it is scraped off by the wiper block 122 and returned to the ink-free state.

The wiper roll 123 shown in FIGS. 4A and 4B.
The same result is obtained for, and FIG.
With respect to the wiper roll 124 of (b), similar results are obtained with respect to the cleaning roll 101.

It should be noted that the above description of the embodiment of the inking device 111 does not describe the limitation of the embodiment by the recording mode of the printer, that is, the serial printer, the line printer, etc. However, it is obvious that the object of the present invention is achieved.

[0022]

By employing the inking device as described above, it is possible to solve the problem of inking quality in the reproduction of the ink film.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

2A is a diagram showing a cause of ink swelling in a conventional inking device, and FIG. 2B is a diagram showing removal of ink swelling by a wiper block according to the present invention.

FIG. 3A is a perspective view showing the shape of a wiper block;
(B) is a figure which shows the use condition of a wiper block.

FIG. 4A is a perspective view showing the shape of a wiper roll;
(B) is a figure which shows the use condition of a wiper roll.

5A is a perspective view showing a shape of a wiper roll press-fitted into a doctor roll, and FIG. 5B is a view showing a usage state of the doctor roll.

FIG. 6 is a cross-sectional view of a conventional printer.

FIG. 7 is a sectional view of a conventional inking device.

8A and 8B are diagrams showing an ink film applied by the inking device of FIG. 7, in which FIG. 8A is a top view and FIG. 8B is FIG.
3 is a cross-sectional view taken along line AA of FIG.

FIG. 9 is a cross-sectional view showing another example of a conventional inking device.

FIG. 10 is a top view of an ink film applied by the inking device of FIG.

FIG. 11 is a sectional view of a conventional thermal transfer printer.

[Explanation of symbols]

 100 Ink Film 101 Cleaning Roll 103 Ink 104 Doctor Roll 105 Return Roller 106 Applicator Roll 107 Pickup Roll 108 Heater 111 Inking Device 118 Thermal Head 121 Paper 122 Wiper Block 123,124 Wiper Roll

Claims (2)

[Claims] 1. An inking device for a thermal transfer printer, in which an endless ink film coated with a heat-melting ink is repeatedly regenerated and used, in an ink tank storing the heat-melting ink that has been heated and melted in advance by a heating means. In addition, a cleaning roll that rotates to remove ink on the ink film, a doctor roll that removes ink on the surface of the cleaning roll, an applicator roll that rotates in the direction opposite to the running direction of the ink film to apply ink to the ink film, A pickup roll that supplies ink from the ink tank and regulates the height of the ink film on the surface of the applicator roll, and both ends of the doctor roll are in close contact with both side parts of the cleaning roll and both end shaft parts, and both side parts of the cleaning roll. Removes ink from both ends , And a wiper roll that regulates the adhesion of ink, and is attached between the applicator roll and both ends of the pickup roll to adhere to both side surfaces and both ends of the applicator roll, and both side surfaces and both ends of the applicator roll. An inking device for a thermal transfer printer, comprising: a wiper block that removes ink adhering to the shaft portion and regulates ink adhering. 2. An inking device for a thermal transfer printer, in which an endless ink film coated with a heat-melting ink is repeatedly regenerated and used, and an ink tank storing the heat-melting ink that has been heated and melted in advance by a heating means. In addition, a cleaning roll that rotates to remove ink on the ink film, a doctor roll that removes ink on the surface of the cleaning roll, an applicator roll that rotates in the direction opposite to the running direction of the ink film to apply ink to the ink film, A pickup roll that supplies ink from the ink tank and regulates the height of the ink film on the surface of the applicator roll, and both ends of the doctor roll are in close contact with both side parts of the cleaning roll and both end shaft parts, and both side parts of the cleaning roll. Removes ink from both ends A wiper roll that controls ink adhesion, and is press-fitted to both ends of the pickup roll to adhere to both side surfaces and both end shaft portions of the applicator roll to remove ink adhered to both side surface portions and both end shaft portions of the applicator roll. And an inking device for a thermal transfer printer, which comprises a cylindrical wiper roll that regulates ink adhesion.