JPH0357492Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical Field] The present invention is a thin, heat-resistant film that is coated with heat-soluble ink on the surface of the ink film, which is locally heated by a thermal head, thereby transferring the molten ink onto recording paper. The present invention relates to an ink application mechanism for repeatedly applying ink to the film in a thermal transfer recording apparatus that performs recording. [Prior Art] In conventional thermal transfer recording devices, a coating device such as a rod coater or a gravure coater is used to coat a long plain film with a heat-melting ink that solidifies at room temperature to a thickness of about several μm. This was cut into a desired length and used as an ink film. However, such ink film can generally only be used once for recording, and the disadvantage is that it consumes the same amount of ink film as the recording paper, resulting in a large amount of waste and high running costs. It was hot. Therefore, recently, in order to eliminate the above-mentioned waste, a film of an appropriate length is formed endlessly and wound around a plurality of rollers so that it can run, and the coating device is used as a mechanism for applying ink to this film. A reproduction type thermal transfer recording apparatus has been proposed in which ink application and recording are repeatedly performed within the recording apparatus. By the way, in this type of thermal transfer recording device, the thickness of the ink layer on the ink film affects the printing quality, so the ink application mechanism has a mechanism that removes ink that remains on the surface of the film even after the previous application and recording. Regardless of whether or not the film is coated with ink, it is required to apply the ink to the film in a uniform thickness, but the coating device is for applying ink to a plain film, so it is necessary to miniaturize it and use a recycling method. When used as an ink application mechanism in a thermal transfer recording device, there is a drawback that the thickness of the reapplied ink layer becomes uneven due to residual ink, and for some reason, the thickness of the reapplied ink layer becomes uneven due to residual ink. If unnecessary ink adheres to the end portion, there is no means to remove it, and this has the disadvantage that the apparatus becomes dirty with this unnecessary ink. [Purpose of the invention] The present invention was made in order to solve the above-mentioned drawbacks of the prior art. It is an object of the present invention to realize an ink application mechanism in a thermal transfer recording device that can apply ink to a film and can also remove unnecessary ink that stains the device from the film. [Summary of the invention] In order to achieve the above-mentioned object, the present invention includes the steps of applying hot-melt ink to an endless film, and locally heating the ink applied to the film using a thermal head. An ink application mechanism in a thermal transfer recording device, which comprises a step of thermally transferring the melted ink to a recording paper,
An ink tank containing heat-fusible ink; a part of the ink tank is immersed in the ink tank; a heat source is provided inside; and the width of the outermost surface that contacts the film surface is narrower than the film width. In addition, the outermost peripheral surface has both ends smooth,
A straightening roller having linear grooves densely carved between both smooth surfaces; an unnecessary ink removing means disposed in contact with the film from the ink application side so as to span the smooth surface of the straightening roller; and a static electricity removing means arranged to face the film, the correction roller is rotated at the same time as the film advances, thereby drawing up the ink in the ink tank and forming an ink pool at the contact portion between the correction roller and the film. At the same time, the ink in the ink reservoir is applied to the surface of the film through the groove of the straightening roller while removing static electricity charged on the film by the static electricity removing means, and at this time, the ink overflows from both sides of the ink reservoir and adheres to both sides of the surface of the film. The unnecessary ink is removed by the unnecessary ink removing means and returned to the ink tank. [Example] An example will be described below with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing an embodiment of an ink application mechanism in a thermal transfer recording apparatus according to the present invention.
is a heat-resistant film, for example, the thickness
It is made of an endless 12.5 μm polyimide film. Reference numeral 2 denotes a back-up roller whose surface is made of an elastic material such as rubber, and is rotatably supported by a frame (not shown). It is wrapped around a roller. 3 is a heat-soluble ink; 4 is an ink tank containing the ink 3; 5 is a correction roller disposed below the back-up roller 2 through the film 1; tank 4
It is immersed in ink 3 inside. Reference numeral 6 denotes a counter roller, which is provided at a position immediately downstream of the correction roller 5 with respect to the traveling direction of the film 1 shown by arrow A. This counter roller 6
Rubber rollers 6a and 6b made of silicone rubber or the like are placed at two positions corresponding to both sides of the film 1.
are formed, and both rubber rollers 6a, 6b
is in contact with the film 1 and also with the front edge 4a of the ink tank 4. 7 is a gear fixed to the end of the back-up roller 2, 8 is a gear fixed to the end of the correction roller 5, and 9 is a gear fixed to the end of the counter roller 6.
The gear 7 is a gear fixed to the end of the gear 8.
The gear 8 also meshes with the gear 9. Reference numeral 10 denotes a tank frame which accommodates the ink tank 4 and rotatably supports the correction roller 5 and counter roller 6. Pressed for even contact. The correction roller 5 passes through the side surface of the ink tank 4, and a seal member 11 is provided at the penetrating portion to prevent the ink 3 in the ink tank 4 from leaking to the outside. Reference numeral 12 denotes a static elimination brush disposed near the backup roller 2 so as to make light contact with the back surface of the film 1. This static elimination brush 12 is a means for eliminating static electricity charged on the film 1. Figure 2 is a view in the X direction of Figure 1, and Figure 3 is a view of Figure 1.
4 is an enlarged cross-sectional view of a part of FIG. 3, and FIG. 5 is a view taken in the Z direction of FIG. 1. The structure of the correction roller will be explained in detail. 3 and 5, the ink tank 4, tank frame 10, etc. are shown removed. The straightening roller 5 puts a heat source 13 such as a nichrome wire into a protective tube 15 together with an oxide powder 14 such as magnesium oxide that has excellent heat resistance, electrical insulation, and thermal conductivity, and further includes a heat conductive material on the outer periphery of the protective tube 15. Protective tube 1
Electric power is supplied to the heat source 13 at both ends of the heat source 13 to generate heat by means such as slipping. Here, the width of the outer tube 16 is wider than the width of the film 1 as shown in FIG. 3, and its outer peripheral surface is smooth at both ends 16a and 16b.
The intermediate portion 16c has a cross-sectional shape V as shown in FIG.
The shaped grooves 17 are carved so as to be in close contact with each other. This groove 17 can be easily cut into a spiral shape by lathe processing. In addition, in FIGS. 2 and 3, 18 is a blade, and the protective tube 15 is removed at the step formed by the difference in the outer diameter of the protective tube 15 and the outer tube 16 of the straightening roller 5.
is arranged so as to be in contact with the outer circumferential surface of the Next, the operation of the ink application mechanism having the above-mentioned configuration will be explained. The straightening roller 5 is controlled to a temperature higher than the melting point of the ink 3 by an internal heat source 13, and this temperature control is performed by contacting the surface of the straightening roller 5. This is done by controlling the power applied to the heat source 13 using a temperature detector (not shown). Therefore, when the film 1 is driven in the direction of arrow A by a drive roller (not shown), the film 1
The back-up propeller 2 rotates in the direction of arrow B as shown in FIGS. The correction roller 5 rotates in the direction of arrow C, and the counter roller 6 rotates in the direction of arrow D. When the correction roller 5 rotates in the direction of the arrow C in this manner, the melted ink 3 in the ink tank 4 is pumped up along the outer circumferential surface of the correction roller 5, and a portion of this pumped ink 3 is released as ink 3a. tube 1
The remaining ink is supplied to the surface of the film 1 through the groove 17 of No. 6, and the remaining ink forms an ink reservoir 3' at the contact portion between the outer tube 16 and the film 1, as shown in FIG. The purpose of providing this ink reservoir 3' is to form a layer of ink 3a with a uniform thickness on the surface of the film 1 at all times. That is, the ink 3a remaining on the surface of the film 1 after the previous recording is completely melted, mixed with the ink 3 drawn up by the rotation of the correction roller 5, and grooves 1 are formed on the film 1.
This is because a certain amount of ink 3a is newly supplied through the ink 7. In addition, the protection tube 15 is removed by rotation of the correction roller 5.
The ink 3 pumped up along the outer peripheral surface of the film 1 is prevented from being pumped up any further by the blade 18 which is in contact with the protection tube 15 in front of the film 1, and is returned into the ink tank 4. Now, as mentioned above, the ink 3a applied to the surface of the film 1 through the groove 17 provided in the outer circumferential surface of the outer tube 16, which is the outermost circumferential surface of the correction roller 5, changes from the state shown in FIG. As shown in (B), the ink 3a gradually spreads and becomes a smooth and uniformly thick layer as shown in (C) of the same figure, and this layer of ink 3a is formed by a thermal head (not shown) until it reaches the position of the recording means. Cools and solidifies naturally. According to experiments, the relationship between the shape of the grooves 17 of the correction roller 5 and the thickness of the ink layer formed on the surface of the film 1 is as shown in the table below. Ink 3a that is always smooth and has a uniform thickness without being affected by
could be repeatedly formed on the film 1.

[Effect of idea]

As explained above, the present invention uses the rotation of a straightening roller with a built-in heat source to pump up the ink in the ink tank and form an ink pool at the contact area with the film, thereby melting the remaining ink on the film surface. Because the grooves cut into the outermost surface of the straightening roller supply and apply a constant amount of ink to the film, it is possible to always apply ink to a constant thickness regardless of the amount of residual ink. In addition, because the means for eliminating static electricity charged on the film is brought into contact with the back side of the film, the ink applied to the film spreads smoothly, forming a smooth and uniform layer of ink at all times. The effect is that it can be regenerated. Furthermore, the straightening roller has a protection tube with a built-in heat source,
It has a stepped structure consisting of an outer tube with smooth surfaces on both ends of the outer peripheral surface and a groove carved between the two smooth surfaces, and removes unnecessary ink that overflows from the ink reservoir and adheres to the film. Since there is a means for removing ink that is returned to the tank, unnecessary ink does not remain on the film surface and contaminate the inside of the device, or go around to the back side and adversely affect print quality. Since a smooth ink layer with a uniform thickness can be formed by repeating the process, it can be used as an optimal ink application mechanism for regeneration type thermal transfer recording devices.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an embodiment of an ink application mechanism in a thermal transfer recording device according to the present invention, FIG. 2 is a view taken in the X direction of FIG. 1, and FIG. 3 is a Y direction of FIG. 4 is an enlarged cross-sectional view of a part of FIG. 3, FIG. 5 is a view taken in the Z direction of FIG. 1, and FIG. 6 shows the process of smoothing the ink applied to the film. It is an explanatory diagram. 1...Film, 2...Backlash propeller,
3... Ink, 4... Ink tank, 5... Correction roller, 6... Counter roller, 7, 8, 9...
Gear, 10...tank frame, 11... sealing member, 12... static elimination brush, 13... heat source, 14
... Oxidized powder, 15 ... Protection tube, 16 ... Outer tube,
17...groove, 18...blade.

Claims (1)

[Claims for Utility Model Registration] A process of applying heat-melting ink to an endless film, locally heating the ink applied to the film with a thermal head, and thermally transferring the molten ink to recording paper. An ink application mechanism for a thermal transfer recording device, which comprises: an ink tank containing a heat-melting ink; a part of the ink tank is disposed so as to be immersed in the ink tank; a heat source is provided inside the ink tank; A straightening roller comprising a width of the outermost circumferential surface that contacts the film surface is narrower than the film width, the outermost circumferential surface has smooth surfaces at both ends, and linear grooves are densely carved between the two smooth surfaces. and, located immediately downstream of the straightening roller with respect to the traveling direction of the film, and brought into contact with the film from the ink-applied surface side at both ends of the film so as to extend substantially from the side edges of the film to the smooth surface of the straightening roller. an unnecessary ink removing means disposed at the same time as the film advances, and a static electricity removing means disposed so as to face the back surface of the film at a position immediately downstream of the correction roller with respect to the film traveling direction, By rotating the correction roller, the ink in the ink tank is pumped up and an ink pool is formed at the contact area between the correction roller and the film, and the static electricity removed from the film is removed by the static electricity removing means. The ink is applied to the surface of the film through the groove of the straightening roller, and unnecessary ink that overflows from both sides of the ink reservoir and adheres to both sides of the film surface is removed by the unnecessary ink removing means and returned to the ink tank. An ink application mechanism in a thermal transfer recording device, characterized in that: