JPH0357493Y2 - - 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 ink is present, it is required to apply ink to the film to a uniform thickness, but the coating device applies 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 a process of applying heat-melting ink to an endless film, and locally heating the ink applied to the film with a thermal head. An ink application mechanism in a thermal transfer recording device, which includes a step of thermally transferring the melted ink onto a recording paper, the ink tank containing the heat-melting ink;
A part of the ink tank is immersed in the ink tank, a heat source is provided inside the ink tank, and the width of the outermost peripheral surface that contacts the film surface is narrower than the film width, and both ends of the outermost peripheral surface are smoothed. a straightening roller having linear grooves densely carved between the two smooth surfaces; unnecessary ink removing means disposed in contact with the film from the ink application side so as to extend from the side edge of the straightening roller to the smooth surface of the straightening roller; and a heating disposed opposite to the unnecessary ink removing means with the film interposed therebetween. means for pumping up the ink in the ink tank by rotating the straightening roller at the same time as the film advances, forming an ink pool in the contact area between the straightening roller and the film, and discharging the ink into the groove of the straightening roller. The unnecessary ink that overflows from both sides of the ink reservoir and adheres to both sides of the film surface is heated from the back side of the film by the heating means, and is removed by the ink removal means to remove it from the ink tank. It is characterized by being made to return to the inside. [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 device according to the present invention.
It is made of an endless 12.5μm 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 of the ink tank 4. 7 is a hot plate as a heating means, which is arranged on the back side of the film 1 so as to face the counter roller 6 with the film 1 interposed therebetween;
This hot plate 7 has the rubber roller 6a,
Heating elements 8a and 8b are attached to positions corresponding to rollers 6b, and springs 9a and 9b push down the film 1 to bring the rubber rollers 6a and 6b into good contact with the film 1. This hot plate 7 also has a heating element 8.
A large number of holes 7a are provided so that the heat generated by a and 8b is well transmitted to the part that contacts the back surface of the film 1, but does not spread to other parts, consuming excess power or raising the ambient temperature. It has a unique structure. It is best to use heating elements having a self-temperature control function as the heating elements 8a and 8b, since a temperature sensor and temperature control are not required. 10 is a gear fixed to the end of the back up roller 2, 11 is a gear fixed to the end of the correction roller 5, and 12 is a gear fixed to the end of the counter roller 6.
The gear 10 meshes with a gear 11, and the gear 11 meshes with a gear 12. Reference numeral 13 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 14 is provided at the penetrating portion to prevent the ink 3 in the ink tank 4 from leaking to the outside. 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 more detail. In addition, in FIG. 3 and FIG. 5, the ink tank 4 and the tank frame 13 are
etc. are removed. The straightening roller 5 puts a heat source 15 such as a nichrome wire into a protective tube 17 together with an oxide powder 16 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 17. Protective tube 1 is covered with a good outer tube 18.
Electric power is supplied to the heat source 15 at both ends of the heat source 15 by means such as a slip ring so that the heat source 15 generates heat. Here, the width of the outer tube 18 is
As shown in the figure, it is narrower than the width of the film 1, and its outer peripheral surface is smooth at both ends 18a and 18b, and a groove 19 with a V-shaped cross section is closely fitted in the middle part 16c as shown in FIG. It is engraved as follows.
This groove 19 can be easily cut into a spiral shape by lathe processing. In addition, in FIG. 2 and FIG. 3, 20 is a blade, and the protective tube 17 is removed at the step formed by the difference in the outer diameter of the protective tube 17 and the outer tube 18 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-described configuration will be explained. The temperature of the straightening roller 5 is controlled by an internal heat source 15 to a temperature higher than the melting point of the ink 3, 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 15 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. 1 and 2 due to the frictional force with the
1 to the gear 12, 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 grooves 19 of 8 and forms an ink reservoir 3' at the contact portion between the outer tube 18 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 9. Incidentally, due to the rotation of the correction roller 5, the protective tube 17
The ink 3 that has been pumped up along the outer peripheral surface of the film 1 is prevented from being pumped up further by the blade 20 that is in contact with the protective tube 17 before the film 1, and is returned to the ink tank 4. Now, as described above, the ink 3a applied to the surface of the film 1 through the groove 19 provided on the outer circumferential surface of the outer tube 18, 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 groove 19 of the correction roller 5 and the thickness of the ink layer 3a 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 film 1.

[Effect of idea]

As explained above, the present invention uses the rotation of the 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 residual ink on the film surface and straightening it. Because the grooves cut into the outermost surface of the roller supply and apply a fixed amount of ink to the film, a smooth and uniformly thick ink layer is always formed and regenerated regardless of the amount of remaining ink. You can get the effect that you can. In addition, 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 at both ends of the outer peripheral surface and a groove between the two smooth surfaces, and removes unnecessary ink that overflows from the ink reservoir and adheres to the film. Since there is an ink removal means that returns the inside of the tank and a heating means that heats unnecessary ink from the back side of the film to help remove unnecessary ink, unnecessary ink does not remain on the film surface and contaminate the device. It is ideal for recycle-type thermal transfer recording devices because it can repeatedly form a smooth ink layer of uniform thickness on a certain area of the film surface without penetrating the back side and adversely affecting print quality. It can be used as an ink application mechanism.

[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, 3'...Ink reservoir, 4...Ink tank, 5...Correcting roller, 6...Counter roller, 7...Hot plate, 8a, 8b...Heating element, 9a, 9b...Spring ,10,1
1, 12... Gear, 13... Tank frame, 1
4... Seal member, 15... Heat source, 16... Oxidized powder, 17... Protection tube, 18... Outer tube, 19...
Groove, 20...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 for storing 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; 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 in the ink tank; and a heating means disposed opposite to the unnecessary ink removing means with the film interposed therebetween; The ink is drawn up to form an ink pool at the contact area between the straightening roller and the film, and the ink is applied to the surface of the film through the groove of the straightening roller. An ink application mechanism for a thermal transfer recording apparatus, characterized in that unnecessary ink adhering to the film is heated from the back side of the film by the heating means, and removed by the ink removing means and returned to the ink tank.