JPH0357491Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The present invention is a thermal transfer recording device that repeatedly applies ink to a transfer medium carrying heat-melting ink, thereby making it possible to reuse the transfer medium. Regarding the improvement of

``Technology of the Prior Application'' The present applicant has previously developed a recording device of this type that made it possible to reuse the transfer medium by arranging an ink application mechanism downstream of the printing position.
We are proposing a line head type thermal transfer recording device. (Japanese Patent Application No. 59-274453) To briefly explain its structure based on FIG. is intermittently driven in the direction.

Reference numeral 3 denotes a print head in which a row of heating resistive elements is arranged at a position facing the platen, and a spring 4 arranged on the back side presses an ink sheet 5 and a recording paper 2 to follow the intermittent drive of the platen 1, thereby printing both 2 and 5. The recording paper 2 and the ink sheet 5 are integrally transported intermittently by the frictional force.

The ink sheet 5 is formed into an endless shape using a heat-resistant resin film, and includes a pair of shafts 6 arranged adjacent to the platen 1, a guide roller 7, and a detour roller 8 arranged facing an ink application mechanism 10 to be described later. , a skew correction roller, a tension roller (not shown), etc., the printing operation by the printing head 3 and the reapplication of ink are repeatedly performed.

The ink application mechanism 10 includes an ink tank 11 that stores ink while maintaining a thermally molten state by a heating element (not shown), and is arranged within the ink tank 11.
Supply roller 1 rotates following the intermittent drive of platen 1 while conveying ink in a thermally molten state.
2, and a straightening rod 13 disposed downstream of the supply roller 12 and on the outlet side of the ink tank 11.

According to the ink application mechanism 10, the ink that is molten due to the heating of the heating element is supported by the supply roller 12, and is conveyed to a position facing the ink sheet 5 that is circulated around the detour roller, and at the facing position, the ink is melted by the heating element. After the ink is transferred to the sheet 5 side, the remaining ink is further rotated and conveyed while being carried by the supply roller 12, and is returned to the ink tank 11 again, and this process is repeated thereafter.

On the other hand, the ink sheet 5 to which the ink has been transferred
The ink sheet 5 is pressed against the circumferential surface of the straightening rod 13 on the downstream side while maintaining the molten state of the ink, and since a thin wire is tightly wound around the circumferential surface of the straightening rod 13, the adjacent thin wire After the excess ink is scraped off to the upstream side leaving the ink remaining in the gaps between the wires and the layer thickness is corrected to a thin film, the above-mentioned process is performed before reaching the pressure contact position with the print head 3 on the downstream side of the ink application mechanism 10. The ink layer is smoothed, cooled and solidified, and the ink sheet 5 carrying a thin and uniform ink layer is recycled.

``Problems to be Solved by the Invention'' However, according to this prior art, paper scum, dust, etc. that adhere to the surface of the ink sheet 5 from the recording paper 2, etc. when the ink sheet 5 is in pressure contact with the print head 3 or when it is rotated, etc. is mixed into the ink carried on the supply roller 12 at the facing position, and the ink is returned to the ink tank 11 while being mixed. Therefore, as the ink sheet 5 continues to be repeatedly applied,
A considerable amount of impurities may be mixed into the ink in the ink tank 11.

The contamination of these impurities may deteriorate the ink in the ink tank 11, or the ink mixed with dust etc. may be transported again to the position facing the ink sheet 5, thereby damaging the ink sheet 5. As a result, the life of the device itself may be shortened and the print quality may deteriorate.

The technical problem to be solved by the present invention is to provide a thermal transfer recording device in which ink stored in the ink tank can be kept clean at all times by preventing the incorporation of paper scraps, dust, etc. shall be.

"Means for solving problems" In order to achieve such technical problems, this invention
In a thermal transfer recording device that repeatedly applies ink to a transfer medium carrying heat-fusible ink, thereby making it possible to reuse the transfer medium, there is an ink tank for melting and storing the heat-fusible ink, and an ink tank for conveying the heat-fusible ink from the ink tank. an ink supply roller that supplies ink to the transfer medium, and an ink that adheres to the roller circumferential surface from a position of the ink supply roller where the ink is supplied to the transfer medium to above the level of the stored ink. We propose a technical means characterized in that a detour is provided to guide the ink onto the liquid surface again after scraping off the ink, and an ink filtering means is disposed within the detour.

In this case, the transfer medium is an endless ink sheet in the case of a line head type recording apparatus, or an endless ink ribbon in the case of a serial head type recording apparatus.

"Operation" According to this technical means, since the ink filtration means is disposed between the ink supply position of the ink supply roller to the transfer medium and above the level of the stored ink, the Since paper powder, dust, and other impurities adhering to the surface of the supply roller are removed, clean ink is always stored in the ink tank, and these impurities are prevented from entering the ink tank. This eliminates the risk of deterioration of the ink in the ink tank, and also prevents scratches on the transfer medium to which ink is applied via the supply roller, resulting in improved durability of the transfer medium. It is possible to improve performance and maintain good print quality.

Furthermore, it is not only difficult to attach the filtering means directly on the circumferential surface of the supply roller, but also
It is difficult to create a configuration that satisfies the filtration function smoothly.

Furthermore, in the case where the filtering means is clogged, with the structure in which the filtering means is directly mounted on the circumferential surface of the supply roller, it is impossible to replace only the filtering means without removing the entire ink reapplying device, and as a result, maintenance is required. The operation becomes extremely complicated.

Therefore, the present invention provides a detour to guide the ink onto the ink surface again after scraping off the ink adhering to the circumferential surface of the roller, and arranges an ink filtering means within the detour. Since the filter itself can function as a support structure for the filtration means, installation and replacement of the filtration means can be facilitated, and filtration efficiency can be improved.

Further, by providing the detour, it is easy to supply ink from the detour side to the ink tank via the filtering means, and the amount of ink stored can also be easily detected, and in any case, maintainability is greatly improved. .

Furthermore, since the ink bypass path scrapes off the ink adhering to the roller circumferential surface and guides it to the filtration means, impurities adhering to the ink circumferential surface can be completely removed and a more complete filtration effect can be obtained. I can do it.

Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this example are as follows, unless otherwise specified.
This is not intended to limit the scope of this invention, but is merely an illustrative example.

FIG. 1 shows a line head type thermal transfer recording apparatus according to an embodiment of the present invention, and the differences from FIG. 2 will be mainly explained.

The ink tank 11 has a heating element 21 embedded in its upper open side through a heat transfer plate 20, and has an ink storage section 22 recessed in a substantially semicircular shape in the center thereof.

One side of the heat transfer plate 20 extends upward along the upstream side wall of the ink reservoir 22 and is bent toward the detour roller 8 at its upper end position, so that its end surface 20a is close to the circumferential surface of the detour roller 8. and place it. As a result, the opening between the detour roller 8 and the ink reservoir 22 can be substantially hidden, and floating substances can be prevented from entering the ink reservoir 22.

Further, the other side of the heat transfer plate 20 is similarly extended along the downstream side wall of the ink storage portion 22, and the end portion 20
b is brought into contact with the circumferential surface of the straightening rod 13. As a result, the heat of the heating element 21 is transferred to the straightening rod 13, and the excess ink scraped upstream by the straightening rod 13 is transferred along the heat transfer plate 20 while maintaining its molten state. It is possible to fall and return to a detour 23, which will be described later.

On the other hand, the downstream side wall of the ink storage section 22 is
recessed along the axial direction of the supply roller 12 to have a U-shaped cross section, and spaced apart from the recessed portion by a predetermined distance;
A detour path 23 is formed by a substantially inverted L-shaped guide plate 24 extending parallel to the axial direction of the supply roller 12 .

Further, the upper end surface of the guide plate 24 is connected to the supply roller 1.
The two circumferential surfaces of the supply roller 12 are brought into contact with each other, and the ink carried on the supply roller 12 is guided into the detour 23 through the guide plate 24.

A filtration filter 25 that can be taken out and replaced from the front wall (not shown) of the ink tank 11 is disposed within the detour 23, and removes impurities from the ink passing through the filtration filter 25. Note that the filter 25 can be made of metal, resin, ceramic, or the like as appropriate.

According to this embodiment, the rotation of the supply roller 12 transports the molten ink in the ink reservoir 22 to the position facing the ink sheet 5, and after applying a predetermined amount of ink to the ink sheet 5 at the facing position, the remaining The ink is guided into the detour 23 by the guide plate 24 while maintaining a molten state, and after being filtered by the filter 25, the ink is transferred to the ink storage section 22.
It will be put back in.

At the same time, the excess ink scraped off by the correction rod 13 is also introduced into the detour 23, filtered by the filtration filter 25, and then returned to the ink reservoir 22. Therefore, according to this embodiment, since all the ink returned to the ink reservoir 22 passes through the filter 25, it is possible to completely prevent impurities from entering the ink tank 11.

"Effects of the Invention" As described above, according to the present invention, the ink stored in the ink tank can always be maintained in a clean state without contamination with impurities, thereby improving the durability of the device itself. It has remarkable effects such as being able to maintain good print quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a thermal transfer recording device that enables reuse of a transfer medium according to an embodiment of the present invention, and FIG. 2 is a schematic explanatory diagram of a thermal transfer recording device according to a prior art. . 5... Transfer medium (ink sheet), 11... Ink tank, 12... Ink supply means (roller), 2
5...Filtering means (filter), 23...Detour.

Claims (1)

[Scope of Claim for Utility Model Registration] An ink that melts and stores heat-fusible ink in a thermal transfer recording device that repeatedly applies ink to a transfer medium carrying heat-fusible ink, thereby making it possible to reuse the transfer medium. an ink tank, and an ink supply roller that supplies the ink conveyed from the ink tank to the transfer medium, and on the circumferential surface of the ink supply roller from the ink supply position to the transfer medium to above the level of the stored ink, A thermal transfer recording apparatus characterized in that a detour is provided for guiding the ink onto the surface of the ink after scraping off the ink adhering to the peripheral surface of the roller, and an ink filtering means is disposed within the detour.