JPH0145435B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer printing device.
By providing a guide bar with grooves that twist in different directions with the line that crosses the eye as the boundary,
When the thermal head presses the transfer paper and recording paper against the platen roller and the heat of the thermal head transfers the ink from the transfer paper to the recording paper, the transfer printing is good because there are no wrinkles on the transfer paper. Moreover, this transfer paper wrinkle prevention mechanism is simple, and does not require extremely high precision in the mounting precision of each roller such as the platen roller, and the surface precision of the thermal head, which makes it cost-effective. The purpose of the present invention is to provide a thermal transfer printing device that can be used as a printer.

In thermal transfer printing devices, which use a thermal head to press the transfer paper and recording paper against the platen roller, and use the heat generated by the thermal head to transfer the ink from the transfer paper to the recording paper for printing, the efficiency of ink transfer is increased. For example, the transfer paper should be approximately
It is necessary to make it extremely thin, such as 10 μm thick.

However, if the paper thickness of the transfer paper is made thinner, the accuracy of the various rollers of the thermal transfer printing device, including the platen roller, the surface accuracy of the thermal head, and the accuracy of the reel must be configured with extremely high precision. When the transfer paper and recording paper are pressed against the platen roller and the ink on the transfer paper is transferred to the recording paper by the heat of the thermal head, wrinkles tend to occur on the transfer paper. If this occurs, colored lines will appear in the transferred image, significantly reducing the image quality.

Therefore, efforts have been made to improve the precision of various rollers and guides to prevent wrinkles from forming on the transfer paper even when the paper is extremely thin, but in reality, there are limits to improving the precision of these parts. Moreover, the more precision is attempted, the higher the cost becomes.

The present invention eliminates the above-mentioned drawbacks, and examples thereof will be described below.

FIG. 1 shows one of the thermal transfer printing apparatuses according to the present invention.
A schematic explanatory diagram of the embodiment, FIG. 2 is an explanatory diagram of the main part thereof.

In the figure, 1 is a platen roller, 2 is a thermal head, and this thermal head 2 is configured to sandwich a recording paper 3 and a transfer paper 4 between them and press them against the platen roller 1. This is a system in which the ink on the transfer paper 4 is transferred to the recording paper 3 by the heat of the head, and printing is performed, and such a thermal transfer printing device has approximately the same structure as a conventional thermal transfer printing device.

Reference numeral 5 denotes a guide bar provided near the inlet side of the transfer paper 4 to the platen roller, and the surface of this guide bar 5 has grooves in opposite directions on each diagonal half of the shaft, as shown in FIG. A shallow substantially spiral groove 5' is formed. In addition, this guide bar 5 is
It is configured so that it can rotate around its axis,
Depending on the direction of strain stress acting on the transfer paper, the shape of the groove at the portion where the transfer paper comes into contact with the substantially spiral groove 5' is made different. That is, when a strain stress is applied to the transfer paper 4 in the direction of arrow C in FIG. In order to obtain the groove shape shown in FIG. 3, and when strain stress is applied to the transfer paper 4 in the direction of arrow D in FIG. Transfer paper 4
The groove shape of the substantially spiral groove 5' at the contact portion with the paper is as shown in FIG. The guide bar 5 is configured so that the guide bar 5 can be adjusted so that the groove shape of the substantially spiral groove 5' at the contact portion between the substantially spiral groove 5' of the guide bar 5 and the transfer paper 4 becomes as shown in FIG. It is being done. In short, a spiral groove is formed on the surface of the guide bar 5 to prevent wrinkles from occurring due to distortion stress in the transfer paper 4, and in the above embodiment, one spiral groove is formed. A plurality of spiral grooves are formed in the guide bar, and the shape of each groove corresponds to various strain stresses so that wrinkles do not occur in the transfer paper.

With the above configuration, the transfer paper and the recording paper are fed between the platen roller 1 and the thermal head 2, and the heat of the thermal head transfers the heat-melting ink on the transfer paper to the recording paper. When moving the transfer paper, for example, even if wrinkles occur on the transfer paper due to eccentricity of the platen roller 1, parallelism between the platen roller 1 and the thermal head 2, or other poor transportation accuracy of the transfer paper, the guide bar 5 Therefore, the transfer paper can be adjusted so that wrinkles do not occur, resulting in good transfer printing.

Furthermore, since such a wrinkle prevention mechanism is simply a guide bar with grooves of an appropriate shape, it can be easily installed and requires a major design change to the configuration of conventional thermal transfer printing devices. There is no need to do this, and it can be carried out at low cost, and furthermore, there is no need to make the various rollers and the thermal head's surface precision extremely high.

As described above, the thermal transfer printing device according to the present invention is a thermal transfer printing device that uses a thermal head to press a transfer paper and a recording paper against a platen roller to transfer and print ink on the transfer paper onto the recording paper. A guide bar is provided on the guide bar, and this guide bar has grooves that twist in different directions with a line that diagonally crosses the surface of the guide bar as a boundary, so even if the transfer paper is thin, wrinkles do not occur during transfer. This makes it possible to prevent wrinkles, which makes transfer printing excellent. Moreover, this wrinkle prevention can be done by simply adding a simple part, and in particular, by adjusting the guide bar, it is possible to deal with multiple types of wrinkles.
That is, it has the advantage that various types of wrinkles can be dealt with with one guide bar, and there is no need to prepare several types of guide bars, so that it can be implemented at extremely low cost.

[Brief explanation of drawings]

FIG. 1 shows one of the thermal transfer printing apparatuses according to the present invention.
FIG. 2 is an explanatory diagram of the main part thereof, and FIGS. 3 to 5 are explanatory diagrams of the strain stress acting on the transfer paper and the groove shape of the guide bar. 1...Platen roller, 2...Thermal head, 5
...Guide bar, 5'...Substantially spiral groove.

Claims (1)

[Claims] 1. In a thermal transfer printing device that uses a thermal head to press transfer paper and recording paper against a platen roller to transfer and print ink on the transfer paper to the recording paper, a guide bar is provided near the platen roller, and a guide bar is provided in the vicinity of the platen roller. A thermal transfer printing device characterized in that grooves are formed with different twisting directions with lines diagonally crossing the surface thereof as boundaries.