JPS5998881A - Thermal transfer type color printer - Google Patents

Abstract

PURPOSE:To obtain a sharp color image by performing accurate gathering printing, by providing a sprocket pins each engaging with the feed holes of paper to both of a platen roller and a reverse roller for feeding paper. CONSTITUTION:Sprocket pins 15, 15... are also provided to the outer periphery of a reverse roller 9 and brought into engagement with the feed holes 2, 2... of paper 1. By this mechanism, the movement of the paper 1 in the width direction thereof is strictly limited by the sprocket pins 14, 14... of a platen roller 3 and the sprocket pins 15, 15... of the reverse roller 9 and, therefore, there is no possibility for staggering of the paper 1 during feeding even if there is a dimensional error in the outer diameter of the reverse roller or the direction of the shaft 9a thereof is shifted a little. By this method, images having various colors are accurately superposed one upon another.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer color printer that performs color printing by appropriately thermally transferring a plurality of color inks coated on an ink ribbon onto paper.

When printing in color using the thermal transfer method, generally yellow,
Using an ink ribbon coated with magenta and cyan ink 1111 times, seven colors are produced by a subtractive color method by performing bloody printing with the yellow, magenta, and cyan colors. The color printing method in this case will be explained below. FIG. 7 is a perspective view showing the configuration of a conventional thermal transfer color printer, and FIG. 2 is a schematic configuration diagram for explaining the operation of this color printer. In Figure 7, 1
2, 2, . . . are feed holes provided on both sides of the paper 1, and engage with sprocket bins 4, 4, . 6 is an ink ribbon, which passes under the platen roller 3 and takes up the winding roller 7.
is wound up. 8 and 9 (see FIG. 2) are reverse rollers 1, 8a, and 9a that assist in conveying the paper 1, respectively.
is their axis. Pulleys 9b are provided at both ends of this shaft 9a (only the front side is shown in the figure).
The rotational force of the platen roller 3 is transmitted to the transmission belt 10, thereby causing the reverse roller 9 to rotate. Further, in this case, the circumferential speeds of the platen roller 3 and the reverse roller 9 are configured to be equal. As shown in FIG. 2, the paper 1 described above is held between the reverse rollers 8 and 9 and then discharged upward through the lower surface of the platen roller 3, and the ink ribbon 6 is held between the shafts 8a and 9a of the reverse rollers 8 and 9. After passing through the platen roller 3
It comes into contact with the paper 1 below, and is then wound up by the take-up roller 7. A thermal head 12 performs heat-generating printing, and is urged toward the platen roller 3 during printing to press the ink ribbon 6 against the paper 1. Further, as shown in FIG. 3, the ink ribbon 6 is coated with yellow, magenta, and cyan ink sequentially in a predetermined length.

Next, the operation of the color printer described above will be explained in detail with reference to FIG. First, the paper 1 is transported to the printing start position, the yellow tip position of the ink ribbon 6, and the printing position of all the thermal heads 12, and then the thermal head 12 is urged toward the platen roller 3 side, and the ink ribbon 6 and the paper 1 are conveyed. 1, and the platen roller 3 and reverse roller 9 rotate in the directions of the arrows shown in the figure to transport the paper 1 and the ink ribbon 6 to the desired reed discharge side (upper part of the figure). death,
Moreover, at the same time, the thermal head 12 performs thermal transfer printing. When thermal transfer printing with yellow ink is completed, the thermal head 12 is returned to its original position and the pressure contact state is released. Next, the platen roller 3 and reverse roller 9 rotate in the opposite direction (in the opposite direction to the arrow), and the paper 1
Only the paper 1 is transported to the paper supply side, and the printing start position of the paper 1 is returned to the printing position of the thermal head 12. At this time, the ink ribbon 6 is slightly wound up by the take-up roller, and the leading edge position of the next color, magenta, is conveyed to the printing position of the thermal head 12. Next, the thermal head 12
is urged toward the platen roller 3, the ink ribbon 6 and paper 1 are brought into pressure contact, and thermal transfer printing similar to that for yellow is performed. Thereafter, the paper 1 is transported in the opposite direction in the same manner as described above, and then thermal transfer printing is performed using cyan ink, and color printing for one page of the paper 1 is completed. In this case, the number of colors produced is ≠
As shown in the diagram, yellow, cyan, magenta, green, evening,
There are seven colors: red and black.

By the way, in order to obtain beautiful color images on a color printer, it is essential that the images of cyan, magenta, and yellow colors overlap accurately, and should be expressed as a poor color density. The color turned out to be different from the original one, which is a shame.

However, in the above-mentioned conventional color 7' printer, the rotational force of the reverse roller 90 is transmitted to the printer only by friction, and the paper 1 is transferred to the reverse roller 8.9.
For example, the outer diameter size of the reverse roller 8.9 or the axis 8a or 9a
If there is a deviation in the orientation of the paper 1, the paper 1 may meander when being conveyed in the reverse direction, resulting in a disadvantage that the printing start position for printing the next color is often shifted.

That is, conventional color printers often have the disadvantage that accurate overprinting cannot be performed and clear color images cannot be obtained.

The present invention takes into consideration the above-mentioned circumstances and provides a thermal transfer color printer that can perform accurate wheel printing and thereby obtain clear color images. The roller mechanism is provided with a tin rocket bin that engages with the feed hole of the paper. Embodiments of the present invention will be explained below with reference to the drawings.

FIG. 5 is a perspective view showing the configuration of an embodiment of the present invention, and FIG. 6 is a schematic configuration diagram for clarifying the embodiment.

The difference between this embodiment and the conventional one described above is that, as shown in FIGS. 5 and 6, tin rocket bins 15, 15... The bins 15.15... engage with the feed holes 2.2... of the paper l, and the reverse roller 8 is omitted. In this way, the sprocket bins 15, 15 and 15 are connected to the reverse roller 9.
. . , the movement of the sheet 1 in the width direction is caused by the tin rocket bins 4, 4, . . . of the platen roller 3, and the tin rocket bins 15, 15, . . . . Therefore, even if there is a dimensional error in the outer diameter of the reverse roller 9, or even if the direction of the shaft 9a is slightly deviated, the paper 1 will not meander during transportation. There is no. Therefore, the paper 1 can be transported extremely accurately along the transport path during reverse transport, so that the printing start position of the paper 1 for printing the next color always accurately reaches the printing position of the thermal head 12, and this The images of each color overlap each other accurately.

As explained above, according to the present invention, sprocket bins are provided on both the platen roller and the reverse roller, and these sprocket bins are engaged with the feed holes of the paper, thereby controlling the movement of the paper in the width direction. Since the paper is regulated at the center, the paper does not meander during reverse transport, and the printing start position of the paper can be matched for each color, making it possible to obtain extremely clear and beautiful color images. can.

[Brief explanation of drawings]

FIG. 7 is a perspective view showing the configuration of a conventional thermal transfer color printer, FIG. 2 is a schematic configuration diagram for explaining the operation of the thermal transfer color printer shown in FIG. 7, and FIG. FIG. 2 is a schematic configuration diagram showing the configuration of the ink ribbon 6, FIG. FIG. 6 is a schematic configuration diagram of the same embodiment. 2...Feed hole, 3...Platen roller, 4.15...Sprocket bin, 9
...Reverse roller.

Claims (1)

[Claims] In a thermal transfer color printer that includes a platen roller and a reverse roller for conveying paper, and performs color printing by conveying the paper multiple times in both forward and reverse directions, A thermal transfer color printer characterized by being provided with sprocket bins that engage with feed holes provided on both sides of the paper.