JPH01285365A - Bidirectional printing thermal transfer serial printer - Google Patents

Abstract

PURPOSE:To make two printing positions by thermal heads coincident with each other in a simple manner, by mounting a printing position correction device consisting of a thermal head height adjusting means and a carriage transverse-movement control means correcting a printing pitch of the thermal heads. CONSTITUTION:A serial printer has a platen 1 and a carriage 2, and two thermal heads 6, 7 are arranged in parallel on the carriage 2. When the carriage 2 is traveled rightward (in a direction of an arrow F), i.e. in a forward direction, the head 6 is pressed against the platen 1 to conduct printing. When the carriage 2 is traveled leftward (in a direction of an arrow R), i.e. in a reverse direction, the head 7 is pressed against the platen 1 to conduct printing. Two vertical position adjusting nuts 11, 12 are engaged with a screw shaft 13 fixed to the carriage 2. By varying the vertical positions of the nuts on the shaft 13, the vertical position of the thermal head 7 is varied; thus, the height of the printing position by the head 7 can be vertically adjusted. In this manner, two printing positions can be made coincident with each other vertically and transversely, and a superior printing accuracy can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer serial printer, and more particularly to a bidirectional printing thermal transfer serial printer that is equipped with two thermal heads and prints in both left and right directions.

[Prior Art] Conventionally, in this type of bidirectional printing thermal transfer serial printer, printing is performed with one thermal head while moving the carriage in one direction, and printing is performed with one thermal head while moving the carriage in the opposite direction. The head is printing.

[Problems to be Solved by the Invention] Conventional bidirectional printing thermal transfer serial printers do not have any device for correcting the mutual printing positions of the two thermal heads. These printing positions are determined by the attachment positions when the two thermal heads are mechanically attached to the carriage. Therefore, if the thermal heads are not mounted accurately, the printing positions of the two thermal heads will be misaligned. Misalignment of the printing position includes misalignment in the vertical direction of the paper and misalignment in the horizontal direction of the paper. In conventional printers, in order to match the printing position, the thermal head mounting mechanism is manufactured with high precision, and parts are also selected for installation, making installation laborious and increasing manufacturing costs. was.

The present invention has been made to solve this problem, and its purpose is to make the two printing positions by the thermal head coincide with blood by newly providing a printing position correction device. be.

[Means for Solving the Problems] In order to achieve the above object, the bidirectional printing thermal transfer serial printer according to the present invention has thermal head height adjustment that matches the printing height positions of the two thermal heads on the carriage of this printer. and carriage lateral movement control means for correcting the printing interval between the two thermal heads.

[Operation] The print position correction device matches the print height positions of the two thermal heads using its thermal head height adjustment means.
Furthermore, the horizontal printing positions of the two thermal heads can be matched by the carriage lateral movement control means.

[Example code] Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partial perspective view of a bidirectional printing thermal transfer serial printer according to an embodiment of the present invention. This serial printer has a platen 1 and a carriage 2. The carriage 2 can move left and right along the platen 1, and rotates on a carriage guide shaft 5 installed between the left and right frames (not shown) of the printer. Specifically, by connecting the timing belt 4 to the carriage 2 and moving the timing belt 4 by rotation of the spacing motor 3, the carriage 2 is moved horizontally in parallel to the platen 1.

Two thermal heads 6.7 are arranged in parallel on the carriage 2. When the carriage 2 moves to the right (in the direction of arrow F), that is, in the forward direction, the thermal head 6 is moved toward the platen 1.
When the carriage 2 moves to the left (in the direction of arrow R), that is, in the reverse direction, the thermal head 7 is pressed against the platen 1 to perform printing.

Figure 2 shows the thermal head height adjustment tUS of this embodiment.
shows a side view. This mechanism allows the height positions of the two thermal heads 6.7 (that is, the heights of the two printing positions by the thermal heads 6.7) to match. Two height adjustment nuts 11 and 12 are engaged with a screw shaft 13 fixed to the carriage 2. Then, the bent M8a of the head support bracket 8 is fixed by sandwiching it between the nuts 11 and 12. A head support 9 is rotatably attached to a support shaft 10 fixed to a head support bracket 8.

The thermal head 7 is fixed to this head support 9. The thermal head 7 can rotate about the support shaft 10 in a direction perpendicular to the axis of the platen 1.

By changing the height position of the nuts 11, 12 on the screw shaft 13, the height position of the thermal head 7 is changed, and as a result, the height of the printing position by the thermal head 7 can be adjusted in the vertical direction.

By simply adjusting the height position of the thermal head 7, the printing position by the thermal head 7 can be made to match the printing position by the white thermal head 6, so a height adjustment mechanism for the thermal head 6 is not required. be. however,
The thermal head 6 may also be provided with a height adjustment mechanism. Of course, the height adjustment mechanism can also be provided only on the thermal head 6 side.

FIG. 3 is a block circuit diagram of a lateral movement control device for the carriage 2. As shown in FIG. As shown in FIG. 1, the two thermal heads 6.7 are located in the horizontal direction (parallel), so the two printing positions by these thermal heads are aligned in the horizontal direction (i.e., the order in which the thermal heads 6 In order to match the print end position or print start position of directional printing and the print start position or print end position of reverse direction print by the thermal head 7 in the horizontal direction, the print positions of the two thermal heads 6 and 7 must be adjusted. The spacing must be corrected.In other words, when the thermal head 6 starts printing in the forward direction and the thermal head 7 starts printing in the reverse direction, the carriage 2 is moved by a distance corresponding to the center-to-center spacing of the thermal heads 6.7. must be moved by the spacing motor 3.

The spacing motor 3 is controlled by a carriage lateral movement control section 14 and driven by a drive circuit 15. The carriage lateral movement control section 14 includes a thermal head 6.
A predetermined number of spacing motor drive steps corresponding to a distance corresponding to a center-to-center spacing of 7 is stored. Therefore, before each forward printing and reverse printing starts, the spacing motor 3 is operated to move the carriage 2 by a distance corresponding to the predetermined number of steps, so that the printing positions in the lateral direction match. When the horizontal printing positions between the thermal heads 6 and 7 do not match, the number of spacing motor drive steps can be corrected by operating the dip switch 16.

[Effects of the Invention] As explained above, the present invention includes a thermal head height adjustment means, a carriage lateral movement control means for correcting the printing interval of the thermal heads, and a carriage lateral movement control means for correcting the printing interval of the thermal heads in order to match the printing positions of the two thermal heads. Since it is equipped with a printing position correction device consisting of a It has the effect of providing printing accuracy. Further, when attaching the thermal head, strict precision is not required for the parts, and there is no need to sort out the parts, which has the effect of significantly reducing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of a bidirectional printing thermal transfer serial printer according to an embodiment of the present invention, FIG. 2 is a side view of a thermal head height adjustment mechanism of this embodiment, and FIG. 3 is a view of a carriage of this embodiment. , is a block diagram of the skin direction movement control device. 1...Platen 2...Carriage 3...Spacing motor 4...Timing belt 6.7...Thermal head 11.12...Height position adjustment nut

Claims (1)

[Scope of Claim] A bidirectional printing thermal transfer serial printer having a carriage that reciprocates along a platen in parallel with the platen, and two thermal heads provided in parallel on the carriage, comprising: A printing position correction device comprising: a thermal head height adjustment means for matching the printing height positions of the thermal heads; and a carriage lateral movement control means for correcting the printing interval of the two thermal heads. A bidirectional printing thermal transfer serial printer.