JPH01135662A - Thermal printer - Google Patents

Abstract

PURPOSE:To enable two way printing to be performed by a simple structure, by a method wherein an ink ribbon and a platen having a width of two track contents are provided, two lines of heating element groups in which a plurality of heating elements are arranged at a same pitch are mutually arranged diagonally, and one side of the heating element groups is used in one side transfer direction and the other heating element group is used in the other transfer direction. CONSTITUTION:Heating element groups 3a, 3b have heating elements arranged along both sides of a thermal head 10 vertically to a head transfer direction, and a width C of an ink ribbon 11 is larger than a printing range D ink its vertical direction. When the transfer direction of the thermal head is the arrow A direction, a LOW signal is outputted from a CPU, and a power source is supplied to only the heating element group 3b. Further, reversely in the arrow B direction, a HIGH signal is outputted, and the heating element 3a is enabled to be driven. After completing one direction printing by moving the head from a point A1 to a point A2 on the ink ribbon, a ribbon winding direction and the head transfer direction are changed, and printing from a point A1 to a point A2 is performed. After transferring from the point B2 to a point A3 by quickly feeding the ink ribbon, indentical printing is started from the point A3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal printer, and more particularly to a thermal transfer thermal printer capable of bidirectional printing with increased high-speed performance.

[Conventional technology]

In recent years, various thermal transfer printers capable of printing in both directions have been devised in order to improve printing speed.

Some of these conventional examples perform printing by moving an ink ribbon cassette up and down.

[Problems to be Solved by the Invention] These conventional examples require a complicated mechanism for moving the ink ribbon cassette up and down.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the conventional printer and to provide a thermal transfer type thermal printer capable of bidirectional printing with a simple structure.

[Means for solving problems]

In the present invention, two rows of heating element groups in which a plurality of heating elements are arranged at the same pitch are arranged diagonally to each other along two vertical ends in the direction of movement of the thermal head in the digit direction. printing control means using one of the heating element groups and using the other heating element group in the other movement direction; an ink ribbon having a width of at least two tracks capable of covering the printing range of the heating element groups on the two sides; This is a thermal printer that has a platen.

[Embodiment] FIG. 1 is a schematic diagram of an embodiment of a thermal head of a thermal printer according to the present invention.

1 is made of ceramics, and has glaze parts 2a, 2 on its surface.
b are arranged in two rows along the end face.

3a and 3b are heating element groups, in which a plurality of heating elements 4 are arranged at the same pitch and are arranged diagonally to each other. 5 is an electrode connected to each heating element, and 6 is a flexible cable.

FIGS. 2(a) and 2(b) are schematic diagrams of the head section of the thermal printer of the present invention.

11 is an ink ribbon, and arrows A and B indicate the moving direction of the thermal head 10. In the direction of arrow B, the heating element group 3b is used, and in the direction of arrow B, the heating element group 3a is used.

The heating element groups 3a and 3b have heating elements arranged along both ends of the thermal head perpendicular to the head movement direction, and the width C of the ink ribbon 11 is larger than the printing range in the vertical direction.

13 is a platen base that holds the platen 14;
Reference numeral 12 indicates a recording paper placed between the platen 14 and the ink ribbon. When printing, the thermal head I
O is pressed in the direction of arrow E and moves to enable printing.

FIG. 3 is a schematic diagram showing the movement of the thermal head 10 and the running state of the ink ribbon.

Guide rollers 15a, 15b, 16a, and 16b guide the ink ribbon, and reels 17a and 17b wind up the ink ribbon.

It is known that the angles θ1 and θ2 at which the ink ribbon is separated from the paper surface affect print quality.

In the present invention, it is possible to make the separation angle the same regardless of the moving directions A and B, and since the heat generating elements are arranged on the end face of the thermal head, it is suitable even for printing paper with low surface smoothness. This makes it possible to obtain accurate printing.

FIG. 4 is a schematic diagram of the control means of a thermal printer according to the invention.

21 is a CPU that generally controls the thermal printer;
Head drive data 22, heating element group selection signal 24, etc. are output. 23 is a head drive circuit, which is a heating element group 3a.
, 3b are moved in common.

A buffer 25 and an inverter 26 are connected to the heating element selection signal, a transistor 29 is connected to the buffer 25, and a transistor 30 is connected to the inverter 26. 27 and 28 are power supply transistors that apply the power supply vh input from the power supply input terminal 31 to the thermal head 10, and when the direction of movement of the thermal head is in the direction of arrow A in FIG. 3, a LOW signal is output from the CPU and heat generation occurs. Group 3
Power is supplied only to b.

Conversely, in the direction of arrow B, a HIGH signal is output and the heating element 3a can be driven.

FIG. 5 is an explanatory diagram of how to use the ink ribbon of the thermal printer of the present invention, from point A1 on the ink ribbon to A
After moving to point 2 and completing printing in one direction, the ribbon winding direction and head movement direction are changed to print 82 points from point B1. After printing for these two tracks is completed, the ink ribbon is quickly fed and moved from point 82 to point A3, and then
Start printing in the same way from point A3.

〔Effect of the invention〕

According to the present invention, bidirectional printing is possible with an extremely simple structure because there is no need to move the ribbon cassette containing the ink ribbon up and down or to move the thermal head up and down.

Furthermore, the same head drive circuit can be used in both directions, which has the advantage that there are few factors that increase costs.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are schematic diagrams of an embodiment of a thermal head of a thermal printer according to the present invention. FIGS. 2(a) and 2(b) are schematic diagrams of the head section of the thermal printer of the present invention. FIG. 3 is a schematic diagram showing the movement of the thermal head 10 and the running state of the ink ribbon. FIG. 4 is a schematic diagram of the control means of the thermal printer of the present invention. FIG. 5 is an explanatory diagram of how to use the ink ribbon of the thermal printer of the present invention. 1... Thermal head base material 3a, 3b... Heating element group 11... Ink ribbon 14... Platen and above Applicant Seiko Epson Corporation Figure 5

Claims (1)

[Claims] In a thermal printer that prints while moving a thermal head arranged with a plurality of heat generating elements in the digit direction, and prints using a thermal head that has two rows of heat generating element groups along two ends perpendicular to the direction of movement. , two rows of heating element groups in which the plurality of heating elements are arranged at the same pitch are arranged diagonally to each other, one of the heating element groups is used in one direction of movement in the digit direction, and the other is used in the other direction of movement. What is claimed is: 1. A thermal printer comprising: a print control means using a heating element group; an ink ribbon having a width of at least two tracks capable of covering the printing range of the two rows of heating element groups; and a platen.