JPH0463790B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Technical Field of the Invention The present invention relates to a method for controlling the ink ribbon feeding speed of a dot line printer equipped with a wire dot type printing head and a fixed ink ribbon feeding device.

(B) Background of the technology A wire dot type dot line printer has a plurality of print heads whose main components are wires arranged in the direction intersecting the print lines, which are arranged side by side in the print line direction and move back and forth in the print line direction. This is a device that prints using a dot line, and is equipped with a fixed type ink ribbon feeding device, that is, a device that does not move back and forth with the print head, and in order to increase the printing speed, printing is performed on both strokes of the print head's reciprocating motion. It's set.

(C) Prior art and problems Assuming that the ink ribbon is always fed in the same direction at a constant speed in response to the reciprocating movement of the print head, when the print head and ink ribbon move in opposite directions, the The relative speed between the print head and the ribbon may be too high to cause damage to the print head wire or the ribbon, and the relative speed between the print head and the ribbon may be low when the print head and the ribbon move in the same direction as each other. There was a problem that the same position on the ink ribbon was sometimes printed twice, resulting in unclear prints.

(D) Object of the Invention An object of the present invention is to change the feeding speed of the ink ribbon according to the direction of movement of the print head in a wire dot type dot line printer, thereby improving the relationship between the print head and the ink ribbon during the forward movement of the print head. The objective is to minimize the difference between the relative speed of the printing head and the ink ribbon during the return path movement.

(E) Structure of the Invention The ink ribbon feed speed control system according to the present invention includes: a wire dot type printing head that moves reciprocally in the printing direction; an ink ribbon feeding device that moves the ink ribbon in one direction along the printing direction; A dot line printer comprising a print head discriminating means for discriminating the direction of movement of the print head, and printing in both strokes of the reciprocating motion while reciprocating the print head in the print line direction, wherein the print head discriminating means detects the dot line printer. The direction of movement of the print head is determined based on the signal, and the difference between the relative speed between the print head and the ink ribbon during the forward movement of the print head and the relative speed between the print head and the ink ribbon during the return movement is reduced. In addition, the ink ribbon feeding speed during the forward path of the print head is made different from the ink ribbon feeding speed during the return path.

(F) Embodiments of the Invention The gist of the present invention will be specifically explained below with reference to illustrated embodiments.

FIG. 1 shows a schematic diagram of a dot line printer, in which a is a plan view and b is a front view. 1 and 2 in the diagram
, 3, 4, 5, and 6 constitute an ink ribbon feeding device, in which 1 is an ink ribbon cassette, 2 is an ink ribbon feed roller, 3 is an ink ribbon, 4 is an ink ribbon guide, 5 is a buffer roller, and 6 is an ink ribbon feed motor. It is. 7 is the dot line printer body, 8 is the print head, and 9 is the print head 8.
10 is a shuttle drive unit that drives the shuttle 9, 11 is a platen, 12 is printing paper, and 13 and 14 are print head position detection devices. , 13 is a slit plate fixed to the shuttle 9 and moves with the printing head 8, 14 is a sensor fixed to the main body 7 of the dot line printer, 15 is a guide shaft of the shuttle 9, and 16 is fixed to the shuttle 9 and the guide shaft 15. It is a linear bearing that slides against the ground.

FIG. 2 shows a configuration diagram of an embodiment of the present invention, in which the same reference numerals as those in FIG. 14-1 is a first photodiode provided in the sensor 14; 14-2 is a second photodiode provided in the sensor 14; 15;
Reference numeral 16 indicates a determination unit that determines the direction of movement of the print head 8 in its reciprocating motion based on the detection signal obtained by the slit plate 13 and the sensor 14;
5, the ink ribbon feed motor 6
This is a control unit that controls the rotation speed of the

Further, a light source (not shown) is provided behind the slit plate 13, and the first slit plate 13-1
The second slit 13-2 and the second photodiode 14-2 detect that the print head 8 has reached the right end of its reciprocating motion. It is detected that 8 has reached the left end of its reciprocation.

On the other hand, the ink ribbon feed roller 2 rotates as shown by arrow A, and the ink ribbon 3 is fed as shown by arrow B.

The determining unit 15 determines based on the detection signal of the first photodiode 14-1 that the print head 8 reverses its movement direction to the left, and the second photodiode 1
Based on the detection signal 4-2, it is determined that the printing head 8 has reversed its movement direction to the right.

The control unit 16 controls the rotational speed of the ink ribbon feed motor 6 in two stages, normal and low speed, according to the determination result of the determination unit 15, and when the print head 8 moves to the left, that is, in the same direction as the ink ribbon 3, the ink The ribbon 3 is fed at a normal speed, and when the print head 8 moves to the right, that is, in the opposite direction to the ink ribbon 3, the ink ribbon 3 is fed at a low speed.

The print head position detection device and the discrimination unit 15, which are composed of the slit plate 13 and the sensor 14, are also used to obtain a control signal for reversing the direction of movement of the shuttle 9, that is, the print head 8, and a print start reference signal for each print line. Can be used.

(G) Effects of the Invention As explained above, according to the present invention, by controlling the feeding speed of the ink ribbon according to the direction of movement of the print head, the difference between the forward movement of the print head and the return movement of the print head is controlled. The difference in relative speed between the print head and the ink ribbon can be reduced. This makes it possible to reduce the difference in print quality between the outward movement of the print head and the return movement of the print head, and also to reduce damage to the ink ribbon and printing pins during printing.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a dot line printer, Figure 2
The figure shows a configuration diagram of an embodiment of the present invention. In the figure, 1 is a cassette, 2 is an ink ribbon feed roller, 3 is an ink ribbon, 6 is an ink ribbon feed motor, 8 is a print head, 13 is a slit plate, 1
4 is a sensor.

Claims (1)

[Scope of Claims] 1. A wire dot type printing head that moves reciprocally in the printing direction, an ink ribbon feeding device that moves the ink ribbon in one direction along the printing direction, and a printing head that determines the direction of movement of the printing head. A method for controlling an ink ribbon feeding speed of a dot line printer, comprising: a discrimination means, and printing is performed in both steps of the reciprocating movement while reciprocating the print head in the printing line direction, the method comprising: a detection signal from the print head discrimination means; determining the direction of movement of the print head, and reducing the difference between the relative speed between the print head and the ink ribbon during the forward movement of the print head and the relative speed between the print head and the ink ribbon during the return movement;
An ink ribbon feed speed control method for a dot line printer, characterized in that the ink ribbon feed speed during the forward path of the print head and the ink ribbon feed speed during the return path are made different.