JPS6099679A - Printing position controller - Google Patents

Abstract

PURPOSE:To facilitate manufacture of an index plate even when a printing area is enlarged to any degree and enhance mounting accuracy of a carriage over the entire part of a moving passage of the carrier, by a method wherein sensors for reading a printing index plate fitted to a carriage are provided at a specified pitch. CONSTITUTION:The printing index plate 3 is horizontally reciprocated together with the carriage 2, while a plurality of sensors 4 are fixed at a pitch substantially corresponding to the length of the index plate 3 so that two and at most only two sensors can simultaneously detect the index plate 3. Accordingly, it is enabled to cope with an increase in the length of the printing area by simply increasing the number of the sensors 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a printing position control device when a print head of an impact type printer, a non-impact type printer, etc. is moved horizontally from side to side.

Structures of Conventional Examples and Problems There are known impact printers such as wire dot printers, and non-impact printers such as thermal printers and inkjet printers. This 1. To print on a printer, a carriage equipped with a print head is moved back and forth in the horizontal direction while facing the print paper, and a print timing signal generated by some method is used as a trigger to drive a wire or spray ink droplets. As a result, characters or figures are formed on the printer paper as a collection of dots. Therefore, the image quality of printed characters or figures is determined by whether or not the dot printing positions of the droplets can be accurately spaced at regular intervals during reciprocating movement.

In the past, various proposals have been made regarding the generation method of the print timing signal to obtain good print image quality, and the first is a method in which it is generated in synchronization with the rotation of the motor, which is the drive source for the horizontal movement of the carriage. 1. A rotary encoder is attached to the motor's rotation speed 11η11 or 1. It is a method that basically uses a pulse signal that is generated to control the rotation of the motor. For example, for the printing density as shown in Fig. 1, move the film (printing index plate) 1 with marking marks 1a at every integer fraction of τ or move it in the direction of movement of the ridge. Marking marks 1a of this printing indicator plate 1 are provided facing each other over the entire printing width.
There is a method based on reading the image by optical or magnetic means as the carriage moves, and generating a print timing signal.

However, these methods have the following problems. The biggest problem with the first method, that is, the method of using a rotary encoder as a print index, is that it does not directly detect the position of the carriage, so there is a transmission between the rotary encoder mounting shaft and the horizontal movement of the carriage. The problem is that the dot misalignment and position errors caused by vibrations and slippage occurring in the system are large. This causes the image quality to deteriorate significantly over time. Furthermore, since the encoder disk cannot be made very large, there is a problem in that the control becomes complicated, requiring a method of rotating the carriage several or even tens of times for one scan.

On the other hand, the second method, that is, the method of removing stains from the printed index plate provided over the entire carriage travel path, almost solves the problem of snow contamination in the first rotary encoder method, and uses flat scanning. This print timing signal generation method has the advantage of directly reading the absolute position of the scanning position of the carriage.

However, a new problem arises here. In other words, the method of reading the printed index board provided over the entire carriage travel path is based on the fact that when the printing density becomes higher, the printed index portions 1a and 1b shown in FIG. If the printing area is expanded, this marking plate must be made longer, which makes it extremely difficult to manufacture the printing marking plate itself, or where the printing plate is placed in relation to the carriage running path throughout the printing area. However, there are problems such as the need to mount them in parallel with high accuracy and install them without bending.

OBJECTS OF THE INVENTION The present invention provides a printing position control method that improves the drawbacks of the method of reading the printed index board provided over the entire carriage travel path, and it is possible to easily manufacture the index board no matter how enlarged the printing area is. The purpose of this invention is to easily solve problems such as mounting accuracy and deflection over the entire carriage travel path.

Structure of the Invention The structure of the print position control system of the present invention is based on an index detection system in which a printed index board is attached to a part of a carriage that moves horizontally from side to side, and a plurality of sensors for reading this printed index board are fixedly arranged along a running path. The arrangement pitch of the sensors constituting this index detection system is such that the printed index plate is at a distance that can be detected by a maximum of two sensors at the same time.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 2 and 3 are conceptual diagrams showing an embodiment of the present invention, and a detailed explanation will be given below based on these diagrams.

The key point of the present invention is to horizontally reciprocate the print index plate 3 together with the carriage 2, fix the sensor 4, arrange a plurality of these sensors, and make the pitch approximately correspond to the length of the mark q index plate. The point is to set the JH signboard so that it can detect only 22 sensors and at most 21 sensors at the same time.

When the carriage 2 is scanned into the effective printing area, the printing indicator plate 3 attached to a part of the carriage 2 reaches the printing indicator reading sensor 4-1, and the waveform of the sensor 1 shown in FIG. 3 is converted into a waveform shaping circuit. 20. When the printing index plate 3 continues scanning from the section where only the sensor 4-1 passes, the printing index plate 3 straddles the sensors 4-1 and 4-2, and the sensor 4-1 and the adjacent sensor 4-2 are printed. Since the index plate 3 is to be read, sensor 1 and sensor 2 (r7 output at the same time. (Already corresponds to L in Figure 3) section)
. These two sensors No. 43 from 4-1 and 4-2 can output nearly coincident read signals by performing spatial phase adjustment of each sensor when configuring the index detection system 5. The OR gate 30 shown in FIG. 3a makes it possible to create a continuous timing pulse train (see FIG. 3). When the carriage 2 is further scanned, the sensor 4-1 passes and the timing pulse train is formed only from the sensor 4-2. As the scanning progresses sequentially, the print index plate 3 attached to the digital camera 2 is scanned one after another by the sensors 4-2, 4-3, . ...4-n, the timing pulse train is formed at the same time as sensor 4-1.
from sensors 4-2 and 4-3.

...4- Transfer n and the forming components. Each sensor 4
-1.4-2. . . . The signals read from 4-n are applied to the OR gate 30 via the waveform shaping circuit 20 and combined to form a print position timing pulse signal.

According to such a configuration, the length of the printed index plate 3 may be short, and if the pitch of the sensors is shortened, the printed index plate 3 can be shortened accordingly. Furthermore, even if the printing area length becomes longer, it is only necessary to increase the number of sensors, so there is no need to make the printing index plate 3 longer. Therefore, the printing index plate can be manufactured very easily, and the mounting accuracy can also be improved. It is possible to increase the printing density by arranging the sensors at a high density within the reading resolution range.

Effects of the Invention As described above, the present invention is equipped with a print head and a print index plate is provided on the ζ carriage, and a plurality of sensors arranged along the running path of the carriage read the print index plate and respond accordingly. In this printing position control device which generates printing timing pulses, the length of the printing index plate can be extremely short regardless of the printing area length, and the difficulty in manufacturing is greatly improved.

At the same time, problems such as deflection related to the mounting of the printed index plate can be completely ignored.

On the other hand, in terms of cost, the print index detection system can be made shorter, so the effect C1 is great.

[Brief explanation of drawings]

FIG. 1 is a plan view of a printing index plate, FIG. 2 is a schematic configuration diagram of a printing position control device according to the present invention, FIG. 3a is a circuit block diagram of a printing position control device according to the present invention, and FIG. FIG. 3 is a signal output waveform diagram corresponding to the block diagram in FIG. 1...Printed index plate, 1a, 1b・Printed index part,
2... Carriage, 3... Printing index plate, 4-
1°4-2. ...4-n...sensor, 5.
...Print index detection system, 6...Print head,
7... Print medium, 20... Waveform shaping circuit, 30-
...OR Kate. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2? 3Figure 4-12ρ Q) Sezo 1-n IhirLrLrL

Claims (2)

[Claims] (1) A printing index board related to printing density provided on a reciprocating carriage carrying a print head, and an index detection system in which sensors for reading the printing index board are fixedly arranged along the travel path of the multi-cylinder carriage. Print position control device with (2) Adjust the sensor arrangement pitch by adjusting the printing index plate at the same time.