JPS63280671A - Print timing control device of printer - Google Patents

Abstract

PURPOSE:To retain high printing quality even if the moving direction of a printing head is wrong by detecting/storing a position shift value in the horizontal movement of the printing head and adjusting bidirectional print timing according to the stored position shift value. CONSTITUTION:A sensor 4 for confirmation of the position of a printing head 1 is provided, and position shift values at the time of the movement to the right of a position of the printing head 1 and at the time of the movement to the left are detected by a position shift value measurement means A, then are stored into a position shift value storage means B. When printing is performed in both directions to the right and left by a bidirectional print execution means C, bidirectional print timing is adjusted by a print timing adjustment means D in accordance with the stored position shift value. Subsequently, a bidirectional error is automatically measured and adjusted when printing quality is improved by repeated printing of the same line twice. Therefore, high printing quality can be maintained, even if the moving directions of the printing head 1 in the first pass and second pass are different.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a printing device and a dot matrix serial printer that performs bidirectional printing.

[Conventional technology]

Some dot matrix type serial printers, which are widely used as output devices for desktop computer systems, improve print quality by printing the same line twice.

In the case of such a printing device, how to adjust the timing of first and second printing is an important technical issue.

Print timing in dot matrix type serial printers is generally controlled by the rotation angle of a motor that moves the print head. In such printers, the relationship between the rotation angle of the motor and the position of the print head differs depending on the direction of movement of the print head.

Furthermore, there are individual differences in this positional relationship for each product. In conventional printers, in order to absorb this individual difference, printing is performed by limiting the printing direction, or a device (for example, DipSW or VR) is installed to identify individual differences, and correction is performed according to pre-adjusted correction values. I used to go there.

[Problem that the invention seeks to solve]

The problems to be solved by the present invention are two problems faced by the conventional technology. The first problem is that the printing direction is limited, which results in wasted head movement time that does not involve printing.The second problem is that an adjustment process is required to initialize the device for identifying individual differences. The problem is that it becomes.

The purpose of the present invention is to eliminate the problems in the prior art,
To easily adjust individual differences in bidirectional printing timing.

[Means for solving problems]

FIG. 1 is an explanatory diagram showing the overall configuration of a print timing control device for a printing apparatus according to the present invention. As shown in the figure, the print timing control device of the present invention includes a print head 1, a carriage 2 that carries the print head 1 and moves in the left-right direction, a carriage drive belt 3, and a sensor 4 that confirms the position of the print head 1. , a carriage drive motor 5, means A for detecting the amount of positional deviation when the print head position moves in the rightward and leftward directions, means B for storing the detected amount of positional deviation, and printing in both left and right directions. and means C for adjusting the bidirectional printing timing according to the stored positional deviation amount.

(Embodiment) The gist of the present invention will be explained in detail with reference to an embodiment shown in Fig. 2. In the figure, 5 is a carriage drive motor, 4 is a home position sensor, 6 is a control unit, and 1 is a print head. It is.

The sensor 4 is a transmission type photosensor and the carriage 2
When it is on the right side of the sensor 4, it outputs a Low signal to the R terminal of the control section 6, and when it passes the sensor 4, it outputs a High signal to the R terminal.

The control unit 6 excites the carriage motor 5 in the order of φ, →φ, →φ, →φ, etc. as shown in FIG. 3(a), and moves the carriage 2 from the right side of the sensor 4 to the left side. Or, the third
As shown in figure (b), φ, →φ.

→ φ1 → φ, etc., the carriage 2 can be moved from the left side to the right side of the sensor 4, and further,
The carriage motor 5 is placed in a certain excitation state φ.

The time t from when the sensor 4 is excited until the sensor 4 changes can be measured.

FIG. 4 is a flowchart showing how the print timing control device of the present invention operates. To explain according to the flowchart, first, when the carriage 2 is moved from right to left (■), the excited soft bacteria φ. After t1 seconds, sensor 4 changes from High to Low (■), and conversely, when moving from left to right (■), sensor 4 changes from Low to High (■) after t3 seconds. Then, it can be seen that the carriage 2 is a mechanical body that has an error of tl when moving to the left and t when moving to the right.

When printing, first determine the printing direction and adjust the print timing using (■) ts when printing from left to right and (■) t when printing from right to left. value Δt
Execute printing using (■) (Effect of the invention) As explained in the above embodiment, according to the present invention, when trying to improve printing quality by printing the same line twice, bidirectional errors can be automatically measured and adjusted. Therefore, high printing quality can be maintained even if the hef-Y movement directions of the first and second passes are different.This effect is not limited to the same line, but also applies to all directions of carriage movement during bidirectional printing. Contributes to preventing printing errors.

[Brief explanation of the drawing]

Figure ti1 is a basic configuration diagram of a dot matrix type serial printer. FIG. 2 is a circuit diagram of one embodiment of the present invention. FIG. 3 shows a timing chart at each terminal of the control unit 6 in FIG.
) is a time chart when moving to the right. Fourth
The figure is a flowchart showing the operation of the present invention. A... Positional deviation measurement means B... Positional deviation storage means C... Bidirectional printing execution means D... Printing timing adjustment means and above Applicant Seiko Epson Co., Ltd. Agent Patent attorney Tsutomu Mogami and others 1 name -4 for -1φ
. For $2 911 y! 'o 5lIz 9G2 9
+11゜Figure 3Figure 4

Claims (1)

[Scope of Claims] A sensor for confirming the position of the print head, means for detecting the amount of positional deviation when the print head position moves to the right and to the left, means for storing the detected amount of positional deviation, and both left and right sides. 1. A printing timing control device for a printing apparatus, comprising means for executing printing in both directions and means for adjusting printing timing in both directions according to a stored amount of positional deviation.