JPS59224366A - Printing process of dot printer - Google Patents

Abstract

PURPOSE:To execute easy and positive correction of printed position at bi- directional logic seek printing, by allowing even or odd dot-printing clocks to be generated and printed independently by the first and the second triggers. CONSTITUTION:By means of a high-speed clock signal from a generating member 21, the basis clock signal corresponding to printing speed is allowed to be generated from CPU22 and by means of a character trigger generating member 23, the character trigger is generated by equal division of periphery with number of clocks per a single character. With respect to this character trigger, in the printing correcting time generating member 24, a trigger delayed by the correcting time T1 for the bi-directional printing is generated and in the generating member 25, a trigger delayed by the time t obtained by division of the zig-zag dot distance by the displacement speed of carriage plus T1 is generated, and in the generating member 26, odd number dot printing clocks and in the generating member 27, even number dot printing clocks are generated respectively. Further, in case of printing in the reversed direction, odd and even number dot printing clocks are generated in an opposed manner. Thus, correction of printed position at bi-directional logic seek printing can be performed easily and positively and high-speed printing can be made, too.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial printer that performs bidirectional logic seek printing using a step motor, and particularly to a dot printer that performs printing using an open loop control method using a microcomputer and has a staggered dot arrangement. This relates to printing methods.

For dot printers with a staggered dot arrangement,
As shown in Figure 1, the staggered dot spacing between even and odd dots is n (an integer) times the pitch of the step motor, or an integer multiple of an integer fraction of the pitch. have been adopted. Therefore, the horizontal dot width of the character is an integral multiple of the motor pitch, or an integral multiple of the least common multiple of the motor pitch and the staggered dot spacing.

FIG. 2 is a diagram showing the printing timing and the position of characters actually printed in a conventional printing method. A method using a basic clock as a trigger as shown in FIG. 2 is adopted. In printers that perform bidirectional printing, the actual print position deviates from the theoretical print position due to the back crash of the drive system that moves the head left and right and the time required to create the print timing. A method is adopted in which a number of correction steps are inserted each time printing is started.

τ1 is the period of the basic clock used to control the printing timing and the driving timing of the step motor, and τ is the time that defines the printing dot pitch, which is an integral multiple of the basic clock.

τ8. τ4 is an adjustment time for aligning the vertical printing positions of characters in a column in the case of bidirectional printing, and has a time width that is an integral multiple of the period τ of the basic clock.

τ3 is the compensation time when printing in the forward direction, and τ4 is the compensation time when printing in the reverse direction.

FIG. 3 is a general flowchart for the CPU to generate a forward print clock in the conventional printing method. Every time the basic clock in FIG. 2 is generated, the basic clock is counted as shown in process 1 in FIG. After determining that the number corresponding to has been counted, in process 3, it is determined that the printing timing clock is an odd number dot print timing clock made by an integral multiple of the basic clock, and in process 4, an odd number dot print clock is output. In process 5, it is determined that the basic clock has been counted for the time corresponding to the zigzag dot interval when printing of odd-numbered dots has started, and the process moves to process 6. In process 6, it is determined that the even number dot printing timing clock has a cycle that is an integral multiple of the basic clock, similar to the odd number dot printing clock, and
In process 7, an even number dot printing clock is output.

On the other hand, in the case of reverse printing, in the printer with the dot arrangement shown in FIG. 1, even numbered dots and sotos must be printed first, so processes 8 to 14 in FIG. 4 are performed. In addition, the printing timing of even numbered dots and odd numbered dots is reversed from that in FIG.

In the conventional printing method, as shown in FIG. 2, printing is performed based on the basic clock, so when printing one line, for example, characters 1. If Il is mixed, printing is possible if the printing dot pitch is an integral multiple of the basic clock as shown in Figure 2, but if the period of the printing dot clock is an integer multiple of the basic clock as shown in Figure 5, then printing is possible. If it is not an integer multiple of that,
Printing dot pitch: I Printing adjustment time: τ3=2T.

Staggered dot r/iJ: n-=3τ.

Delay time for printing characters with different printing dot pitch: τ4 = m2τ1 (m2 is not an integer),
This τ2. Printing is not possible because the timing of τ4 cannot be set.

In addition, in conventional technology, the vertical position of two lines of printing in bidirectional printing is often corrected based on a basic clock that is synchronized with the steps and knobs of the motor, so the correction is only performed at intervals of one step of the motor. I can't. That is, the second
The maximum dot shift d in the two vertical columns in the figure is τ. Therefore, if the period of the basic clock is shortened, accuracy can be further improved, but since the number of processing steps shown by general 70- in FIGS. 3 and 4 increases, the processing time also increases, and the printing speed increases. subject to restrictions. It is basically clocked by a microcomputer as shown in Figure 3.

This is because a cycle shorter than the minimum period X that can process the general flow shown in FIG. 4 cannot be used.

The purpose of the present invention is to enable use of any pitch between staggered dots, to enable printing even when characters with different printing dot pitches coexist in one line, and to enable printing even when printing in both directions. Enables accurate correction of printing position,
An object of the present invention is to provide a printing method for a dot printer that enables high-speed printing compared to conventional methods that require a microcomputer operated by a machine clock.

The printing method of the slow dot printer of the present invention performs bidirectional logic printing and generates a character trigger for each character printed by the dot printer whose print head has a staggered dot arrangement. Generate a first trigger delayed by a first compensation time for compensating the print dot position, and add the first compensation time to the time obtained by dividing the interval between staggered dots by the moving speed of the print head. A second trigger is generated that is delayed with respect to the character trigger, and the first and second triggers independently generate an even number dot print clock and an odd number dot print clock to cause the print head to print. shall be.

An embodiment of the invention is shown in block diagram form in FIG.
8 shows the operation timing.

A high-speed clock generation section 21 generates a high-speed clock,
Based on this, the basic clock is 1 cPU according to the printing speed.
22, and the character trigger generating section 23 divides the frequency by the number of clocks for the basic clock e1 character to generate a character trigger.

The print correction time generating section 24 generates a trigger that is delayed by the correction time T1 for bidirectional printing with respect to the character trigger, and the generating section 25 generates a trigger that is delayed by the correction time T1 for bidirectional printing, and the generation section 25 moves the carriage of the print head at staggered dot intervals for the correction time. Compensation time TI+t, which is the sum of time t divided by speed, =T.

causes a delayed trigger to occur.

When the dot arrangement is as shown in FIG. 1, when performing forward printing, a print direction command from the CPU 22 is used, and a trigger generated by the generator 24 as shown in FIG. The generating section 26 generates a lock at a period corresponding to the pitch of the characters, and the characters I, 9 characters, ■2 characters, and the like are printed.

When printing in the reverse direction, similarly, the printing direction command from the CPU 22 is applied to the generating section 2 as shown in FIG.
The trigger generated in step 4 causes the ``generate print clock'' to be generated at a period corresponding to the pitch of the character, and the character 19 is printed.
Character ■2 Print like the character I.

In this way, serial printers that perform bidirectional logic printing, particularly dot printers that print using an open-loop control method using a step motor and have a staggered dot arrangement, are susceptible to mechanical backlash in the direction of head movement. Taking into account the time delay in printing control, set the compensation time 11 and the compensation time T for the pitch between dots, and in the case of forward printing, the characters 4 characters I 2 characters ■ 9 are printed at the timing shown in Figure 7. When printing the letter I and printing in the reverse direction, the letter I1 character■ is printed at the timing shown in Figure 8.
1 character lit is printed, and the vertical printing positions of the character [2 character ■ character ■ in Figure 7 and the character I9 character ■9 character ■ in Figure 8 are made to match.

Furthermore, by outputting the odd-number dot printing clock and the even-number dot printing clock independently and asynchronously with the basic clock, the even-number and odd-number dot printing processes in the conventional technology shown in Figs. 3 and 4 can be separated. Figures 7 and 8
Diagram character I2 character ■.

It is possible to print characters with different printing pitches, such as the character ■, and the printing speed can be reduced by dividing processing.

According to the present invention, a dot printer that can easily and reliably adjust the print position when performing bidirectional logic seek printing, can print characters of all printing dot pitches mixed in a line, and can print at high speed. can be realized.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a well-known staggered dot arrangement of printed dots, Fig. 2 is an explanatory diagram showing the operation of a conventional example, Figs.
FIG. 6 is a flowchart showing the operation of the CPU in the conventional example, FIG. M5 is a timing diagram showing the drawbacks of the conventional example, FIG. 6 is a block diagram showing an embodiment of the present invention, and FIGS. It is an explanatory diagram showing operation of. 21...High-speed clock generation section, 22...
・CPU. 23...Character trigger generation part, 24...
・Printing compensation time generation section, 25... Printing compensation time generation section, 26... Odd number dot printing clock generation section, 27... Even number dot printing clock generation section,
28...Odd number dot data output section, 29...
. . . Even number do/nod data output section, 30 . . . Print head section, 31 . . . Step motor driver section. Medicine Figure 1 No. 7 Dot Odd Number) Dot # 5 ℃1 Figure 2 d d ・ 岑 3 Figure 4

Claims (1)

[Claims] A character trigger is generated for each character printed by a dot printer that performs bidirectional logic seek printing and the print head is arranged in a staggered dot arrangement. A first trigger is generated delayed by a compensation time of , and a second trigger is delayed with respect to the character trigger by a time equal to the staggered dot interval divided by the print head movement speed plus the first compensation time. 20. A printing method for a dot printer, characterized in that a trigger is generated, and the first and second triggers independently generate an even number dot printing clock and an odd number dot printing clock to cause the print head to print.