JPH01123754A - Printing control system - Google Patents

Abstract

PURPOSE:To print with high throughput without interrupting a printing operation by dividing printing data into predetermined blocks, counting dots in each block, comparing it with a threshold value, and controlling to print it corresponding to a discriminated printing density. CONSTITUTION:A shift register 1 can input printing data in parallel by light pulses from a CPU, and output the data loaded by clocks 9. When any of counters 2-1-2-n is counted up at the timing of the clock through any of AND gates 6-1-6-n, selected by a selector 3 when the data is '1' and the data are written predetermined times, the select signal of the counter is switched, and another counter is counted up by next printing data. The dots of all the data are finished counting, comparators 5-1-5-n respectively compare the counted results of the counters 2-1-2-n with threshold value data preset in a data register 4, and output signals V1-Vn representing the printing speeds of the respective blocks.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device, and particularly to a printing control system suitable for performing graphic printing with a small-capacity power supply in a dot printer.

[Conventional technology]

For example, in the conventional apparatus, when the total number of dots in one line is larger than a predetermined setting value (z5 described in Japanese Patent Application Laid-open No. 60-120072), the - line is scanned multiple times and printed in one piece. There is a known method that controls the temperature rise of the print head to a constant level (the hidden effect is to suppress the power consumption per unit time to a constant level). Furthermore, as described in Japanese Patent Application Laid-Open No. 60-21265, the degree of drop in the print head drive voltage is monitored by circuit means, and the print head drive voltage drops to a predetermined set value for high-density printing. It is known that the printer stops the printing operation after completing printing of a predetermined printing block, and after the ct pressure recovers, packs a space and resumes printing from the first printing block. Also.

As described in Japanese Unexamined Patent Publication No. 55-82586, a device is known in which high or low printing density is determined and printing is performed by changing the printing speed.

[Problems to be Solved by the Invention and Problem 5] However, in the method of JP-A-60-120072, the number of scans of one line is divided into a plurality of times for printing, resulting in a significant sacrifice in throughput. In addition, since the determination is based on the total number of dots in the - line, uniform control is performed even when the printing density is uneven (scanning is performed multiple times even in areas with low printing density). In the example of No. 21265, since the print head performs a sequential printing operation, when performing graphic printing (printing without separators such as characters), Mechano Pack Rack 1. The printing quality deteriorates due to uneven shading of the ink ribbon, and the throughput is significantly sacrificed. In addition, in the example of JP-A-55-82386, it is only determined whether the printing density is high (kanji) or low (alphanumeric or kana) regarding print data, and it is difficult to judge whether the print density is high (kanji) or low (alphanumeric or kana). If the printing density of the printing data cannot be determined in advance, it is not possible to determine whether the printing density is high or low, and it is not possible to print by changing the printing speed. In view of the above-mentioned problems of the prior art, it is an object of the present invention to determine the printing density of printing data such as graphic patterns for which the printing density cannot be determined in advance using a control code, and to determine the printing density from the result. By determining the corresponding printing speed and printing without exceeding the power supply or print head capacity, and without interrupting the printing operation (for serial printers), you can significantly increase throughput. No deterioration, no deterioration in print quality.

An object of the present invention is to provide a printing control system that allows graphic printing to be performed using a small and small-capacity power source.

[Means for solving problems]

The above purpose is to divide print data into predetermined blocks,
Count the number of dots in each block.

This is achieved by comparing the printing density with a threshold value, determining the printing density, determining the printing speed corresponding to the printing density, and performing printing control.

[Effect]

As means for counting the number of busy dots for each block, a parallel-in/serial-out shift register and a counter provided for each block are used. When print data is loaded into the shift register, the data is output one bit (corresponding to one dot) every clock, and the counter is counted up only when the bit is "1°" (in other words, indicating there are more dots). .The count result (i.e. the number of dots) by the counter is compared with the threshold data by a comparator, and a signal for determining the printing speed is output from the comparator.The selection of each counter is made by using the write pulse of the print data. This is performed by a selector that sequentially changes the select signal of the counter after counting the number of times equal to the number of print data of each print block.

Only the counter selected by the selector is counted up by the dot signal output from the shift register. The printing speed for each printing block is determined by the above method.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The shift register 1 is connected to a path 7 of a CPU (not shown), and multiple print data can be input in parallel to the write pulse 8. In addition, the shift register 1 serially outputs the print data loaded onto the clock 9, and when the data is @1'', it is selected by the selector 3 (
Selector output signal is “1”) AND gate (6-1~
counter (any one of 2-1 to 2-n) at one moment of locking.
count up. When the print data is written to the shift register 1 a predetermined number of times by the write pulse 8, the selector 3 counts this number of times and writes the data to the shift register 1.
The select signals of the counters 2-1 to 2-n are switched, and another counter is counted up from the primary print data. After counting the number of dots of all print data, the count results of counters 2-1 to 2-n are compared with the threshold data set in advance in data register 4 by comparators 5-1 to 5-n, Signals VI to ■o indicating the printing speed of each flock are output. The print control unit (not shown) sends signals ■1 to ■ to indicate the printing speed. After reading, set the printing speed for each block.

Perform printing. FIG. 2 shows an example of the printing operation in the third embodiment of the present invention, and FIG. 5 shows how the print head drive @IE changes. Divide the print data into blocks A - H, 5 blocks, 5 blocks, low print density, B, E, F.
is printed at high speed, and C, D, G, and H, which have high printing density, are printed at low speed. In this way, even when printing with high printing density, the drop in print head drive voltage can be suppressed, and with its small size and small capacity, graphic printing can be performed at high throughput without deteriorating print quality. There is an effect. In addition, Fig. 2 and Fig. 6 are
An example of the prior art described in Japanese Patent No. 265 is shown by a dotted line.

〔Effect of the invention〕

According to the present invention, upon graphic printing.

The printing density can be determined in detail, and the printing speed corresponds to the printing density without interrupting the printing operation.
It has the advantage of being able to print at a higher throughput than conventional devices, without the need for a small, small-capacity power supply that would cause deterioration in print quality.

[Brief explanation of the drawing]

FIG. 1 shows block 1 of an embodiment of the present invention. FIG. 2 is an explanatory diagram of an example of printing operation, and FIG. 5 is a diagram showing changes in print head drive voltage. 1...Shift register, 2-1 to 2-n...Counter. 5...Selector, 4...Data register. 5-1 to 5-n: customary comparators. 6-1 to 6-OAND gate.

Claims (1)

[Claims] 1. A dot serial printer, which divides one line into a plurality of blocks, includes means for counting the number of driven dots for each block based on print data, compares the count result with a threshold value, and calculates the number of dots for each block. A printing control method comprising a means for determining the printing speed of the blocks, and is characterized in that areas with high printing density are printed at low speed, and areas with low printing density are printed at high speed.