JPH01108061A - Serial dot matrix printer - Google Patents

Abstract

PURPOSE:To attain high-speed printing by providing a dot thinning-out circuit adapted to thin out the output of data by the number of times equal to the number of times of the output of a first dot in the event that there are two or more serial data. CONSTITUTION:A printer of the invention includes a micro processor (CPU) 1, a memory 3 in which printing data is stored, a dot thinning-out circuit 2 for thinning out dots of the printing data and a driver 5 adapted to drive a printing head 6 on the basis of printing data selected by a selector 4 connected to the CPU 1 and the dot thinning-out circuit 2, the CPU 1 reads out printing data from the memory 3 and outputs a printing dot pattern S1. The so output printing dot pattern S1 and a dot thinning-out processing pattern S2 obtained after the printing dot pattern S1 has passed through the dot thinning-out circuit 2 are fed into the selector 4. When the selector 4 selects the dot thinning-out processing pattern S2 on the basis of a output selecting signal S6, the signal is delivered to the P/H head 6 via the P/H driver 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a serial dot matrix printer;
More particularly, it relates to a serial dot matrix printer having a dot thinning circuit.

[Conventional technology]

Conventionally, in this type of serial dot matrix link, dot thinning processing has been performed by hardware (F/W).

[Problem that the invention seeks to solve]

In the conventional serial dot matrix printer mentioned above, the dot thinning process was performed by F/W, so when trying to increase the printing processing speed, dot thinning printing is performed, but printing is performed by increasing the number of dots thinned out. The further an attempt is made to increase the processing speed, the more processing time it takes in the F/W, resulting in a disadvantage that the printing processing speed does not become as fast as expected.

[Means for solving problems]

The serial dot matrix printer of the present invention has a dot thinning circuit that thins out the output of data by the number of outputs of the first one dot when there are two or more consecutive pieces of data.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the invention. In FIG. 1, one embodiment of the present invention includes a microprocessor (CPU) 1,
A memory 3 in which print data is stored, a dot thinning circuit 2 that thins out dots in the print data, a selector 4 that is connected to the CPUI and the dot thinning circuit 2, and selects one of the print data; and a dry parameter that drives the print head 6 based on the print data.

The CPUI reads print data from the memory 3 and outputs a print dot pattern S1. The output printed dot pattern S1 and the dot thinning processing pattern S2 obtained by passing the printed dot pattern S1 through the dot thinning circuit 2 are input to the selector 4. When the selector 4 selects the dot thinning process pattern S2 using the output selection signal S6, it outputs the signal to the P/H head 6 via the P/H dry parameter.

FIG. 2 shows a dot thinning circuit 2 used in one embodiment of the present invention. In FIG. 2, this dot thinning circuit 2 is configured to perform thinning when the number of thinned out dots is 3, for example, as shown in FIG. 3 (a).
), the number of thinned out dots is given by the number of flip-flops (LS74) 7 and the number of inputs to the NOR gate 8. Therefore, if you want to reduce the number of dots to be thinned out to N, then use N flip-flops (
This can be easily realized by using LS74) 7 and N-input NOR gate 8.

FIG. 3(b) is an example of the output data S4, where ■ is the number of output dots without thinning processing, and ■ is the output dot string after passing ■ through the dot thinning circuit 2. Wavy circles indicate thinned out dots.

〔Effect of the invention〕

As explained above, the present invention allows printing data to be easily thinned out by providing a dot thinning circuit, and
The number of dots to be thinned out can also be easily set using H/W.

Since the processing speed is much faster than when dot thinning processing is performed by F/W, it is possible to sufficiently increase the printing speed even when performing dot thinning processing for high-speed printing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing a dot thinning circuit of this embodiment, and FIG. 3 is a diagram showing a timing chart and output data of this embodiment. 1...CPU, 2...-dot thinning circuit, 3...
Memory, 4...Selector, 5...P/H driver,
6...P/H head, 7...Flip-flop (L
S74), 8...3-man powered NOR gate, 9...2-man powered AND gate, 10...2-man powered NAND gate, S
l... Print dot pattern, S2... Dot thinning processing pattern, S3... Impact synchronization clock,
S4...Output data, S5...Address, data bus, S6...Output selection signal.

Claims (1)

[Claims] In the output print data of a serial dot matrix printer, if there are two or more consecutive pieces of data, the printer has a dot thinning circuit that thins out the data by a certain set number after outputting the first dot. Serial dot matrix printer with special features.