JPS5941274A - Printing method for dot-matrix printer - Google Patents

Abstract

PURPOSE:To simplify the circuit configration of a dot-matrix printer, by employing a data transferred from a control unit as an ROM address signal. CONSTITUTION:A print address data is transferred from a central control unit 1 to a buffer 2 and is then transferred to a buffer 3. The print address data transferred to the buffer 3 is counted up/down at a print timing to scan the address of an ROM in a character generator 4 to take out a character pattern, which is given to a print unit 7 in synchronism with a print timing pulse.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing method for a dot matrix printer.

When printing with a dot matrix printer,
Print a matrix-like character dot pattern by pressing R on the print control unit.
Information such as JIS code and column number is given as character information and print information from the central control unit to OM (Read Only Memory), and from this information, the address where the character is stored in the ROM is calculated, and the address of the character is stored in the ROM. f dot information
The gt-out method is usually used. However, with this method, when printing regardless of whether the gutter is moving in the right or left direction (reciprocating printing), the RO of the character is
There were inconveniences such as converting the M address or print pattern based on direction information. Therefore, the circuit tends to become complicated.

In addition, dot matrix printing control is based on providing print data (dot patterns) to the head drive unit of the print unit in synchronization with the timing from the print unit, and the higher the speed, the faster the print control unit There is no time left for data processing, and management of drive pulse time intervals, time widths, etc. becomes complicated. In order to avoid the drawbacks of such processing, conventional printers have a DMA (direct memory access) type circuit in the print control section or a microconbeater dedicated to printer control, and exchange print data with the central control section. Or, most of the processing content of the central control unit is occupied by printing unit processing, which makes the circuit complicated and expensive, or sacrifices the ability to control multiple input/output devices simultaneously. The disadvantage was that it had to be done.

The present invention obviates these drawbacks.

Specifically, the print character dot pattern is stored in the ROM in the print control unit, and the central control unit stores the start address (if the print head moves to the right) or the end address (in the same way) of the area where the character is stored. (in the case of moving leftward), address information is written in synchronization with the printing timing, and dot patterns are sequentially retrieved from the ROM and printed. At that time, it is determined whether the ROM address is to be moved up or down depending on whether the print head is traveling to the right or to the left.

According to this method, the information transferred from the control section becomes the JROM address as it is, so the circuit can be simplified and configured at low cost.

Further, since a two-buffer system is adopted, the central control unit can have a margin in the timing of information transfer, which is advantageous when controlling a plurality of input/output devices at the same time.

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

Figure 1 shows the circuit configuration. 1 is a central control unit including a main memory, 2 is a front-stage buffer, 3 is a back-stage buffer, 4 is a character generator containing a ROM containing character patterns, and 5 is an interrupt controller that generates all interrupt signals for the central control unit 1; 6 is a timing that controls the pre-stage buffer 2, post-stage buffer 3, and interrupt controller 6 according to the printing timing from the printing unit, etc. Controller 7 is a printing unit including a head drive circuit, and
to 6 constitute a print control section.

Figure 2 shows the ROM in the character generator 4 in Figure 1.
This is a model of how character pattern information is stored and how it is addressed.

Figure 3 shows a circuit operation chart for an example of a pseudo 9x7 dot matrix printer with 40 characters/line. Timing to transfer information, 口 is the motor to move the print head: A-7 signal % C is the home positive/con signal of the print head, 2 is the print timing for driving the print head wire, E is central control from the print control unit 1 indicates the interrupt timing to section 1, 1 indicates the contents of the first stage buffer 2, and 1 indicates the contents of the second stage buffer 3, respectively.

Next, the operation of this embodiment will be explained.

First, the central control unit 1 transfers the print information of the first print character, that is, the address information 1, from the memory in the central control unit to the pre-stage buffer 2 immediately before turning on the motor, and the print head deviates from the home position. At the leading edge of the interrupt timing signal (FIG. 3, E) just before the print pulse starts to appear, information Ir;, 1 is transferred from the front buffer 2 to the rear buffer 3, and at the trailing edge, an interrupt is issued to the central control unit 1. , the central control unit 1 prints the second printed information 2 in the previous stage (nofa 2).
Transfer to. The print address information of the tiger 1 transferred to the subsequent buffer 3 is increased or decreased depending on the printing timing, and the specified number of addons are scanned from the address of the ROM in the character register 4, and the information is output one after another. In synchronization with the print timing pulse, the character pattern is input to the printing unit 7 and printed by a head drive pulse generated within the character generator 4. The second and subsequent numbers are printed in the same way. Interrupt timing (
(e) is generated by the timing controller 6 by frequency dividing the print timing signal 2, character by character.

The print address information is, for example, “1” as shown in FIG.
”, when the print head is in the left direction, press F120.
The address is 1d10 when facing to the right.

As is clear from the above explanation, the transfer of the inth print address information from the central control unit to the previous stage 79 software is
This can be done just before the end of the n-1)th printing operation, which reduces the peak load factor, such as when the central control unit is controlling multiple human output devices at the same time.

1, as shown in Figure 2, the print address is specified in the right direction,
It is constant regardless of the direction to the left, and the circuit can be simplified in this respect as well.

As is clear from the description of the above embodiments, according to the present invention, it is possible to configure a printing control system without using hardware such as a DMA system or a microcomputer system, and furthermore, it is possible to configure a printing control system without using hardware such as a DMA system or a microcomputer system. This can provide more time for data processing and greatly contributes to the construction of systems with high processing power at low cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus for carrying out a dot matrix printing method according to an embodiment of the present invention, FIG. 2 is a schematic diagram of the memory contents of the dot pattern and the addressing method of the same apparatus, and FIGS. FIG. 3 is an explanatory diagram of the operation of the device. DESCRIPTION OF SYMBOLS 1... Central control unit, 2... Pre-stage buffer, 3... Post-stage buffer, 4... Character generator, troller, 7...... Printing section.

Claims (2)

[Claims] (1) The character storage address of the storage device in which the dot matrix of printed characters is stored is characterized by specifying the first address or one tail address according to the right or left direction movement of the gutter to print. Dot matrix printer printing method. (2) A first buffer l temporarily stores character storage addresses in the storage device, and a second buffer is provided to which information is transferred from the first buffer each time one character is printed, and the second buffer is used for printing. The print timing signal from the unit is used as a trigger to count up or down according to the right or left movement of the gutter to print.