JPH0613225B2 - Printing method of serial dot printer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a print control system for a dot printer that uses a pulse motor for spacing the print head.

(Prior Art) The print control of a dot printer that employs a pulse motor for conventional spacing is as follows. As shown in FIG. 2, one character has 12 pitches in the horizontal direction, and the character matrix is printed as 9 (horizontal) × 7 (vertical). Since the standard character pitch is 10 characters / inch (10 CPI), if the 1/120 inch print head is stepped by driving the pulse motor in one step, one character is 1/10 in 12 steps.
The inch print head stepped forward, and the drive timing of the print head and the pulse motor was set to 1 to facilitate control.

Looking at the print control, the character pitch of the printer is 12 C / inch (12 CPI) in addition to 10 CPI.
There are 7 characters / inch (17 CPI) or the like, and the number of drive pulses per character of the space pulse motor is 12 pulses at 10 CPI, 10 pulses at 12 CPI, and 7 pulses at 17 CPI. The drive timings of the space pulse motor and the print head at this time are as shown in FIG. 3, and the drive timings are deviated and controlled as shown. For this reason, two timers are used to generate the respective timings in order to make the drive timings of the space pulse motor and the print head.

(Problems to be Solved by the Invention) However, the above-described conventional printer has a problem in that the number of circuit components increases and the cost increases because two timers are used for printing control.

The present invention has been made in consideration of the above points, and provides a printing method for an inexpensive dot printer having a small number of parts by generating the drive timing of the space pulse motor and the print head with one timer.

(Means for Solving the Problems) In the print control method of this type, the present invention sets a timing calculated from the common divisor of the driving timing cycle of the spacing pulse motor and the print head, and 1 is set according to the set timing. It is configured such that each timer is repeatedly driven and the required number of outputs are counted.

(Operation) With the above configuration, the timing calculated from the common divisor of the driving timing cycle of the spacing pulse motor and the print head is set according to the change in the character pitch of the printer, and the output of the set timer is set. The detection and counting are performed, and when the count value reaches a value corresponding to the driving timing cycle of the spacing pulse motor or the print head, the corresponding portion is driven.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention, in which a microprocessor (CPU) 1 for controlling a printer and a read-only memory (ROM) in which pattern data such as programs and character symbols are stored. ) 2, and a random access memory (RAM) 3 for temporarily storing data received from the outside,
A timer (TM) 4 for timing generation, an I / O driver 5 driven by a command from the CPU 1, the CPU 1 and the ROM
2, a RAM 3, a TM 4, and a bus line 6 connecting the I / O driver 5. Further, the I / O driver 5 has an interface circuit with an external device (not shown),
A print head, a line feed motor, and a spacing pulse motor that moves the print head in the printing direction are connected.

In the circuit configured in this way, the CPU 1 uses a program stored in the ROM 2 to print data (character code) and control data (usually called a control code for character pitch designation and character modification designation) from an interface unit (not shown). To receive. The printer starts printing when the above print data for one line is received, but the spacing pulse motor switches the phase according to the timing obtained from TM4 by the following method under the control of CPU1 to perform the spacing operation. To do.

FIG. 4 shows one row of speed control of the spacing pulse motor, which is composed of acceleration, constant speed, and deceleration portions, and printing is performed at the constant speed portion.

TM4 starts counting by timer clock 4a (clock cycle is t _CLK ) when space timing data (S _n ) is set through bus line 6 under the control of CPU 1.
The timer output 4b occur after a time lapse of S _n × t _CLK CPU1
Let us know.

The CPU 1 retains a table of space timing data in a part of the built-in program, and sequentially stores space timing data (S _n ) from the table according to the speed modes of acceleration, constant speed and deceleration as shown in FIG. Set to TM4 and obtain the timer output 4b to switch the phase of the space pulse motor and control the speed. Here, the control when the acceleration is completed and the speed is constant (printing) will be described by taking an example of a printer having a printing speed of 100 characters per second (100 CPS).

At a printing speed of 100 CPS, one character is processed in 10 ms. Therefore, the drive timings of the space pulse motor and the print head at the character pitch of 10, 12, 17 CPI are as shown in Table-1.

Hereinafter, each case will be described.

First, regarding the character pitch of 10 CPI, the drive timing of the space pulse motor and the print head is the same, and the CPU 1 sets the timing data (S _n ) in TM4 to obtain the timer output 4b of 0.833 ms, and from this TM4. The space pulse motor and the print head are driven simultaneously by detecting the timer output 4b.

In the case of 12 CPI, the space pulse motor timing cycle 1.0 ms and the print timing cycle 0.833 shown in Table-1.
ms, Space pulse motor step number per character 10,
Taking the common divisor of two timing cycles from the number of divisions per character of 12 gives 0.167 ms. Therefore, the space pulse motor timing cycle is 0.167 x 6 = 1.002 ms, and the print timing cycle is 0.167 x 5 = 0.835 ms. The space pulse motor and print timing are obtained by an integral multiple of one timing (0.167 ms in this case). You can That is CP
U1 sets the timing data (S _n ) that obtains the timer output 4b of 0.167 ms to TM4 every time, and every time the space pulse motor is detected every time the timer output 4b is detected
The print head may be driven once every five times. FIG. 5 illustrates and clarifies this timing relationship. FIG. 6 shows a flowchart controlled by a program, which is all controlled by the CPU 1.

Further, in the case of 17 CPI, from Table 1 above, the common divisor of the timing cycle is 0.119 ms, the space pulse motor timing cycle is 0.119 × 12 = 1.428 ms, and the printing timing cycle is 0.119 ms × 7 = 0.833 ms. Therefore, 0.119ms
The drive timing of the space pulse motor and the print head can be obtained once every 12 times and once every 7 times of the timer output 4b.

In addition, when controlling the drive time of the print head, 0.167 ms, 1 for 12 CPI without adding a timer.
In the case of 7 CPI, drive time can be obtained at intervals of 0.119 ms. This can be achieved by driving the print head at the print timing, counting the timer output 4b, and turning off the drive of the print head when the desired number of times is reached. Also, 0.833ms for 10 CPI
Can be easily realized by increasing, for example, 8 minutes to 0.104 ms.

As described above, the case where one character is divided into 12 has been described in the present embodiment, but the same method can be applied to the case of dividing into 18 and 24, and the present invention is not limited by the number of divided characters.

(Effect of the Invention) As described above, according to the present invention, the space pulse motor of the dot printer, the drive timing of the print head, and the drive time of the print head can be controlled by one timer, so that a large number of circuit parts can be provided. It is possible to provide an inexpensive printer by reducing

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram of a dot printer printing example, FIG. 3 is a drive pulse diagram of a space pulse motor and a print head at various character pitches, and FIG. FIG. 5 is a speed control diagram of the printer, FIG. 5 is a time chart of a character pitch of 12 CPI according to the present invention, and FIG. 6 is a flow chart of a program controlled by the present invention. 1 is CPU, 2 is ROM, 3 is RAM, 4 is timer, 4a is timer clock, 4b is timer output, 5 is I / O driver,
6 is a bus line.

Claims (1)

[Claims] 1. A printing method for a serial dot printer in which characters, symbols, etc. are printed by a set of dots, and a pulse motor is used for spacing the print head. One timing is set according to the number, one timer is repeatedly operated at the set timing, the output is counted, and the driving timing of the spacing pulse motor and the print head is obtained according to the count number. A printing method for serial dot printers.