JPS6019237B2 - Pulse motor speed control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention controls the speed of a pulse motor using firmware, and relates to a speed control method that is particularly effective when used for, for example, spacing of a printer where the speed needs to be changed arbitrarily. .

Recently, it has become common to use pulse motors for sweeping in serial dot printers, but due to temporal or thermal limitations in the drive cycle of the dot head, the sweeping speed is limited. Switching by elite pitch "■ ANK, kanji" or full graphic printing, ■ increase/decrease in the number of copies, ■ switching due to dot head temperature alarm detection, etc. will require switching.

Furthermore, when printing continuously, it is necessary to perform spacing at a predetermined speed;
If there is a need for high-speed feeding, various speed switching becomes necessary.

This will be explained below using the drawings.

FIG. 1 is a block diagram showing an example of a conventional pulse motor speed control method, FIG. 2 is a partially detailed view of FIG. 1, and FIG. 3 is a diagram for explaining an example of the operation of FIG. 1. It is.

In FIG. 1, 1 is a microcomputer, and 2 is a speed table 2A to 2N that stores several speed changes.
Read-only memory (hereinafter referred to as ROM) with
, 3 is a pulse motor control circuit controlled by the microcomputer 1, and 4 is a timer for creating a pulse interval necessary for the pulse motor control circuit 3.

Next, FIG. 2 is a diagram showing details of the timer 4 in FIG. are sequentially read out under the control of the microcomputer and set at the timing of the set pulse.

Next, each time a clock is input, it is counted by -1 (or 11) according to the set contents, and a borrow (or carry) signal is output.

Therefore, the microcomputer 1 controls the pulse motor control circuit according to this world power signal.

FIG. 3 shows an example of the operation when applied to printer spacing according to the contents stored in each speed table 2A to 2N of ROM 2. The vertical axis shows speed and the machine axis shows speed. It represents a vine (column).

In this example, all speed tables are accelerated from the start position S to A, printed at a predetermined speed from A to B, and skipped at high speed from B to C. In the meantime, print at the specified speed,
This shows the case where the speed is reduced from D to E to finish printing one line.

However, this method has the disadvantage that in order to perform several types of printing speed changes, it is necessary to have a speed table storing the number of speed changes and to perform complicated table selection control. Therefore, the present invention attempts to perform arbitrary speed change control with only one speed table by providing a programmable timer.

FIG. 4 shows an embodiment of the present invention, in which the same parts are given the same numbers.

In FIG. 4, a programmable timer 5 is set to a desired value by the microcomputer 1, and the time for outputting the ratio k signal varies depending on the set value. The programmable timer is a circuit that stores the set value and generates timing of the same cycle thereafter until the value is reset and updated. Next, in order to simplify the explanation, the operation of the present invention will be described using as an example a case where the speed is switched from a speed of 20 ratio ps (character number seconds) to a speed of 10 ratio ps.

First, assuming that the speed table 2 stores speed information similar to the speed table 2A shown in Fig. 3, when performing sweeping with the speed change shown in Fig. 3 2a at a speed of 20 ratio ps, Programmable timer 5
is set to a predetermined number M (for example, 1), and the microcomputer 1 sequentially reads out the contents of the speed table 2 and sets it in the timer 2. Then, the programmable timer is set by the clock signal from the microcomputer 1. The output signal (tck) obtained when a predetermined number of counts is counted is used as the clock of timer 4, and the speed of the pulse motor (tck) is determined by the output signal (tsp) obtained from the timer. This can be achieved by controlling the timing of phase switching.

When switching to a speed of 100 ps, the output signal (tc
The interval k) is doubled, so the interval at which the output signal (Gp) of the timer 4 is output is also doubled, and the pulse motor rotates at 1/2 speed, so the toss basing speed is switched to 10 ratio ps.

In addition, in the above explanation, only the case where the speed is reduced to 1/2 was explained, but if you have 1 byte (8 bits) as the actual data set in the programmable timer 5, the output timing of (Mae 1) = 25 Choren can be set. can get.

As explained in detail above, according to the present invention, desired speed information is sequentially read out from a speed table (ROM) storing speed information, set in a timer, and the rotation of the pulse motor is controlled by the output from this timer. In a pulse motor control method, a programmable timer is provided, a value corresponding to a desired speed is set in the programmable timer, the contents of a speed table are sequentially read to the timer, and the output of the programmable timer is used as a clock to control the timer. By counting with the timer and controlling the pulse moder with the output from this timer, it is possible to create a speed table for storing speed information, and it is possible to cope with numerous speed changes with just one.

Therefore, the ROM for the speed table is reduced and the control is simplified, making it possible to provide a small and inexpensive device.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of a conventional pulse motor control method, Fig. 2 is a partially detailed view of Fig. 1, and Fig. 3 is an example of the relationship between printer spacing and speed. FIG. 4 is a block diagram showing an embodiment of the present invention. 1...Microcomputer, 2...ROM, 3...
...Pulse motor control circuit, 4...Timer, 5...Programmable timer. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In a pulse motor control method in which desired speed information is sequentially read from a speed table storing speed information and set in a timer, and the rotational speed of the pulse motor is controlled by the output from the timer according to the set contents. , is equipped with a programmable timer, and sets a value according to the desired speed of this programmable timer, and
A method for controlling the speed of a pulse motor, characterized in that the contents of a speed table are sequentially read into a timer, the output of the programmable timer is used as a clock and the timer counts, and the speed of the pulse motor is controlled by the output from the timer. .