JPS6050154B2 - printer control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides control of a simple dot matrix printer using a micro central processing unit (centralPrOcess).
The present invention provides a control device that simplifies a program for controlling a unit (hereinafter referred to as a CPU) in parentheses.

For use in cash registers, POS, measuring instruments, etc.
There is a simple dot matrix printer.

Although this type of printer is characterized by its low cost and small size, it is rather difficult to control. In other words, the information obtained from the printer is 1
There are only the signal I, which occurs only once per printing cycle, and the signal ■, which has a frequency proportional to the rotation of the printer's motor.
Furthermore, the printer's printing cycle is performed mechanically using a single motor transmission mechanism. Therefore, in order to control, determine all the timings necessary for printing from the signals I and ■, issue a signal if necessary at that timing,
Make the user perform a predetermined action. Even if a signal is issued at a different timing, the printer operates in a mechanical sequence, so it will be ignored or cause a printer error. In other words, printer printing, paper feed, red printing or black printing,
Timing is determined for all operations, such as whether to turn off the motor after printing one line, whether to print the next line continuously, and whether to feed the paper only one line or several lines. Therefore, it must be determined based on the timing signals 1 and 2 above. FIG. 1 shows a more specific example of controlling as described above.

The operation shown in FIG. 1 will be explained as follows. Timing signals 1 and 2 from the printer are taken into the CPU. C
The memory section of the PU contains a program that detects timing from signal I and signal Π, and a program that detects timing from signal I and signal Π.
For example, a sequence is programmed to determine whether paper should be fed or not. For example, when feeding paper, the CPU outputs a paper feeding signal, which is transmitted to the printer. Paper feeding is performed in this manner. Although the control method described above has the advantage of simplifying the circuit,
It has the following shortcomings and points. (1) This is fine if the CPU can be used exclusively for the printer, but if the CPU is also used to control other devices, timing may be missed.

That is, when controlling the keyboard at the same time, if a key is also pressed at a predetermined printer timing, depending on the program, the key will be accepted and the printer timing will be missed. (2) Timing signals from the printer must be constantly monitored until one printing cycle of the printer is completed.

As a result, the CPU usage efficiency deteriorates. (3) Above (1)
) If you try to avoid the problems listed above, it will become difficult to program.

Also, as the program becomes longer, the amount of memory increases.
There is a risk that the price will increase. The present invention aims to overcome the above-mentioned drawbacks.

One embodiment will be described below with reference to the drawing of FIG. 2.

Note that FIG. 3 is a timing diagram necessary for explaining the operation of FIG. 2. In Figure 2, 1 is the CPU, 2 is its CPU
A latch circuit 3 that holds data from Ul uses a motor as a drive source, and its transmission mechanism mechanically determines the sequence of one printing cycle, and also connects the signal 1 generated once during one printing cycle to the rotation of the motor. 4 is a timing preprocessing circuit, 5 is a timing circuit, and 6, 7, 8, 9 are logics between the output signal of the timing circuit 5 and the output signal of the latch circuit 2; An AND circuit 10 which takes the product is an OR circuit which takes the logical sum of the output signal of the AND circuit 6 and the output signal of the AND circuit 7, and is connected as shown.

Then, the signals 1 and 2 from the printer 3 enter the timing preprocessing circuit 4. Of the signals 1 and 2, I occurs only once in one print cycle, as shown in FIG. On the other hand, the signal (2) is a signal whose frequency is proportional to the rotational speed of the motor while the motor of the printer 3 is rotating. In addition, the printing cycle of the printer 3 is mechanically transmitted through gears, cams, etc.! Therefore, the timing for control can be obtained from the signal (2), but the reference for that signal (2) is not clear. Therefore, using the signal 1, the timing preprocessing circuit 4 numbers them as Tl, T2, . . . . Therefore, timing T1 uniquely determines where the print head is located. The output of this preprocessing circuit 4 is input to a timing circuit 5 mainly composed of a counter and an encoder. The timing circuit 5 starts counting from T1 in FIG. 3, encodes the count value, and outputs each operation timing determined by the printer 3. In other words, as shown in Figure 3, the timing to pull the red printing solenoid and the timing to feed (I, ■ and 2 in the feed timing)
There is one that substitutes a fast-forward function, such as feeding 2 lines if both feeds and 11 feeds are executed, and 1 line if only one of them is executed), and then outputting the power off timing. These timings always occur when the printer 3 starts up and the motor rotates. CPUl is information about one printing cycle after turning the motor of the printer 3 to 0N, that is, whether to print red or black, whether to feed after printing or not, and if feeding, 1 or 2 lines, after one printing cycle is completed. , information such as whether to turn off the motor or continue with the next printing cycle is stored in the 4-bit latch circuit 2. The output of each bit of the latch circuit 2 is paired with the same function as each timing output of the timing circuit 5 and input to AND circuits 6, 7, 8, and 9. timing circuit 5
Since a signal is always output at a predetermined timing, the bit whose output from the latch circuit 2 is "゜1" is transmitted to the printer 3 and performs a predetermined operation.As described above, at the beginning of the print cycle , if the CPU outputs the operation mode related to the print cycle once, the CPU 1 does not need to monitor the timing regarding the operation mode of the printer 3 at the start of the next print cycle. According to the printer control device of the present invention, there are the following advantages.

(1) The CPU only needs to issue the operating mode once, so
Programming becomes easier.

(2) As a result, idle time of the CPU occurs, which can be used to control other devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional printer control device, FIG. 2 is a block diagram of an embodiment of the printer control device according to the present invention, and FIG. 3 is a timing diagram of the same device. 1...Central processing unit (CPU), 2...
Latch circuit, 3... Printer, 4... Timing preprocessing circuit, 5... Timing circuit, 6
, 7, 8, 9...AND circuit, 10...OR circuit.

Claims (1)

[Claims] 1 The sequence of one print cycle is mechanically determined by a central processing unit, a latch circuit that holds data from the central processing unit, and a transmission mechanism using a motor as a drive source, and occurs once during one print cycle. A printer that generates a signal I and a signal II having a frequency proportional to the rotation of the motor, a timing circuit that receives the signals I and II as input and outputs timing signals such as motor off, feed, red printing, etc., and the timing thereof. 1. A printer control device comprising: an AND circuit that performs a logical product of an output signal of the circuit and an output signal of the latch circuit.