JPH0260760A - Thermal head control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal control method for a thermal head, and in particular, it relates to antecedent control, which is one of the means to improve print quality, that is, the current application time of the thermal head. The present invention relates to a thermal head control method that is suitable when using control that is determined by considering both current print data and past print data.

[Conventional technology]

In conventional prior history control of a thermal head, a plurality of prior history times and printing times are controlled by one energization time control timer.

FIG. 4 is a block diagram for implementing this method, and shows the case of two stages of previous history. FIG. 5 shows the control flow. The operation of the conventional system will be described using FIGS. 4 and 5. In Figure 4,
1 is a CPU (central processing unit); 5 is a thermal head; 8 is an energization time control timer that controls the energization time of the thermal head 5;
9 is a print data register that stores print data; 2 is an energization strobe control circuit that controls the thermal head 5 to output an energization print pulse signal according to the data stored in the print data register 9; 4 is a print data register This is a head driver that amplifies the signal of 9. First, the CPU 1 sets the previous history data 1 in the print data register 9 (step 401), and then sets the energization time data of the previous history data 1 in the 1 energization time control timer 8 (-(step 402).
), an energization start instruction is output to the energization strobe control circuit 2 (step 403). In response to this energization start instruction, the dots of the thermal head 5 corresponding to the previous history data are energized, and at the same time, the energization time control timer 8 is operated. CPU
I always checks the state of the energization time control timer 8 and waits until the energization time control timer 8 counts up (steps 404, 405). When the energization time control timer 8 counts up, the CPU sets the next previous history data 2 to the print data register 9 (step 40).
6) L,, the energization time data of the previous history data 2 is sent to the energization time control timer 8 (I-) step 407). Next, C
The PUI checks the state of the energization time control timer 8 (steps 408 and 409) L in the same way as above, and when the energization time control timer 8 counts up, the print data and the energization time data of the print data are stored in the print data register 9.
, set the energization time control timer 8 (step 410゜4
11) Do. When the energization time control timer 8 counts up, the CPU controls the energization strobe control circuit 2.
An instruction to end the energization is output to stop the energization of the thermal head 5.

Incidentally, as a prior art of this type of prior history control method, there is, for example, Japanese Patent Application Laid-Open No. 57-107867. Here, prior history control, as mentioned above, is a method in which the energization time of the thermal head is determined not only based on the current print data but also in consideration of past print data.An example of this is shown in Fig. 6. . 0 indicates an energized state, and 0 indicates an OFF state.

As shown in the fourth row of FIG. 6, the dots of the thermal head that were energized two times before and the previous time have a previous history of 1. Neither the previous history 2 is energized, and as in the second stage, for the dots of the thermal head that were energized two times before and were not energized last time, the previous history 1 is not energized and the previous history 2 is energized.

The temperature of the thermal head is controlled by such operations.

The period of the energizing strobe is the sum of the periods of previous history 1, previous history 2, and printing, and the respective periods of l'liJ history 1, previous history 2, and printing vary depending on the sum of the number of energized dots.

[Problem to be solved by the invention]

In the above conventional technology, since the CPU always checks the state of the energization time control timer 8 while the thermal head 5 is energized, other operations such as calculation of the next print data etc. There is a time limit to carry out the
There was a problem that the operating efficiency of U1 was poor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal head control method that can improve the operating efficiency of the CPU by eliminating time restrictions on the CPU while the thermal head is energized in the antecedent control.

[Means to solve the problem]

The above purpose is achieved by providing a plurality of energization time control timers that control the energization time of the thermal head and a plurality of print data registers that store previous history data and print data that are energization data of the thermal head, and performing the following control. achieved. Before starting printing, the CPU stores all previous history data and print data corresponding to one print in a print data register.

Furthermore, after setting all the energization time data corresponding to these previous history data and print data in the energization time control timer, the 1 energization strobe control circuit is instructed to start energization. The energization strobe control circuit receives the instruction to start energization, and
Among the plurality of energization time control timers, the energization time control timer a to which the energization time of the first previous history data is set is operated, and at the same time, print data a is read from the print data register a in which the first previous history data is stored. The dots of the thermal head are energized in accordance with the outputted first antecedent data. When the energization time control timer a counts up, the energization time control timer b to which the energization time for the next previous history data is set automatically operates, and at the same time, print data is read from the print data register b in which the next previous history data is stored. b is output, and the dots of the thermal head are energized in accordance with the output next previous history data. This action
-CPU until all data for the egg is output.
By repeating automatically without any intervention, the object of the present invention is achieved.

[Effect]

Before starting printing, the CPU stores in a plurality of energization time control timers and a print data register, respectively, the energization time of all previous history data and the energization time of print data for one print, and the previous history data and print data. Next, the CPU
Instructs the energization strobe control circuit to start energization. In response to this energization start instruction, the first energization time control timer a operates, and at the same time, the first previous history data is output from the print data register a, and the thermal head is energized in accordance with the output data. In subsequent printing energization control, as the first energization time control timer a counts up, the operation of the next energization time control timer b and the next data output from the print data register b are automatically performed without the intervention of the CPU. Controlled by what is done.

Therefore, after the CPU outputs the energization start instruction to the energization strobe control circuit, the CPU does not need to check the state of the energization time control timer and is in a free state, thus solving the problems with the prior art described above.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3. FIG. 1 is a diagram showing an example of a block diagram of a thermal head control circuit according to the present invention, FIG. 2 is a time chart of signals of each part for explaining its operation, and FIG. 3 is a flowchart 1 of the operation of the CPU. In this embodiment, a two-stage previous history control is adopted as an example. In FIG. 1, 1 is a CPU,
2 is an energization strobe control circuit, 3 is a print data selection control circuit, 4 is a head driver, 5 is a thermal head, 6 is a print data selector, and 7 is an energization strobe register clear control gate. Further, 11, 13° and 15 are energization time control timers a, b, and a, respectively, and 12, 14, and 16
are stator registers a, b, and Q, respectively, and 17,
18 and 19 are print data registers a, b, and Q, respectively.

The CPUI controls the entire printing process. The energization time control timer all controls the energization time for previous history data and the energization time for print data. Stator register aL2 indicates the state of one energization time control timer all. The print data register a17 stores previous history data and print data. The energization strobe control circuit 2 controls the energization of the thermal head 5 and instructs the energization time control timer ALL to start energization. The print data selection control circuit 3 sends a control signal to the print data selector to select the print data of the print data register a17, print data register b18, and print data register c19 according to the states of the status register a12, the status register b14, and the status register c16. Output to 6. The head driver 4 amplifies the print data 111 signal output from the print data selector 6 and controls the energization of the thermal head 5 using the strobe signal 110 output from the energization strobe control circuit 2 . The thermal head 5 performs printing by applying a printing pulse signal output from the head driver 4 and generating heat through a heating resistor. The print data selector 6 selects print data according to the control signal output from the print data selection control circuit 3 and outputs the selected print data to the head driver 4 .

The energization strobe register control gate 7 operates when the states of the status register a12, status register b14, and status register c16 are all "0"', that is, when the energization time control timer all, the energization time control timer b13, and the energization time control timer c15 are all When the count-up state occurs, a signal for clearing the strobe is output to the energization strobe control circuit 2.

In Fig. 2, energizing time data is written in the single solid line portions b''e period, c''f period, and dg period of energizing time control timer a, energizing time control timer b, and energizing time control timer C. The double solid line part e to f period + f""g period pg"
``h period indicates that the energization time control timer is in operation. bf period when status register a, status register b, and status register C are in high state,
Periods C to g and periods dh each indicate whether the energization time data has been written to the energization time control timer or whether the energization time control timer is in operation.

The e-h period in which the strobe is in a high state indicates that the thermal head is energized.

Next, the operation of this embodiment will be explained using FIGS. 1, 2, and 3. First, CPU1 prints data register a17.
．． b18. Previous history data 1, previous history data 2, and print data are output to c19 (step 301). Next, the energization time data 1 of the previous history data 1 is output to the energization time control timer all (step 302). At this time (point b in Figure 2)
, the status register a12 is in a high state, that is, a state indicating that the energization time data 1 has been written to the energization time control timer all.0Next, the CPU inputs the energization time of the previous history data 2 to the energization time control timer b13. data 2
is output (step 303).

At this time (point C in Figure 2), status register b14
is in a high state, that is, a state in which energization time data 2 is written in the energization time control timer b13. Similarly,
The CPUI outputs the energization time data 3 of the print data to the energization time control timer c15 (step 304). At this time (point d in FIG. 2), the status register c16 is
It becomes a high state, that is, a state indicating that the energization time data 3 has been written to the energization time control timer c15. Next, the CPUI outputs an instruction to start energization to the energization strobe control circuit 2 (step 305). After this point (point e in FIG. 2), the CPUI is completely free. C
The energization strobe control circuit 2 receives the energization start instruction from the PUI and outputs the energization start instruction to the energization time control timer all. Upon receiving the energization start instruction signal, the energization time control timer ALL starts counting (at time e in FIG. 2), and at the same time, the energization strobe control circuit 2 starts the strobe signal 11.
0 is set to high, and energization of the thermal head is started.

At this time, the print data selection control circuit 3 outputs a signal for selecting the print data register a17 to the print data selector 6, and the print data selector 6 outputs a signal to select the print data register a17.
The previous history data 1 from 17 is given to the head driver 4.

The energization time control timer all counts up (second
At time f in the figure), the energization time control timer all outputs a signal to clear the status register a12, and the status register a12 is cleared. At the same time, the energization time control timer b13 starts counting. At this time, the print data selection control circuit 3 outputs a signal for selecting the print data register b18 to the print data selector 6, and the print data selector 6 receives the previous history data 2 from the print data register b18.
is output to the head driver 4. Next, when the energization time control timer b13 counts up (time 6 in Fig. 2),
The energization time control timer b13 is the status register b14.
Outputs a signal to clear status register b14.
is cleared. At the same time, the energization time control timer c15 starts counting. At this time, the print data selection control circuit 3 outputs a signal for selecting the print data register c19 to the print data selector 6, and the print data selector 6 transfers the print data from the print data register c19 to the head driver 4.
Output to.

When the last energization time control timer c15 counts up (time h in FIG. 2), the energization time control timer c15 outputs a signal to clear the status register c16, and the status register c16 is cleared. Status register a12. Status register b14. When all the status registers c16 are cleared, the energization strobe register clear control gate 7 outputs a signal to clear the energization strobe control circuit 2, the energization strobe control circuit 2 is cleared, and the energization of the thermal head is stopped.

During the period when the CPUI is operating during one printing operation,
This is the period a”-’e in Figure 2, and after time e, C
PUI will be free. Comparing the free time of the CPU between the prior art and this method, in the case of the prior art it is after time g in FIG. 2, and in this method it is after time e in FIG. 2. Therefore, in this method, the free period of the CPU is longer than in the conventional technology, and control other than printing control is also possible, and the operating efficiency of the CPU is improved.

〔Effect of the invention〕

According to the present invention, the CPU writes the previous history data and print data to the plurality of print registers, writes the energization time of the previous history data and the energization time of the print data to the plurality of energization time control timers at once, and energizes the energization start instruction. Just by outputting to the strobe control circuit, the operation of the energization time control timer and the output of previous history data and print data from the print register will be performed automatically. Thereafter, the control becomes free, and controls other than printing control can be performed while the thermal head is energized, improving the operating efficiency of the CPU.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a time chart for explaining its operation, Fig. 3 is its processing flow, Fig. 4 is a block diagram of the prior art, and Fig. 5 is its processing. FIG. 6 is an explanatory diagram of the previous history control. 1... CPU, 2... Energization strobe control circuit, 3
...Print data selection control circuit, 4...Head driver, 5...Thermal head, 6...Print data selector, 11°13.15...Electrification time control timers a, b,
c, 12.14.16--Status register a, b
. C117, 18, 19...Print data register a. b, c, 110... Strobe signal, 111... Print data signal. Figure 1 Each Z-mouth eel diagram

Claims (1)

[Claims] 1. Previous history control method that determines and controls the energization time of the thermal head, which prints by generating heat by applying a printing pulse signal to a plurality of heating resistors arranged in an array, according to current printing data and past printing data. In controlling the thermal head, a plurality of print data registers that store previous history data and print data, and a plurality of energization time control timers that control the energization time of each of the above data are provided, and the central processing unit controls all the data corresponding to one print. After storing the previous history data and print data in the print data register and the energization time of each previous history data and print data in the energization time control timer, instruct the energization strobe control circuit that controls the energization of the thermal head to start energization. Then, the energization time control timer that stores the energization time of the first previous history data operates, and at the same time, print data is output from the print data register that stores the first previous history data, energizes the thermal head, and controls the energization time described above. As the timer counts up, the energization time control timer, which stores the energization time of the next previous history data, operates, and at the same time, the corresponding print data is output from the corresponding print data register to complete a series of control operations for energizing the thermal head. A thermal head control system that automatically repeats printing until it is finished.