JPH0515344B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a print control circuit for a serial printer using a thermal head, and in particular a print control circuit that has two printing modes, high print quality and high speed printing, and is capable of switching print speeds. This invention relates to a print control circuit for a serial printer.

[Conventional technology]

Conventional, high print quality mode, high speed print mode
The high-speed printing mode of this type of printer, which has two printing configurations, omit every other printing dot in the row direction as a means of high-speed printing while maintaining the same printing duty due to constraints on the driving duty of each heating element. The so-called thinning printing method was common.

[Problem that the invention seeks to solve]

The conventional high-speed printing mode described above is a method that omits every other printing dot in the line direction, so it is limited to alphanumeric characters and special symbols with relatively simple character shapes, and is difficult to print kanji with complex character shapes. The disadvantage was that it was not suitable.

The present invention provides a print control circuit that enables clearer printing in a high print quality mode and prints a normal dot pattern at high speed in a high speed print mode.

[Means for solving problems]

In order to achieve the above object, a print control circuit for a thermal printer according to the present invention includes a print head, a print speed control means, a high speed print control means, and a low speed print control means, and the print head is caused to travel back and forth. This is a print control circuit for a thermal printer that prints by printing, and the print head has a large number of heating elements. The printing speed control means selectively switches between two high and low speeds: a high speed printing mode with different printing speeds and a high printing quality mode. The control means sets the printing mode to high-speed printing mode, and uses each pair of heating elements to alternately print each dot adjacent in the line direction.The low-speed printing control means sets the printing mode to high-speed printing mode. The high printing quality mode is set and a pair of a preceding heating element and a following heating element is used to divide the same dot into two printing tasks.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a conceptual diagram showing the operation of the present invention, and FIG. 3 is a time chart showing the operation of the embodiment of FIG.

Referring to FIG. 1, 10 is a RAM (random access memory) that stores various data generated during information processing by a microprogram;
is an RM (read only memory) that stores microprograms and fixed data necessary for information processing;
30 is a one-chip CPU that performs information processing based on the microprogram stored in the RM 20. One chip CPU 30 includes an MPU (microprocessing unit) 31, a counter timer 32, an interrupt controller 33, and an output port 34.
are connected to each other by an internal bus H. Furthermore, the RAM10, RM20,
The MPUs 31 are interconnected by a data bus E and an address bus F. 40 is a head driver that drives the thermal head, and 50 is a heating element that prints according to the dot pattern. 70 is a step motor for reciprocating the thermal head in the row direction, and is driven via the motor driver 60. J is a head drive pulse, and L is head drive data.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to FIGS. 2 and 3.

Figure 2a shows the relationship between each heating element and printing dots in the high print quality mode, and shows the relationship between the preceding heating elements A and C.
After preheating the transfer film or thermal paper at the printing dot location, subsequent heating elements B and D heat it to the final printing temperature. That is, since one dot is heated twice by two heating elements, the energization time for each heating element is short, and clear printing with less dot trailing can be achieved. The relationship between the driving time of each heating element and the printing cycle in this high printing quality mode is shown in the time chart of FIG. 3a.
In FIG. 3, K is a driving pulse that controls the printing period and the driving period of the step motor 70, and the head is moved to one dot pitch and printing is performed every interruption. M indicates a motor control signal, and A and B indicate heating elements. On the other hand, FIG. 2b shows the relationship between each heating element and printing dots in the high-speed printing mode, where heating elements A, B, C, and D print individual dots simultaneously. Since one heating element is responsible for one dot, the energization time for each heating element A and B becomes longer as shown in Fig. 3b, but since it is sufficient to print every other dot in the row direction, the printing speed is reduced. Printing speed can be increased by shortening the cycle.

〔Effect of the invention〕

As explained above, the present invention has a high print quality mode in which two adjacent heating elements print the same dot twice, and a high-speed printing mode in which two heating elements print every other dot in the row direction. By having two printing formats in the mode, the high print quality mode allows clearer printing, and the high speed printing mode allows you to print kanji with complex character shapes at high speed with normal dot patterns without thinning out the dots. It has the effect that it can be printed on.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Figures 2a and b are conceptual diagrams showing the operation of the present invention;
Figures a and b are time charts showing the printing operation of Figure 1. 10...RAM, 20...RM, 30...1
Chip CPU, 31...MPU, 32...Counter timer, 33...Interrupt controller, 34...Output port, 40...Head driver, 50...Thermal head, 60...Motor driver, 70...
...Step motor, E...Data bus, F...Address bus, H...Internal bus, J...Head drive pulse, K...Interrupt pulse, L...Head drive data, M...Motor control signal.

Claims (1)

[Scope of Claims] 1. A print control circuit for a thermal printer that has a print head, a print speed control means, a high speed print control means, and a low speed print control means, and prints by moving the print head back and forth. The printing head has a large number of heating elements, and the heating elements are a pair of heating elements arranged adjacently at one dot intervals parallel to the row direction, and a row of dots arranged perpendicular to the row direction. , the printing speed control means selectively controls switching between two high and low speeds, a high-speed printing mode and a high-print quality mode, which have different printing speeds, and the high-speed printing control means sets the printing mode to the high-speed printing mode. Each pair of heating elements is used to alternately print each dot adjacent to each other in the row direction. 1. A printing control device for a thermal printer, characterized in that it has a pair of a heating element and a succeeding heating element, and divides the printing of the same dot into two printing tasks.