JP2817221B2 - Printing method of thermal printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a printing method for a thermal printer.

2. Description of the Related Art Regarding pulse width control of a conventional head, energy is first applied to the head by a basic main pulse, and then subtle energy is dividedly applied in several stages.

Problems to be Solved by the Invention In a thermal head equipped with a head driver, data is transferred to the head in a serial manner, and the coloring time is set for all elements.
It is determined collectively by the STB signal and the like. For this reason, when trying to control the applied pulse width for each head heating element, it is necessary to change the pulse width for each time width for controlling all data. For example, when data is transferred to 100 heating elements, a total of 1000 μS = 1 ms is required if the response processing time of the head is 10 μS for each element. Therefore, the minimum time width for controlling the head is limited to 1 ms.

However, recent thermal printers tend to require high-resolution graphics printing and the like, and the number of heating elements of the head is increasing, and the number of data to be transferred is also increasing in proportion thereto. The minimum time width tends to be longer.

On the other hand, a thermal printer that requires high-speed printing requires control in a shorter time width depending on various printing conditions such as a previous history condition and an adjacent condition.

For this reason, in high-speed printing with graphics, conflicting requirements arise for the minimum time width to be controlled.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-speed thermal printer having a high print quality by reducing the minimum time width for controlling the head in consideration of the above problems.

Means for Solving the Problems In order to achieve the above object, the present invention has a thermal head and control means for controlling the thermal head, and prints a pulse to the thermal head with a main pulse and a plurality of correction pulses. The main pulse and the data of the plurality of correction pulses are transferred from the control means to the thermal head, and the data is transferred for each of the main pulse and the plurality of correction pulses. A printing method of a thermal printer configured to be longer than any application time and shorter than an application time of a main pulse, wherein one of a plurality of correction pulses is protected immediately before and after the main pulse. This is a printing method of a thermal printer applied continuously with a pulse.

That is, the present invention decomposes a print pulse width into a main pulse and a correction pulse for control in order to control the applied pulse width for a head to be first colored, and the correction pulse is used to control the head. The content of the data to be transferred to the head is determined as 1 or 0 depending on the content. For example, when performing the adjacent correction, if there is no coloring on both sides of the head to be colored, the data content of the main pulse is set to 1 and the correction pulses A and B are set to 1 to apply energy to the head. When there is color development on both sides, the data content of the main pulse is 1 and the correction pulses A and B are both 0 to apply energy to the head.

Note that the coloring order of the correction pulses A and B is fixed in advance by a program, and does not change depending on the data content every time.

Operation With this configuration, it is possible to control the thermal head in a shorter time than the time determined from the response processing time of the head and the number of heating elements, and high-speed printing can be performed.

An embodiment will be described below with reference to FIGS. 1 to 3 showing an embodiment of the present invention.

FIG. 2 shows a schematic configuration of a thermal line printer. In FIG. 2, 1 is a thermal head, 2 is a driver section of the thermal head 1, 3 is a data terminal, 4 is a clock terminal, 5 is a latch terminal, and 6 is a strobe. Terminals 7 are microcomputers for outputting control signals to these terminals, 8 is a pulse motor, and 9 is a driver section of the pulse motor 8, which is controlled by the microcomputer 7.

Hereinafter, the operation of the embodiment will be described assuming that the history control is performed. The contents of the previous history control are such that when there is no coloring history before the dot to be colored, the data transferred to the head for both the main pulse and the correction pulses A and B is 1. When there is a previous color development, the main pulse data is 1 and the correction pulses A and B are 0.
When the color is generated two times before, the data of the main pulse and the correction pulse A is set to 1 and the data of the correction pulse B is set to 0. The widths of the three types of pulses increase in the order of correction pulse B <correction pulse A <main pulse. The coloring order is correction pulse B, main pulse,
The order of the correction pulse A is as follows. The dot period T2 is 3 ms, the correction pulse width B (S1) is 150 μS, and the correction pulse width A (S
3) is 250 μS, and the main pulse width (S2) is 1.1 mS. The number of heating elements is 100, and the response processing time of the head is 10 μS.

Explaining with reference to the timing chart of FIG. 1, the content of the first strobe (S1) is the correction pulse B,
The content of the strobe (S2) is the main pulse, and finally the content of the third strobe (S3) is the correction pulse A.

During the period up to the first strobe (T2-T1), the data (D1) of the correction pulse B is transferred to the head, and the content is held by the latch pulse (L1). Further, the second strobe data (D2 = main pulse data) is transferred to the head.
At this time, the latch operation is not yet performed. The operation up to this point can be performed without any particular problem since there is enough time until the head develops color. Next, the first strobe is colored. Even if the first strobe (S1) is shorter than the data transfer time (100 × 10 μS), the coloring operation can be performed only for the time of the latch operation (L2). The time when the latch operation (L2) is performed is the start of the second strobe. The second strobe (S2) requires a time longer than the data transfer time (100 × 10 μS), during which the data (D3) of the correction pulse A is transferred. The last strobe (S3) starts when the data (D3) of the correction pulse A is latched (L3). For the last strobe, the next data does not need to be transferred, so that the coloring time may be shorter than the data transfer time.

4a and 4b show a flowchart of the printing method of the present invention. The application to the head is started in the main routine, and the application is stopped by a timer interrupt. For the sake of explanation, the start and stop of the application to the head are performed for each strobe, but actually, the start of application at the time of output of the first strobe and the stop of application at the third strobe may be sufficient.

As described above, according to the present invention, it is possible to control the thermal head in a time shorter than the time determined from the response processing time of the head and the number of heating elements, and it is possible to realize a high-speed printing thermal printer. it can.

[Brief description of the drawings]

FIG. 1 is a timing chart showing a printing method according to an embodiment of the present invention, FIG. 2 is a circuit configuration diagram of a thermal printer control unit and a thermal head, and FIG. 3 is a flowchart showing an example of a thermal head control program. . 1 ... thermal head, 2 ... head driver, 3 ...
Data terminal, 4 ... clock terminal, 5 ... latch terminal,
6 ... Strobe terminal, 7 ... Microcomputer.

Claims (1)

(57) [Claims] A thermal head; and control means for controlling the thermal head, wherein a pulse applied to the thermal head comprises a main pulse and a plurality of correction pulses. The data of the main pulse and the plurality of correction pulses are transferred, and the data is transferred for each of the main pulse and the plurality of correction pulses, and the data transfer time is determined by applying any one of the plurality of correction pulses. A printing method for a thermal printer configured to be longer than a time and shorter than an application time of the main pulse, wherein one of the plurality of correction pulses is respectively provided immediately before and after the main pulse. A printing method for a thermal printer, wherein the printing method is applied continuously with a main pulse.