JPH05294040A - Method for controlling thermal printer - Google Patents

Abstract

PURPOSE:To provide a thermal printer capable of reducing the number of timers as compared with a conventional printer to perform printing, having effect from a systematic aspect and capable of being inexpensively produced. CONSTITUTION:When motor phase changeover timing does not coincide with a thermal head current supply start timing, a thermal head current supply part is started in motor phase changeover timing and null data is transmitted to the driver of a thermal head up to thermal head current supply start timing so as to make a separate timer unnecessary in order to start the thermal head current supply part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer for printing by the heat generated by a thermal head, and more particularly to a thermal printer for controlling the motor phase switching of a stepping motor for driving a carriage and the energization timing of the thermal head. Control method.

[0002]

2. Description of the Related Art In the above-mentioned thermal printer,
While the carriage is running along the platen by the stepping motor, in the thermal printer, the thermal paper is used. In the thermal transfer printer, the thermal head is pressed against the platen through the ink ribbon and the paper. By selectively energizing the elements according to the printing information to heat the heating elements, the thermal paper will develop color in thermal printers and the ink from the ink ribbon will be transferred to the paper in thermal transfer printers for printing. I am supposed to do it.

In such a thermal printer, the timing of switching the phase of the stepping motor and the thermal head energization start timing have conventionally been controlled by separate timers.

FIG. 4 shows an outline of such a conventional thermal printer control method. A timer 1 is provided to control the timing of phase switching of a stepping motor, and the thermal head energization is performed. The timer 2 was provided to control the start timing. Then, the phase of the stepping motor is sequentially switched by the timer 1, and the thermal head energization start timing is controlled by the timer 2. After the start of energization of the thermal head, another timer 3 controls the energization timing of energizing the thermal head (energizing each heating element of the thermal head so as to correspond to print data).

[0005]

In the conventional thermal printer control method described above, a total of three timers must be used for the control directly related to printing. Also many timers are needed. For example, an interface synchronization timer or a watchdog timer for checking whether or not the software for periodically setting a flag is running normally.

[0006] Therefore, if the number of timers used for control directly related to printing can be reduced, a margin is created in the timers, the timers can be diverted to other purposes, and the total number of timers can be reduced to manufacture inexpensively. be able to.

In view of the above-mentioned points, the present invention is a thermal printer which can print with a smaller number of timers than the conventional one, is systemically effective, and can be manufactured at low cost. The purpose is to provide a control method.

[0008]

In order to achieve the above-mentioned object, the control method of the thermal printer according to claim 1 of the present invention is such that when the motor phase switching of the stepping motor for driving the carriage does not coincide with the thermal head energization start timing. In addition, the thermal head energization unit is activated at the motor phase switching timing, and null data is transferred to the driver of the thermal head until the thermal head energization start timing.

According to a second aspect of the present invention, there is provided a thermal printer control method, wherein at least a part of a motor phase switching timing of a stepping motor for driving a carriage coincides with a thermal head energization timing. When the phase switching and the thermal head energization start timing do not match, the thermal head energization section is activated at the motor phase switching timing, and null data is transferred to the thermal head driver until the thermal head energization start timing. ..

Further, according to a third aspect of the present invention, in a thermal printer control method, at least a part of a motor phase switching timing of a stepping motor for driving a carriage coincides with a thermal head energization timing. If the motor phase switching and the thermal head energization start timing do not match, the motor phase switching is started at the startup timing of the thermal head energization section, and the motor phase is switched at each thermal head energization timing that matches the motor phase switching timing. It is characterized in that null data is transferred to the driver of the thermal head until the thermal head energization start timing while switching is performed.

[0011]

According to the thermal printer control method of the first and second aspects of the present invention, since the thermal head energizing section is activated at the motor phase switching timing, a separate timer is used to activate the thermal head energizing section. do not need. Particularly, in the control method for the thermal printer according to the second aspect, at least a part of the motor phase switching timing of the stepping motor coincides with the energization timing of the thermal head, so that the motor phase switching timing coincides with the energization timing of the thermal head. In this case, the timer for measuring one timing can measure the timing for the other, so that the other timer can be used for another purpose.

According to the thermal printer control method of the third aspect of the present invention, the switching of the motor phase is started at the activation timing of the thermal head energizing portion, and the motor phase is changed every integer multiple of the energizing cycle of the thermal head. Since the phase switching is performed, even the motor phase switching can be controlled only by the timer that controls the energization timing of the thermal head.

[0013]

The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment corresponding to the method of controlling a thermal printer according to claim 2 of the present invention.

In the thermal printer of this embodiment,
In particular, the motor phase switching cycle of the stepping motor that drives the carriage is an integral multiple of the energization cycle of the thermal head. Therefore, the motor phase switching timing of the stepping motor always coincides with one of the thermal head energization timings. In FIG. 1, the motor phase switching timing is matched every five thermal head energization timings.

The start timing of the stepping motor for driving the carriage is earlier than the energization start timing of the thermal head corresponding to the print timing which is started after the speed of the carriage is accelerated and becomes constant. Therefore, in the embodiment of FIG. 1, the motor phase switching start timing and the thermal head energization start timing do not match.

Therefore, in the embodiment of FIG. 1, the motor phase switching start timing and each motor phase switching timing are set by the timer 1 as in the conventional case, and the thermal head energization is performed at the motor phase switching start timing. Match the start timing. Therefore, the timer 2 used in the conventional method becomes unnecessary in the embodiment of FIG.

By the way, when the energization of the thermal head is started, after that, it is necessary to transfer the data for selectively energizing each heating element of the thermal head to the driver of the thermal head. However, as described above, the motor phase switching start timing and the thermal head energization start timing are inevitably different from each other in timing, and therefore some timing may be required before the actual printing start controlled by another timer 3. Data needs to be transferred to the thermal head driver. Therefore, in the present invention, dummy data, that is, null data, which is completely blank print data, is transferred to the thermal head driver in place of the actual print data until the actual printing is started. There is. Then, when the actual print timing comes, the actual print data is transferred to the driver of the thermal head.

As described above, according to this embodiment, since the thermal head energization start timing is matched with the motor phase switching start timing, the stepping for driving the carriage is performed without using the timer 2 used in the conventional method. It is possible to control the phase switching of the motor and the start of energization of the thermal head.

In the thermal printer of the above-mentioned embodiment, the motor phase switching cycle of the stepping motor for driving the carriage is set to be an integral multiple of the energization cycle of the thermal head. The timer 2 can be omitted even if the switching cycle is not an integral multiple of the thermal head energization cycle and the motor phase switching timing does not match the thermal head energization timing. However, if there is a case where the motor phase switching timing coincides with the energizing timing of the thermal head, at that time, the motor phase switching timing and the thermal head energizing timing can be measured by the timer 1 or 3 on one side. , The other timer 3 or 1 can be used for other purposes.

In FIG. 1, the motor phase switching cycle is an integral multiple of 5 times the energization cycle of the thermal head, but as shown in FIG. 2, the motor phase switching cycle and the energization of the thermal head are as follows. As in the cycle of 2: 5, only a part of the motor phase switching timing of the stepping motor may coincide with the energization timing of the thermal head.

FIG. 3 shows an embodiment corresponding to the control method of the thermal printer according to claim 3 of the present invention. Regarding FIG. 3, only the configuration different from FIG. 1 will be described. Of course, also in the thermal printer of this embodiment, the motor phase switching cycle of the stepping motor for driving the carriage is an integral multiple of the energization cycle of the thermal head, as in the embodiment of FIG.

This embodiment is a method in which the motor phase switching timing is also controlled only by the timer 3 which controls the thermal head energization timing for actual printing.

In the embodiment of FIG. 3, the thermal head energization start timing is set by the above-mentioned timer 3 which controls the thermal head energization timing for actual printing, and the motor phase switching start timing is also thermal. It is performed in accordance with the head energization start timing. After that, the thermal head energization timing is controlled by the timer 3 every moment, and null data is transferred to the driver of the thermal head instead of the actual print data until the actual printing is started. Then, the actual print data is transferred to the thermal head driver.

On the other hand, each motor phase switching timing is set to be an integral multiple (five times in this embodiment) of the energization timing of the thermal head.

In this embodiment, since the driving timing of the thermal head is associated with the stepping motor that drives the carriage at the slow-up time, the motor phase switching cycle and the thermal head energization cycle are available at the slow-up time of the stepping motor. Becomes gradually shorter and eventually reaches an equilibrium state.

As described above, according to this embodiment, the motor phase switching start timing is matched with the thermal head energization start timing, and the motor phase switching timings are matched with each integral multiple of the thermal head energization timing. It is possible to control the phase switching of the stepping motor for driving the carriage and the start of energization of the thermal head by only the timer 3 without using the timer 1 and the timer 2 used in the conventional method.

The present invention is not limited to the above-described embodiment, but various modifications can be made if necessary.

[0029]

As described above, according to the present invention, it is possible to perform printing with a smaller number of timers than the conventional one, which is effective in terms of system and can be manufactured at low cost. It is possible to achieve the effect.

[Brief description of drawings]

FIG. 1 is a timing diagram showing a first embodiment of a control method for a thermal printer of the present invention.

FIG. 2 is a timing diagram showing a second embodiment of the control method for the thermal printer of the present invention.

FIG. 3 is a timing diagram showing a third embodiment of the thermal printer control method of the invention.

FIG. 4 is a timing diagram showing a control method of a conventional thermal printer.

Claims (3)

[Claims] 1. When the first motor phase switching of the stepping motor for driving the carriage does not coincide with the thermal head energization start timing, the thermal head energization section is activated at the first motor phase switching timing until the thermal head energization start timing. A method of controlling a thermal printer, characterized in that null data is transferred to a driver of a thermal head. 2. In a thermal printer in which at least a part of the motor phase switching timing of a stepping motor for driving a carriage coincides with the energization timing of the thermal head, the first motor phase switching does not coincide with the thermal head energization start timing. In addition, a method for controlling a thermal printer is characterized in that the thermal head energization unit is activated at the first motor phase switching timing, and null data is transferred to the driver of the thermal head until the thermal head energization start timing. 3. In a thermal printer in which at least a part of motor phase switching timing of a stepping motor for driving a carriage coincides with energization timing of a thermal head, the first motor phase switching does not coincide with the thermal head energization start timing. In addition, the switching of the motor phase is started at the activation timing of the thermal head energizing section, and the motor phase is switched at each energizing timing of the thermal head that matches the motor phase switching timing.
A method of controlling a thermal printer, wherein null data is transferred to a driver of the thermal head until the thermal head energization start timing.