JP2878011B2 - Printer drive control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer drive control method, and more particularly to a printer drive control method capable of increasing the efficiency of interrupt processing by a CPU and increasing the printing speed.

[0002]

2. Description of the Related Art In general, a thermal head is mounted on a carriage which is reciprocally movable along a platen, and the thermal head is operated while moving the carriage so that the thermal head is moved between the platen and the thermal head. 2. Description of the Related Art Thermal printers that perform desired printing by transferring ink from an ink ribbon to a conveyed sheet are often used.

In such a thermal printer,
The CPU for controlling the printer outputs drive control signals to the thermal head, a carriage drive motor including a stepping motor for driving the carriage, and a winding drive motor including a stepping motor for winding the ink ribbon. Thus, desired print control is performed.

Conventionally, an interrupt request is issued from the timer for the thermal head and the timer for the carriage drive motor or the take-up drive motor at separate periods, and the CPU issues an interrupt request from each of these timers. In addition, interrupt processing for outputting a drive control signal independently of the thermal head and the carriage drive motor is performed.

[0005]

However, in the conventional printer drive control means, the thermal head and the carriage drive motor or the take-up drive motor are driven by a separate timer in response to interrupt requests made at different periods. Since the interrupt processing for outputting the drive control signal is performed, the efficiency of the interrupt processing by the CPU is extremely low. In addition, when an interrupt is requested, the energizing control of the thermal head and the driving of the carriage drive motor or the take-up drive motor are performed. In addition to the original interrupt processing called control,
Since processing such as calculation of an interrupt address specific to interrupt processing and saving of registers are performed, the content of interrupt processing by the CPU becomes extremely large, and there is a problem that the CPU processing cannot catch up. As a result, the thermal head and the carriage driving motor,
There is a problem that interrupt processing for the winding drive motor cannot be performed at a high speed, and the printing speed cannot be increased to a certain speed or more.

Further, since it is necessary to provide a timer for the thermal head and a timer for the motor, there is also a problem that the structure is complicated and the manufacturing cost is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a simple configuration, is inexpensive, can increase the efficiency of interrupt processing by a CPU, and can increase the printing speed. It is an object of the present invention to provide a driving control method.

[0008]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a CPU for controlling the driving of a printer when a timer interrupt is requested; by performing the interrupt processing for outputting a drive control signal to more than one stepping motor for performing driving such taken simultaneously, the drive control method for a printer for performing printing drive control, the drive timing of each of the stepping motor A cycle ratio is set to be an integer ratio, and a drive control signal for each of the stepping motors is simultaneously output in each cycle when interrupting the CPU by an interrupt request from one timer. Is what you do.

[0009]

[0010]

According to the first aspect of the present invention, the ratio of the cycle of the drive timing of two or more stepping motors is set to be an integer ratio, and the CP by the interrupt request of one timer.
At the time of the interrupt processing of U, since the drive control signals of the stepping motors are simultaneously output in each cycle,
Ri by the single interrupt request by one timer, 2 or more can be performed a plurality of drive control of the stepping motor, as a result, it is possible to reduce the content of the interrupt processing, considerably the efficiency of the interrupt processing by the CPU This allows the CPU to perform more marginal interrupt processing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 and FIG. 2 show an embodiment of a thermal printer to which the method for controlling the drive of a printer according to the present invention is applied. A main body frame 1 is provided with an elongated flat platen 2. A guide shaft 3 is provided between the left and right frames 1 a and 1 b, which are part of the main body frame 1, substantially parallel to the platen 2. A carriage 4 is hung over the front frame 1c of the main body frame 1 and is slidably mounted on the guide shaft 3 along the axial direction of the guide shaft 3. A thermal head 5 having a plurality of heating elements formed on the opposite surface of the platen 2 is mounted so as to be capable of driving toward and away from the platen 2. A take-up bobbin 6 for taking up an ink ribbon accommodated in a ribbon cassette (not shown) is provided on the upper surface of the carriage 4, and the guide edge is provided at an inner edge of the front frame 1c. A rack 7 is formed parallel to the shaft 3.

Further, on the rear upper surface of the platen 2,
A paper insertion port 8 for supplying a predetermined paper is formed,
Below the platen 2, a paper feed roller 9 for conveying the paper supplied from the paper insertion slot 8 between the platen 2 and the thermal head 5, and a pressure roller 10 pressed against the paper feed roller 9 are rotatably arranged. Has been established. A paper feed motor 12 is connected to the paper feed roller 9 via a reduction gear group 11.
The paper feed motor 9 is rotated by the rotation of the paper feed motor 12 to convey the paper sandwiched between the paper feed roller 9 and the pressure roller 10.

A carriage driving motor 13 composed of a stepping motor is provided inside the carriage 4. An output pinion 14 of the carriage driving motor 13 has a carriage meshed with the rack 7. The drive gear 15 is engaged. The carriage 4 is driven to reciprocate along the guide shaft 3 by forward and reverse rotation of the carriage drive motor 13. Further, inside the carriage 4,
A winding drive motor 16 composed of a stepping motor is provided, and an output pinion 17 of the winding drive motor 16 is connected to the winding bobbin 6 via a transmission gear 18.
And a take-up drive gear 19 coaxially attached to the gear.

FIG. 3 shows an embodiment of the control device of the thermal printer. The CPU 20 for controlling the printer includes the thermal head 5, the carriage driving motor 13 and the winding drive motor 16 as shown in FIG. Are connected to each other, and the CPU 20 includes a timer 21
Interrupt processing for outputting a drive control signal to the thermal head 5, the carriage drive motor 13 and the take-up drive motor 16 at a predetermined timing according to the interrupt request. In the present embodiment,
By adjusting the gear ratio of the carriage drive gear 15, the cycle of the drive timing of the carriage drive motor 13 is set to be an integer ratio with respect to the cycle of the print drive timing of the thermal head 5. When the CPU 20 performs an interrupt process in response to an interrupt request from the timer 21, drive control signals for the thermal head 5 and the carriage drive motor 13 are simultaneously output.

Next, a drive control method according to this embodiment will be described with reference to FIG.

In this embodiment, the CPU 20 comprises:
When an interrupt request is issued by the timer 21, a drive control signal is output to the thermal head 5 and the carriage drive motor 13 based on a predetermined print signal, whereby the rotation of the carriage drive motor 13 is performed. The carriage 4 via the carriage drive gear 15
While moving the head, a desired heating element of the thermal head 5 is energized, and the heat of the heating element melts the ink of the ink ribbon to perform desired printing.

In this case, in the present embodiment, the ratio of the cycle of the driving timing of the thermal head 5 to the timing of the timing of the carriage driving motor 13 is set to 1: 2. A drive control signal is output and interrupt request timing 2
A drive control signal is output to the carriage drive motor 13 at the same time as a drive control signal to the thermal head 5 at a time. Thus, two driving controls of the thermal head 5 and the carriage driving motor 13 can be performed by one interrupt request from one timer 21.

Therefore, in this embodiment, two driving controls of the thermal head 5 and the carriage driving motor 13 can be performed by one interrupt request from one timer 21, so that the content of the interrupt processing is reduced. Therefore, the efficiency of the interrupt processing by the CPU 20 can be remarkably increased, and the CPU 20 can perform a marginal interrupt processing. As a result, interrupt processing for the thermal head 5 and the carriage driving motor 13 can be performed at high speed, and the printing speed can be increased.

Also, since the thermal head 5 and the carriage driving motor 13 can be controlled by one timer 21, a plurality of timers 21 are not required as in the prior art, and the structure is simple, easy and easy. , And can be manufactured at low cost.

As another embodiment of the present invention, the carriage driving motor 13 and the winding drive motor 16 may be synchronized.

In this case, by adjusting the gear ratio of the carriage drive gear 15 and the gear ratio of the take-up drive gear 19, respectively, the cycle of the drive timing of the carriage drive motor 13 and the take-up drive motor 1
6 is set to be an integer ratio with the drive timing cycle.
The drive control signal for the carriage drive motor 13 and the take-up drive motor 16 is simultaneously output when the interrupt processing is performed by the control unit 20. Other configurations are the same as those of the above embodiment.

In this embodiment, as shown in FIG.
The CPU 20 outputs a drive control signal to the carriage drive motor 13 and the take-up drive motor 16 based on a predetermined print signal when an interrupt request is issued by the timer 21. The carriage 4 is moved via the carriage drive gear 15 by the rotation of the motor 13, and the winding bobbin 6 is rotated by the rotation of the winding drive motor 16 via the transmission gear 18 and the winding drive gear 19, respectively. While winding the ink ribbon of the cassette, a desired heating element of the thermal head 5 is energized, and the heat of the heating element melts the ink of the ink ribbon to perform desired printing. in this case,
The drive of the thermal head 5 is independently controlled.

In this case, in this embodiment, the ratio of the cycle of the timing of the carriage drive motor 13 to the cycle of the take-up drive motor 16 is set to 1: 2, and the carriage drive motor 13 is set at each interrupt request timing. A drive control signal to the carriage drive motor 13 and a drive control signal to the carriage drive motor 13 at a rate of once every two interrupt request timings.
A drive control signal. Thereby, by one interrupt request by one timer 21,
Carriage drive motor 13 and winding drive motor 1
6 can be performed.

Therefore, in this embodiment, two drive controls of the carriage drive motor 13 and the take-up drive motor 16 can be performed by one interrupt request from one timer 21. In addition, the content of interrupt processing can be reduced,
20, the efficiency of the interrupt processing by the CPU 20 can be remarkably increased, and the CPU 20 can perform a marginal interrupt processing. As a result, the interrupt processing can be performed at a high speed, and the printing speed can be increased. .

Further, since the control can be performed by one timer 21, a plurality of timers 21 are not required unlike the related art, the structure is simplified, and the manufacturing can be performed easily and at low cost.

The present invention is not limited to the above embodiment, but can be variously modified as needed.

[0028]

As described above, the drive control method of the printer according to the present invention can perform a plurality of drive controls of two or more stepping motors by one interrupt request by one timer. Can be significantly reduced, the efficiency of interrupt processing by the CPU can be significantly increased, the CPU can perform more marginal interrupt processing, and as a result, the interrupt processing can be performed at high speed, and the printing speed can be improved. Can be made faster. In addition, since the control can be performed by one timer, a plurality of timers are not required, and the structure is simplified, and it is possible to easily and inexpensively manufacture.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a thermal printer for applying a printer drive control method according to the present invention.

FIG. 2 is a plan view of a carriage part of FIG. 1;

FIG. 3 is a block diagram showing an embodiment of a control device of the thermal printer of FIG. 1;

FIG. 4 is a timing chart of a drive control signal according to the drive control method of the present invention.

FIG. 5 is a timing chart of a drive control signal according to another drive control method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body frame 2 Platen 4 Carriage 5 Thermal head 6 Take-up bobbin 13 Carriage drive motor 15 Carriage drive gear 16 Take-up drive motor 19 Take-up drive gear 20 CPU 21 Timer

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/32-2/325 B41J 2/35-2/355 B41J 29/38 B41J 19/18 B41J 23/00 B41J 5 / 30 B41J 33/00 H02P 8/00

Claims (1)

(57) [Claims] To 1. A when an interrupt request by the timer, the CPU for performing drive control of the printer, a drive control signal to more than one stepping motor for performing winding drive, etc. reciprocating or ink ribbon carriage same
A printer drive control method for performing print drive control by performing interrupt processing that is output at
The setting ratio of the period of the driving timing of each of the stepping motors to be an integral ratio, when the interrupt processing of the CPU according to the interrupt request of one timer, at the same time outputs a drive control signal of the respective stepping motors for each cycle And a drive control method for the printer.