JP2003088189A - Driver for stepping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly drive a stepping motor, and to swiftly accelerate the stepping motor to a speed optimum for driving, even when the stepping motor is driven by a speed slower than a drive startable speed. SOLUTION: The base point speed of a speed table 5 is set by a maximum drive startable speed of the stepping motor 2, and speeds slower than the base point speed are set by stages in the speed table 5 on the basis of an acceleration deceleration graph.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepping motor driving device, and more particularly to a stepping motor driving device which drives based on a preset speed table.

[0002]

2. Description of the Related Art Conventionally, stepping motors have been used as means for driving various rotary drive mechanisms such as a paper feed roller of a printer. This stepping motor is generally designed to drive every pulse based on the drive speed set in the speed table. By driving the stepping motor in accordance with the drive speed set in the speed table in this way, The drive of the paper feed roller and the like is controlled. Hereinafter, a conventional example of the speed table will be described.

FIG. 4 is a conceptual diagram showing an example of a conventional speed table. When the drive start speed of the stepping motor is used as a base speed and the fastest speed at which the drive can be started from the beginning is 600 pps, As shown in FIG.
In the conventional speed table, the base speed is set to STEP0,
This base point speed is 600pps (Pulse PerSe
cond), and based on the acceleration / deceleration graph of the stepping motor obtained in the relationship between speed and time in consideration of noise, vibration, etc. when driving the stepping motor as shown in FIG. 600 which is speed
Speeds faster than pps are set in stages.

In the case of driving the stepping motor based on such a conventional speed table, first, when a drive start signal is inputted to the control section for controlling the driving of the stepping motor, the control section is stored in the memory. 600p of STEP0 which is the base speed from the speed table
The speed of ps is extracted, and the driving of the stepping motor is started at the speed of 600 pps. next,
In the case of accelerating the driving of the stepping motor, from the speed table, a speed higher than the base point speed, for example, STEP1
The speed of 700 pps is extracted, and the stepping motor is driven based on the speed of 700 pps.

On the other hand, there are cases where it is necessary to drive the stepping motor at a speed slower than 600 pps, which is the fastest speed at which driving can be started. In such a case, for example, when printing is performed by a line printer using a divided energization control method in which energization to each heating element is divided into several and dividedly driven, and when the number of energized divisions of one line is large. Can be considered. In this case, the speed lower than the base speed is not set in the speed table, so
The control unit drives the stepping motor at the self-starting frequency without using the speed table.

As another conventional speed table,
As shown in FIG. 6, the base speed is set to 100 pps, which is slower than the maximum speed of 600 pps that can start driving the stepping motor, and the speed is gradually set to be higher than 100 pps, which is the base speed. ing.

When the stepping motor is driven on the basis of such another conventional speed table, the control unit uses the speed table to set 100 as the base speed of STEP0.
The speed of pps is drawn to start driving the stepping motor. Next, when accelerating the stepping motor, the speed is drawn from the speed table faster than the base point speed and driven based on the speed. On the other hand, when the stepping motor is driven at a speed lower than 600 pps, which is the highest speed at which the stepping motor can be started, a speed of STEP4 or lower, which is slower than 600 pps, is extracted from the speed table and driven based on the speed. .

[0008]

However, the base point speed as described above is 600 pp which is the fastest speed at which driving can be started.
When driving the stepping motor using the speed table set to s, when driving at a speed slower than 600 pps, the stepping motor is driven at the self-starting frequency, so the acceleration or deceleration of the stepping motor must be controlled. I can't. Therefore, when the stepping motor is driven at a speed of 100 pps, the current driving speed is drastically increased by 100 ps.
After decelerating to ps and driving, when the driving was finished, it was accelerated to 600 pps and driven. For this reason,
Vibration and noise caused by rapid acceleration or deceleration of the stepping motor have been problems.

On the other hand, when the base speed is set to a speed lower than 600 pps, which is the highest speed at which driving can be started, and when the stepping motor is driven at a speed lower than 600 pps, STEP 4 set in the speed table is set. Since the following speeds are driven for driving, acceleration or deceleration can be controlled, and as a result, smooth driving can be performed. However, since the base speed is set to a speed slower than the fastest speed at which driving can be started, driving of the stepping motor is started from the speed of STEP0 slower than 600 pps until the optimum speed for driving the stepping motor is reached. There was a problem that it took time to accelerate.

The present invention has been made in view of these points, and even when the stepping motor is driven at a speed slower than the speed at which the driving can be started, the stepping motor can be driven smoothly and can be driven quickly. It is an object of the present invention to provide a stepping motor drive device capable of accelerating to an optimum speed.

[0011]

In order to achieve the above object, a stepping motor driving device according to the present invention is a stepping motor driving device having a speed table in which a driving speed of a stepping motor is set. The base speed of the table is set to the highest speed at which the driving of the stepping motor can be started, and speeds slower than the base speed are set in stages in the speed table. .

According to the stepping motor drive device of the present invention, since the speed that is slower than the base speed is set in the speed table, the stepping motor is driven at a speed slower than the base speed. However, the acceleration / deceleration of the stepping motor can be controlled. Further, it is not necessary to start driving at a speed lower than the fastest speed at which driving can be started.

Another stepping motor drive device according to the present invention is characterized in that a speed slower than the base point speed set in the speed table is set based on the acceleration / deceleration graph.

According to another stepping motor driving device of the present invention, even when the stepping motor is driven at a speed lower than the base point speed, noise, vibration, etc., which are generated when the stepping motor is driven are taken into consideration in advance. The drive speed of the stepping motor can be controlled based on the acceleration / deceleration graph set in the relationship between speed and time.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a stepping motor drive device according to the present invention will be described below with reference to FIGS.

Here, in the present embodiment, a stepping motor drive device for rotationally driving the paper feed roller of the line printer using the divided energization control method will be described.

FIG. 1 is a conceptual diagram showing a stepping motor driving device 1 according to this embodiment. As shown in FIG. 1, the stepping motor driving device 1 controls the driving of a stepping motor 2. Controller 3 and D
A memory 4 including a RAM and the like is installed.
The memory 4 also stores a speed table 5 in which the driving speed of the stepping motor 2 is set.
In principle, the control unit 3 drives the stepping motor 2 based on the set drive speed set in the speed table 5.

Further, the stepping motor driving device 1
Assuming that the fastest speed at which the stepping motor 2 can be driven is 600 pps, the speed table 5 can start driving the stepping motor 2 as a base speed, as shown in FIG. The speed of 600 pps, which is a normal speed, is set to STEP 0, and the speed higher than the base point speed is determined by taking into consideration noise, vibration, etc. when driving the stepping motor 2 as shown in FIG. Based on the acceleration / deceleration graph of the motor 2, it is set to STEP 1 and below stepwise.
In this embodiment, the base point velocity is 600 pp.
The speed increasing from s to every 100 pps is set stepwise.

Further, in the speed table 5, speeds slower than the base point speed are set stepwise to STEP-1 or higher based on the acceleration / deceleration graph as shown in FIG. In the present embodiment, speeds that gradually decrease from the base point speed of 600 pps to 100 pps are set in stages.

Next, the stepping motor driving device 1
A line printer that uses is explained.

This line printer is provided with a line thermal head having a length dimension capable of facing the recording range in the width direction of the recording medium, and the line thermal head is arranged in the conveying direction of the recording medium. A large number of heating elements are arranged in an orthogonal direction. An energization drive control device for controlling energization drive of the line thermal head is installed in the line printer, and the energization drive control device analyzes the input record information and is used for recording in one line. The energization division number is determined by the number of heating elements, and the line thermal head is energized based on the analyzed recording information for one line and the energization division number.

Next, a method of determining the driving speed of the stepping motor driving device 1 used in the line printer will be described.

The control unit 3 calculates the drive speed of the stepping motor 2 for one line based on the number of power distributions determined by the power drive controller, and sets the calculated drive speed and the speed table 5. Compare the set drive speeds. If the set drive speed is slower, the stepping motor 2 is driven based on the set speed. On the other hand, when the calculation driving speed is slower, the driving speed close to the calculation driving speed is drawn from the speed table 5 and the stepping motor 2 is driven based on the driving speed.

This is because when the number of energized divisions to the line thermal head is large, the time obtained by multiplying the energized time to each heating element by the number of energized divisions is one line of the energizing period of the line thermal head. The energization cycle for a minute becomes longer. Here, the energization cycle and the drive cycle of the stepping motor 2 for rotating the paper feed roller 6 by one line are compared, and when the energization cycle is longer, the stepping motor 2 is efficiently driven. To do so, it is necessary to drive the stepping motor 2 at the same cycle as the energization cycle. Then, when the energization period is longer than the drive period, the operation drive speed is slower than the set drive speed, and therefore it is necessary to drive the stepping motor 2 based on the operation drive speed. This is because the control unit 3 of the stepping motor drive device 1 drives the stepping motor based on the arithmetic drive speed when the arithmetic drive speed is slower than the set drive speed as described above. This is because the calculation driving speed may be slower than the base point speed.

Next, the operation of this embodiment will be described.

According to the present embodiment, the calculated drive speed obtained on the basis of the energization division number for one line is the speed table 5.
When the calculated drive speed is slower than the set drive speed set to, the drive speed close to the calculated drive speed is derived from the speed table 5 even if the calculated drive speed is slower than the base speed set in the speed table 5. Then, the stepping motor 2 is driven based on the driving speed. At this time, in the speed table 5, the speed lower than the base speed is STE.
Since it is set to P-1 or less, the stepping motor 2 is decelerated so that the stepping motor 2 is driven at the drive speed determined based on the calculated drive speed according to the acceleration / deceleration graph shown in FIG. Also, the acceleration / deceleration can be performed according to the record information input thereafter.

Further, among the input record information, the calculated drive speed obtained by the energization division number based on the record information of the first line to start recording is compared with the base point speed set in the speed table 5. Then, when the base speed is slower, the driving of the stepping motor 2 is started based on the base speed set in STEP0.

Therefore, even when the stepping motor 2 is driven at a speed slower than the base point speed, the driving speed of the stepping motor 2 can be controlled by the speed table 5 set based on the acceleration / deceleration graph. Therefore, it is possible to prevent noise, vibration, etc. generated by driving the stepping motor 2, and it is possible to drive the stepping motor 2 smoothly. Further, as a result, good image recording can be obtained by using the stepping motor driving device 1 in a line printer.

Further, when starting the driving of the stepping motor 2, if the base speed is slower than the arithmetic drive speed, the driving of the stepping motor 2 can be started by the base speed, and the driving of the stepping motor 2 is started. Since the speed that can be performed is set in the speed table 5 as the base speed, the stepping motor 2 can be efficiently driven, and the speed can be accelerated to the optimum speed for driving quickly.

In this embodiment, the stepping motor driving device 2 is the paper feed roller 6 of the line printer.
However, the present invention is not limited to this, and may be any one used for a stepping motor that may be driven at a speed lower than the base speed.

Further, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made if necessary.

[0032]

As described above, according to the stepping motor drive device of the present invention, even when the stepping motor is driven at a speed lower than the base speed, the speed table drives the stepping motor. Since the stepping motor can be controlled, it is possible to prevent noise, vibration, etc. generated by the activation of the stepping motor, and it is possible to smoothly drive the stepping motor. Furthermore, the fastest speed that can start driving the stepping motor is set in the speed table as the base point speed, so the stepping motor can be driven efficiently and the speed is accelerated to the optimum speed for driving. Can be made.

According to another stepping motor driving device of the present invention, the driving speed of the stepping motor can be controlled by the speed table set based on the acceleration / deceleration graph. It is possible to further prevent noise, vibration, etc., and to smoothly drive the stepping motor.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of a printer using a stepping motor drive device according to the present invention.

FIG. 2 is a conceptual diagram showing a speed table stored in the stepping motor drive device shown in FIG.

FIG. 3 is an acceleration / deceleration graph serving as a reference for setting the speed table shown in FIG.

FIG. 4 is a conceptual diagram showing a speed table stored in a conventional stepping motor drive device.

5 is an acceleration / deceleration graph serving as a reference for setting the speed table shown in FIG.

FIG. 6 is a conceptual diagram showing a speed table stored in another conventional driving device for a stepping motor.

[Explanation of symbols]

1 Stepping motor drive 2 stepping motor 3 control unit 4 memory 5 speed table 6 Paper feed rollers 7 recording media

Claims (2)

[Claims] 1. A stepping motor drive device having a speed table in which a drive speed of a stepping motor is set, wherein a base speed of the speed table is the fastest speed at which the drive of the stepping motor can be started. A stepping motor drive device, wherein the speed is set and the speeds slower than the base speed are set in stages in the speed table. 2. The stepping motor drive device according to claim 2, wherein a speed slower than a base speed set in the speed table is set based on an acceleration / deceleration graph.