JPH04150798A - Drive controller for step motor - Google Patents

Abstract

PURPOSE:To lessen the vibration and noises of a motor at time of stopping it using a control method of stopping it without a deceleration period, by causing to output to a motor controlling means a driving signal which causes currents to flow into coils, for a constant time after stopping applying exciting voltage. CONSTITUTION:The output 16 of a power source does not lower immediately after a power supply control signal 10 is cut off. If a CPU 4 outputs a motor control signal 11 for time T after the power supply control signal 10 is cut off, motor current 13 flows for the time T. Since the motor current flows during the slash section 20, the step motor 1 rotates in accordance with the driving current during that time also even after the power supply control signal 10 is cut off. And as the motor current 13 lowers, the motor 1 gradually becomes unable to follow the motor control signal 11 being the same control speed as that in time of a constant speed, and stops finally. In this way, as a result of allowing the motor to rotate by the inertia during the stopping movement of the motor, the generation of noises and vibration is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a step motor drive control device that can stop the step motor used for driving the optical system of a copying machine in a good condition. Regarding.

[Prior art] Conventionally, in drive stop control of a step motor, the third
As shown in the figure, deceleration control is usually performed after acceleration and constant speed control. In particular, when stopping, a memory for deceleration drive pulse data as shown in FIG. 4 or a deceleration program as shown in the flowchart shown in FIG. 5 is required. Furthermore, if the step motor drive torque has too much margin, this will cause noise and vibration during deceleration. Therefore, for example, JP-A-62-118
As shown in Japanese Patent No. 794, there is a system in which the amount of current supplied is controlled during deceleration.

However, all of these stop control methods require program software for the deceleration routine, a drive pulse during deceleration, and drive current amount control means, and require a large amount of memory.

Furthermore, if the stop position is not important, there is also a control method that does not include a deceleration period, as shown in FIG.

In this case, since there is no need to use deceleration pulses, the memory used can be reduced, and the
There is no need to configure a deceleration routine as program software for A motion.

[Problem to be solved by the invention] By the way, in this control method of stopping the step motor from a constant speed state without a deceleration period, the motor control signal is abruptly turned off, so the motor drive current is rapidly reduced. It disappears. In contrast, a motor tends to rotate due to inertia. For this reason, noise and vibration are likely to occur when the motor is stopped.

The present invention has been made in order to solve the above-mentioned problems, and provides a step motor that uses a control method that stops without a deceleration period and can reduce vibration and noise when stopping. An object of the present invention is to provide a drive control device.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a power supply means for applying an excitation voltage to a coil of a step motor, a power supply control means for controlling the power supply means, and a power supply means for applying an excitation voltage to a coil of a step motor. In a step motor drive control device comprising a motor drive control means for controlling energization to the coil and controlling the motor drive, the energization to the coil is stopped for a certain period of time after the excitation voltage is no longer applied by the power supply means. A drive signal that enables the motor drive control means is output to the motor drive control means.

[Function] With the above configuration, the power supply means supplies excitation current to the step motor, the power supply control means controls the power supply means, the motor drive control means performs drive control of the step motor, and the step motor is driven. A drive signal is output to the motor drive control means for a certain period of time after the voltage is no longer supplied by the power supply means. Therefore, a current that gradually decreases due to rotational energy due to inertia flows through the coil of the motor for the certain period of time.

[Example 1] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a step motor drive control device according to this embodiment.

The personal step motor drive control device includes a power supply means 2 that supplies excitation current to the step motor 1, a step motor drive circuit 3 that drives the step motor 1, and a CP that controls the step motor drive circuit 3 and the power supply means 2.
It is composed of U4. The step motor 1 has C
A power control signal is outputted from the PU 4 to the power supply hand P12 via the power supply signal bus 6, whereby power is supplied to the step motor 1. Further, an excitation signal (motor control signal) is outputted from the CPU 4 to the step motor drive circuit 3 via an excitation signal bus, so that an excitation current (motor current) flows through the step motor 1.

FIG. 2 shows the control timing of this embodiment.

Even if the power supply control signal 10 is turned off, the power supply output 16 does not drop immediately; the time T after this power supply control signal 10 is turned off
If the motor control signal 11 is output from the CPU 4 only during this period, the motor current 13 will flow during the period T.

Conventionally, the motor control signal 11 was turned off at the same timing as the power supply control signal 10, as shown by the broken line 12, so the motor current immediately became zero, as shown by the broken line 14. Since the motor current in the embodiment flows only in the shaded portion 20, the step motor 1 continues to rotate in accordance with the drive current even after the power supply control signal 10 is turned off during that time. And step motor 1
As the motor current 13 decreases, the motor gradually stops following the motor control signal 11 at the same control speed as at constant speed, and finally stops. As a result of allowing the motor to rotate due to inertia when the motor is stopped, the generation of noise and vibration is prevented.

Incidentally, the present invention is not limited to the above-mentioned example, and various modifications are possible. Further, the time T of the motor control signal 11 output from the CPU 4 after the power control signal 10 is turned off may be appropriately set in consideration of the characteristics of the motor and the load.

[Effects of the Invention] As described above, according to the present invention, a drive signal that enables energization of the coil is sent to the motor drive control means for a certain period of time after the excitation voltage is no longer applied to the motor coil by the power supply means. Since the step motor is outputted, stop control of the step motor drive when there is no deceleration period can be performed with reduced vibration and noise.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a step motor drive control device according to an embodiment of the present invention, Fig. 2 is a timing chart of the control of the same device, and Fig. 3 shows the operation of the step motor when using acceleration/deceleration. FIG. 4 is a diagram showing the drive data of the step motor when acceleration/deceleration is used, FIG. 5 is a flowchart thereof, and FIG. 6 is a diagram showing the operation of the step motor when there is no deceleration. 1... Step motor, 2... Power supply means, 3.
・・Step motor drive circuit (motor drive control means),
4...CPU (power control means). Figure Figure Figure Figure Figure

Claims (1)

[Claims] (1) A power supply means for applying an excitation voltage to the coil of a step motor, a power supply control means for controlling the power supply means, and a motor drive control means for controlling energization of the coil by the excitation voltage to control motor drive. A step motor drive control device comprising: a drive signal that enables energization of the coil for a certain period of time after the excitation voltage is no longer applied by the power supply means to the motor drive control means; A step motor drive control device characterized by: