Control device and method for stepper motor that ensure improved performance of stepper motor during activation period

Patent metadata

Field	Value
Publication number	US-9780708-B2
Application number	US-201615154716-A
Country	US
Kind code	B2
Filing date	May 13, 2016
Priority date	May 25, 2015
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A control device for a stepper motor drives in a 1-2-phase excitation method in response to an input of a drive signal. The control device includes a control signal generating unit and a drive signal generating unit. The control signal generating unit generates a pulsed control signal. The drive signal generating unit generates the drive signal for rotating by a predetermined step angle every time the control signal is input. The predetermined step angle is a half of a step angle of a 2-phase excitation method. The control signal generating unit configures a higher pulse rate of a first to an n-th (n is an integer equal to or more than 2 and equal to or less than 3) control signals in an activation period of the stepper motor than a pulse rate of the control signals following the n-th control signal.

First claim

What is claimed is:

1. A control device for a stepper motor that drives in a 1-2-phase excitation method in response to an input of a drive signal, comprising:
a control signal generating unit that generates a pulsed control signal; and
a drive signal generating unit that generates the drive signal for rotating by a predetermined step angle every time the control signal is input, the predetermined step angle being a half of a step angle of a 2-phase excitation method,
wherein the control signal generating unit configures a higher pulse rate of a first to an n-th (n is an integer equal to or more than 2 and equal to or less than 3) control signals at a start of an activation period of the stepper motor than a pulse rate of the control signals following the n-th control signal, and
the control signal generating unit configures a higher converted value than a maximum self-activating frequency of the stepper motor, the converted value being the pulse rate of the first to the n-th control signals converted into a frequency of the control signal.

2. The stepper motor control device according to claim 1 ,
wherein the n is 2.

3. The stepper motor control device according to claim 1 ,
wherein the n is 3.

4. The stepper motor control device according to claim 1 ,
wherein the control signal generating unit configures a higher pulse rate of the first to the n-th control signals than a pulse rate of the control signal in a constant speed operation of the stepper motor.

5. A control device for a stepper motor that drives in a W1-2-phase excitation method in response to an input of a drive signal, comprising:
a control signal generating unit that generates a pulsed control signal; and
a drive signal generating unit that generates the drive signal for rotating by a predetermined step angle every time the control signal is input, the predetermined step angle being a quarter of a step angle of a 2-phase excitation method,
wherein the control signal generating unit configures a higher pulse rate of a first to an n-th (n is an integer equal to or more than 4 and equal to or less than 7) control signals at a start of an activation period of the stepper motor than a pulse rate of the control signals following the n-th control signal, and
the control signal generating unit configures a higher converted value than a maximum self-activating frequency of the stepper motor, the converted value being the pulse rate of the first to the n-th control signals converted into a frequency of the control signal.

6. The stepper motor control device according to claim 5 ,
wherein the n is 4.

7. The stepper motor control device according to claim 5 ,
wherein the n is an integer equal to or more than 5 and equal to or less than 7.

Assignees

• Kyocera Document Solutions Inc

Inventors

• Ishida Hirotaka

Classifications

• H02P8/04 Primary

  Arrangements for starting · CPC title

• H02P8/18

  Shaping of pulses, e.g. to reduce torque ripple {(Reducing overshoot H02P8/32 takes precedence)} · CPC title

• H02P29/50

  Reduction of harmonics · CPC title

• H02P8/22

  Control of step size; Intermediate stepping, e.g. microstepping · CPC title