Stepping motor control circuit, semiconductor device, and analog electronic timepiece

Patent metadata

Field	Value
Publication number	US-9729095-B2
Application number	US-201514735432-A
Country	US
Kind code	B2
Filing date	Jun 10, 2015
Priority date	Jul 30, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A stepping motor control circuit includes a drive pulse generation section that generates forward-rotation drive pulses that drive a stepping motor stepwise in a forward rotation direction and reverse-rotation drive pulses that drive the stepping motor stepwise in a reverse rotation direction and a forward/reverse rotation switching control section that switches the drive pulses outputted to the stepping motor from one of the forward-rotation drive pulses and the reverse-rotation drive pulses to the other, and the forward/reverse rotation switching control section switches the drive pulses outputted to the stepping motor from one of the forward-rotation drive pulses and the reverse-rotation drive pulses to the other and then provide a predetermined period before the other drive pulses are outputted to the stepping motor.

First claim

What is claimed is:

1. A stepping motor control circuit that controls a stepping motor driven stepwise in a forward rotation direction or a reverse rotation direction based on a drive pulse, the control circuit comprising:
a drive pulse generation section that generates, as the drive pulse, a forward-rotation drive pulse that drives the stepping motor stepwise in the forward rotation direction and a reverse-rotation drive pulse that drives the stepping motor stepwise in the reverse rotation direction; and
a forward/reverse rotation switching control section that switches the drive pulse outputted to the stepping motor from one of the forward-rotation drive pulse and the reverse-rotation drive pulse to the other one of the forward-rotation drive pulse and the reverse-rotation drive pulse in response to a control input to reverse a rotation direction of the stepping motor, and
outputs the other one of the forward-rotation drive pulse and the reverse-rotation drive pulse to the stepping motor subsequent to the control input after a predetermined period has elapsed from the one of the forward-rotation drive pulse and the reverse-rotation drive pulse is outputted to the stepping motor prior to the control input.

2. The stepping motor control circuit according to claim 1 ,
wherein the predetermined period is an integer multiple of one cycle of the one of the forward-rotation drive pulse and the reverse-rotation drive pulse.

3. A semiconductor device comprising the stepping motor control circuit according to claim 2 .

4. An analog electronic timepiece comprising:
an indicating hand;
a stepping motor that is driven stepwise based on inputted drive pulses to move the indicating hand in a forward rotation direction or a reverse rotation direction; and
the stepping motor control circuit according to claim 2 .

5. The stepping motor control circuit according to claim 1 ,
wherein the predetermined period is an integer multiple of the sum of one cycle of the one of the forward-rotation drive pulse and the reverse-rotation drive pulse and one cycle of the other one of the forward-rotation drive pulse and the reverse-rotation drive pulse.

6. A semiconductor device comprising the stepping motor control circuit according to claim 5 .

7. An analog electronic timepiece comprising:
an indicating hand;
a stepping motor that is driven stepwise based on inputted drive pulses to move the indicating hand in a forward rotation direction or a reverse rotation direction; and
the stepping motor control circuit according to claim 5 .

8. The stepping motor control circuit according to claim 1 ,
wherein the predetermined period is produced in a masking process.

9. A semiconductor device comprising the stepping motor control circuit according to claim 8 .

10. An analog electronic timepiece comprising:
an indicating hand;
a stepping motor that is driven stepwise based on inputted drive pulses to move the indicating hand in a forward rotation direction or a reverse rotation direction; and
the stepping motor control circuit according to claim 8 .

11. A semiconductor device comprising the stepping motor control circuit according to claim 1 .

12. An analog electronic timepiece comprising:
an indicating hand;
a stepping motor that is driven stepwise based on inputted drive pulses to move the indicating hand in a forward rotation direction or a reverse rotation direction; and
the semiconductor device according to claim 11 .

13. An analog electronic timepiece comprising:
an indicating hand;
a stepping motor that is driven stepwise based on inputted drive pulses to move the indicating hand in a forward rotation direction or a reverse rotation direction; and
the stepping motor control circuit according to claim 1 .

14. The analog electronic timepiece according to claim 13 ,
wherein the analog electronic timepiece is a chronograph timepiece in which the indicating hand is formed of a plurality of indicating hands.

15. The stepping motor control circuit according to claim 1 ,
wherein the control input is inputted manually by a user.

Assignees

• Seiko Epson Corp
• Sieko Epson Corp

Inventors

• Yamada Osami

Classifications

• H02P8/06 Primary

  in selected direction of rotation · CPC title

• G04C3/143

  Means to reduce power consumption by reducing pulse width or amplitude and related problems, e.g. detection of unwanted or missing step · CPC title

• H02P8/02

  specially adapted for single-phase or bi-pole stepper motors, e.g. watch-motors, clock-motors · CPC title