Electronic apparatus including a motor driving device

Patent metadata

Field	Value
Publication number	US-9690288-B2
Application number	US-201514721506-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	May 30, 2014
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

The present invention provides a motor driving device for easily and accurately detecting an abnormal status of a motor. The motor driving device ( 21 ) includes a control circuit ( 100 ) for generating a driver control signal (S 10 ); a driving circuit ( 200 ) for generating a motor driving signal (S 3 ) according to the driver control signal (S 10 ); an initial position detecting circuit ( 300 ) for detecting an initial position of a motor ( 22 ); and a rotation detecting circuit ( 400 ) for detecting a rotation status of the motor ( 22 ). Before the motor ( 22 ) starts to rotate normally, the control circuit ( 100 ) repeatedly performs a serial activation processing including detecting an initial position; applying an initial torque and detecting a motor rotation, and when the repetition number reaches a threshold value “m” (for example, m=5), the motor ( 22 ) is forced stop.

First claim

What is claimed is:

1. An electronic apparatus, comprising:
a motor driving device integrated as a semiconductor device, the motor driving device comprising:
a control circuit operable to generate a driver control signal;
a driving circuit operable to generate a motor driving signal according to the driver control signal;
an initial position detecting circuit operable to detect an initial position of a motor; and
a rotation detecting circuit operable to detect a rotation status of the motor,

wherein before the motor starts rotate normally, the control circuit repeatedly performs a serial activation processing including detecting an initial position, applying an initial torque and detecting a motor rotation, and forces to stop driving the motor when a repetition number reaches a threshold value;
a sensorless motor driven by the semiconductor device;
a digital signal processor operable to generate a target rotation speed signal; and
a PLL (phase locked loop) circuit operable to generate an acceleration signal and a deceleration signal to the semiconductor device by performing a phase synchronization control of the target rotation speed signal input from the digital signal processor and a motor rotation speed signal input from the semiconductor device.

2. The electronic apparatus of claim 1 , further comprising:
a first substrate to support the digital signal processor and the PLL circuit; and
a second substrate to support the semiconductor device and the sensorless motor.

3. The electronic apparatus of claim 1 , wherein the initial position detecting circuit is operable to detect the initial position by inductive sensing.

4. The electronic apparatus of claim 1 , wherein the rotation detecting circuit is operable to monitor voltage induced in a motor coil, for detecting the rotation status of the motor.

5. The electronic apparatus of claim 4 , wherein
the rotation detecting circuit is operable to generate a zero crossing signal for each phase according to the voltage induced in the motor coil, and to generate a motor rotation speed signal corresponding to a motor rotation speed according to the zero crossing signal of each phase, and
the control circuit is operable to monitor the zero crossing signal of each phase or the motor rotation speed signal for detecting whether the rotation status of the motor is normal.

6. The electronic apparatus of claim 1 operable such that when the rotation status of the motor becomes abnormal, the control circuit performs the activation processing again.

7. The electronic apparatus of claim 1 operable such that during the activation processing, the control circuit repeatedly performs multiple sets of the detecting an initial position and the applying an initial torque, and then performs the motor rotation detection.

Assignees

• Rohm Co Ltd

Inventors

• Kunida Yuji
• Yoshiya Takashi

Classifications

• H02P1/022 Primary

  Security devices, e.g. correct phase sequencing · CPC title

• H02H7/0851

  for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal · CPC title

• H02P29/0241

  the fault being an overvoltage · CPC title

• H02P1/029

  Restarting, e.g. after power failure · CPC title

• G05B23/00 Primary

  Testing or monitoring of control systems or parts thereof (monitoring of program-control systems G05B19/048, G05B19/406) · CPC title