Motor control device, sheet conveying device, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9944482-B2
Application number	US-201615198154-A
Country	US
Kind code	B2
Filing date	Jun 30, 2016
Priority date	Jul 2, 2015
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A motor control device includes: an electric-current detection unit configured to detect an electric current that flows through a motor at a time when the motor is not to be driven; a voltage-polarity determining unit configured to determine polarity of a voltage corresponding to the detected electric current; and an operating-state management unit configured to perform control of stopping the motor depending on the polarity of the voltage.

First claim

What is claimed is:

1. A motor control device comprising:
an electric-current detection unit configured to detect an electric current that flows toward a ground from a power supply passing through a motor at a time when the motor is not to be driven;
a voltage-polarity determining unit configured to determine a polarity of a voltage corresponding to the detected electric current; and
an operating-state management unit configured to perform control of the motor depending on the polarity of the voltage corresponding to the detected electric current, including controlling stopping the motor in response to the polarity of the voltage being positive.

2. The motor control device according to claim 1 , wherein the operating-state management unit notifies a host control device that the motor is being rotated from outside in response to the polarity of the voltage being negative.

3. The motor control device according to claim 1 , wherein the electric-current detection unit is a shunt resistor used for detection of over-current during a time when the motor is to be driven.

4. A sheet conveying device comprising:
the motor control device according to claim 1 ;
the motor; and
a roller member configured to rotate by power of the motor and convey a sheet.

5. An image forming apparatus comprising:
the sheet conveying device according to claim 4 ; and
an image forming unit configured to form an image on the conveyed sheet.

6. A motor control device comprising:
an electric-current detection unit configured to detect an electric current that flows toward a ground from a power supply passing through a motor at a time when the motor is not to be driven;
a voltage-polarity determining unit configured to determine a polarity of a voltage corresponding to the detected electric current; and
an operating-state management unit configured to
perform control of stopping the motor depending on the polarity of the voltage, and
notify a host control device that an abnormality has occurred in response to stopping the motor.

7. A motor control device comprising:
an electric-current detection unit configured to detect an electric current that flows toward a ground from a power supply passing through a motor at a time when the motor is not to be driven;
a voltage-polarity determining unit configured to determine a polarity of a voltage corresponding to the detected electric current in response to a value of the voltage exceeding a reference value; and
an operating-state management unit configured to perform control of stopping the motor depending on the polarity of the voltage.

8. A motor control device comprising:
an electric-current detection unit configured to detect an electric current that flows toward a ground from a power supply passing through a motor at a time when the motor is not to be driven;
a voltage-polarity determining unit configured to determine a polarity of a voltage corresponding to the detected electric current;
an operating-state management unit configured to perform control of stopping the motor depending on the polarity of the voltage;
a control-signal output unit configured to output a drive signal corresponding to a control voltage to be applied to the motor and a brake signal to stop the motor; and
a motor driver configured to drive the motor based on the drive signal and interrupt power to the motor in response to the brake signal being turned on, wherein the operating-state management unit is configured to instruct the control-signal output unit to turn on the brake signal to stop the motor.

9. The motor control device according to claim 8 , wherein:
the motor driver includes a first terminal for inputting the drive signal, a second terminal for inputting the brake signal, and a third terminal for inputting a start/stop signal, and drives the motor based on the input drive signal in response to the start/stop signal indicating a start,
the first terminal for inputting the drive signal and the second terminal for inputting the brake signal are coupled to the control-signal output unit via respective harnesses, and
an output to the third terminal for inputting the start/stop signal is fixed to indicate the start.

10. The motor control device according to claim 9 , wherein the second terminal for inputting the brake signal is made such that the brake signal is fixed to on in response to an abnormality occurring on a harness connecting the second terminal and the control-signal output unit.

11. The motor control device according to claim 8 , wherein the electric-current detection unit is a shunt resistor used for detection of over-current during a time when the motor is to be driven.

12. A sheet conveying device comprising:
the motor control device according to claim 8 ;
the motor; and
a roller member configured to rotate by power of the motor and convey a sheet.

13. An image forming apparatus comprising:
the sheet conveying device according to claim 12 ; and
an image forming unit configured to form an image on the conveyed sheet.

14. A sheet conveying device comprising:
a motor;
a motor control device; and
a host control device,
the motor control device comprising:
an electric-current detection unit configured to detect an electric current that flows through the motor at a time when the motor is not to be driven;
a voltage-polarity determining unit configured to determine whether the motor is erroneously operating depending on polarity of a voltage corresponding to the detected electric current; and
an operating-state management unit configured to notify the host control device that abnormality has occurred in response to the motor being determined to be erroneously operating, and notify the host control device that the motor is being rotated from outside in response to the motor being determined to be not erroneously operating,

the host control device comprising a host operation-command unit configured to output an abnormal stop command to stop overall operation of the sheet conveying device in response to notification that the abnormality has occurred from the operating-state management unit, and cause the sheet conveying device to continue to operate without outputting the abnormal stop command in response to notification that the motor is being rotated from outside from the operating-state management unit.

15. The sheet conveying device according to claim 14 , wherein the operating-state management unit performs control of stopping the motor in response to the motor being determined to be erroneously operating.

16. The sheet conveying device according to claim 15 , wherein
the host control device further comprises a motor operation-command unit configured to output a stop command of the motor to the operating-state management unit in response to notification that the abnormality has occurred from the operating-state management unit, and
the operating-state management unit performs control of stopping the motor in response to the stop command output from the motor operation-command unit.

17. An image forming apparatus comprising:
the sheet conveying device according to claim 14 ; and
an image forming unit configured to form an image on a conveyed sheet,
the abnormal stop command output by the host operation-command unit being configured to stop overall operation of the image forming apparatus.

Assignees

• Asano Yoshihiro
• Nagatsuka Shingo
• Murata Takuya
• Kurosu Kentaroh
• Takahashi Motoharu
• Ricoh Co Ltd

Inventors

• Asano Yoshihiro
• Nagatsuka Shingo
• Murata Takuya
• Kurosu Kentaroh
• Takahashi Motoharu

Classifications

• B65H7/20 Primary

  Controlling associated apparatus · CPC title

• B65H2220/02

  indicating an entity which is controlled, adjusted or changed by a control process, i.e. output · CPC title

• B65H2515/702

  Operations & Transport · mapped topic

• H02P3/025

  holding the rotor in a fixed position after deceleration · CPC title

• B65H2801/06

  Office-type machines, e.g. photocopiers · CPC title