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

Patent metadata

Field	Value
Publication number	US-2017001822-A1
Application number	US-201615198154-A
Country	US
Kind code	A1
Filing date	Jun 30, 2016
Priority date	Jul 2, 2015
Publication date	Jan 5, 2017
Grant date	—

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 he 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 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.

2 . The motor control device according to claim 1 , wherein, assuming that the polarity of the voltage corresponding to the electric current that flows toward a ground from a power supply passing through the motor is positive, the operating-state management unit performs the control of stopping the motor if the polarity of the voltage is positive.

3 . The motor control device according to claim 1 , wherein the operating-state management unit notifies a host control device that abnormality has occurred if stopping the motor.

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

5 . The motor control device according to claim 1 , wherein the voltage-polarity determining unit determines the polarity or the voltage if a value of the voltage exceeds a reference value.

6 . The motor control device according to claim 1 , further comprising:
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 if the brake signal is on, wherein the operating-state management unit instructs the control-signal output unit to turn on the brake signal to stop the motor.

7 . The motor control device according to claim 6 , wherein the motor driver includes a terminal for inputting the drive signal, a terminal for inputting the brake signal, and a terminal for inputting a start/stop signal, and drives the motor based on the input drive signal if the start/stop signal indicates a start,
the terminal for inputting the drive signal and the terminal for inputting the brake signal are coupled to the control-signal output unit via respective harnesses, and an output to the terminal for inputting the start/stop signal is fixed to indicate the start.

8 . The motor control device according to claim 7 , wherein the terminal for inputting the brake signal is made such that the brake signal is fixed to on if abnormality occurs on the harness connecting the terminal and the control-signal output unit.

9 . 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.

10 . A motor control device comprising:
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; and 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.

11 . 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.

12 . An image forming apparatus comprising:
the sheet conveying device according to claim 11 ; and an image forming unit configured to form an image on the conveyed sheet.

13 . 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.

14 . The sheet conveying device according to claim 13 , wherein the operating-state management unit performs control of stopping the motor in response to the motor being determined to be erroneously operating.

15 . The sheet conveying device according to claim 14 , 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.

16 . An image forming apparatus comprising:
the sheet conveying device according to claim 13 ; and an image forming unit configured to form an image on the conveyed sheet, the abnormal stop command output by the host operation-command unit being 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

• B65H5/06

  by rollers {or balls, e.g. between rollers (transport by suction rollers B65H5/226)} · CPC title

• B65H2403/92

  Electric drive · CPC title

• H02P3/025

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

• B65H2801/06

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