# US 2017/0255152 A1 · Motor connection detecting device, motor connection detecting method, image forming device, and conveyance device

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- Number: US 2017/0255152 A1
- Document ID: US20170255152A1
- Status: Published application
- Kind: A1
- Application number: 15/428,269
- Filed: 2017-02-09
- Published: 2017-09-07
- Earliest claimed: 2016-03-02
- Assignees: Ricoh Company, Ltd.
- Inventors: Hiroshi OKAMURA; Tomohide KONDOH; Hayato FUJITA
- Web page: https://patentgrep.com/patent/US20170255152A1

## CPC

- G03G 15/6529: {Transporting (G03G15/6555 takes precedence)}
- G03G 15/80: {Details relating to power supplies, circuits boards, electrical connections}
- H02P 8/12: Control or stabilisation of current
- H02P 8/36: Protection against faults, e.g. against overheating or step-out; Indicating faults
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS

## Abstract

A motor connection detecting device includes: a bipolar stepping motor; a motor driver adapted to control current to be supplied to the bipolar stepping motor; and a controller connected to the bipolar stepping motor and the motor driver. The controller detects voltage of regenerative current generated during motor ON time in which current flows in the bipolar stepping motor, and determines abnormal connection of the bipolar stepping motor. The detected voltage is voltage generated during a fast decay period according to a current attenuation method of the regenerative current.

## Claims

### Claim 1

A motor connection detecting device comprising:
a bipolar stepping motor;
a motor driver configured to control current to be supplied to the bipolar stepping motor; and
a controller connected to the bipolar stepping motor and the motor driver and configured to detect voltage of regenerative current generated during motor ON time in which current flows in the bipolar stepping motor, and determine abnormal connection of the bipolar stepping motor,
wherein the detected voltage is voltage generated during a fast decay period according to a current attenuation method of the regenerative current.

### Claim 2 (depends on 1)

The motor connection detecting device according to claim 1, wherein
the controller detects the voltage when the bipolar stepping motor is set in an excitation holding state.

### Claim 3 (depends on 2)

The motor connection detecting device according to claim 2, wherein
the motor driver performs chopping control drive for the bipolar stepping motor, and
the controller detects the voltage at timing of the fast decay period which represents an OFF period during the chopping control drive performed by the motor driver.

### Claim 4

A motor connection detecting method comprising:
controlling current to be supplied to a bipolar stepping motor by a motor driver;
detecting, by a controller connected between the bipolar stepping motor and the motor driver, voltage of regenerative current generated during a motor ON time in which current flows in the bipolar stepping motor; and
determining abnormal connection of the bipolar stepping motor based on the voltage detected in the detecting,
the detected voltage being a voltage generated during a fast decay period according to a current attenuation method of the regenerative current.

### Claim 5 (depends on 4)

The motor connection detecting method according to claim 4, wherein
in the detecting, the voltage is detected when the bipolar stepping motor is set in an excitation holding state.

### Claim 6 (depends on 5)

The motor connection detecting method according to claim 5, wherein
in the controlling, chopping control drive is performed for the bipolar stepping motor, and
in the detecting, the voltage is detected at timing of the fast decay period which represents an OFF period during the chopping control drive performed in controlling the current.

### Claim 7 (depends on 1)

The motor connection detecting device according to claim 1, wherein
the controller generates a control command to provide a command for a control amount of the current by the motor driver.

### Claim 8 (depends on 7)

An image forming device comprising:
the motor connection detecting device according to claim 7,
wherein the bipolar stepping motor is applied to at least one of a DC motor configured to drive a conveyance roller and a drum drive motor configured to rotationally drive a drum.

### Claim 9 (depends on 7)

A conveyance device comprising:
the motor connection detecting device according to claim 7,
wherein the bipolar stepping motor is applied to a motor configured to drive a conveyance roller.