Stepping motor driving apparatus, image carrier rotation driving apparatus and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9621087-B2
Application number	US-201514656894-A
Country	US
Kind code	B2
Filing date	Mar 13, 2015
Priority date	Mar 28, 2014
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A stepping motor driving apparatus includes a stepping motor having a rotor, a driving unit configured to drive the stepping motor, and a rotation position detection unit configured to detect a rotation angle of the rotor. A control unit calculates a magnetic pole position of the stepping motor based on a first detection result and a second detection result. The stepping motor rotates by a predetermined step in one rotation direction from an initial position and thereafter rotates by the predetermined step in the other rotation direction so that the stepping motor is in a first held state. The first detection result is detected in the first held state. The stepping motor rotates by the predetermined step in the other rotation direction from the initial position and thereafter rotates by the predetermined step in the one rotation direction so that the stepping motor is in a second held state.

First claim

What is claimed is:

1. A stepping motor driving apparatus, comprising:
a stepping motor having a rotor;
a driving unit configured to drive the stepping motor;
a rotation position detection unit configured to detect a rotation angle of the rotor of the stepping motor; and
a control unit configured to output a signal to control the driving unit and configured to calculate a magnetic pole position of the stepping motor based on a detection result detected by the rotation position detection unit,
wherein the control unit is configured to calculate the magnetic pole position based on a first detection result and a second detection result,
wherein the control unit causes the stepping motor to rotate by a predetermined step in one rotation direction from an initial position and thereafter the control unit causes the stepping motor to rotate by the predetermined step in an opposite rotation direction so that the stepping motor is in a first held state,
the first detection result is detected by the rotation position detection unit in the first held state, and
wherein the control unit causes the stepping motor to rotate by the predetermined step in the opposite rotation direction in the first held state and thereafter the control unit causes the stepping motor to rotate by the predetermined step in the one rotation direction so that the stepping motor is in a second held state, and the second detection result is detected by the rotation position detection unit in the second held state.

2. The stepping motor driving apparatus according to claim 1 , wherein:
the stepping motor has a plurality of initial positions including a first initial position, a second initial position, . and an Nth initial position (N=2, 3, .);
the first and second detection results are detected for each initial position, and
the control unit calculates the magnetic pole position based on the first and second detection results corresponding to the plurality of initial positions.

3. The stepping motor driving apparatus according to claim 2 , wherein the plurality of initial positions are 0°, 90°, 180°, and 270°.

4. The stepping motor driving apparatus according to claim 1 , further comprising:
a storage unit configured to store the first detection result and the second detection result,
wherein the control unit is configured to calculate the magnetic pole position based on the first detection result and the second detection result stored in the storage unit.

5. The stepping motor driving apparatus according to claim 1 ,
wherein the control unit sets an intermediate value between the first detection result and the second detection result as the magnetic pole position of the stepping motor.

6. The stepping motor driving apparatus according to claim 1 , further including:
a storage unit configured to store a detection result of the rotation position detection unit,
wherein the control unit is configured to calculate a magnetic position of the stepping motor based on the first detection result and the second detection result stored in the storage unit.

7. An image carrier rotation driving apparatus comprising:
an image carrier; and
a stepping motor driving apparatus according to claim 1 ,
wherein the stepping motor directly rotates and drives the image carrier.

8. An image forming apparatus comprising:
an image carrier; and
the stepping motor driving apparatus according to claim 1 , wherein the stepping motor is a driving apparatus of the image carrier.

9. The image forming apparatus according to claim 8 , comprising:
a plurality of the image carriers,
wherein each of the image carriers is driven by a corresponding stepping motor driving apparatus.

10. The image forming apparatus according to claim 9 , further comprising:
four image forming stations to form yellow, magenta, cyan, and black images,
wherein, in each image forming station, an image carrier driven by the stepping motor driving apparatus is respectively provided.

11. The stepping motor driving apparatus according to claim 1 , wherein
the control unit defines a midpoint position between one position corresponding to the first detection result and another position corresponding to the second detection result, as the magnetic pole position.

Assignees

• Canon Kk

Inventors

• Okumura Yasuhiko

Classifications

• H02P8/08

  Determining position before starting · CPC title

• G03G15/757

  Drive mechanisms for photosensitive medium, e.g. gears · CPC title

• G03G15/80

  Details relating to power supplies, circuits boards, electrical connections · CPC title

• G03G15/5008

  Driving control for rotary photosensitive medium, e.g. speed control, stop position control · CPC title

• H02P8/34 Primary

  Monitoring operation (H02P8/36 takes precedence) · CPC title