Phase detecting device, motor system, image forming apparatus, conveyance device, and sensor level obtaining method

Patent metadata

Field	Value
Publication number	US-10326387-B2
Application number	US-201715656110-A
Country	US
Kind code	B2
Filing date	Jul 21, 2017
Priority date	Aug 5, 2016
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

A phase detecting device includes a signal level detector configured to detect a first level of a signal according to a phase of a rotor of a motor, a level memory configured to store the first level of the signal preliminarily detected at each phase of the rotor as a second level of the signal at the phase of the rotor, and a phase detector configured to detect the phase of the rotor based on the second level of the signal inputted from the signal level detector.

First claim

What is claimed is:

1. A phase detecting device configured to detect a phase of a rotor of a motor, the phase detecting device comprising:
a signal level detector configured to
detect a first level of a signal corresponding to the phase of the rotor of the motor;

a level memory configured to store a preliminary level detected at each of a plurality of phases of the rotor as one of a plurality of second levels of the signal, each of the plurality of second levels of the signal corresponding to one of the plurality of phases of the rotor; and
a phase detector configured to detect the phase of the rotor based on the first level input from the signal level detector and the plurality of second levels stored in the level memory,
wherein the level memory is configured to
store the preliminary level detected by the signal level detector at predetermined time intervals as one of the plurality of second levels of the signal at each of a plurality of predetermined phases of the rotor during constant speed rotation of an external motor coaxially coupled to the motor, or
store the preliminary level of the signal detected by the signal level detector at predetermined time intervals as one of the plurality of second levels of the signal at each of a plurality of predetermined phases of the rotor during uncontrolled rotation of the motor, or
store the preliminary level of the signal detected by the signal level detector at time when an external motor coaxially coupled to the motor is controlled to one of a plurality of predetermined phases of the rotor as one of the plurality of second levels of the signal at the at the one of the plurality of predetermined phases of the rotor.

2. The phase detecting device according to claim 1 ,
further comprising a peak detector configured to detect a peak of the signal and notify the phase detector of the peak detection,
wherein the phase detector specifies a start point to start detecting the phase of the rotor of the motor based on the peak detection by the peak detector.

3. The phase detecting device according to claim 1 ,
the signal inputted to the signal level detector is a shaped signal that is shaped from a sensor signal a magnetic sensor or a synthesized signal synthesized from a plurality of sensor signals.

4. The phase detecting device according to claim 1 ,
wherein the phase detector is configured to detect the phase of the rotor that corresponds to the one of the plurality of second levels of the signal closest to the first level of the signal as the phase of the rotor of the motor on detection of the first level of the signal.

5. A motor system comprising:
the motor; and
the phase detecting device according to the claim 1 , configured to detect the phase of the rotor of the motor.

6. An image forming apparatus comprising:
an image forming device to form an image on a sheet;
a conveyance roller to convey the sheet; and
the motor system according to claim 5 , configured to drive the conveyance roller.

7. A conveyance device comprising:
a conveyance roller to convey an object; and
the motor system according to claim 5 , configured to drive the conveyance roller.

8. A phase detecting device configured to detect a phase of a rotor of a motor, the phase detecting device comprising:
circuitry configured to
detect a first level of a signal corresponding to the phase of the rotor of the motor; and

a level memory configured to store a preliminary level detected at each of a plurality of phases of the rotor as one of a plurality of second levels of the signal, each of the plurality of second levels of the signal corresponding to one of the plurality of phases of the rotor,
the circuitry configured to detect the phase of the rotor based on the first level of the signal and the plurality of second levels stored in the level memory,
wherein the level memory is configured to
store the preliminary level detected by the circuitry at predetermined time intervals as one of the plurality of second levels of the signal at each of a plurality of predetermined phases of the rotor during constant speed rotation of an external motor coaxially coupled to the motor, or
store the preliminary level of the signal detected by the circuitry at predetermined time intervals as one of the plurality of second levels of the signal at each of a plurality of predetermined phases of the rotor during uncontrolled rotation of the motor, or
the preliminary level by the circuitry when an external motor coaxially coupled to the motor controlled to one of a plurality of predetermined phases of the rotor as one of the plurality of second levels of the signal at the at the one of the plurality of predetermined phases of the rotor.

9. A method for obtaining a sensor level to detect a phase of a rotor of a motor, the method comprising:
detecting a first level of a signal corresponding to the phase of the rotor of the motor during constant speed rotation of the motor;
storing a plurality of preliminary levels of the signal detected at predetermined time intervals as a plurality of second levels of the signal, each of the plurality of second levels corresponding to one of a plurality of phases of the rotor; and
detecting the phase of the rotor based on the first level of the signal and the plurality of second levels of the signal,

wherein the storing includes
storing the preliminary level detected at predetermined time intervals as one of the plurality of second levels of the signal at each of a plurality of predetermined phases of the rotor during constant speed rotation of an external motor coaxially coupled to the motor, or
storing the preliminary level of the signal detected at predetermined time intervals as one of the plurality of second levels of the signal at each of a plurality of predetermined phases of the rotor during uncontrolled rotation of the motor, or
store the preliminary level of the signal detected at time when an external motor coaxially coupled to the motor is controlled to one of a plurality of predetermined phases of the rotor as one of the plurality of second levels of the signal at the at the one of the plurality of predetermined phases of the rotor.

Assignees

• Kamatani Tomohiko
• Ricoh Co Ltd

Inventors

• Kamatani Tomohiko

Classifications

• H02P6/16

  Circuit arrangements for detecting position · CPC title

• H02P6/14 Primary

  Electronic commutators · CPC title

• G01R31/343

  in operation · CPC title

• H02K11/20

  for measuring, monitoring, testing, protecting or switching (rectifiers H02K11/04; power electronics H02K11/33) · CPC title