Invention Grant
- Patent Title: Motor controller and image forming apparatus
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Application No.: US16713087Application Date: 2019-12-13
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Publication No.: US11387758B2Publication Date: 2022-07-12
- Inventor: Hiroyuki Yoshikawa , Yuta Tachibana , Daichi Suzuki
- Applicant: KONICA MINOLTA, INC.
- Applicant Address: JP Tokyo
- Assignee: KONICA MINOLTA, INC.
- Current Assignee: KONICA MINOLTA, INC.
- Current Assignee Address: JP Tokyo
- Agency: Buchanan Ingersoll & Rooney PC
- Priority: JPJP2018-236409 20181218
- Main IPC: H02P9/18
- IPC: H02P9/18 ; H02P8/20 ; H02P21/18 ; H02P21/22 ; G03G15/00 ; H02P27/12

Abstract:
A motor controller estimates an initial position of a magnetic pole of a rotor of a brushless DC motor in an inductive sensing scheme. The motor controller controls a drive circuit to apply an AC voltage to a stator winding at a first energization angle, and subsequently to apply an AC voltage to the stator winding at a second energization angle before a residual current flowing through the stator winding returns to zero. At each energization angle, the motor controller corrects a peak value of a current in the stator winding based on the residual current detected immediately before a voltage is applied to the stator winding or at a time when voltage application to the stator winding is started. Based on the corrected peak value, the control circuit estimates the initial position of the magnetic pole of the rotor.
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