The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 15, 2022
Filed:
Mar. 11, 2020
Rohm Co., Ltd., Kyoto, JP;
Masanori Tsuchihashi, Kyoto, JP;
Mitsuo Okada, Kyoto, JP;
ROHM CO., LTD., Kyoto, JP;
Abstract
A back electromagnetic force detection circuit detects a counter EMF generated in a coil of a stepping motor. A revolution count detection circuit generates a revolution count detection signal. A determining circuit generates a determination signal that is asserted if the revolution count detection signal is stable across multiple consecutive cycles. A current value setting circuit generates a current setting value indicating a target value of a coil current. The current value setting circuit sets the current setting value to a predetermined value in a period in which the determination signal is negated, and adjusts the current setting value according to the counter EMF in a period in which the determination signal is asserted. A constant current chopper circuit generates a pulse modulation signal that modulates by way of having a detection value of a coil current approach close to a target value of the current setting value.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile