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:
Jan. 21, 2025
Filed:
Jan. 24, 2023
Alps Alpine Co., Ltd., Tokyo, JP;
ALPS ALPINE CO., LTD., Tokyo, JP;
Abstract
A rotation angle detection device includes a current meter that measures a current flowing in a direct current motor; a filter that extracts a ripple component from the current; a ripple detector that detects a ripple from a signal that has passed through the filter; and a rotation angle detector that detects a rotation angle of the direct current motor based on the number of ripples. The rotation angle detector measures an observation period based on consecutive ripples, calculates an estimation period between the consecutive ripples based on the observation period, determines whether the observation period is within a normal range based on the estimation period and the observation period, and in response to determining that the observation period is within the normal range and an immediately-previous observation period is outside the normal range, calculates a number of correction ripples CRN so as to correct the number of the ripples.