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:
Sep. 16, 2014
Filed:
Jul. 17, 2012
Masaya Sasaki, Hirosaki, JP;
Masaya Sasaki, Hirosaki, JP;
Canon Precision Inc., Hirosaki-shi, JP;
Abstract
The motor speed detection apparatus detects rotational speed of a motor. The apparatus includes an FG coil () and a magnet () to be relatively moved with rotation of the motor, the FG coil outputting an alternating-current signal to be sampled by the apparatus, an A/D converter () to convert the alternating-current signal into a digital signal, an integrator () to perform time integration on the digital signal, a first determiner () to determine which one of plural threshold ranges includes an integration value obtained by the integrator, a second determiner () to determine whether change of the integration value is increase or decrease, and a logical product calculator () to produce a binary signal showing a logical product of determination results of the first and second determiners. The apparatus calculates the rotational speed based on a production cycle of the binary signal.