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:
Dec. 01, 2015
Filed:
Aug. 07, 2012
Daisuke Sato, Osaka, JP;
Daisuke Sato, Osaka, JP;
Abstract
A motor driving device according to the present invention includes: a PWM duty ratio detecting unit for detecting a target rotational speed based on a duty ratio of a PWM signal input from a host system; a PWM period detecting unit for detecting a period of the PWM signal; a PWM period error calculating unit for calculating an error between a PWM period output from the PWM period detecting unit and a PWM period previously set as a reference calculated by using the operational clock generator; a position detecting sensor for detecting a permanent magnet of the rotor; and an actual rotational speed calculating unit for calculating an actual rotational speed of the rotor by using a signal output from the position detecting sensor. The present motor driving device controls a speed while correcting the actual rotational speed based on the PWM period error.