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:
Aug. 27, 2013
Filed:
Apr. 14, 2011
Kesatoshi Takeuchi, Shiojiri, JP;
Kesatoshi Takeuchi, Shiojiri, JP;
Seiko Epson Corporation, , JP;
Abstract
An electromechanical device includes: a magnet coil; a PWM driving circuit; and a control unit, wherein the control unit performs a first control of setting an excitation interval which is an interval in which a PWM drive signal is supplied to the magnet coil and a second control of changing a duty ratio of the PWM drive signal, and wherein the control unit performs an advance angle control of putting the phase of the center of the excitation interval earlier than the phase in which a counter-electromotive force generated in the magnet coil has the maximum value in the first control, and increases the duty ratio of the PWM drive signal in the second control so that a gain is greater than 100% when the gain is 100% at the time of generating the PWM drive signal so as to have a sinusoidal shape.