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:
Nov. 25, 2014
Filed:
Aug. 10, 2011
Tatsuya Ninomiya, Kyoto, JP;
Tatsuya Ninomiya, Kyoto, JP;
Rohm Co., Ltd., , JP;
Abstract
A driving circuit drives a voice coil motor having a spring return mechanism. A driving current generating unit supplies, to a coil of the voice coil motor, a driving current that corresponds to an analog control signal. Waveform memory stores digital waveform data which indicates the time waveform of a driving current to be supplied to the voice coil motor. A predetermined frequency component is removed from the frequency components of the waveform data. A control unit reads out the waveform data from the waveform memory at a rate that corresponds to the resonance frequency of the voice coil motor, and outputs the waveform data thus read out as a digital code. A D/A converter converts a digital code into an analog control signal, and outputs the analog control signal to the driving current generating unit.