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:
Jul. 01, 2003
Filed:
Jul. 25, 2001
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A disk drive apparatus reproduces an information signal from a disk and/or records an information signal on the disk. FET power transistors of a power supplying part execute high-frequency switching operation and form current paths to three-phase windings so as to rotate the disk. A voltage detecting part compares terminal voltages of the three-phase windings and produces a detected pulse signal in response to a comparison result. An activation operation block controls active periods of the FET power transistors in response to the detected pulse signal. A commanding part produces a command signal in response to an output pulse signal of the voltage detecting part. A switching operation block produces a switching pulse signal in response to a comparison result of a current-detection signal with the command signal, and causes at least an FET power transistor of the power supplying part to perform high-frequency switching in response to the switching pulse signal. The switching operation block changes a timing of the switching pulse signal in response to detection of the detected pulse signal so that the voltage detecting part can accurately achieve the next detection of the detected pulse signal. Further, an excellent speed control of the disk can be achieved by the accurate output pulse signal of the voltage detecting part.