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:
May. 23, 2000
Filed:
Dec. 18, 1996
Bryan Scott Rowan, San Jose, CA (US);
Mantle Man-Hon Yu, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and apparatus for controlling a spindle motor having at least one winding in a storage device are proposed, the storage device having at least one data storage medium rotatably supported by the spindle motor and having a plurality of tracks on each surface thereof including data regions and nondata regions, and a transducer assembly for selectively positioning a transducer over each data storage surface of the storage medium for reading and writing of information stored on the medium. The method and apparatus control rotation of the spindle motor by providing a voltage waveform to each winding at selected switching times during each rotation such that switching does not occur while the head is positioned over data. In a first embodiment, switching during nondata regions is assured by setting the switch points to coincide in time with a fixed data storage surface format. Alternatively, the data storage surface is written with servo sectors to coincide in time with preselected switch points. In a third embodiment, the time for switching is advanced or delayed until the transducer is located over a nondata region near to the nominal switching point by providing a processor executing control code and a delay circuit for delaying switching from a zero-crossing in the spindle motor control circuit. Optional enhancements are also presented.