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. 16, 2003
Filed:
Sep. 28, 2001
Jeffrey A. Heydt, Oklahoma City, OK (US);
David R. Street, Oklahoma City, OK (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
Method and apparatus for initializing a disc drive to bring a spindle motor to a final, operational velocity after a disc drive processor reset condition. The spindle motor is rotated using electronic commutation and back electromotive force (bemf) detection. Upon initialization of the disc drive, a control circuit checks for the presence or absence of detected bemf. The absence of bemf indicates the spindle motor is either at rest or is rotating at a relatively low velocity. In the absence of bemf, the electrical rotational position of the spindle motor is determined, a short braking pulse is applied to the motor, and rotation of the spindle motor is detected in relation to changes in the electrical rotational position. Further breaking pulses are applied until no apparent change in electrical rotational position is detected, after which the spindle motor is accelerated from rest to the final, operational velocity.