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. 06, 2003
Filed:
Apr. 30, 1999
Erno Hilbrand Klaassen, Santa Clara, CA (US);
Bryan Scott Rowan, Los Gatos, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A disk drive includes a read/write head mounted on an actuator, a disk having an inner diameter region and an outer diameter region, the head being radially movable by the actuator between the inner diameter region and the outer diameter region. An unload ramp is positioned at the outer diameter region. A controller outputs control signals upon sensing a power down condition. A feedback circuit is adapted to sense a back emf generated by the actuator and to use the back emf to apply a counter-acting voltage to the actuator that tends to bring the actuator to a stop. A switch is responsive to the control signals to (i) connect the feedback circuit to the actuator to enable the actuator to be brought to a stop while the disk continues to rotate and (ii) for then causing the actuator to move the head to the unload ramp. The switch further applies a voltage which causes the actuator to bring the head to the inner diameter region of the disk, before causing the actuator to move the head to the unload ramp.