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:
Sep. 25, 2007
Filed:
Feb. 10, 2006
Peter Kuikong Ho, Morgan Hill, CA (US);
Lee Duyly Nguyentran, San Jose, CA (US);
Bond-yen Ting, San Jose, CA (US);
Phong Van VU, San Jose, CA (US);
Peter Kuikong Ho, Morgan Hill, CA (US);
Lee DuyLy Nguyentran, San Jose, CA (US);
Bond-Yen Ting, San Jose, CA (US);
Phong Van Vu, San Jose, CA (US);
HItachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A magnetic recording hard disk drive (HDD) uses adaptive braking of the voice coil motor (VCM) actuator upon unexpected loss of power during a track seek. An adaptive braking controller applies a preselected value of brake voltage to the VCM to reverse the motion of the freely-moving actuator. The value of the selected brake voltage is determined from the actuator velocity. A set of brake voltage values is stored in memory in the HDD, and each brake voltage value corresponds to a band of track seek lengths, with each band representing a range of actuator velocities. For each seek, the value of brake voltage corresponding to the band in which the seek length falls is stored in a register. If emergency power-off (EPO) occurs during the seek, the value of brake voltage is recalled from the register and applied to the VCM to brake the VCM. After the VCM has been adaptively braked in this manner, actuator retract occurs to unload the heads.