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:
Mar. 25, 2008
Filed:
May. 09, 2002
Qiang BI, Singapore, SG;
Xiong Liu, Singapore, SG;
Leeling Tan, Singapore, SG;
Wen-jun Cao, Singapore, SG;
Choonkiat Lim, Singapore, SG;
Qiang Bi, Singapore, SG;
Xiong Liu, Singapore, SG;
LeeLing Tan, Singapore, SG;
Wen-Jun Cao, Singapore, SG;
ChoonKiat Lim, Singapore, SG;
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
A method of preventing a write operation to a disc in a disc drive during a shock event without the use of a separate shock sensor comprises steps of monitoring an actuator voice coil motor (VCM) control plant output signal, generating an actuator voice coil motor (VCM) plant model module output signal, comparing the VCM plant model module output signal to the VCM control plant module output signal to produce a difference signal, and triggering a write protect gate if the difference signal exceeds a predetermined threshold value. The system comprises a voice coil motor (VCM) control plant module sensitive to a shock event providing a VCM control plant module output, a voice coil motor (VCM) plant model module initially insensitive to the shock event producing a VCM plant model module output, a first comparator module coupled to receive the VCM control plant module output and the VCM plant model module output, operable to generate a difference signal between the model plant module output and the VCM control plant module output, and a triggering module receiving the difference signal for generating a write protect gate signal if the difference signal exceeds a predetermined shock threshold.