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:
Jun. 16, 1998
Filed:
Sep. 09, 1996
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for cancelling optical servo crosstalk within an optical disk drive is disclosed. In accordance with the method and system of the present invention, the optical disk drive system includes a focus control module, a tracking control module, a variable frequency notch filter, and a lookup table. The focus control module is utilized for moving an objective lens in response to a focus error signal in order to maintain a laser beam in an in-focus condition on an optical disk. The tracking control module is utilized for moving a moving optical element in response to a tracking error signal to direct the laser beam onto a desired track position of the optical disk. The lookup table within the focus control module is utilized for storing several sets of tap coefficients for the variable frequency notch filter. An appropriate set of tap coefficients from the lookup table is supplied to the variable frequency notch filter in response to a head velocity signal from the tracking control module such that the effects caused by a false FES in the optical disk drive system are reduced.