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:
Jan. 20, 2015
Filed:
Sep. 26, 2013
Applicant:
Optical Devices, Llc, Peterborough, NH (US);
Inventor:
Ron J. Kadlec, Longmont, CO (US);
Assignee:
Optical Devices, LLC, Peterborough, NH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 21/08 (2006.01); G11B 7/09 (2006.01); G11B 7/085 (2006.01);
U.S. Cl.
CPC ...
G11B 7/094 (2013.01); G11B 7/08541 (2013.01); G11B 7/08529 (2013.01);
Abstract
A focus servo system for an optical disk drive includes an optical pick-up unit comprising at least one photodetector. At least one analog to digital converter is configured to digitize signals received from the at least one photodetector. At least one processor is configured to execute a digital servo algorithm to process the versions of the digitized signals to calculate a focus error signal (FES) from the versions of the digitized signals and to indicate a focus open condition based on the FES and the versions of the digitized signals.