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. 05, 1999
Filed:
Jun. 24, 1997
John C Brazas, Hilton, NY (US);
Ronald E Gerber, Rochester, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
An apparatus for providing a focus error signal, a push-pull tracking error signal, and a differential phase tracking error signal for controlling an application of a radiation beam from an optical source to a data track of an optical storage medium is disclosed. The apparatus includes a transparent substrate arranged between said optical source and said optical storage medium such that said radiation beam passes through said substrate; a grating beam splitter supported by said transparent substrate and having at least six grating elements. The arrangement of the grating elements being selected to produce signals which are particularly adapted to produce signals which are received by a detector array. The detector array responds to these signals to produce the focus error signal and responsive to signals from the first, second, fifth, and sixth detectors to produce the push-pull tracking error signal, and a differential phase tracking error signal.