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:
Oct. 01, 1996
Filed:
Aug. 21, 1995
Clarke K Eastman, Rochester, NY (US);
Daniel L Nelson, Penfield, NY (US);
Gerald J Smart, Penfield, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
A method and apparatus for, in an optical data recorder, focusing a recording light beam on a recording medium. In the apparatus, an optical head has focusing means movable in a direction perpendicular to the recording medium for changing the focus position of the recording light beam on the recording medium. The method comprises the steps of: i) detecting light reflected from the optical recording medium and for producing a corresponding focus error signal; ii) generating a mark formation effectiveness signal for each of a plurality of trial focus positions, each mark formation effectiveness signal being associated with a given value of the focus error signal; iii) determining the mark formation effectiveness signal corresponding to an in-focus position and determining an offset value of the associated focus error signal; and iv) during data recording periods, in response to the focus error signal, adjusting the position of the movable focusing means so that the value of the focus error signal is maintained at the offset value.