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. 01, 2004
Filed:
Jun. 20, 2000
Ludwig Ceshkovsky, Irvine, CA (US);
Discovision Associates, Irvine, CA (US);
Abstract
An apparatus and method conducts a high-speed search on an optical medium having a plurality of tracks on which information is recorded. At least a first light spot and a second light spot are directed by the apparatus onto the optical medium. The light spots traverse across the tracks in one of a first direction and a second direction. A photodetector unit receives a reflected component of the first light spot to form a first electrical signal and a reflected component of the second light spot to form a second electrical signal. Digital shaping circuitry respectively converts the first electrical signal and the second electrical signal into a first digital signal and a second digital signal. A quadrature detector is configured to receive the first digital signal and the second digital signal. The first digital signal and the second digital signal are arranged in a quadrature relationship to each other. The quadrature detector produces from the first digital signal and the second digital signal an up-count signal indicating that the light spots are traversing the tracks in the first direction and a down-count signal indicating that the light spots are traversing the tracks in the second direction. A counter counts, during the search, the up-count signal and the down-count signal to determine a number of tracks traversed by the light spots.