Patent ID: 6466531
Filing Date: 2002-10-15
Classification: G11B

Abstract:
A disc discriminator of an optical disc player system having an optical pickup unit using a hologram element for focusing an incident laser beam onto a disc and concentrating said beam reflected therefrom, comprising:a 4-split photo-detector for converting said beam, concentrated by said optical pickup unit upon reflection, into an electric signal by means of a plurality of photo diodes divided in first through fourth quadrants; a push-pull signal generator for amplifying a difference between two signals, each signal generated from a respective pair of photo diodes and each respective pair of photo diodes disposed symmetrically on a respective side of a center of a track direction, and generating a push-pull signal; and a comparator for comparing said push-pull signal generated from said push-pull signal generator to a predetermined reference voltage, and generating a digital video disc/compact disc discrimination signal discrimination between a digital video disc and a compact disc.