Patent ID: 6466526
Filing Date: 2002-10-15
Classification: G11B

Abstract:
An apparatus for recording and replying information on option information record medium, comprising:a light source for radiating a light beam to an information-bearing layer of the optical information record medium; a hologram device for splitting reflected light from said optical information record medium, said hologram device comprising a central region formed at the central area thereof and a hologram grating surface region arranged at the outer periphery of said central region; a photoreceptor device for receiving split light beams from said hologram device, said photoreceptor device comprising a first multiple-part split photoreceptor element for receiving light beams from said central region and two second multiple-part split photoreceptor elements for receiving light beams from said hologram grating surface region, means for generating a tracking error signal from signals from said first multiple-part split photoreceptor element; means for generating a focus error signal from signals from said two second multiple-part split photoreceptor elements; and means for performing a tracking control and a focus control based on said tracking error signal and said focus error signal, respectively, to record or replay information on the optical information record medium.