Patent ID: 7345820

Claim:
An optical pick-up apparatus comprising: a light source; an objective lens for focusing light emitted from the light source into an optical disk; a hologram for splitting the light reflected by the optical disk, and diffracting rays split from the light; and a photodetector for detecting a reproduction signal and a servo signal from the reflected rays split by the hologram, wherein the hologram comprises first and second diffraction regions extended in the tangential direction of the optical disk, and third to sixth diffraction regions formed at both sides of the first and second diffraction regions in the radial direction of the optical disk, and wherein the photodetector comprises a first bisected light-receiving portion for receiving negative first-order rays diffracted at the first and second diffraction regions, a first single light-receiving portion for receiving positive first-order rays diffracted at the first and second diffraction regions, third to sixth single light-receiving portions for respectively receiving negative first-order rays diffracted at the third to sixth diffraction regions, and third to sixth bisected light-receiving portions for respectively receiving positive first-order rays diffracted at the third to sixth diffraction regions.