Patent ID: 7079474

Claim:
An optical pickup apparatus for reading information from a plurality of types of discs at different reading wavelengths, comprising: a light source having integrated light emitting portions for emitting first and second laser beams of different wavelengths, said light source being adapted to selectively emit one of the first and second laser beams of different wavelengths; an optical system that generates a main beam and two subbeams from a selected laser beam of the first and second laser beams and directs the main beam and the subbeams towards an object disc; a first four-division photodetector; a second four-division photodetector, wherein the first and second four-division photodetectors are arranged such that central division lines of said first and second four-division photodetectors are in alignment with one another and coincident with a tangential direction of a track of the object disc; and a first sub-photodetector disposed on one side of the first and second four-division photodetectors in a direction along which the central division lines extend; and a second sub-photodetector disposed on another side of the first and second four-division photodetectors in the direction along which the central division lines extend, wherein the optical system directs a main beam reflected from the object disc to a corresponding one of the first and second four-division photodetectors and directs the subbeams reflected from the object disc to the first and second sub-photodetectors.