Patent ID: 7821901

Claim:
An optical pickup device operable to perform recording or reproduction of information with respect to a plurality of types of optical disks by irradiating either one of three types of laser light having different wavelengths on a recording surface of the optical disk, the optical pickup device comprising: a first laser emitter operable to emit a first laser light having a first wavelength; a second laser emitter operable to emit a second laser light having a second wavelength and a third laser light having a third wavelength, the second wavelength being longer than the first wavelength, the third wavelength being longer than the second wavelength; a first diffraction grating configured to divide the first laser light into at least three first light beams; a second diffraction grating configured to respectively divide the second laser light and the third laser light into at least three second light beams and at least three third light beams; and an optical sensor comprising a first light receiving surface divided into four areas, a second light receiving surface divided into four areas, and a third light receiving surface divided into at least two areas, wherein: the optical sensor is so configured that the first light beams reflected from the optical disk reach the first light receiving surface, the second light receiving surface and the third receiving surface, respectively; the optical sensor is so configured that none of the second light beams reflected from the optical disk reaches the third light receiving surface; and the optical sensor is so configured that the third laser light beams reach the first light receiving surface, the second light receiving surface and the third light receiving surface, respectively.