Patent ID: 6813235
Filing Date: 2004-11-02
Classification: G11B

Abstract:
An optical pickup apparatus comprising:a light emitter having a first light emitting section for emitting a first laser beam, and a second light emitting section for emitting a second laser beam having a wavelength different from that of said first laser beam, for selectively emitting a laser beam from one of said first and second light emitting sections; and an optical system formed with a irradiation light path for leading the laser beam emitted from said light emitter to a recording medium, and a reflection light path for leading the laser beam reflected by said recording medium to a light detector, said irradiation light path including an optical axis correcting element for allowing said first laser beam to pass therethrough and for diffracting said second laser beam that the first order diffracted light of said second laser beam and the 0-order light of said first laser beam respectively reflected by said recording medium overlap each other on a light receiving surface of said light detector; and said optical axis correcting element being configured to diffract said second laser beam such that the centers of gravity of light amount distributions of spots of said first and second laser beams match on light receiving surface of said photodetector.