Patent ID: 6501715
Filing Date: 2002-12-31
Classification: G11B

Abstract:
An optical pickup apparatus capable of detecting a tracking state of a beam for reading information from an optical recording medium, said optical pickup apparatus comprising:a light source for emitting a beam; a first diffraction element for dividing said beam emitted from said light source into a plurality of beams for tracking state detection; an objective lens being provided to be movable in the radial direction of said optical recording medium for condensing said plurality of beams divided by said first diffraction element on said optical recording medium; a photodetector having a plurality of photoreceiving parts for receiving a plurality of returned beams based on said plurality of beams for tracking state detection condensed on said optical recording medium respectively and outputting detection signals responsive to received light quantities; an adjusting circuit for correcting deviation of said objective lens and capable of changing at least one of said detection signals outputted from said plurality of photoreceiving parts of said photodetector relatively to another of said detection signals; and a lens driving part for moving said objective lens in said radial direction in response to a prescribed signal being based on the detection signal adjusted by said adjusting circuit.