Patent ID: 7227819

Claim:
An optical information apparatus, comprising: an optical pick-up head including: a light source emitting a light beam; a condensing unit receiving a beam from the light source and condensing the beam onto an optical recording medium; a beam splitter receiving the beam reflected from the optical recording medium and splitting the beam; and a photodetector receiving the beams split by the beam splitter and outputting signals in accordance with amounts of the received light beams; wherein the photodetector has a plurality of light-receiving portions, and a tracking error signal generator generating a tracking error signal for irradiating a desired track with a beam, wherein the optical recording medium has tracks arranged substantially at a constant pitch, an average of the pitch is tp, the beams are received by the plurality of light-receiving portions, and the tracking error signal generator performs a differential arithmetic operation with respect to signals output from the light-receiving portions to generate a push-pull signal, and in a case where an amplitude of the push-pull signal, obtained at a pitch tp when the light beam is scanned in a direction orthogonal to the tracks of the optical recording medium, is charged at a pitch different from the pitch tp, the push-pull signal is generated without using a region in a vicinity of a center of the beam.