Patent ID: 7283440

Claim:
An optical recording and reproducing apparatus, comprising: an optical pickup including an optical splitting device which splits light emitted from a first light source into a source main light beam and at least four sub-light beams which are symmetrical with respect to the main light beam, and irradiates the split source main and sub-light beams on a recording medium, and a light detection device which receives a reflected main light beam and reflected sub-light beams reflected by the recording medium, and outputs detection signals corresponding to the received reflected main and sub-light beams, so as to detect tracking error signals in a three-beam method and at least one of a push-pull method and an improved push-pull method; and a signal processor which receives the detection signals output by the light detection device and detects a first tracking error signal in the three-beam method and a second tracking error signal in one of the push-pull method and the improved push-pull method, wherein the sub-light beams which are symmetrical with respect to the main light beam comprise first two sub-light beams and second two sub-light beams, the first two sub-light beams being closer to the main light beam than the second two sub-light beams, wherein the signal processor comprises: a first detection portion which detects the tracking error signal in the push-pull method or the improved push-pull method from second detection signals of the second two sub-light beams and main detection signals of the main light beam; and a second detection portion which detects the tracking error signal in the three-beam method from first detection signals of the first two sub-light beams, and wherein the light detecting device includes a switch selectively outputting the first and second detection signals to the first and second detecting portions, respectively.