Tilt error signal producing apparatus using multiple tracking error signals

摘要

An apparatus for producing a tilt error signal representative of the tilt of an optical disk is disclosed. The apparatus includes a source of laser light for focusing a laser beam onto the disk and reflecting such beam from the disk, a beamsplitter positioned to receive the reflected light beam and to direct the light beam in a first direction, and a structure for separating the reflected light beam from the beamsplitter into at least four portions and for producing detection signals for each portion. The apparatus further includes circuitry responsive to the detection signals for producing first and second tracking error signals, the first and second tracking error signals being produced by different combinations of the detection signals and both being sensitive to cross-track diffraction, and circuitry responsive to the first and second tracking error signals for producing the tilt error signal.