Patent ID: 7969836

Claim:
An optical pickup apparatus for reading an information signal recorded on a recording surface of an optical disk along a track by projecting a light beam, comprising: an objective lens for converging said light beam onto said recording surface; an objective lens moving device for moving said objective lens in a radial direction of said optical disk; and a divisional photosensing device for receiving return light reflected by said optical disk in a plurality of divided regions, wherein said divisional photosensing device comprises: a first divisional photosensing device for receiving a first region including both edge portions in said radial direction of said return light, in two divided areas in said radial direction; a second divisional photosensing device for receiving a second region including both edge portions in a direction which perpendicularly crosses said radial direction of said return light, in two divided areas in said radial direction; and a third divisional photosensing device for receiving a third region including an almost center portion of said return light, in two divided areas in said radial direction, said optical pickup apparatus further comprising: a tracking error detecting device for arithmetically operating an output signal from said first divisional photosensing device and detecting a relative displacement between said track and the light beam converged onto said recording surface; an objective lens displacement detecting device for arithmetically operating an output signal from said second divisional photosensing device and detecting a displacement of said objective lens; a local offset detecting device for arithmetically operating an output signal from said third divisional photosensing device and detecting a local offset; a first amplifying device for applying a predetermined weight to an output signal from said objective lens displacement detecting device; a second amplifying device for applying a predetermined weight to an output signal from said local offset detecting device; DC offset correcting device for subtracting an output signal from said first amplifying device from an output signal from said tracking error detecting device and correcting a DC offset; and a local offset correcting device for subtracting an output signal from said second amplifying device from an output signal from said DC offset correcting device and correcting a local offset.