Patent ID: 7016269

Claim:
An optical pickup apparatus having an irradiation optical system for condensing a light beam into a spot on a track on a recording plane of an optical recording medium and a photodetection optical system for guiding return light reflected back from said spot to a photodetector, said optical pickup apparatus detecting the focal error of said light beam, said optical pickup apparatus comprising: a holographic lens provided in the optical path of said return light in said photodetection optical system for outputting 0-th order diffracted light and ±1st order diffracted light based on said return light; an optical element provided in one of two positions, a first position in front of and a second position behind said holographic lens in the optical path of said return light in said photodetection optical system for providing astigmatism a photodetector for receiving the 0-th order diffracted light output from said holographic lens; a photodetector for receiving the ±1st order diffracted light output from said holographic lens; a servo-signal generating operation circuit for the 0-th order diffracted light connected to said photodetector for the 0-th order diffracted light for generating a first focus error signal having a first capture range based on the output signal of the photodetector; and a servo-signal generating operation circuit for the ±1st order diffracted light connected to the photodetector for said ±1st order diffracted light for generating a second focus error signal having a second capture range different from said first capture range based on the output signal of the photodetector.