Abstract: An aberration correction apparatus includes an optical pickup having a liquid crystal panel for correcting an aberration of a light beam emitted from a light source and irradiated on a recording medium and a control unit which applies, to the liquid crystal panel, a bias voltage in order to correct the aberration. The bias voltage is a voltage at which a diffraction generated in the light beam passing through an electrode gap portion between electrode portions of the liquid crystal panel is minimum. For instance, the bias voltage is the voltage at which a phase difference between the light beam passing through the electrode portions of the liquid crystal panel and the light beam passing through the electrode gap portion is an integral multiple of a wavelength of the light beam. It is thereby possible to prevent unnecessary diffracted light from being generated by the liquid crystal panel for correcting the aberrations.

Abstract: An aberration correction apparatus includes an optical pickup having a liquid crystal panel for correcting an aberration of a light beam emitted from a light source and irradiated on a recording medium and a control unit which applies, to the liquid crystal panel, a bias voltage in order to correct the aberration. The bias voltage is a voltage at which a diffraction generated in the light beam passing through an electrode gap portion between electrode portions of the liquid crystal panel is minimum. For instance, the bias voltage is the voltage at which a phase difference between the light beam passing through the electrode portions of the liquid crystal panel and the light beam passing through the electrode gap portion is an integral multiple of a wavelength of the light beam. It is thereby possible to prevent unnecessary diffracted light from being generated by the liquid crystal panel for correcting the aberrations.

Abstract: An aberration detector for easily detecting aberration of a lens in a short time period by utilizing an interferometer. The aberration detector includes a laser diode, a beam splitter for dividing a light beam into two light beams, an optical system for supporting a lens and converging a light beam passing through the lens to a converging point, a spherical mirror for reflecting the light beam passing through the lens, an image pickup element for detecting an interference pattern obtained by interference of a reference light and the light reflected on the spherical mirror, and an analyzer for analyzing the interference pattern. A center of a sphere constituting the spherical mirror is arranged in a position displaced from the converging point such that a plurality of circular fringes are concentrically arranged on the interference pattern.

Abstract: An aberration detector for easily detecting aberration of a lens in a short time period by utilizing an interferometer. The aberration detector includes a laser diode, a beam splitter for dividing a light beam into two light beams, an optical system for supporting a lens and converging a light beam passing through the lens to a converging point, a spherical mirror for reflecting the light beam passing through the lens, an image pickup element for detecting an interference pattern obtained by interference of a reference light and the light reflected on the spherical mirror, and an analyzer for analyzing the interference pattern. A center of a sphere constituting the spherical mirror is arranged in a position displaced from the converging point such that a plurality of circular fringes are concentrically arranged on the interference pattern.

Abstract: Disclosed is an optical disk player capable of suppressing the influence of side lobes of an irradiated spot on the reflected light from an optical disk, thereby ensuring an improved recording/reproducing characteristic. The optical disk player comprises an optical irradiation system for focusing a laser beam as a spot along an information recording portion of an optical disk, and an optical detection system for guiding reflected light from the spot to a photosensor, whereby recorded information is reproduced based on an output signal from the photosensor. The information recording portion is formed of a reflection film whose reflectance increases gradually or stepwise in accordance with an increase in intensity of incident light. The optical irradiation system has an amplitude filter or a phase filter.