Abstract: An optical recording and reproducing apparatus which suppresses the generation of a noise component in a servo signal while preventing a deterioration in using efficiency of a light beam is provided. The optical recording and reproducing apparatus has an optical pickup including a liquid crystal correcting element, a liquid crystal element control unit, a memory, and an operation mode control unit. The memory stores a plurality of correction data sets respectively corresponding to a plurality of refractive index distribution to be formed by the liquid crystal correcting element. The liquid crystal element control unit selectively reads out the correction data set corresponding to the operation mode designated by the operation mode control unit from the memory and supplies a driving voltage according to the read-out correction data set to the liquid crystal correcting element.

Abstract: The present invention is to provide an improved aberration correction device formed by inserting an electro-optic panel such as a liquid crystal panel in an image-formation optical system to correct aberrations in the image-formation optical system, characterized in that such a correction device is capable of correcting three or more kinds of aberrations using only one electro-optic panel. Divided areas concerning coma aberration correction and divided areas concerning astigmatism correction are formed in one of the transparent electrodes of the electro-optic panel, while the rest of divided areas concerning coma aberration correction and divided areas concerning spherical aberration correction are formed in the other of the transparent electrodes.

Abstract: A kind of an optical disc is discriminated by a disc discriminating section, an order of aberrations to be corrected is set by an order setting section by the kind of the optical disc, drive of a liquid crystal optical element is controlled by a drive control section through a liquid crystal driver, and an aberration of an optical beam is corrected based on the order of the aberration. The level of importance of the aberration correction differs by the kind of the optical disc, and the order of the aberration is set by the level of importance of the aberration correction.

Abstract: An optical pickup to be used for both DVD and CD is provided with an aberration correcting device using liquid crystal on an input side of an objective lens. A spherical aberration of a CD is corrected by using an electrode for DVD spherical aberration correction and electrodes for DVD astigmatism correction.

Abstract: An optical recording and reproducing apparatus which suppresses the generation of a noise component in a servo signal while preventing a deterioration in using efficiency of a light beam is provided. The optical recording and reproducing apparatus has an optical pickup including a liquid crystal correcting element, a liquid crystal element control unit, a memory, and an operation mode control unit. The memory stores a plurality of correction data sets respectively corresponding to a plurality of refractive index distribution to be formed by the liquid crystal correcting element. The liquid crystal element control unit selectively reads out the correction data set corresponding to the operation mode designated by the operation mode control unit from the memory and supplies a driving voltage according to the read-out correction data set to the liquid crystal correcting element.

Abstract: An optical pickup to be used for both DVD and CD is provided with an aberration correcting device using liquid crystal on an input side of an objective lens. A spherical aberration of a CD is corrected by using an electrode for DVD spherical aberration correction and electrodes for DVD astigmatism correction.

Abstract: A kind of an optical disc is discriminated by a disc discriminating section, an order of aberrations to be corrected is set by an order setting section by the kind of the optical disc, drive of a liquid crystal optical element is controlled by a drive control section through a liquid crystal driver, and an aberration of an optical beam is corrected based on the order of the aberration. The level of importance of the aberration correction differs by the kind of the optical disc, and the order of the aberration is set by the level of importance of the aberration correction.

Abstract: The present invention is to provide an improved aberration correction device formed by inserting an electro-optic panel such as a liquid crystal panel in an image-formation optical system to correct aberrations in the image-formation optical system, characterized in that such a correction device is capable of correcting three or more kinds of aberrations using only one electro-optic panel. Divided areas concerning coma aberration correction and divided areas concerning astigmatism correction are formed in one of the transparent electrodes of the electro-optic panel, while the rest of divided areas concerning coma aberration correction and divided areas concerning spherical aberration correction are formed in the other of the transparent electrodes.

Abstract: A lens driving apparatus for driving a movable body in a focus direction and a tracking direction is provided with: a holder, to which a focus coil, a tracking coil and a lens are installed, to thereby constitute the movable body; and a magnetic circuit for applying magnetic fluxes to the focus coil and the tracking coil, to thereby drive the movable body in the focus direction and the tracking direction. The tracking coil includes two sets each having upper and lower two coils arrayed in the focus direction such that the two sets are arrayed in the tracking direction. The magnetic circuit applies the magnetic fluxes opposite to each other along a jitter direction, with respect to the upper two coils and the lower two coils without applying the magnetic fluxes with respect to portions adjacent to the upper and lower two coils.

Abstract: An optical pickup apparatus (100) is provided with: a carriage body (80); an optical parts accommodation module (70) mounted on said carriage body and accommodating at least (i) a light beam emitting portion (41, 42, 55) for emitting a light beam, (ii) a light beam receiving portion (57, 65), (iii) a beam splitter (44) and (iv) a grating (43) for generating a sub beam for a tracking adjustment out of the light beam emitted from said light beam emitting portion; and a grating adjustment mechanism (62, 63) for rotating said optical parts accommodation module. The optical parts accommodation module is mounted on said carriage body in such a condition that said optical parts accommodation module is allowed to rotate with an axis line of the light beam, which is irradiated toward a disc, as a rotational center.

Abstract: A tilt detecting device detects and corrects a disc tilt without a dedicated tilt sensor. There is a correlation between an amplitude level of a prepit detection signal and a disc tilt quantity on a disc on which prepits are formed in advance. Namely, the amplitude level of the prepit signal becomes maximum when the disc tilt quantity is zero. Therefore, by controlling a tilt correction quantity such that the amplitude level of the prepit detection signal becomes maximum, the tilt correction can be executed without utilizing a dedicated tilt sensor and the like.

Abstract: A lens driving apparatus for driving a movable body in a focus direction and a tracking direction is provided with: a holder, to which a focus coil, a tracking coil and a lens are installed, to thereby constitute the movable body; and a magnetic circuit for applying magnetic fluxes to the focus coil and the tracking coil, to thereby drive the movable body in the focus direction and the tracking direction. The tracking coil includes two sets each having upper and lower two coils arrayed in the focus direction such that the two sets are arrayed in the tracking direction. The magnetic circuit applies the magnetic fluxes opposite to each other along a jitter direction, with respect to the upper two coils and the lower two coils without applying the magnetic fluxes with respect to portions adjacent to the upper and lower two coils.

Abstract: An optical pickup apparatus (100) is provided with: a carriage body (80); an optical parts accommodation module (70) mounted on said carriage body and accommodating at least (i) a light beam emitting portion (41, 42, 55) for emitting a light bean, (ii) a light beam receiving portion (57, 65), (iii) a beam splitter (44) and (iv) a grating (43) for generating a sub beam for a tracking adjustment out of the light beam emitted from said light beam emitting portion; and a grating adjustment mechanism (62, 63) for rotating said optical parts accommodation module. The optical parts accommodation module is mounted on said carriage body in such a condition that said optical parts accommodation module is allowed to rotate with an axis line of the light beam, which is irradiated toward a disc, as a rotational center.

Abstract: There is provided an optical pickup for use in an information reproducing apparatus for playing an optical disc, said optical pickup comprising: a main pickup body carrying an objective lens; a sub-pickup body pivotably connected with the main pickup body; a connecting structure formed in connection with the main pickup body for pivotably supporting the sub pickup body. A space having a predetermined size is formed between the main pickup body and the connecting structure. The material thickness between the main pickup body and the connecting structure is made thinner by virtue of the formation of said groove.