Abstract: The present invention provides an optical pickup device comprising a light condensing means for condensing light emergent from a light source to an optical disk, a light condensing holder on which the light condensing means is mounted, a suspension holder for elastically supporting the light condensing holder, a focus coil mounted on the light condensing holder, a tracking coil mounted on the light condensing holder, and a magnetic field impression means for impressing a magnetic field upon the focus coil and the tracking coil, wherein the tracking coil is composed of a first to a third tracking coil portion combined with each other.

Abstract: Provided is a focus and tracking control method for an optical pick-up apparatus which is used for recording and reproduction of a small-sized optical disc and which can carry out stable focus control and stable tracking control. A focus control method for an optical pick-up apparatus comprising a light source, an objective lens, a light receiving means having divided four light receiving zones and a polarizing means having divided for lattice zones, characterized in that when the reflected light beam is incident upon the four light receiving zones by way of the four lattice zones, focus control is carried out in accordance with a difference signal between the groups, in the radial direction, of the four light receiving zones which are divided into two groups in the radial direction by the division line in parallel with the tangential direction, respectively through the four lattice zones which are divided into two groups in the tangential direction by a division line in parallel with the radial direction.

Abstract: An optical disk apparatus, which decreases probability of impossibility of correcting an error in reading, is provided, where the error results from deviation of a writing-resuming position in resumption of writing. When an amount of data in a buffer becomes not more than a given amount of data, a buffer-underrun-detecting-circuit judges that the data are in a buffer-underrun-condition. According to the judgement, a writing-interrupting-and-resuming-circuit detects an end position of the last pit for writing, and the position is stored in a time-information-memory, and the optical disk apparatus becomes in a pause condition of writing. When the buffer-underrun-condition is avoided, the optical disk apparatus releases the pause condition of writing, and reads the position of interruption of writing from the time-information-memory, and then synchronizes data written on an optical disk and the data for writing.

Abstract: The invention provides a motor which can reduce a generation of a cogging, has a thin size, and can generate a strong torque. In a motor having an armature including a back yoke formed in a cylindrical shape and a wound coil and a magnet formed in a cylindrical shape and magnetized by a plurality of magnetic poles on a cylindrical circumferential surface, the back yoke forms a convex portion protruding from the back yoke toward the magnet in a current switching portion of the coil. The invention further provided a disc apparatus using the motor mentioned above.

Abstract: In an optical pickup device for emitting at least two laser beams suitable for respective optical recording mediums selectively operated on an optical disk driver so that a signal is read out from and/or recorded onto the selected one of the optical recording mediums, an anamorphic system is arranged to change a cross-sectional shape of one of the laser beams from an oval toward a circle between a divergence point and a confluence point along the one of the laser beam between an upstream common optical paths of the laser beams from the light beam source and a downstream common optical paths of the laser beams toward the objective lens, at which divergence point the laser beams from the upstream common optical path diverge from each other, and at which confluence point the laser beams converge into the downstream common optical path.

Abstract: The present invention provides an optical pickup device comprising a light condensing means for condensing light emergent from a light source to an optical disk, a light condensing holder on which the light condensing means is mounted, a suspension holder for elastically supporting the light condensing holder, a focus coil mounted on the light condensing holder, a tracking coil mounted on the light condensing holder, and a magnetic field impression means for impressing a magnetic field upon the focus coil and the tracking coil, wherein the tracking coil is composed of a first to a third tracking coil portion combined with each other.

Abstract: Provided are an integrated optical component which can prevent a detection optical system being affected by variation in working temperature, and a pick-up device using the integrated optical component. The integrated optical component for guiding a light beam emitted from a light emitting element to an optical disc, and for separating a required light beam from reflected light from the optical disc, wherein the integrated optical component includes therein a plurality of optical surfaces, and a diffraction grating for extracting light beams required from tracking control and focus control, from the reflected light is formed in any one of the optical surfaces.

Abstract: An optical recording/reproducing apparatus has a light source that radiates a laser beam, an optical detector that detects reflected light from the optical disc, a collimator lens that converts the radiated light of the light source into a fine divergent pencil of rays, and an objective lens that focuses these rays on the optical disc. The collimator lens has a surface that is curved to form a wavefront shape that increasingly corrects a coma aberration of the radiated light in correspondence to a radial distance between the center of the collimator lens and a position at which the radiated light intersects the collimator lens.

Abstract: A small-sized, inexpensive optical pickup apparatus can be assembled with high accuracy. The optical pickup apparatus has a various-purpose semiconductor laser, an integrated optical assembly for guiding outgoing light to an optical disk and for separating reflected light, a light receiver for receiving light and converting the received light into an electrical signal, and a coupling member for retaining a positional relationship among the various-purpose semiconductor laser, the integrated optical assembly, and the light receiver. By using a various-purpose semiconductor laser, the optical pickup apparatus can be made in a small size at low cost, and can be accurately assembled. The apparatus is also capable of accurately and efficiently detecting the optical power of the various-purpose semiconductor laser.

Abstract: Provided are a thin optical pick-up apparatus which can record and reproduce data to and from both high recording density disc and low recording density disc, and a thin optical disc unit using this optical pick-up apparatus. The optical pick-up apparatus comprises a short wave LDA 11, a long wave LDAB 12, a beam splitter 41, a riser prism 23 for turning an optical axis into an optical axis perpendicular to the optical disc, a composite filter 33 being integrally incorporated with the objective lens 32 while a surface of the composite filter 33 is opposed to an oblique surface of the riser prism 23 in parallel with each other.

Abstract: Provided is a focus and tracking control method for an optical pick-up apparatus which is used for recording and reproduction of a small-sized optical disc and which can carry out stable focus control and stable tracking control. A focus control method for an optical pick-up apparatus comprising a light source, an objective lens, a light receiving means having divided four light receiving zones and a polarizing means having divided for lattice zones, characterized in that when the reflected light beam is incident upon the four light receiving zones by way of the four lattice zones, focus control is carried out in accordance with a difference signal between the groups, in the radial direction, of the four light receiving zones which are divided into two groups in the radial direction by the division line in parallel with the tangential direction, respectively through the four lattice zones which are divided into two groups in the tangential direction by a division line in parallel with the radial direction.

Abstract: The invention provides a disc drive apparatus which is suitable for making the apparatus compact, light and thin and make it possible to automatically mount and discharge the disc. The disc drive apparatus has pick-up means and transfer means, and the transfer means has medium driving means, synchronous driving means and positioning means which is brought into contact with an outer peripheral edge of the disc. Accordingly, the disc can be transferred in a direction of a disc surface and can be positioned by the positioning means.

Abstract: Provided are an optical pickup apparatus which is used for recording and reproducing a small-sized optical disc and which is small-sized, lightweight and inexpensive, and an optical disc unit, including an optical head which comprises a lens holder engaged and fixed to an arm, an objective lens fixed to that side which is opposed to the optical disc, a semiconductor laser arranged on a surface side which is in rear of the former surface, and a reflection mirror for guiding a light beam to the objective lens, the semiconductor laser being arranged on an OEIC through the intermediary of a submount, on that surface side which is on the rear surface side of the lens holder.

Abstract: An optical disk apparatus, which decreases probability of impossibility of correcting an error in reading, is provided, where the error results from deviation of a writing-resuming position in resumption of writing. When an amount of data in a buffer becomes not more than a given amount of data, a buffer-underrun-detecting-circuit judges that the data are in a buffer-underrun-condition. According to the judgement, a writing-interrupting-and-resuming-circuit detects an end position of the last pit for writing, and the position is stored in a time-information-memory, and the optical disk apparatus becomes in a pause condition of writing. When the buffer-underrun-condition is avoided, the optical disk apparatus releases the pause condition of writing, and reads the position of interruption of writing from the time-information-memory, and then synchronizes data written on an optical disk and the data for writing.

Abstract: The invention provides a motor which can reduce a generation of a cogging, has a thin size, and can generate a strong torque. In a motor having an armature including a back yoke formed in a cylindrical shape and a wound coil and a magnet formed in a cylindrical shape and magnetized by a plurality of magnetic poles on a cylindrical circumferential surface, the back yoke forms a convex portion protruding from the back yoke toward the magnet in a current switching portion of the coil. The invention further provided a disc apparatus using the motor mentioned above.

Abstract: In an optical pickup device for emitting at least two laser beams suitable for respective optical recording mediums selectively operated on an optical disk driver so that a signal is read out from and/or recorded onto the selected one of the optical recording mediums, an anamorphic system is arranged to change a cross-sectional shape of one of the laser beams from an oval toward a circle between a divergence point and a confluence point along the one of the laser beam between an upstream common optical paths of the laser beams from the light beam source and a downstream common optical paths of the laser beams toward the objective lens, at which divergence point the laser beams from the upstream common optical path diverge from each other, and at which confluence point the laser beams converge into the downstream common optical path.

Abstract: An object of the invention is to provide an optical pickup apparatus which restricts a generation of a coma aberration caused by an objective lens shift, maintains a high quality signal reproduction, improves an accuracy of recording position and can restrict a loss of a recording optical power, and an optical disc apparatus using the optical pickup apparatus. The optical pickup apparatus is provided with optical units having light sources radiating laser beams and optical detectors detecting reflected lights, a collimator lens converting the radiated beam into a fine divergent light and an objective lens, and the collimator lens is formed in a wavefront shape corresponding to the fine divergent light in a center area close to an optical axis, and is formed in a wavefront shape correcting a coma aberration in correspondence to an increase of a radius of the collimator lens. Further, there is provided the optical apparatus using the optical pickup apparatus.

Abstract: Provided are an integrated optical component which can prevent a detection optical system being affected by variation in working temperature, and a pick-up device using the integrated optical component. The integrated optical component for guiding a light beam emitted from a light emitting element to an optical disc, and for separating a required light beam from reflected light from the optical disc, wherein the integrated optical component includes therein a plurality of optical surfaces, and a diffraction grating for extracting light beams required from tracking control and focus control, from the reflected light is formed in any one of the optical surfaces.

Abstract: A small-sized, inexpensive optical pickup apparatus can be assembled with high accuracy. The optical pickup apparatus has a various-purpose semiconductor laser, an integrated optical assembly for guiding outgoing light to an optical disk and for separating reflected light, a light receiver for receiving light and converting the received light into an electrical signal, and a coupling member for retaining a positional relationship among the various-purpose semiconductor laser, the integrated optical assembly, and the light receiver. By using a various-purpose semiconductor laser, the optical pickup apparatus can be made in a small size at low cost, and can be accurately assembled. The apparatus is also capable of accurately and efficiently detecting the optical power of the various-purpose semiconductor laser.

Abstract: An optical pickup capable of recording or reproducing information from optical disks having different recording densities includes a first optical unit having a light source which emits rays having a first wavelength for DVDs and a first light sensor which detects reflected rays, a second optical unit having a light source which emits rays having a second wavelength for CDs and a second light sensor which detects reflected rays, a beam splitter which directs the rays having the first wavelength and the rays having the second wavelength along substantially the same optical axis, and directs reflected rays from an optical disk to the first light sensor and the second light sensor, and an objective lens which has a numerical aperture (NA) of 0.6 or more, a focal length of 2.5 mm or less, an effective diameter of incidence of 3.0 mm or less and a working distance of 1.2 mm or less. The light pickup as a whole has a thickness of 7.5 mm or less as measured from a bottom surface of the optical disk.