Matsushita Electric Industrial Co., Ltd.

Fuminobu Furukawa

Shogo Horinouchi

Kouki Kojima

Hiroshi Goto

Masaharu Fukakusa

Takashi Haruguchi

Tsuyoshi Kakuta

Taiichi Mori

Kazuyuki Nakashima

Hideki Yoshinaka

Shin Ishibashi

Toshihiro Koga

Kensei Fukuda

Yoshinobu Soeda

Shigeki Takeuchi

Junya Aso

Tsutomu Egashira

Junichi Mutoh

Hirohiko Oowaki

Hideru Goto

Kouji Okada

Akihiro Nishiyama

Nobuo Jikuya

Minoru Nagata

Syuji Narahara

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.

Optical pickup device and optical disk device

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. Further, the tracking control for the pick-up apparatus is characterized in that tracking control is carried out in accordance with a difference signal between two groups in the tangential direction.

Optical disc apparatus

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.

Motor having characteristic structure in armature and disc apparatus

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.

Optical pickup device for emitting laser beams having different wavelengths and optical disk driver for use therewith

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.

Integrated optical component and optical pick-up device

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.

Optical pickup apparatus restricting aberration and optical disc apparatus using the same

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.

Optical pickup apparatus

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.

Disc drive apparatus of slot loading type

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. The light pickup is capable of reproducing information from optical disks having different recording densities, is composed of a small number of parts, and is compact and thin.

Light pickup

An optical pickup is disclosed which is capable of recording or reproducing information from optical disks having different recording densities and 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. The light pickup is capable of reproducing information from optical disks having different recording densities, is composed of a small number of parts, and is compact and thin.

Light pickup of thin type

An optical pickup for recording on and reproduction from recording media of different recording densities (e.g. a high density disk such as a DVD and a lower density disk such as an ordinary CD), and having a compact, thin and low power-consumption design. The optical pickup includes an objective lens, a first optical unit having a light-emitting element and a light-receiving element which are used for recording on and reproduction from the high-density optical disk, a second optical unit having a light-emitting element and a light-receiving element which are used for recording on and reproduction from the low-density optical disk, a beam splitter for guiding optical axes of the first and second optical units to the same optical axis, and a wavelength filter for changing a diameter of light beams incident on the objective lens between at the time of recording and reproduction for the high-density optical disk and at the time of recording and reproduction for the low-density optical disk.

Optical pickup

An object of the present invention is to provide an optical disk reproducing method and apparatus which allows for influence on focus servo control and tracking servo control involved in outputting voice information. The optical disk reproducing apparatus includes an optical pickup, a tracking servo control for causing the optical pickup to trace a track on the optical disk, a focus servo control and a pair of speakers for outputting reproduced voice information to the outside. When an information determining unit determines that the reproduced information includes voice information, the tracking servo control and the focus servo control are operated so as to provide a servo characteristic suitable for reproduction of voice information by the speakers to thereby reproduce information in the optical disk.

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Onojo, Japan

Fuminobu Furukawa