Sony Corporation

Koji Mitsumori

Keiichi Shibata

Takamichi Tomiyama

Hidehiro Kume

Yoshiyuki Matsumoto

Hiroshi Oinoue

Hideo Ohkuma

Etsufumi Yamamoto

You Yoshitoshi

Shigekazu Yamamoto

Hiroyasu Uchida

Tomoyuki Ishida

The apparatus and methods of the present invention provide for a biaxial actuator, an optical pickup device, and an information optical processing device, in which the biaxial actuator is favorably mounted using a single structure. The mounting structure includes first fastening portions protruding from a bottom plate affixed to a substrate. Connecting portions are provided in the first fastening portions through first stress concentration points. The connecting portions are also provided in second fastening portions through second stress concentration points. A mounting portion is provided between the second fastening portions and yokes are formed on the bottom plate to establish a magnetic circuit. A fixing portion of the biaxial actuator is mounted on the mounting portion. By deforming each stress concentration point, a reference state of the objective lens can be determined at an arbitrary position.

Biaxial actuator apparatus and a method for mounting and adjusting the biaxial actuator

A biaxial actuator for an objective lens of an optical pickup that prevents the occurrence of tangential skew when the objective lens is moved in a focussing direction, and thereby improves optical performance. The actuator includes a lens holder that supports an objective lens , elastic supporting members each having one end fixed to the lens holder and the other end fixed to a fixed part The supporting members support the lens holder movably in a radial direction of a disc-form recording medium D and two directions intersecting orthogonally with this direction. The elastic supporting members are provided such that at least one pair on both sides of the objective lens are lined up in the optical axis direction of the objective lens. The pair of elastic supporting members have the spacing h1 of their fixing places on the lens holder side so set as to be narrower than the spacing h of their fixing places provided on the fixed part side. The elastic supporting members have expanding/contracting portions that elastically slightly expand and contract along the direction in which the elastic supporting members extend.

Actuator for an objective lens of an optical pickup for preventing skew of the optical axis

An objective lens drive device that can be assembled with a high production efficiency, without any adhesives being forced out. The objective lens drive device is in the form of a bi-axial actuator having empty chambers 25a, 25b formed by a portion of a bobbin holder 15, a portion of a lens holder 2, and a portion of a coil bobbin 4. The empty chambers 25a, 25b are filled with an adhesive 3 to bond the coil bobbin 4 to the lens holder 2. Thus, no adhesives are forced out, and the adhesive can be cured within a short time.

Objective lens drive device

A lens moving apparatus of the present invention is used in an optical pickup of, for example, an optical recording/reproducing system. The apparatus includes a moving assembly holding an objective lens and provided with a coil bobbin, elastic supporting devices which support the moving assembly along the focusing dimension and the tracking dimension, focusing coils and tracking coils wound on the coil bobbin, and a magnetic circuit formed by a yoke and a magnet. The center of gravity of the moving assembly is positioned so that the product of the distance from an effective section of the focusing coil to the center of gravity of the moving assembly and the force produced at the effective section is about equal to the product of the distance from a noneffective section of the focusing coil to the center of gravity of the moving assembly and the force produced at the noneffective section.

Lens moving apparatus preventing resonance without using yoke bridge and

An objective lens driving device used in an optical recording and/or reproduction apparatus comprises a lens holder, elastic supporting members, a coil bobbin and a yoke. An objective lens is mounted in the lens holder. The elastic supporting members have one end attached to the lens holder and the other end attached to a mounting part. The elastic supporting members support the lens holder movably in a direction parallel to the optical axis of the objective lens and in a plane perpendicular to the optical axis. A coil for focusing and coils for tracking are wound on the coil bobbin. A magnet is mounted on the yoke, and the width of this magnet is selected so that flux from the magnet acts only on effective portions of the coils for tracking.

Objective lens driving device

A biaxial actuator with a first or focusing coil and a second or tracking coil wound around a bobbin and disposed opposite to a magnet, wherein the bobbin has a hollow cylindrical body and flanges formed at both ends of the cylindrical body. Coil retaining portions are formed in the flanges, and the first coil is wound around the cylindrical body, while the second coil is wound around the retaining portions, whereby accidental slip-off of the coils can be prevented. The tracking coil is wound around the retaining portions with inclination of a predetermined angle to the magnet. And both the focusing coil and the tracking coil are retained at projections formed on at least one of the flanges.

Biaxial actuator

An objective lens drive device has a supporting member to which an objective lens is attached. The supporting member is freely translated in a direction parallel to the optical axis of the objective lens and in a plane perpendicular to the optical axis. The supporting member is attached a stationary portion, and a magnetic circuit provided on the supporting member forms a closed magnetic path. A focusing coil and a plurality of tracking coils attached to the focusing coil drive the objective lens in cooperation with the magnetic circuit so that the objective lens is translated in the direction parallel to the optical axis and in the direction perpendicular to the optical axis. The focusing coil and the tracking coils are mounted on the stationary portion so as to oppose the magnetic circuit with a predetermined spacing therebetween.

Optical pickup device with movable objective lens and stationary

An objective lens drive device used in a an optical recording and/or reproducing apparatus includes a lens holder, a plurality of elastic supporting members and a coil bobbin. The lens holder holds an objective lens. Each one end portion of the plurality of elastic supporting members are fixed to the lens holder and each other end portion of the elastic supporting members are fixed to a fixed portion. The plurality of elastic supporting members movably support the lens holder in a parallel direction of the objective lens and a horizontal direction ortjogonal to the optical axis of the objective lens. A focussing coil is wound around the coil bobbin. At least one tracking coil is attached to the focussing coil. The coil bobbin is provided with a plurality of terminals to project therefrom. The terminals are wound with the end portions of the focussing coils and the end portions of the tracking coil.

Objective lens drive device and coil bobbin thereof

A method is provided for producing an objective lens actuator in which a first resin portion which is a stationary portion and a second resin portion which is a movable portion on which an objective lens is to be mounted are integrally formed to plate-like bases in which a plurality of elastic support portions for movably supporting the movable portion relative to the stationary portion in a direction of an optical axis of the objective lens are formed in parallel with each other, so that the first resin portion and the second resin portions are connected to each other by the elastic support portions. At the same time, connecting portions provided between each of the elastic support portions and each plate-like base portion are formed so as not to overlap each other as viewed in the direction of the optical axis of the objective lens. The plurality of elastic support portions are cut away from the bases at the connecting portions.

Method for producing an objective lens actuator having elastic supports

An objective lens driving apparatus has a driving mechanism for moving a bobbin provided with an objective lens in a direction parallel to the optical axis of the objective lens and in a direction perpendicular to the optical axis of the objective lens. Each of first and second supporting members comprises a pair of hinge portions and parallel links coupling the hinge portions for supporting the bobbin so that it is movable in the direction parallel to the optical axis and in the direction perpendicular to the optical axis. The first and second supporting members are attached to a frame, and the bobbin is movable in the direction parallel to the optical axis by the first and second supporting members and in the direction perpendicular to the optical axis by a third parallel link formed of the bobbin, the first and second supporting members and a part of the frame.

Objective lens driving apparatus including parallalogram structure

An optical head device for use in a disc player comprises a movable optical assembly in which an objective lens, first and second mirrors, and a light beam generating and detecting unit are supported in common by a supporting member, and a driving mechanism for moving the movable optical assembly in both a first direction along an optical axis of the objective lens and a second direction perpendicular to the first direction, wherein, in the movable optical assembly, a light beam generated in the light beam generating and detecting unit is reflected twice by the first and second mirrors to be changed in its traveling direction, and focused by the objective lens at a position on the optical axis of the objective lens, and a light beam coming from the outside of the movable optical assembly is received by the objective lens to pass therethrough to the second mirror, reflected twice by the second and first mirrors to be changed in its traveling direction, and guided to a photodetector contained in the light beam generating and detecting unit.

Optical head devices for use in disc players

A focusing error detecting apparatus having a first photo-detector of which the light receiving portion is halved to provide first and second light receiving portions asymmetrical with respect to the center of a beam spot of a bundle of incident laser beams, the first photo-detector being located in the optical path ahead of the focusing point of the bundle of the incident laser beams, a second photo-detector of which the light receiving portion is halved to provide first and second light receiving portions asymmetrical with respect to the center of a beam spot of a bundle of incident laser beams, the second photo-detector being located in the optical path behind a focussing point of the bundle of the incident laser beams and a calculating circuit for calculating a difference between a difference of detected outputs from the first and second light receiving portions of the first photo-detector and a difference of detected outputs from the first and second light receiving portions of the second photo-detector, thereby to derive a focusing error signal from the output of the calculating circuit.

Optical pickup device

An optical pickup device having a semiconductor laser element mounted on a substrate, a photo detector formed on the substrate to receive a laser beam emitted from the semiconductor laser element and an optical element mounted on the substrate to cover the photo detector to branch the direction of optical path of the laser beam, the optical element having its face opposing the semiconductor laser element formed as an inclined face on which a semitransparent reflection film is deposited. The optical path branching optical element is provided with preventing means by which, of laser beams incident on the optical element, a laser beam reflected and/or scattered within the optical element is prevented from irradiating the photo detector.

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Chiba, Japan

Koji Mitsumori