Teac Corporation

Mitsubishi Electric Corporation

Kenji Shimozawa

Hiroshi Tsuyuguchi

Takashi Kamisaka

Yasushi Noda

Tsutomu Morita

Kazuhiko Nakane

Kenichi Sato

Isao Watanabe

Yoshihiro Kiyose

Masayoshi Shimamoto

Keiji Nakatsu

Masami Horita

Hiroshi Konuma

Masaharu Yoshimura

A laser power measuring jig is adapted for use in measuring a laser power of a laser beam which is emitted from an optical head of an optical disk unit which records and/or reproduces information on and/or from a medium. The laser power measuring jig supplies power information related to the laser power of the laser beam to a power meter which measures the laser power. The laser power measuring jig includes a main jig body which has a size and a shape which are approximately the same as those of the medium, and this main jig body is loaded into the optical disk unit. The laser power measuring jig also includes a mechanism for outputting the power information outside the optical disk unit and supplying the laser power information to the power meter when the main jig body is loaded into the optical disk unit.

Laser power measuring jig for optical disk unit

In an optical head in a magneto-optical disk storage, an angle of a polarized light surface of a laser beam can be adjusted so that the strength of a tracking error signal can be maximized. Therefore, the optical head and the magneto-optical disk storage having the optical head is applicable to both p-polarized light type and s-polarized light type magneto-optical disks. Hereupon, the laser beam corresponding to the p-polarized light type magneto-optical disk transmits parallel to the grooves on the magneto-optical disk. On the other hand, the laser beam corresponding to the s-polarized light type magneto-optical disk transmits vertical to the grooves on the magneto-optical disk. Thus, according to the present invention, just one optical head can handle both types of magneto-optical disks.

Magneto-optical disk storage device having optical head applicable to

An optical head apparatus applicable to an optical disc apparatus having an optical disc comprises a light source emitting a light beam, and an optical system transmitting the light beam emitted from the light source onto a surface of the optical disc and transmitting a light beam reflected on the surface of the optical disc to a first optical detector and to a second optical detector. The optical system includes a beam splitter splitting the light beam reflected by the surface of the optical disc into a first light beam traveling toward the first optical detector and a second light beam traveling toward the second optical detector, and a transparent member fixed to the beam splitter, through which the second light beam passes and causing astigmatic difference in the second light beam.

Optical head apparatus applicable to optical disc apparatus

An optical disc apparatus comprises a light source, an optical disc, a beam splitting element for splitting a light beam from the light source into a first beam and a second beam, a light detection element for detecting the second beam and outputting a detection signal, a control circuit for controlling an intensity of the light beam from the light source on the basis of the detection signal from the detection element, so that an intensity of the light beam from the light source is uniform, and an optical system through which the first beam passes, to reproduce the information recorded on the optical disc.

Optical disc apparatus

A focusing control system comprises a lens system having a plano-convex lens part and a cylindrical lens part formed as a unitary body such that an optical axis of the plano-convex lens and an optical axis of the cylindrical lens coincides with an optical axis of the lens system for receiving an incident optical beam reflected by the rotary recoridng medium at its one side and for transmitting the optical beam thus received to the other side of the lens system, and a photo detector array disposed so as to receive the optical beam transmitted from the lens system. The photo detector array has a quadrant detecting plane comprising four detecting sub-planes arranged in a row and column formation, and each of the sub-planes is connected to a corresponding photo detector which produces an output electrical signal when an optical beam transmitted from the lens system is irradiated on its detecting sub-plane.

Focusing control system

An optical recording/reproducing module comprises a housing defined with a depression, a focusing actuator provided on one side of the housing for carrying an objective lens such that the lens is movable in a direction perpendicular to the aforementioned one side, an optical system accommodated in the depression, the optical system includes an optical source for producing a first optical beam to be directed to the objective lens, an optical detector for detecting a second optical beam received by the objective lens and incident to the optical detector, the optical detector further produces an electrical output signal responsive to the second optical beam, and an array of optical elements for guiding the first optical beam produced by the optical source to the objective lens and for guiding the second optical beam received by the objective lens to the optical detector, a cover lid adapted to be mounted on the one side of the housing, the cover lid has a shape adapted to close the depression, and an electrical system provided on the cover lid for driving the optical source and for amplifying the electrical output signal from said optical detector.

Optical recording/reproducing module having reduced size

An objective lens drive apparatus includes an objective lens holder supporting an objective lens and provided with drive coils, a base fixing permanent magnets, printed circuit boards fixing the base at a monolithic portion thereof, and a plural number of flexible support members electrically and mechanically connected at their base ends to the printed circuit board, and with their distal ends supporting the objective lens holder so as to be flexibly displaced to a position where the drive coils oppose the permanent magnets, and wherein terminals of the drive coils are electrically connected to the flexible support members which are different with each other, and a drive current is supplied to the drive coils from the printed circuit board to pass through the flexible support members.

Optical disc apparatus lens drive apparatus and method for the

An optical head apparatus applicable to an optical disc apparatus comprises, a case body having an open surface and a window through which an opto-electronic component can be positioned and housing optical components inside it, a lid being attachable and detachable with respect to the open surface of the case body, and a flexible printed circuit board having a base portion which is adhered to the lid and on which electronic components are mounted and a protruding portion protruding from the base portion and having an opto-electronic component fixed to the distal end portion of it, the opto-electronic component being electrically connected with an electronic circuit which is formed by the electronic components, the distal end portion of the protruding portion of the flexible printed circuit board being fixed to the case body so that the opto-electronic component is position to the window.

A magneto-optical recording system comprises a first optical system carried by a first focusing actuator disposed at a first side of a magneto-optical recording medium and second optical system carried by a second focusing actuator disposed at a second side of the magneto-optical recording medium. When recording an information signal on the first side of the magneto-optical recording medium by means of an optical beam focused by the first optical system, the second focusing actuator is supplied with a biasing current and produces a magnetic field for recording. When recording an information signal on the second side of the magneto-optical recording medium, the first focusing actuator is supplied with a biasing current and produces a second magnetic field for recording.

Magneto-optic recording apparatus for recording information selectively

An optical assembly of an optical recording/reproducing apparatus for focusing an optical beam produced by a light source on a recording medium and for directing the optical beam reflected back from the recording medium to detectors comprises a first optical system including a first objective lens for focusing an optical beam on a first recording surface at a first side of a recording medium, a second optical system including a second objective lens for focusing the optical beam on a second recording surface at a second side of the recording medium, and an optical path switching means switched between a first and second states for selectively establishing an optical path connecting an optical processing unit including the light source and detectors to either one of the first and second optical subsystems.

Growing community of inventors

Musashino, Japan

Kenji Shimozawa