Abstract: To provide an optical head device, which can detect an excellent focus error signal for a dual layer optical recording medium, and optical information recording/reproducing device. Reflected light from a dual layer optical recording medium is diffracted by a diffractive optical element divided into four regions, and is received by a photodetector. Optical spots are equivalent to negative first order diffracted light from the four regions of the diffractive optical element, and are received by four dual-divided light receiving sections, respectively, to be used for detection a focus error signal by a Foucault's method. The four dual-divided light receiving sections are provided with positive component light receiving sections for outputting the received light as a positive component of the focus error signal and negative component light receiving sections for outputting the received light as a negative component of the focus error signal, respectively.

Abstract: The present invention relates to a clamping apparatus for a disc player which is able to accurately release a clamper from a turntable while improving miniaturization and thinning.

Abstract: According to one aspect, an optical recording and/or reproducing device for reading and/or writing an optical disc includes a base, optical pickup head, and a moving mechanism for slidably moving the optical pickup head. The moving mechanism includes a worm gear, a motor for rotating the worm gear, and a rack disposed between the worm gear and the optical pickup head for transferring motion from the worm gear to the optical pickup head. The rack includes a fastening portion for fixing the rack to the optical pickup head, an engaging portion for engaging with the worm gear, a restricting portion connected to the engaging portion for preventing the engaging portion from running out of the worm gear, and a connecting portion for connecting the fastening portion with the restricting portion.

Abstract: The present invention provides an optical pickup in which the transmission diffraction efficiency of plural recording and/or reproducing light beams of different wavelengths, radiated from plural light sources, may be prevented from being lowered, and in which the transmission diffraction efficiency and the angle of diffraction are both optimized.

Abstract: A chucking mechanism according to the present invention includes a claw member which retains a discoid disk and is arranged between a plurality of claw portions which put a radial force outwardly to a central opening portion of the disk and a plurality of claw portions, a receiving portion and a sliding portion.

Abstract: An optical pickup for performing recording and/or playback of information by selectively irradiating the corresponding wavelength optical beam to first through third optical discs having a protection layer with different thickness, includes emission units for emitting first-wavelength through third-wavelength optical beams corresponding to the respective optical discs respectively, a condensing optical device for condensing each wavelength optical beam on an optical disc signal recording face, a divergence angle transformation device, which can be moved in the optical axis direction, for transforming the divergence angle of each wavelength optical beam according to the moved position in the optical axis direction so as to obtain a predetermined divergence angle, and a detector having a common light receiving unit for receiving each wavelength optical beam separated by an optical path separating unit and returned, with the condensing optical device condensing each wavelength optical beam on the corresponding o

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

Abstract: The present invention discloses an optical disc drive including a pickup head for reading data from a disc; a spindle motor for supporting and rotating the disc; a loading/ejecting apparatus for loading or ejecting the disc; and an emergency ejecting apparatus. The emergency ejecting apparatus includes a slider for connecting the loading/ejecting apparatus, a rack, an elastic component for connecting the slider and the rack and a rotator rotated with the movement of the slider. When a user drives the rotator and the elastic component is elastically deformed, the slider is moved in the optical disc drive to drive the loading/ejecting apparatus to eject the disc.

Abstract: The optical disk recording apparatus has the function of correcting the timing shift of the write strategy signal caused by the change in the operating environment of the digital signal processing circuit including the write strategy generating circuit, the laser drive circuit for driving the laser at the time of recording and the flexible printed board for electrical connection between the digital signal processing circuit and the laser drive circuit. Upon determination that the timing shift correction is required, the timing shift is reduced by operating the timing shift correcting function.

Abstract: The position of an optical pickup with respect to a disk is maintained accurately by preventing the free end portion of a cantilever movable member from being displaced lower than its proper position during the rotation of the disk even if the movable member is heavy to have improved vibration characteristics. There are provided a movable member 4, a chassis 1, a clamp mechanism 3, and a cam mechanism 5. The cam mechanism 5 includes a shift lever 51 connected to the free end portion of the movable member 4 via elastic bodies 42 and a cam main body 55. Positioning means 8 is composed of a protrusion 53 on the shift lever 51, a stepped engaging surface 15 for supporting the protrusion 53 thereon, and a guide mechanism 71. There is also provided anti-positioning means 9 for disengaging the protrusion 53 from the engaging surface 15.

Abstract: An information reproducing method using PRML technology which provides asymmetry compensation and also assures media interchangeability. To compensate for asymmetry, target levels are basically adapted to readout signals and either restriction type (1) (time reversal and level reversal symmetry) or restriction type (2) (time reversal symmetry) is imposed between target levels. As a consequence, asymmetry compensation is made regardless of a readout signal distortion such as mark shift which might deteriorate media interchangeability.

Abstract: An optical disc apparatus, comprising a tray 2, attached to be insertable within housings 9 and 10, and within the housings are included a disc motor 3, an optical pickup 4 and a moving mechanism thereof, and also a unit mechanism chassis 5 for moving the optical pickup thereon and a controller substrate 71 disposed below the unit mechanism chassis for controlling the optical pickup, and further, a wide-width flexible cable 8 for electrical connection between the controller substrate and the optical pickup, wherein the optical pickup mounts laser units 41, 42 and 43 including three (3) pieces of elements, each emitting a laser light different in the wavelength thereof, a penetrating portion 2b and a wall portion 2e are provided in a part of left bottom surface of the tray, while forming a cutoff portion 55 in a part of the chassis, thereby guiding the airflow generated accompanying with rotation of the optical disc onto the optical pickup, with certainty.

Abstract: An objective lens actuator in an optical pickup, having a semiconductor laser diode, electro-optic parts, such as a lens or the like, as well as, the objective lens actuator, etc., in a case, comprises: a holder, which mounts an objective lens and a coil thereon, as being a movable part; a magnetic circuit part, which is made up with a magnet for magnetically driving said holder and a yoke; a plural number of elastic support parts which elastically supports said holder; and a support part, which supports other ends of said elastic support parts, wherein said support part has a part, which is cut open in parallel with the elastic support parts, between said elastic support parts, and has a through hole, in which said elastic support part passes through for each of said elastic support parts, and thereby to provide the objective lens actuator for lowering the unwanted vibration mode of the objective lens, and also enabling a stable control thereof.

Abstract: A disc clamping mechanism includes a clamp board, a clamp base, a first supporting unit and a second supporting unit. The clamp board rotatably clamps a disc in cooperation with a turntable to be rotated in a housing. The clamp base rotatably supports the clamp board at a position opposite to the turntable, and is movable so as to move away from or come into contact with the turntable. The first supporting unit comes into contact with a first peripheral edge of the clamp board protruding from the clamp base when the clamp board moves away from the disc according to the movement of the clamp base, to exert pushing force in a direction of the turntable side and pushing force in a direction of the clamp base side against the first peripheral edge. The second supporting unit is provided at the clamp base, and securely supports the second peripheral edge of the clamp board situated at a position opposite to the first peripheral edge when the first peripheral edge is pushed by the first supporting unit.

Abstract: The present invention discloses an optical disc drive including a pickup head for reading data from a disc; a spindle motor for supporting and rotating the disc; a loading/ejecting apparatus for loading or ejecting the disc; and an emergency ejecting apparatus. The emergency ejecting apparatus includes a slider for connecting the loading/ejecting apparatus, a rack, and an elastic component for connecting the slider and the rack. When a user drives the slider and the elastic component is elastically deformed, the slider is moved in the optical disc drive to drive the loading/ejecting apparatus to eject the disc.

Abstract: An optical information recording medium includes a substrate, n information recording layers provided on the substrate, and spacer layers, each of which is provided so as to be interposed between the information recording layers, wherein each of (n?1) or more of the information recording layers has a layer number information part that is formed in correspondence with one or more recording marks X and contains layer number information, where n represents an integer of not less than 2, and the layer number information is information used for determining which a given information recording layer is among the n information recording layers. Each recording mark X has a length in a circumferential direction longer than a length of a recording mark Y used for recording another information in the information recording layers.

Abstract: The present invention relates to a disc loading apparatus that has the capability of simplifying the assembly while improving thinning and reducing the number of components. With a disc loading apparatus according to the present invention, a portion of a top panel of the frame is designed to be a second mounting unit and another portion of the top panel to be a first mounting unit, the upper surface of the second mounting unit is sagged downward more than the lower surface of the first mounting unit, notches are provided appropriately at the steeped unit between the first and the second mounting units, the second mounting unit is a portion of the disc guide, the interlocking mechanism is mounted on the upper surface of the second mounting unit, and the pair of disc detection members is mounted on the lower surface of the first mounting unit, and these detection members are arranged throughout the lower surface of the first mounting unit and the upper surface of the second mounting unit through the notches.

Abstract: An apparatus, system, and method are disclosed for calibrating a holographic storage device. A read channel reads a factory-stored hologram from a holographic media. A calculation module calculates a read difference between the read factory-stored hologram and a first holographic pattern that digitally describes the factory-stored hologram. In one embodiment, a calibration module calibrates the read channel with the read difference.

Abstract: Provided is an optical disc apparatus including: a recording unit configured to record data on an optical disc with laser lights of recoding powers set for first and second layers thereof; and a control unit configured to record/reproduce test data on/from these layers, determine first and second optimum recording powers for these layers, and set the determined first and second optimum recording powers in the recording unit, wherein the control unit changes the recording power across a predetermined search width, centering on a first recommended value for the first layer to determine the first optimum recording power, and corrects a second recommended value for the second layer on the basis of the first recommended value and the first optimum recording power and changes the recording power across the search width, centering on the corrected second recommended value to determine the second optimum recording power.

Abstract: A feeding device of a slot-in disk drive is disposed in a casing of the disk drive and includes a traverse. A bolt is disposed on and protrudes from a side of the traverse. A flange extends from the side of the traverse near the bolt. A pre-stressed piece is a bended elastic body. One end of the pre-stressed piece is fixed to the flange of the traverse, and the other end is fixed to the casing. The pre-stressed piece presses the traverse downward by its elastic force. A slider includes a protrusion with a groove formed on a side of the protrusion. The bolt is inserted into and slides within the groove. The groove includes an unloading end, an inserting portion and a loading end. An opening is formed on the upper surface of the slider near the inserting portion for reducing the thickness of the disk drive.