Abstract: Embodiments of the invention provide a magnetic disk unit in which there has been adopted a structure fixing a base and a top plate and preventing a deformation by a bimetal effect. In one embodiment, the magnetic disk unit includes a magnetic disk; a head drive mechanism in which is mounted a head accessing the magnetic disk; a base accommodating the magnetic disk and the head drive mechanism, and possessing a flat part, in which a threaded hole has been formed, in a circumference of an opening edge; and a top cover which is formed by a material whose thermal expansion coefficient differs from that of the base, in which there is provided an escape hole, for a screw, position-aligned to the threaded hole of the flat part, and which is attached to the base by the screw penetrating through the threaded hole and the escape hole for the screw.

Abstract: There is provided a disc changer for a disc drive unit, including: a disc accommodation section capable of accommodating plural discs: a disc pushing mechanism that pushes a disc from a specific rack of the disc accommodation section to a disc discharge position within the disc drive unit; and a disc discharge mechanism that securely sends the disc at the disc discharge position, to a disc insertion/discharge opening of the disc drive unit. The disc exchanger further includes a disc guiding device that has: an upper and a lower guiding members, which are provided in an area within the disc drive unit adjacent to the disc insertion/discharge opening, and guide the disc pushed by the pushing mechanism, to the disc insertion/discharge opening; and a drive mechanism of the guiding members, that opens the lower guiding member from the upper guiding member, when the pushing mechanism pushes the disc.

Abstract: The number of recording layers of the loaded disc is determined using the blue laser light. If the number of recording layers is two, drawing is performed in the recording layer on the near side when seen from the laser light entering side, and demodulation is performed with the HDDVD decoder. If demodulatable, the disc is determined as a disc in which two HDDVD layers are arranged. If not demodulatable, determination is made on whether or not the data of the recording layer is demodulatable with the DVD decoder. If demodulatable with the DVD decoder, the laser light is switched to the red laser light and the number of recording layers is determined. If two recording layers are detected in this determination, the disc is determined as a disc in which two DVD layers are arranged. On the other hand, if one recording layer is detected, the disc is determined as a hybrid HDDVD in which one HDDVD layer and one DVD layer are arranged.

Abstract: A disk-storing disk may include multiple supporting members for supporting disks and being stacked in the axial direction; a supporting member selecting mechanism for moving a supporting member to a selecting position; a driving unit having a rotational driving unit for clamping and rotating a disk held by the supporting member at the selecting position; a transporting mechanism for transporting a disk inserted from an insertion opening of the casing to the selected supporting member at the selecting position; and a restriction guide member having a restriction face and being turnably supported between a guiding attitude and a non-acting attitude; wherein, when a disk is transported toward a supporting member at the selecting position by the transporting mechanism, the restriction guide member turns to the guide attitude, and when the supporting member is moved by the supporting member selecting mechanism, the restriction guide member turns to the non-acting attitude.

Abstract: Embodiments of the invention provide a perpendicular magnetic writing head with a suppressed effective track width to be written on a magnetic medium while increasing writing magnetic field gradient. In one embodiment a trailing side shield is disposed by way of a gap film to a main pole of a perpendicular writing magnetic head. A gap distance (Gt) on a trailing side of the main pole and a gap distance (Gs) on a lateral side of the main pole is defined as Gt<Gt, and a thickness (Gd) from an air bearing surface of the shield is made equal to or less than a throat height. Alternatively, the thickness of Gd on the side of the main pole is reduced to less than that on the trailing side of the main pole. Further, for preventing defoliation of the shield upon fabrication of the air bearing surface, a thickness for a portion away from the main pole is increased.

Abstract: A slider having an improved atmospheric pressure variation characteristic can be provided by ensuring the desired amount of inflow of air flowing to the air bearing surface in a region where it is difficult to ensure the desired air inflow amount, e.g., a region where the slider/disk relative speed is low or a region where the area of the air bearing surface is small by forming a groove configuration surface in a specified shape. In the negative pressure utilization type slider, a groove configuration surface lower in height than an air in flow surface is formed between the disk inner peripheral end and the disk outer peripheral end of the air inflow surface in the air flow incoming end side of a pressure generating surface, separately from a negative pressure generating surface.

Abstract: An optical disc apparatus includes an emitter which emits a laser beam to a optical disc, a divided photodetector including a first divided portion and a second divided portion disposed in a light path of the reflected beam from the optical disc, and producing a first photodetector signal and a second photodetector signal, a phase difference detector which produces a phase difference signal from a phase difference between the first and the second photodetector signals, an integrator which produces a integral signal from a integration of the phase difference signal, a tracking controller configure to perform tracking control based on the integral signal, and a limiter which limits a signal to be supplied from the divided photodetector to the phase difference detector or a signal to be supplied from the phase difference detector to the integrator based on a detection status of a signal detected by the divided photodetector.

Abstract: To provide a disk drive capable of being prevented from rattling due to vibrations by a motor or eccentricity of a disk, support arms formed at both sides of a U-shaped traverse holder of a traverse unit have ribs protruding therefrom. Shaft portions protrude outward from front ends of the arms while bearing portions are provided on sidewalls of a chassis. The bearing portion has an axial hole formed in the side wall and a flexibly deformable, resilient arm extending forward spaced from the sidewall by a given distance, the axial hole having a front portion and a rear portion, the front portion being smaller in height than the rear portion, and the height of the front portion of the axial hole being slightly larger than outside diameter of the shaft portions. The shaft portions are fitted in the axial holes. The ribs are squeezed within the resilient arms.

Abstract: In an optical disk apparatus, for reproducing information recorded on a recording surface of an optical disk, by setting such a focus condition that a tracking servo-error level comes to be maximum with a reflection light from the recording surface, while irradiating a light beam of a semiconductor laser, within a signal processor portion 300 for amplifying a RF signal reproduced from the optical disk is provided an equalizer 330 for lifting up high-frequency region of the RF signal, wherein an optimal control is made on an amount of lifting (i.e., EQ Boost Value) by the equalizer, depending upon a difference (?AF) between a focus offset amount at which the RF signal reproduced comes to be maximum and a focus offset amount at which jitter of the RF signal reproduced come to be minimum.

Abstract: A system for recording/reproducing a photosensitive recording medium, comprising: a photosensitive recording medium cartridge including a cartridge body, a shutter, and a lock mechanism as defined herein; and a recording/reproducing device including a housing, an insertion port shutter, an unlock mechanism, and a shutter opening mechanism as defined herein.

Abstract: It is an object of the present invention to improve a margin to meet good recording quality by conducting a realtime correction of a recording condition of a medium with different recording characteristics for inner and outer circumferences. To accomplish the object, control factors for power and a pulse width are independently detected and corrected using an mT pulse having a length of m?T as a pulse for power control and an nT pulse having a length of n?T as a pulse for pulse width control; more specifically, power correction for mT pulse and pulse width correction for nT pulse are conducted in realtime, wherein a recording pulse stream including the mT pulse and nT pulse is irradiated onto a medium by a recording laser beam as well as pits and spaces formed by irradiation of the recording pulse stream are reproduced by a reproducing laser beam to detect the effects of power and pulse width variations independently.

Abstract: A high-density optical disc such as BD-RE (Blu-ray Disc Rewritable) or BD-ROM, and a recording/reproducing method thereof are disclosed. Diverse additional information such as disc reflectivity information, disc layer information or disc type information is efficiently recorded in a particular information field included in a data unit recorded on the burst cutting area of a high-density optical disc or a particular 1-byte address field included in an address unit recorded on the high-density optical disc so that it can be read when the high-density optical disc is loaded in an optical disc apparatus or when a data recording or reproducing operation for the high-density optical disc is carried out. Accordingly, it is possible to achieve optimal optical power control and automatic gain control or identification of a current position, while enabling a normal data recording or reproducing operation corresponding to the type of the optical disc.

Abstract: An optical disc drive may include a tray movable for the sake of mounting and dismounting a disc, a disc rotation mechanism arranged at the center to rotate the disc, and a pickup arranged on a backside of the center to write and read the disc within a housing. The optical disc drive may be arranged with a first opening for inhaling outside air in a height range between the bottom surface of the tray and the proximity to the bottom end of the pickup on a back surface or a side surface around a corner on a right side viewed from the backside of the housing, and a second opening for exhausting internal air, arranged higher than a top surface of the tray on the back surface or a side surface around a corner on a left side viewed from the backside.

Abstract: Gimbal designs are provided that minimize adverse dynamic performance of a HDD suspension, particularly subsequent to head-disk-interface (HDI) interactions. The improvement of operational performance can be seen in graphical representations of the vibrational modes of a gimbal mounted slider subsequent to such HDI interactions. Each gimbal design includes a ramp limiter formed as two separated arms connected by one or two transverse bars and a routing of conducting traces that relieves stress and minimally contacts these bars.

Abstract: A disk device includes a driving unit and a restricting mechanism that are disposed in a housing. The driving unit moves between a withdrawal position and a driving position. The withdrawal position is separated from an outer peripheral edge of a disk that is positioned in the housing, and the driving position is where the disk is rotationally driven. When the driving unit is at the withdrawal position, the restricting mechanism restricts movement of the driving unit toward the driving position.

Abstract: There is provided an information recording/reproducing apparatus for recording or reproducing an information to or from an information recording medium having a plurality of recording layers stacked on a substrate which can always perform stable spindle rotation control irrespective of an error of a desired frequency value or the like, and which includes an optical head for recording or reproducing an information to or from the recording layers by use of an optical beam; a spindle motor for rotating the recording medium; and a drive voltage holding circuit for holding a drive voltage of the spindle motor when the optical head performs switching between the recording layers for recording/reproducing.

Abstract: A magnetic write head structure that maximizes write field strength while minimizing stray fields. The write pole structure maximizes write field strength by minimizing saturation of the magnetic pole tips, and minimizes stray field writing by preventing magnetic fields from extending laterally from the sides of the magnetic pole. The write head structure includes a write pole having a pole tip configured with a stair notched shape and a steep shouldered base beneath the stair notched portion. This configuration maximizes the amount of flux that can be delivered to the pole tip while also avoiding stray fields. The magnetic pole can also be configured with wing shaped extensions that extend laterally from the pole tip region but which are recessed from the ABS by a desired amount.

Abstract: In one embodiment, a seed layer, an underlayer, and a magnetic domain control layer are laminated on both sides of a magnetoresistive sheet unit. A lower electrode film is thinly formed on an upper portion of the magnetic domain control film. A portion of the lower electrode film near the magnetoresistive sheet unit does not protrude substantially from an upper surface of the magnetoresistive sheet unit. Should the portion protrude, a step from the upper surface of the magnetoresistive sheet unit is about 14 nm or less. This portion and the upper surface of the magnetoresistive sheet unit are formed into a flat surface. An upper electrode film is formed thickly on an upper portion of the lower electrode film on an outside thereof so as to circumvent the flat surface. A protective layer, an upper gap film, and an upper magnetic shield film are also formed.

Abstract: A recording medium driving device which records information in or reproduces information from the recording medium, includes a device body in which a recording medium is inserted and from which the recording medium is removed, a conveying mechanism that conveys the recording medium in a loading direction and an eject direction, a mounting section on which the recording medium is mounted, a conveyance arm that moves according to movement of the recording medium in the loading direction and the eject direction and conveys the recording medium, and a driving mechanism that has a driving source for imparting a driving force for moving the conveyance arm. The conveyance arm includes a contact section that brought into contact with the recording medium and an urging member that urges the contact section in the eject direction of the recording medium.

Abstract: A media drive system includes a housing and a drive unit at least partially disposed within the housing. A media handler arrangement defines a plurality of queuing positions for media objects, and a receiving area within the housing receives storage units defining at least one other queuing position. The drive system reduces latency through the use of the queuing positions to speed transfer and access to media objects.