Abstract: A removable cover assembly for a data storage device comprises a first cover coupled with a casing base of a data storage device via a plurality of screws. A second cover is disposed upon a rib of the casing base and is coupled with the rib. The second cover is configured with a groove which delineates a perimeter separating an interior region of the second cover from an exterior region of the second cover. A space between the first cover and the casing base is filled with a low-density gas. The groove defines the region in the second cover in which separation of the interior region from the exterior region is to occur to expose the screws.

Abstract: Embodiments of the present invention provide a magnetic disk unit capable of attaining miniaturization, lower cost, lighter weight, lower profile, and higher density. According to one embodiment, only a carriage and a spindle motor among respective constituent components of a hard disk drive (HDD) are securely attached to a support plate made of a hard metal material higher in rigidity than a shroud. All the constituent components of the HDD, except the carriage, and the spindle motor, (a voice coil motor, a ramp, a latch lever, an HDD connector and so forth), that is, the respective constituent components of the HDD, of which assembling precision, rigidity, and so forth are not required, are attached to the shroud small in wall-thickness, and lighter in weight, formed of a resin material such as plastics and so forth.

Abstract: A method for re-injecting low density gas into a disk drive including a hermetically sealed disk enclosure. The method includes providing a disk drive including a hermetically sealed disk enclosure. In addition, the method includes re-injecting low density gas from a hole penetrating the hermetically sealed disk enclosure from an exterior of the disk drive to an interior of the disk drive. Moreover, the method includes covering the hole with a sealing label including a metal layer and an adhesive layer.

Abstract: Embodiments of the present invention help to effectively suppress vibration of the disk in a Hard Disk Drive (HDD) with low density gas sealed therein, and securely prevent leakage of the low density gas from the base. In an embodiment, helium gas is sealed in a hermetically sealed enclosure of an HDD, and a shroud is formed integrally with a base. In manufacturing the base, a magnetic disk facing surface of the shroud is shaped by cutting after die-casting. This accomplishes a small and precise size of the gap between the magnetic disk facing surface and the circumferential edge of the disk. Cutting the shroud formed independently from the exterior walls, which ensure the hermeticity with the shroud, suppresses the vibration of the magnetic disk and eliminates the necessity of cutting of the inner surfaces of the exterior walls for the purpose of suppression of the vibration to reduce the risk of helium leakage.

Abstract: An embodiment of a magnetic disk apparatus in accordance with the present invention includes a magnetic recording medium, a magnetic head assembly having a magnetic head which reads and writes data on the magnetic recording medium, and a motor coil assembly rotationally driving a spindle motor rotation body, in which plural motor coils are arranged on a circumference around the rotation center of the spindle motor rotation body so that intervals in the circumferential direction are equal, in a stator base surrounding a periphery of the spindle motor rotation body and having a shape in which a prescribed moving locus portion of at least the magnetic head assembly is cut out.

Abstract: A method for re-injecting low density gas into a disk drive including a hermetically sealed disk enclosure. The method includes providing a disk drive including a hermetically sealed disk enclosure. In addition, the method includes re-injecting low density gas from a hole penetrating the hermetically sealed disk enclosure from an exterior of the disk drive to an interior of the disk drive. Moreover, the method includes covering the hole with a sealing label including a metal layer and an adhesive layer.

Abstract: A disk drive configured with micro-actuator interconnect conditioning. The disk drive includes a disk, a head, an actuator, a piezoelectric element, a hardened conductive adhesive, a voltage-supply circuit, and a controller. The head is configured to access the disk. The actuator includes a suspension supporting the head, and an arm supporting the suspension. The piezoelectric element is disposed on the suspension, is electrically connected to a first drive line and a second drive line, and is configured to change the position of the head. The hardened conductive adhesive is electrically connected to at least one connecting part of the piezoelectric element and the first drive line. The voltage-supply circuit is configured to supply a voltage to the piezoelectric element. The controller is configured to control a voltage-control circuit each time a designated process is executed, and to apply a voltage to the piezoelectric element with a prescribed maximum absolute value.

Abstract: Embodiments of the present invention help to effectively suppress vibration of the disk in a Hard Disk Drive (HDD) with low density gas sealed therein, and securely prevent leakage of the low density gas from the base. In an embodiment, helium gas is sealed in a hermetically sealed enclosure of an HDD, and a shroud is formed integrally with a base. In manufacturing the base, a magnetic disk facing surface of the shroud is shaped by cutting after die-casting. This accomplishes a small and precise size of the gap between the magnetic disk facing surface and the circumferential edge of the disk. Cutting the shroud formed independently from the exterior walls, which ensure the hermeticity with the shroud, suppresses the vibration of the magnetic disk and eliminates the necessity of cutting of the inner surfaces of the exterior walls for the purpose of suppression of the vibration to reduce the risk of helium leakage.

Abstract: Embodiments of the invention provide a magnetic disk drive promoting even higher densities, greater capacities, and further reduction in size, while relaxing component accuracy requirements. In one embodiment, the magnetic disk drive includes a magnetic disk receiving member and a magnetic disk holding member, a magnetic disk being rotatably held with the magnetic disk clamped therebetween. The receiving member makes a line contact with a surface of the magnetic disk on a circumference of a circle formed around a rotational axis of the magnetic disk.

Abstract: Embodiments of the invention prevent trouble caused by an increase in viscosity of grease generated when a ball bearing operates at a low temperature, and fretting that an inner ring and/or an outer ring comes in contact with balls to produce wear when vibration is applied thereto. In one embodiment, a ball bearing is configured such that a plurality of balls are arranged between an outer ring and an inner ring. Grease is filled between the balls, the inner ring and the outer ring. A holder is provided with a spring plate, and an extreme end thereof is always in contact with the balls. The spring plate is formed of a sufficiently softer material than the balls so as not to damage the balls. The mounted direction is one along the direction in which the balls are desired to be rotated. Appropriate spring pressurization can be applied to the balls at an angle defined by the holder and the spring plate in the root at which the holder is attached to the spring plate.

Abstract: Embodiments of the present invention provide a magnetic disk unit capable of attaining miniaturization, lower cost, lighter weight, lower profile, and higher density. According to one embodiment, only a carriage and a spindle motor among respective constituent components of a hard disk drive (HDD) are securely attached to a support plate made of a hard metal material higher in rigidity than a shroud. All the constituent components of the HDD, except the carriage, and the spindle motor, (a voice coil motor, a ramp, a latch lever, an HDD connector and so forth), that is, the respective constituent components of the HDD, of which assembling precision, rigidity, and so forth are not required, are attached to the shroud small in wall-thickness, and lighter in weight, formed of a resin material such as plastics and so forth.

Abstract: An embodiment of a magnetic disk apparatus in accordance with the present invention includes a magnetic recording medium, a magnetic head assembly having a magnetic head which reads and writes data on the magnetic recording medium, and a motor coil assembly rotationally driving a spindle motor rotation body, in which plural motor coils are arranged on a circumference around the rotation center of the spindle motor rotation body so that intervals in the circumferential direction are equal, in a stator base surrounding a periphery of the spindle motor rotation body and having a shape in which a prescribed moving locus portion of at least the magnetic head assembly is cut out.

Abstract: Embodiments of the invention prevent trouble caused by an increase in viscosity of grease generated when a ball bearing operates at a low temperature, and fretting that an inner ring and/or an outer ring comes in contact with balls to produce wear when vibration is applied thereto. In one embodiment, a ball bearing is configured such that a plurality of balls are arranged between an outer ring and an inner ring. Grease is filled between the balls, the inner ring and the outer ring. A holder is provided with a spring plate, and an extreme end thereof is always in contact with the balls. The spring plate is formed of a sufficiently softer material than the balls so as not to damage the balls. The mounted direction is one along the direction in which the balls are desired to be rotated. Appropriate spring pressurization can be applied to the balls at an angle defined by the holder and the spring plate in the root at which the holder is attached to the spring plate.

Abstract: Embodiments of the invention provide a magnetic disk drive promoting even higher densities, greater capacities, and further reduction in size, while relaxing component accuracy requirements. In one embodiment, the magnetic disk drive includes a magnetic disk receiving member and a magnetic disk holding member, a magnetic disk being rotatably held with the magnetic disk clamped therebetween. The receiving member makes a line contact with a surface of the magnetic disk on a circumference of a circle formed around a rotational axis of the magnetic disk.

Abstract: A spindle motor for magnetic disc device includes a hub having an inside and an outer peripheral side on which a magnetic disc is mounted, a rotary shaft having an axial direction and coupled with the hub so as to be integrally rotated therewith, with the motor being arranged on the inside of the hub. The hub, the rotary shaft and a part of the motor constitute a rotary body. A radial bearing having a length in the axial direction of the rotary shaft, for supporting the rotary body in a direction crossing the rotary shaft, and a thrust bearing for supporting the rotary body in the axial direction of the rotary shaft are provided. The thrust bearing has an outer diameter greater than the length of the radial bearing, and is arranged at a position which is inside of the motor and diametrically inward of the hub.

Abstract: A spindle motor used in a magnetic disc apparatus having a hub to which a magnetic disc is mounted and a rotary shaft to which the hub is fixed. The rotary shaft is located in a bearing casing having one end opened and the other end closed by a hydrodynamic pressure radial bearing, the rotary shaft being supported by a hydrodynamic pressure thrust bearing and the hydrodynamic pressure radial bearing. An inner diameter D and a width L of the hydrodynamic pressure radial bearing having a relationship of L/D<1.

Abstract: A spindle motor used in a magnetic disc apparatus having a hub to which a magnetic disc is mounted and a rotary shaft to which the hub is fixed. The rotary shaft is located in a bearing casing having one end opened and the other end closed by a hydrodynamic pressure radial bearing and hydrodynamic pressure thrust bearing, an inner diameter D and a width L of the hydrodynamic pressure bearing having a relationship of L/D<1.

Abstract: A magnetic disc device includes a magnetic disc and a rotary shaft rotatably supporting the magnetic disc. The magnetic disk is laid in a bearing casing having one end opened, and having a bearing member at the other end. The rotary shaft is supported by a first hydrodynamic fluid bearing and a second hydrodynamic fluid bearing provided in the bearing member. The inner diameter D and the width L of the first hydrodynamic fluid bearing exhibits such a relationship as L/D>1.

Abstract: An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

Abstract: A rotary shaft is rotatably supported by a hydrodynamic fluid radial bearing and a hydrodynamic fluid thrust bearing which are excellent in shock resistance, an bearing arrangement in which vibration in a translation mode of the shaft, among vibration components caused by unbalance force exerted to the rotary shaft, is supported by the radial bearing, and vibration in conical mode is supported by the thrust bearing, magnetic fluid is used as lubrication oil, and a permanent magnet is located between the radial bearing and the thrust bearing so as to apply a magnetic attracting force between the rotary shaft and the thrust bearing so as to carry out axial positioning in order to use the magnetic disc device in an arbitrary attaching posture.