Abstract: A magnetic disk drive unit includes a first read amplifier connected to an inductive head, a second read amplifier connected to a magneto-resistive head, a selective output unit for selecting either an output of the first read amplifier or an output of the second read amplifier and supplying a selected output to a demodulator, and a control unit for supplying a switching control signal. When reading servo information written onto a data surface of a magnetic recording medium, the control unit controls the switching control signal and thus causes the selective output unit to select an output of the first read amplifier associated with the inductive head. By the constitution, servo information can be detected in a wide range using a relatively simple data-surface servo pattern. This realizes high-precision off-tracking compensation.

Abstract: This invention relates to a method of producing a high-melting powder of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!propane characterized by comprising a step of adding water to a solution of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!-propane in an organic solvent in the presence of a surfactant to give a water-in-oil emulsion and a step of removing the organic solvent from the emulsion in the presence of a crystal nucleus to induce crystallization to give an aqueous dispersion of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!propane. In accordance with this invention, crystallization is carried out in the state of an emulsion under assistance of a surfactant so that an ordinary stirrer can be used in production without resort to any special high-shear stirring equipment. Moreover, since a high-melting grade of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!propane is obtained as an aqueous dispersion, workability and safety in the subsequent processing are improved.

Abstract: Disclosed is a magnetic disk apparatus having a large internal accommodation space. This magnetic disk apparatus comprises a case defining accommodation space inside, magnetic disks disposed in the accommodation space, a spindle motor, magnetic heads and a rotary actuator. The case includes a cover having a first flat portion and a first upright portion standing upright on the first flat portion at a peripheral portion thereof, and a base having a second flat portion and a second upright portion standing upright on the second flat portion at a peripheral portion thereof. This design can ensure a sufficient strength even if the case is made thin, thus allowing the internal accommodation space to be increased. The magnetic disk apparatus also has a printed circuit board, which is provided at the case and has a control circuit mounted thereon for controlling the magnetic heads. The printed circuit board supplies a source voltage to the case.

Abstract: A chain cable retainer includes a plurality of same-size link members made of a resilient material and connected to each other in a longitudinal direction to form a flexible guide for guiding a cable. Each member includes a bottom plate and a pair of side plates integrally attached to the bottom plate. The pair of side plates includes a pair of front, outside plates and a pair of rear, inside plates integrally connected to the respective ends of the outside plates. The inside plates are provided with projections and outside plates are provided with holes engaged with the projections, in such a manner that a link member can be pivotably engaged with respect to an adjacent link member. A low-rigidity part, such as a longitudinal groove, is provided on each of the side plates, so that the pair of inside plates can easily be inserted into the pair of outside plates to allow the projections to engage with the holes.

Abstract: A breather filter unit for a magnetic disk drive including a base and a cover fixed to the base, the cover having a vent. The breather filter unit includes a casing fixed to an inner surface of the cover, the casing having a vent inlet communicating with the vent of the cover and a vent outlet communicating with an inside of the magnetic disk drive, and a first filter contained in the casing at a position adjacent to the vent inlet, the first filter being formed from a plurality of fibers extending in a direction substantially parallel to that of an air flow from the vent inlet to the vent outlet. The breather filter unit further includes a second filter bonded to the casing so as to cover the vent outlet, and an activated carbon layer contained in the casing at a position between the first filter and the second filter.

Abstract: A magnetic disk drive having one or more magnetic disks, one or more read/write heads each recording or reproducing information for a corresponding one of the magnetic disks, a servo head reading control information from a predetermined one of the magnetic disks, and an actuator supporting the one or more read/write heads and the servo head includes first leads extending from the one or more read/write heads along one side of the actuator, and second leads extending from the servo head along the other side of the actuator so that the second leads can be distanced in space from the first leads.

Abstract: A magnetic disk apparatus including magnetic disks and a magnetic head assembly for access to the magnetic disks. The magnetic head assembly includes a head carriage having a hub and integral head arms, magnetic heads being carried by the head arms. A flexible printed circuit is attached to the side surface of the head carriage via a double sided pressure sensitive adhesive tape which provides a layer of elastomeric material to mitigate a deformation of the head carriage relative to the flexible printed circuit and the bearings supporting the head carriage to improve the off-track of the magnetic disks.