Abstract: There is provided a compact, lightweight, inexpensive head/disk test device. A spin stand is provided that supports a magnetic head to enable attaching and removal and comprises a fluid dynamic bearing motor that continues rotating even when the magnetic head is attached or removed. Alternatively, the spin stand comprises a fluid dynamic bearing motor and a detector for detecting changes in the back electromotive force or changes in the magnetic flux density generated by the rotation of the fluid dynamic bearing motor and for generating an index signal. Furthermore, the spin stand is provided with a fluid dynamic bearing motor and encloses a conductive fluid in a bearing of the fluid dynamic bearing motor and the bearing is grounded.

Abstract: A spin stand which comprises a disk rotator for rotating a magnetic disk and a head mover for supporting the magnetic head in such a way that it can be attached or removed and moving the magnetic head at least in the direction of the track width of the disk, and the head mover is provided with a fine positioner capable of positioning with high accuracy within a very small range of motion and a coarse positioner for setting the very small range of motion of this fine positioner at a prescribed discrete position.

Abstract: A method for measuring the track profile in a head-disk tester having a device that rotates the disk and a device that positions a head relative to the disk comprises a step wherein the position of the head on the disk on which a data track and a first servo burst group comprises at least two servo bursts have been written is changed in the direction of the disk radius as the signal amplitude of the data track is measured by the head at each head position and the first servo burst group is read, and the step wherein the measurement results for signal amplitude are mapped at the corresponding position of the head obtained from the readings of this first servo burst group. The magnetic dimensions of the head are found using the track profile obtained by the method.

Abstract: A spindle unit installed in a spinstand for testing at least one component selected from the group consisting of: a head and a disk, wherein the spindle unit comprises a disk rotation device for holding and rotating a disk and a spindle base loaded with the disk rotation device. The spindle unit has a spindle base that is fixed to the spinstand so as to enable installation and removal by the operator of the spinstand. The disk is detachably attached to the disk rotation device.

Abstract: A testing apparatus for testing a disk and/or head of a disk drive that includes a disk rotating device that rotates the disk and a rotary-positioning device that rotates and positions the head, with the rotary-positioning device supporting the head such that the attitude of the head relative to the center of rotation of the rotary-positioning device is tilted in comparison to the attitude of the head relative to the rotation center of the head in the disk drive.

Abstract: A head/disk testing device including an air-bearing plate with which disk mounting and removal are simplified. The head/disk testing device including an air-bearing plate and a means with which the disk and air-bearing plate are moved away from one another so that the disk and air-bearing plate do not contact one another when a disk is being mounted or demounted.

Abstract: The support that bears and positions the head in a head holding apparatus is further supported by a heat-compensating member, so that when the support is expanded by the heat source of the head holding apparatus, the heat-compensating member expands in the direction opposite to the direction of expansion of the support. Moreover, supplying of heat to the support and heat-compensating member is further alleviated by insulating said heat source with an insulating material. The amount of displacement of the recording element per unit of time with exposure to heat is controlled by the above-mentioned structure and effects.

Abstract: The support that bears and positions the head in a head holding apparatus is further supported by a heat-compensating member, so that when the support is expanded by the heat source of the head holding apparatus, the heat-compensating member expands in the direction opposite to the direction of expansion of the support. Moreover, supplying of heat to the support and heat-compensating member is further alleviated by insulating said heat source with an insulating material. The amount of displacement of the recording element per unit of time with exposure to heat is controlled by the above-mentioned structure and effects.

Abstract: A magnetic disc device of half-height type comprising: a base; four magnetic discs disposed one above the other on the base; five head arms rotatable about a pivot for seeking motion on both surfaces of each magnetic disc; eight magnetic heads each attached to an end of the head arm through springs facing a surface of each disc; a rotational drive unit for swinging the head arms; a main printed circuit board disposed on a rear side of the base; and, a cover which covers an upper surface of the base.

Abstract: A magnetic disc device of half-height type comprising: a base; four magnetic discs disposed one above the other on the base; five head arms rotatable about a pivot for seeking motion on both surfaces of each magnetic disc; eight magnetic heads each attached to an end of the head arm through springs facing a surface of each disc; a rotational drive unit for swinging the head arms; a main printed circuit board disposed on a rear side of the base; and, a cover which covers an upper surface of the base.

Abstract: A magnetic disc device of half-height type has a base, four magnetic discs disposed one above the other on the base, five head arms rotatable about a pivot for seeking motion on both surfaces of each magnetic disc, eight magnetic heads each attached to an end of the head arm through springs facing a surface of each disc, a rotational drive unit for swinging the head arms, a main printed circuit board disposed on a rear side of the base, and a cover which covers an upper surface of the base.

Abstract: A divided housing for supporting magnetic disk devices therein is described. The housing is separated into a shell which supports a magnetic disk pack and a magnetic head positioner, and a cover to close the opening of the shell. Spindles of the disk pack and the head positioner are respectively held at opposite ends by ball bearings. Supporting holes for supporting the bearings are formed in side walls of the shell facing each other with one boring process. The centers of the bearings are aligned precisely coaxial to each other. The plane which separates the housing into the shell and the cover intersects the side walls almost parallel to the line connecting the center of both spindles, but away from those supporting bearings. The supporting holes are perface circles, and the open edge of the shell has no cut-in portion or grooves. This increases mechanical stength of the shell, and assures a stable holding of the spindles. Therefore, the reliability of the magnetic disk device is improved.

Abstract: A magnetic disc device comprising a case composed of a base and a cover; a plurality of magnetic discs housed within the case; a plurality of magnetic heads for read/write operations and conducting a seeking motion on each magnetic disc surface; and arms for driving the magnetic heads, wherein a recess for accommodating a printed circuit board is formed on the outer surface of the base in an area outside of the range of movement of the magnetic heads and the arms.

Abstract: An encoder motor comprising: an encoder incorporated in the encoder motor, for carrying out positional detection and having an encoder code wheel fitted to a motor rotary shaft of the encoder motor; a coil formed as a moving coil movable together with the motor rotary shaft; a magnet operative with respect to the moving coil; and a bobbin in the form of cylinder on which the moving coil is disposed. The bobbin is arranged concentrically with respect to the motor rotary shaft and directly fixed to the code wheel of the encoder.

Abstract: A divided housing for supporting magnetic disk devices therein is described. The housing is separated into a shell which supports a magnetic disk pack and a magnetic head positioner, and a cover to close the opening of the shell. Spindles of the disk pack and the head positioner are respectively held at opposite ends by ball bearings. Supporting holes for supporting the bearings are formed in side walls of the shell facing each other with one boring process. The centers of the bearings are aligned precisely coaxial to each other. The place which separates the housing into the shell and the cover intersects the side walls almost parallel to the line connecting the center of both spindles, but away from those supporting bearings. The supporting holes are perfect circles, and the open edge of the shell has no cut-in portion or grooves. This increases mechanical stength of the shell, and assures a stable bolding of the spindles. Therefore, the reliability of the magnetic disk device is improved.