Mitsumi Electric Company Ltd.

Koichi Seno

Yoshihito Otomo

Makoto Konno

Hisashi Shibata

Akira Shibata

Takashi Watanabe

Hisateru Komatsu

Masaki Kato

Hideaki Hayasaka

Makoto Takahashi

Masashi Sato

Hiroshi Sampei

Yoshihiro Okuyama

Mitsutoshi Ohizumi

Kenji Katoh

Kouichi Hosoya

In an FDD control apparatus for controlling a floppy disk drive for driving a floppy disk loaded in the floppy disk drive, an FDD control part including a floppy disk controller (FDC) is disposed in an FDD side in lieu of a host side (a SET side). The host side (SET side) is loaded with a USB connector connected to the FDD control part. The FDD control part includes a flash ROM for storing a program for adjusting a step timing of a stepping motor.

Floppy disk drive control apparatus capable of ensuring seek operation using a stepping motor having a low torque

In a photointerrupter comprising a light emitting diode and a photo transistor which are opposed to each other, the photo transistor has an emitter which is grounded through a resistor while the light emitting diode has a cathode which is connected to an input terminal of a one IC chip for controlling a flexible disk drive. The one IC chip incorporates a constant current source which is connected to the input terminal through an npn-type bipolar transistor. The one IC chip incorporates a logic circuit having an output terminal which is connected to a base of the npn-type bipolar transistor.

Photointerrupter driving circuit capable of decreasing the number of

A structure for preventing head judder of a magnetic disk drive is disclosed. The structure comprises an opening provided at front end portion of an upper plate of a head carriage, a gimbal disposed within the opening, a magnetic head hangingly disposed on a central lower face of the gimbal, a pivot spacer disposed between the upper plate and a central upper face of the magnetic head, and at least one pair of adhesive tapes, inner ends of the adhesive tapes are respectively stuck on near central upper face of the gimbal, and the adhesive tapes symmetrically extend towards right and left end of the gimbal.

Structure for preventing head judder of magnetic disk drive

In an integrated circuit for use in controlling a flexible disk drive for driving a flexible disk loaded therein, a power on reset circuit produces a reset signal after a predetermined time duration elapses where a power supply voltage is stable from a time when a power supply is applied. The power on reset circuit comprises a voltage detecting circuit for detecting a power supply voltage to produce a voltage detected signal and a delay circuit for producing, responsive to the voltage detected signal, the reset signal after the predetermined time duration elapses. Disposed between a selectable function circuit and a logic circuit, an output holding circuit holds output signals of the selectable function circuit as held signals and supplies the held signals to the logic circuit. The output holding circuit consists of two D-type flip-flops which are disposed in correspondence with two output signal lines of a logical circuit.

Integrated circuit for a flexible disk drive capable of always

A DD motor in a magnetic disk drive is disclosed. The DD motor comprising a sheet of metal plate formed in a two-stage disk-shaped, which includes an upper stage portion having an opening at the center thereof and a lower stage portion provided continued from the upper stage portion, a spindle shaft served as a central axis of the DD motor and inserted into the opening of the upper stage portion, and a resin portion formed integrally on a top face and a back face of the upper stage portion, in which magnetic material powder is mixed, wherein the resin portion connects the spindle shaft and the metal plate uniformly. Central axes of the small diameter disk-shaped upper stage portion and the large diameter disk-shaped lower stage portion are located coaxially. A peripheral edge of the upper stage portion is bent downwards to form a rim.

DD motor in magnetic disk drive

A cramping structure of a guide bar for a head carriage in a magnetic disk drive is disclosed. The structure comprises a head carriage, a guide bar provided in parallel to the head carriage, a guide bar cramp provided along the guide bar in opposite side of the head carriage, wherein the head carriage includes a long plate-like base and a pair of cramp arms having a slit respectively, and extending from both ends of the base to the side of the guide bar which faces to the head carriage such that the cramp arm covers above of the guide bar; and a pair of engaging pieces provided under the pair of cramp arms respectively, wherein the pair of engaging pieces respectively includes a projection engaging the slit of the cramp arm and a notch supporting the guide bar from below thereof, wherein the pair of cramp arms urges the guide bar downwards, and the urging forces are received by the pair of notches of the engaging pieces.

Cramping structure of guide bar for head carriage in magnetic disk drive

A sub-printed board 40 is disposed on a main plate of a main frame 30 at a position close to a front bezel 37. A main printed board 31 is provided on the main plate at a position opposite to the front bezel. A rotation drive mechanism for magnetic disks is mounted on the sub-printed board. A loading mechanism is assembled over the rotation drive mechanism in order to mount and eject the magnetic disks on and out of the magnetic disk drive. A head carriage 34 is disposed above the main printed board by means of a first supporting member provided on the main plate.

Magnetic disk drive of a structure capable of being lightened in weight

In a floppy disk driver controlling circuit which is for use in controlling a floppy disk driver including a stepping motor (23) and which comprises a stepping motor driver (21) for producing a driving current to drive the stepping motor and a control section (22) for controlling the stepping motor driver, each of the control section and the stepping motor driver includes CMOS transistors as switching transistors. A combination of the control section and the stepping motor driver is formed as a single CMOS integrated circuit (25). The stepping motor driver produces the driving current between 80 mA and 250 mA, both inclusive, to drive the stepping motor when the stepping motor has a diameter which is substantially equal to 15 mm.

Compact circuit for controlling a floppy disk driver

An improved disc drive is capable of compensating the relative positional shift of a head caused mainly by a temperature change. The disc drive includes a frame having a disc holder for rotatably driving a disc, a head for reading information recorded in the disc, a head carriage which is movable in a predetermined radial direction of the disc, a rotation shaft extending in parallel with the radial direction, a driving mechanism for moving the head carriage in the radial direction by engaging with the rotation shaft, an adjustment mechanism for compensating the positional shift of the head due to a change of ambient temperature by providing an additional deformation of the adjustment mechanism to the carriage.

Disc drive having positional shift adjustment

A control circuit adapted to control a motor includes a first circuit part for generating an excitation current to be supplied to the motor and having a predetermined period that is dependent on a predetermined rotation period of the motor, and a second circuit part for superimposing on the excitation current pulses having a period that is small compared to the predetermined period of the excitation current.

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Yamagata, Japan

Koichi Seno