Mitsumi Electric Company Ltd.

Toshimitsu Itoh

Yoshihide Majima

Toshiharu Shimizu

Teruo Shimazu

Hidetsugu Touji

Yoshinori Tangi

Eiichi Yoneyama

Yoshihiro Okano

Tsuneo Uwabo

Hisakazu Hironaka

In a recording/reproducing device for use in recording and reproducing data on and from a recording medium while moving read/write head means relative to the recording medium in a moving direction, which comprises a carriage supporting the read/write head means and guided by a guiding member in the moving direction, and a voice coil motor comprising a voice coil and a magnetic circuit device for driving the carriage in the moving direction. The carriage has a coil holding portion by which the voice coil is fixedly held in the condition that the coil axis is arranged in the moving direction. The voice coil is applied with a driving electric current for driving the carriage. The magnetic circuit device is fixedly disposed adjacent to the voice coil to generate a magnetic field intersecting the driving current flowing through the voice coil, the voice coil moving in the moving direction together with the carriage by an interaction of the driving current and the magnetic field.

Recording/reproducing device with read/write head carriage supporting voice coil of voice coil motor for driving the carriage assembly

In a large-capacity FD comprising a disk-shaped recording medium on which a plurality of tracks are arranged with concentric circles, each track is divided into a predetermined number of sectors having a length equal to one another. Each sector consists of a serve field and a data field. The servo field in each sector includes a sector number field in which a sector number and alternation contents of the magnetic disk medium are written and a track number field in which a track number is written. The sectors on each track may be assigned with serial sector numbers in a circumferential direction in order with skipping over any defective sector. The plurality of tracks may be separated in a radial direction into a plurality of zones each including at least one alternate track. The plurality of tracks may be separated in a radial direction into a user data area and an alternate area which has an information identification sector for storing historic information in respect to preparation of the disk-shaped recording medium.

Disk-shaped recording medium and formatting method thereof wherein historic information including a storage capacity of the disk-shaped recording medium is recorded thereon

In a method of carrying out defect management on reading data from a disk-shaped magnetic recording medium comprising a plurality of tracks separated into a user data area available to a user, an alternate area, and a management area, the method comprises the steps of retrying reading operation of data up to a maximum retry count when an error is detected on reading of data for a target sector in the user data area and of registering the target sector in a defect table in the management area and writing read-out data in an alternate sector in the alternate area in a case where a retry count is not less than a specific count when retry results in a success. Alternatively, the method comprises the steps of retrying reading operation of data up to a maximum retry count when an error is detected on reading of data for a target sector in the user data area, of overwriting read-out data in the target sector in a case where a retry count is not less than a specific count when retry results in a success, and of registering the target sector in a defect table in the management area and writing read-out data in an alternate sector in the alternate area in a case where an error is detected when overwritten data is reread from the target sector.

Defect management method for a magnetic recording medium

In a motor drive for driving a motor having three-phase coils in both a high rotation speed mode in which the motor rotates at a high rotation speed and a low rotation speed mode in which the motor rotates at a low rotation speed which is extremely lower than the high rotation speed, the motor drive includes a mode selection circuit for making a connection of the three-phase coils unipolar and bipolar connections on the high and the low rotation speed modes, respectively. A frequency generation pattern detects a rotation speed of the motor. On the basis of the rotation speed detected by the frequency generation pattern, a combination of a PLL circuit and a driving transistor drives the motor at the high and the low rotation speeds in the high and the low rotation speed modes, respectively.

Removable type magnetic recording/reproducing device

Recording/reproducing device with read/write head carriage supporting

In a disk protection method for protecting a magnetic recording disk upon ejection thereof from a removable magnetic recording/reproducing device by an eject mechanism through operation of an eject button, data writing relative to the magnetic recording disk is inhibited in response to a data write inhibit signal which is generated immediately after the operation of the eject button and before the eject mechanism actually starts the ejection of the magnetic recording disk. The eject mechanism actually ejects the magnetic recording disk from the removable magnetic recording/reproducing device in a condition where the data writing is inhibited.

Disk protection method for removable magnetic recording/reproducing

In a method of starting rotation of a magnetic disk medium of a large-capacity flexible disk by a spindle motor for use in a high-density type flexible disk drive for carrying out data recording and reproducing operation to and from the magnetic disk medium of the large-capacity flexible disk which requires to rotate at a high rotation speed on recording and reproducing, the method includes: a first step of rotating the spindle motor at a low rotation speed lower than the high rotation speed on rotation starting of the magnetic disk medium; a second step of rotating the spindle motor at the high rotation speed subsequently to rotating of the spindle motor at the low rotation speed; a third step of rotating the spindle motor at the low rotation speed subsequently to rotating of the spindle motor at the high rotation speed; and a fourth step of rotating the spindle motor at the high rotation speed subsequently to rotating of the spindle motor at the low rotation speed at the third step. The second and the fourth steps are carried out to ensure that the spindle motor chucks a disk hub of the large-capacity flexible disk. Each of the second and the fourth steps includes the steps of increasing the rotation speed of the spindle motor from the low rotation speed up to the high rotation speed by a predetermined abrupt acceleration; and rotating the spindle motor at a constant speed equal to the high rotation speed.

Method capable of surely chucking a FD inserted in a high-density type

In a high-density FDD for driving a magnetic disk medium of an FD inserted thereinto, a switch unit 50 detects whether the inserted FD is a large-capacity FD or a small-capacity FD. A control device 60 is connected to the switch unit 50, a control device 60 controls drive of a spindle motor 100 so as to rotate the spindle motor 100 at a high rotation speed when the inserted FD is identified as a large-capacity FD, and so as to rotate the spindle motor 100 at a low rotation speed when the inserted FD is identified as a small-capacity FD.

Control method for a high-density type FDD capable of automatically

A flexible disk drive includes a carriage spaced from a main frame and holding a magnetic head, a pair of guide bars for guiding the carriage, rubber dampers fixed on each of the guide bars at both axial end portions thereof, and a linear motor for moving the carriage in a given radial direction of a flexible disk. When the linear motor excessively in the carriage in the given radial direction, the rubber dampers work to stop the carriage in a manner so as to prevent a shock.

Magnetic recording/reproducing device having head carriage with shock

In a magnetic recording/reproducing device, a voice coil motor includes a voice coil and a magnetic circuit for producing a magnetic field intersecting the electric current flowing through the voice coil. The voice coil motor drives a carriage holding a magnetic head. A flexible printed circuit is disposed adjacent to the voice coil for feeding the electric current to the voice coil and sending signals to and from the magnetic head. Between the voice coil and the flexible printed circuit is interposed a magnetic shield for preventing to noise from influencing the flexible printed circuit upon feeding the electric current to the voice coil.

Magnetic recording/reproducing device with magnetic shield between voice

A magnetic recording/reproducing device which incorporates a lift arm and presser assembly, wherein the lift arm and presser assembly includes a lift arm holding a magnetic head, a carriage attached with the lift arm which is movable relative to the carriage, and a lift arm pressing spring attached to the carriage for pressing the lift arm. The lift arm pressing spring presses the lift arm at a position closer to the magnetic head than to a middle point between the magnetic head and a center portion of the lift arm.

Magnetic recording/reproducing device having a magnetic head and a lift

A flexible disk drive includes a magnetic head carriage, a linear motor for moving the carriage, and a carriage locking mechanism for locking the carriage in response to ejecting action of a flexible disk from the flexible disk drive. A lever unit has an ejecting lever and a locking lever. The ejecting lever is a part of an ejecting mechanism for ejecting the flexible disk from the flexible disk drive. The locking lever is disposed in the vicinity of the carriage, and locks the carriage from movement after the flexible disk is ejected from the flexible disk drive by the ejecting lever. The lever unit is made of non-magnetic material such as resin as one body.

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Atsugi, Japan

Toshimitsu Itoh