Method and apparatus for releasing a magnetic head

Claim 3

A method claimed in claim 1, wherein in step (b), the drive current to the second motor is gradually increased.

Claim 4

A magnetic disk memory unit which comprising: a magnetic disk; first motor means, mechanically connected to the disk, for rotating the disk; a magnetic head; actuator means for supporting and actuating the head along substantially a radial direction of the disk; second motor means, mechanically connected to the actuator means, for driving the actuator means; stopper means, provided at a part of the actuator means with elastic material, for restricting a movement of the actuator means; and drive circuit means, electrically connected to the second motor means, for supplying the second motor means, upon starting the first motor means, with a drive current which has a polarity to make the actuator means compress the elastic material and a waveform that gradually rises, is maintained until at least and disk actually begins to rotate and gradually falls.

Claim 5

A magnetic disk memory unit which comprising: a magnetic disk; first motor means, mechanically connected to the disk, for rotating the disk; a magnetic head; actuator means for supporting and actuating the head along substantially a radial direction of the disk; second motor means, mechanically connected to the actuator means, for driving the actuator means; stopper means, provided at a part of the actuator means with elastic material, for restricting a movement of the actuator means; and drive circuit means, electrically connected to the second motor means, for supplying the second motor means, upon starting the first motor means, with a drive current which has a polarity to make the actuator means compress the elastic material and a waveform that gradually rises, is maintained until at least and disk actually begins to rotate and gradually falls.

Claim 6

A magnetic disk memory unit as claimed in claim 3, wherein the drive circuit means includes; switch means, connected to a predetermined voltage source, for selectively supplying the predetermined voltage, in response to an adhesion release signal, for a predetermined period of time; time constant means, connected to the switch means, for transforming the selectively supplied predetermined voltage into a gradually rising and gradually falling voltage waveform; and amplifying circuit means, connected to the time constant means and to the second motor, for supplying the drive current, which is proportional to the voltage waveform, to the second motor.

Claim 9

A method for releasing adhesion in a magnetic disk file unit according to claim 5, wherein the magnetic disk file unit includes an elastic stopper, step (b) includes moving the magnetic head so as to gradually compress the elastic stopper, and step (d) includes gradually releasing the magnetic head from the elastic stopper.

Claim 10

A method for releasing adhesion in a magnetic disk file unit according to claim 6, wherein the magnetic disk unit includes a drive motor for driving the magnetic head, and step (b) further includes: applying a drive current to the drive motor, the drive current having a gradual rise characteristic.

Claim 11

A method for releasing adhesion in a magnetic disk file unit according to claim 7, wherein step (d) further includes removing the drive current such that it has a gradual fall characteristic.

Claim 12

A magnetic disk file unit having a magnetic head and a magnetic disk having a data area and a guard area, comprising: means for initiating rotation of the magnetic disk upon starting the disk file unit; means for gradually moving the magnetic head radially with a small acceleration along the disk towards the guard area before the magnetic disk begins to rotate; means for holding the magnetic head in the guard area until the magnetic disk begins to rotate; and means for permitting the magnetic head to move toward the data are after the magnetic disk begins to rotate.

Claim 13

A magnetic disk file unit having a magnetic head and a magnetic disk having a data area and a guard area, comprising: means for initiating rotation of the magnetic disk upon starting the disk file unit; means for gradually moving the magnetic head radially with a small acceleration along the disk towards the guard area before the magnetic disk begins to rotate; means for holding the magnetic head in the guard area until the magnetic disk begins to rotate; and means for permitting the magnetic head to move toward the data are after the magnetic disk begins to rotate.

Claim 14

A magnetic disk file unit according to claim 9, wherein said magnetic disk file unit further includes; an elastic stopper means for restricting movement of the magnetic head in the radial direction such that said means for gradually moving the magnetic head radially gradually compresses said elastic stopper.

Claim 15

A magnetic disk file according to claim 10, wherein said magnetic disk unit further includes: a drive motor operatively connected to the magnetic head; and said means for gradually moving the magnetic head radially includes means for applying a drive current to the drive motor having a gradual rise characteristic.

Claim 16

A method for releasing adhesion according to claim 5, wherein step (d) includes the step of gradually permitting the magnetic head to move toward the data area.

Claim 17

A magnetic disk file unit according to claim 9, wherein said means for permitting the magnetic head to move includes means for gradually moving the magnetic head towards the data area.