Control device, magnetic disk control system, and control method for controlling disk storage device

Patent metadata

Field	Value
Publication number	US-2018096704-A1
Application number	US-201715717035-A
Country	US
Kind code	A1
Filing date	Sep 27, 2017
Priority date	Sep 30, 2016
Publication date	Apr 5, 2018
Grant date	—

Abstract

A control device is provided which can perform a retraction operation of a head included in a disk storage device with lower power consumption.
The control device of the disk storage device includes a control unit that controls a motor and retracts the head from over a disk to a ramp mechanism when power supply is shut down, an acquisition unit that acquires information related to a moving distance of the head that retracts to the ramp mechanism, and a calculation unit that calculates the moving distance of the head based on the information acquired by the acquisition unit. The control unit switches an operation of the motor from a first retract operation to a second retract operation when determining that the head reaches a first position after passing through an inclined surface of the ramp mechanism based on the moving distance calculated by the calculation unit.

First claim

What is claimed is:

1 . A control device for controlling a disk storage device,
wherein the disk storage device includes
a disk for storing data,
a head for reading data stored in the disk or writing data to the disk,
a motor for moving the head in a radial direction of the disk, and
a ramp mechanism including an inclined surface, the ramp mechanism being for preventing the head and the disk from coming into contact with each other by causing the head to pass through the inclined surface,
wherein the control device includes
a control unit that controls the motor and retracts the head from over the disk to the ramp mechanism when power supply is shut down, an acquisition unit that acquires information related to a moving distance of the head that retracts to the ramp mechanism, and
a calculation unit that calculates the moving distance of the head based on the information acquired by the acquisition unit, and
wherein the control unit is configured to switch an operation of the motor from a first retract operation to a second retract operation when determining that the head reaches a first position after passing through the inclined surface of the ramp mechanism based on the moving distance calculated by the calculation unit.

2 . The control device according to claim 1 ,
wherein the control unit supplies power to the motor to retract the head at a predetermined speed in the first retract operation.

3 . The control device according to claim 1 ,
wherein the control unit applies a predetermined voltage to the motor for a predetermined period of time in the second retract operation.

4 . The control device according to claim 1 ,
wherein the information related to the moving distance of the head includes a value related to a back electromotive force generated in a coil of the motor.

5 . The control device according to claim 1 ,
wherein the information related to the moving distance of the head includes a rotation angle of the motor.

6 . The control device according to claim 4 ,
wherein the calculation unit calculates the moving distance by integrating a value related to the back electromotive force.

7 . The control device according to claim 1 ,
wherein the calculation unit calculates the moving distance of the head after the head reaches a second position.

8 . The control device according to claim 7 ,
wherein the disk storage device further includes a stop mechanism for stopping movement of the head, and wherein the second position includes a position of the head when the movement of the head is stopped by the stop mechanism.

9 . The control device according to claim 7 ,
wherein the second position includes a position at which the head reaches the ramp mechanism. 10 . The control device according to claim 9 , wherein the information related to the moving distance of the head includes a value related to a back electromotive force generated in a coil of the motor, wherein the control unit determines that the head reaches the ramp mechanism based on the value related to the back electromotive force, and wherein the calculation unit calculates the moving distance of the head after the control unit determines that the head reaches the ramp mechanism.

11 . The control device according to claim 9 ,
wherein the control device
supplies power to the motor to retract the head at a predetermined speed in the first retract operation, and
determines that the head reaches the ramp mechanism based on a value related to the power supplied to the motor, and
wherein the calculation unit calculates the moving distance of the head after the control unit determines that the head reaches the ramp mechanism.

12 . A magnetic: disk control system comprising:
a magnetic disk for storing data; a first motor for rotating the magnetic disk; a magnetic head for reading data stored in the magnetic disk or writing data to the magnetic disk; a second motor for moving the magnetic head in a radial direction of the magnetic disk; a ramp mechanism including an inclined surface, the ramp mechanism being for preventing the magnetic: head and the magnetic: disk from coming into contact with each other by causing the magnetic: head to pass through the inclined surface; and a control device for controlling the second motor, wherein the control device includes
a control unit that controls the second motor and retracts the magnetic head from over the magnetic disk to the ramp mechanism when power supply is shut down,
an acquisition unit that acquires information related to movement of the magnetic head that retracts to the ramp mechanism, and
a calculation unit that calculates a moving distance of the magnetic head based on the information acquired by the acquisition unit, and
wherein the control unit is configured to switch an operation of the second motor from a first retract operation to a second retract operation when determining that the magnetic head reaches a first position after passing through the inclined surface of the ramp mechanism based on the moving distance calculated by the calculation unit. 13 . A control method for controlling a disk storage device, wherein the disk storage device includes a disk for storing data,
a head for reading data stored in the disk or writing data to the disk,
a motor for moving the head in a radial direction of the disk, and
a ramp mechanism including an inclined surface, the ramp mechanism being for preventing the head and the disk from coming into contact with each other by causing the head to pass through the inclined surface,
wherein the control method includes the steps of retracting the head from over the disk to the ramp mechanism by controlling the motor when power supply to the disk storage device is shut down, acquiring information related to a moving distance of the head that retracts to the ramp mechanism, and calculating the moving distance of the head based on the information acquired by the step of acquiring the information, and wherein the step of retracting the head includes the steps of
determining whether or not the head reaches a first position of the ramp mechanism based on the calculated moving distance, and
switching an operation of the motor from a first retract operation to a second retract operation when it is determined that the head reaches a first position after passing through the inclined surface of the ramp mechanism.

Assignees

• Renesas Electronics Corp

Inventors

• Kurosawa Minoru
• Itagaki Kichiya
• Ishiji Seigi

Classifications

• G11B19/2081

  emergency power-down · CPC title

• G11B21/02

  Driving or moving of heads · CPC title

• G11B21/12

  Raising and lowering; Back-spacing or forward-spacing along track; Returning to starting position {otherwise than during transducing operation} · CPC title

• G11B19/2063 Primary

  Spindle motor power-down sequences · CPC title

• G11B19/04

  Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions · CPC title