APPARATUS AND METHOD TO CONTROL FLYING HEIGHT OF MAGNETIC HEAD IN RETRY MODE AND DISK DRIVE USING THE SAME

• US 20070230019A1
• Filed: 04/02/2007
• Published: 10/04/2007
• Est. Priority Date: 04/04/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: SONG, Myung-wook, Cho, Hyun-bum
• Granted Patent: US 7,602,571 B2
• Time in Patent Office: Days
• US Class Current: 360/75
• CPC Class Codes: G11B 5/6005 Specially adapted for spacing from a rotating disc using a fluid cushion
• CPC Class Codes: G11B 5/6064 using air pressure

Abstract

An apparatus and method to retry data read and write while changing a flying height of a magnetic head in a disk drive. The apparatus includes the magnetic head including a magnetic read element to sense a magnetic field on a disk and a magnetic write element to magnetize the disk, having a structure to generate an air bearing surface between the surface of the disk and the magnetic read and write elements, and includes a heater heating an assembly to generate the air bearing surface, a controller to generate a power control signal to adjust a flying height of the magnetic head in a retry mode, and a heater power supply circuit to generate power corresponding to the power control signal and to supply the power to the heater.

Claims

1. An apparatus to control a flying height of a magnetic head in a retry mode, the apparatus comprising:

a magnetic head comprising;

a magnetic read element to sense a magnetic field on a disk and a magnetic write element to magnetize the disk, having a structure to generate an air bearing surface between a surface of the disk and the magnetic read and write elements, and

a heater to heat an assembly to generate the air bearing surface;

a controller to generate a power control signal to adjust the flying height of the magnetic head in the retry mode; and

a heater power supply circuit to generate power corresponding to the power control signal and to supply the power to the heater.

2. The apparatus of claim 1, wherein the controller generates the power control signal in only a specific retry process among a plurality of retry processes included in the retry mode.

3. The apparatus of claim 1, wherein the controller generates the power control signal to change the flying height of the magnetic head according to a number of retries.

4. The apparatus of claim 1, wherein the controller generates the power control signal to differentiate an amplitude of power supplied to the heater in a read retry mode and in a write retry mode.

5. The apparatus of claim 4, wherein the power control signal is determined so that the power supplied to the heater is lower in the write retry mode as compared to in the read retry mode.

6. The apparatus of claim 1, wherein the power control signal is determined to maintain a same flying height of the magnetic head in the read retry mode and in the write retry mode.

7. The apparatus of claim 1, wherein the controller disables the heater power supply circuit when the retry mode is terminated.

8. A method of controlling a flying height of a magnetic head in a retry mode, the method comprising:

determining whether the retry mode starts in a disk drive;

if the retry mode starts, adjusting the flying height of the magnetic head with respect to a surface of a disk; and

performing a retry process while changing predetermined parameters according to a pre-set sequence after adjusting the flying height of the magnetic head.

9. The method of claim 8, wherein the flying height of the magnetic head is adjusted by changing power supplied to a heater included in the magnetic head.

10. The method of claim 8, wherein the retry mode includes a read retry mode and a write retry mode.

11. The method of claim 9, wherein in the adjusting of the flying height of the magnetic head, the flying height of the magnetic head is adjusted to be the same in the read retry mode and in the write retry mode.

12. The method of claim 8, wherein in the adjusting of the flying height of the magnetic head, the flying height of the magnetic head is adjusted in only a specific retry process among a plurality of retry processes included in the retry mode.

13. The method of claim 8, wherein the flying height of the magnetic head is adjusted differently according to a number of retries of the retry process.

14. A computer readable recording medium to store a computer readable program to execute a method of controlling a flying height of a magnetic head in a retry mode, the method comprising:

determining whether the retry mode starts in a disk drive;

if the retry mode starts, adjusting the flying height of the magnetic head with respect to a surface of a disk; and

performing a retry process while changing predetermined parameters according to a pre-set sequence after adjusting the flying height of the magnetic head.

15. The computer readable recording medium of claim 14, wherein the flying height of the magnetic head is adjusted differently according to a number of retries of the retry process.

16. A disk drive, which is a data storage unit, comprising:

a host interface to perform a data transmitting/receiving process with a host device;

a disk to store information;

a magnetic head comprising;

a magnetic read element to sense a magnetic field on the disk and a magnetic write element to magnetize the disk, having a structure to generate an air bearing surface between a surface of the disk and the magnetic read and write elements, and

a heater to heat an assembly generating the air bearing surface;

a write/read circuit to perform a data write process on the disk or to reproduce data read from the disk;

a controller to execute a retry routine by generating a power control signal to adjust the flying height of the magnetic head when an error occurs in the data write and read process performed by the write/read circuit; and

a heater power supply circuit to generate power corresponding to the power control signal and to supply the power to the heater.

17. The disk drive of claim 16, wherein the controller generates the power control signal in only a specific retry process among a plurality of retry processes included in the retry mode.

18. The disk drive of claim 16, wherein the controller generates the power control signal to change the flying height of the magnetic head according to a number of retries.

19. The disk drive of claim 16, wherein the controller generates the power control signal to differentiate the amplitude of power supplied to the heater in a read retry mode and in a write retry mode.

20. The disk drive of claim 16, wherein the power control signal is determined to maintain a same flying height of the magnetic head in the read retry mode and in the write retry mode.

21. The disk drive of claim 16, wherein the controller disables the heater power supply circuit when the retry mode is terminated.

22. A disk drive comprising:

a magnetic head to read data from a disk and to write data to the disk;

a positioning unit to move the magnetic head with respect to the disk to create an adjustable air bearing surface between the surface of the disk and the magnetic head; and

a controller to generate a power control signal to control the positioning unit in a retry mode of the reading of data or writing of data.

23. The disk drive of claim 22, wherein the controller generates the power control signal to adjust the air bearing surface by a certain amount based on a number of retries of the reading or writing operation.

24. The disk drive of claim 22, wherein the magnetic head is disposed at a flying height with respect to the disk and the controller adjusts the flying height in a retry mode and disables the power control signal when the retry mode is terminated, and when the retry mode is terminated the magnetic head is returned to a predetermined flying height.

25. A method of operating a disk drive to read data from a disk and to write data to the disk, the method comprising:

reading data from or writing data to a disk using a magnetic head;

generating a power control signal having a value based on a number of retries of the reading data or writing data; and

adjusting a position of the magnetic head with respect to the disk based on the generated power control signal.