Magnetic disk apparatus and magnetic disk apparatus control method
A magnetic disk apparatus has a heater for heating a head incorporated in the magnetic disk apparatus, an atmospheric pressure detector for detecting a change in atmospheric pressure in the magnetic disk apparatus, and an adjuster for adjusting a thermal dose supplied to the head by the heater according to the change in atmospheric pressure detected by the atmospheric pressure detector.
1. A magnetic disk apparatus, comprising:
a heater for heating a head incorporated in the magnetic disk apparatus;
an atmospheric pressure detector for detecting a change in atmospheric pressure in the magnetic disk apparatus; and
an adjuster for adjusting a thermal dose supplied to the head by the heater according to the change in atmospheric pressure detected by the atmospheric pressure detector,
wherein the atmospheric pressure detector detects a change in atmospheric pressure according to a ratio between a change of AGC (automatic gain control) gain corresponding to an output from the head and a change of the thermal dose.
2. The magnetic disk apparatus according to claim 1 ,
wherein the atmospheric pressure detector detects a change in atmospheric pressure in powering on the magnetic disk apparatus, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
3. The magnetic disk apparatus according to according to claim 1 ,
wherein the atmospheric pressure detector detects a change in atmospheric pressure at specific time intervals, and the adjuster adjusts the thermal dose supplied to the head by the heater upon the atmospheric pressure detector detects the change in atmospheric pressure.
4. The magnetic disk apparatus according to according to claim 1 ,
wherein the atmospheric pressure detector detects a change in atmospheric pressure when the head fails to write or read data, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
5. The magnetic disk apparatus according to claim 1 ,
wherein the atmospheric pressure detector reads data written by the head to check for errors, and the adjuster adjusts the thermal dose supplied to the head by the heater according to a result of the check.
6. The magnetic disk apparatus according to claim 1 , wherein the atmospheric pressure detector detects a change in atmospheric pressure in powering on the magnetic disk apparatus, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
7. The magnetic disk apparatus according to claim 1 , wherein the atmospheric pressure detector detects a change in atmospheric pressure at specific time intervals, and the adjuster adjusts the thermal dose supplied to the head by the heater upon the atmospheric pressure detector detecting the change in atmospheric pressure.
8. The magnetic disk apparatus according to claim 1 , wherein the atmospheric pressure detector detects a change in atmospheric pressure when the head fails to write or read data, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
9. The magnetic disk apparatus according to claim 1 , wherein the atmospheric pressure detector reads data written by the head to check for errors, and the adjuster adjusts the thermal dose supplied to the head by the heater according to a result of the check.
10. A magnetic disk apparatus, comprising:
a heater for heating a head incorporated in the magnetic disk apparatus;
an atmospheric pressure detector for detecting a change in atmospheric pressure in the magnetic disk apparatus; and
an adjuster for adjusting a thermal dose supplied to the head by the heater according to the change in atmospheric pressure detected by the atmospheric pressure detector,
wherein the atmospheric pressure detector detects a change in atmospheric pressure according to a tracking accuracy that represents whether the head is positioned above a track to which data are written or from which data are read on a recording medium incorporated in the magnetic disk apparatus.
11. The magnetic disk apparatus according to claim 10 , wherein the atmospheric pressure detector detects a change in atmospheric pressure in powering on the magnetic disk apparatus, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
12. The magnetic disk apparatus according to claim 10 , wherein the atmospheric pressure detector detects a change in atmospheric pressure at specific time intervals, and the adjuster adjusts the thermal dose supplied to the head by the heater upon the atmospheric pressure detector detecting the change in atmospheric pressure.
13. The magnetic disk apparatus according to claim 10 , wherein the atmospheric pressure detector detects a change in atmospheric pressure when the head fails to write or read data, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
14. The magnetic disk apparatus according to claim 10 , wherein the atmospheric pressure detector reads data written by the head to check for errors, and the adjuster adjusts the thermal dose supplied to the head by the heater according to a result of the check.
15. A magnetic disk apparatus, comprising:
a heater for heating a head incorporated in the magnetic disk apparatus;
an atmospheric pressure detector for detecting a change in atmospheric pressure in the magnetic disk apparatus; and
an adjuster for adjusting a thermal dose supplied to the head by the heater according to the change in atmospheric pressure detected by the atmospheric pressure detector,
wherein the atmospheric pressure detector detects a change in atmospheric pressure according to a ratio between a change of a specific frequency element output from the head and the change of the thermal dose.
16. The magnetic disk apparatus according to claim 15 , wherein the atmospheric pressure detector detects a change in atmospheric pressure in powering on the magnetic disk apparatus, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
17. The magnetic disk apparatus according to claim 15 , wherein the atmospheric pressure detector detects a change in atmospheric pressure at specific time intervals, and the adjuster adjusts the thermal dose supplied to the head by the heater upon the atmospheric pressure detector detecting the change in atmospheric pressure.
18. The magnetic disk apparatus according to claim 15 , wherein the atmospheric pressure detector detects a change in atmospheric pressure when the head fails to write or read data, and the adjuster adjusts the thermal dose supplied to the head by the heater after the atmospheric pressure detector detects the change in atmospheric pressure.
19. The magnetic disk apparatus according to claim 15 , wherein the atmospheric pressure detector reads data written by the head to check for errors, and the adjuster adjusts the thermal dose supplied to the head by the heater according to a result of the check.
20. A magnetic disk apparatus control method for detecting a change in atmospheric pressure in a magnetic disk apparatus, and for adjusting a thermal dose supplied to a head incorporated in the magnetic disk apparatus by a heater according to the change in atmospheric pressure detected,
wherein the change in atmospheric pressure is detected according to the ratio between the change of the AGC (automatic gain control) gain corresponding to the output from the head and the change of the thermal dose.
21. A magnetic disk apparatus control method for detecting a change in atmospheric pressure in a magnetic disk apparatus, and for adjusting a thermal dose supplied to a head incorporated in the magnetic disk apparatus by a heater according to the change in atmospheric pressure detected,
wherein the change in atmospheric pressure is detected according to the tracking accuracy representing whether the head is positioned above a track to which data are written or from which data are read on a recording medium incorporated in the magnetic disk apparatus.
22. A magnetic disk apparatus control method for detecting a change in atmospheric pressure in a magnetic disk apparatus, and for adjusting a thermal dose supplied to a head incorporated in the magnetic disk apparatus by a heater according to the change in atmospheric pressure detected,
wherein the change on atmospheric pressure is detected according to the ratio between the specific frequency element output from the head and the change of the thermal dose.