BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are block diagrams of a magnetic dick device showing an embodiment of a storage device according to the present invention;
FIG. 2 is an explanatory diagram of a mechanical structure of the magnetic disk device according to the present embodiment;
FIGS. 3A and 3B are explanatory drawings of a head structure of the present embodiment;
FIG. 4 is a block diagram showing details of a functional configuration of an MPU in the present embodiment;
FIG. 5 is an explanatory diagram of a clearance control information table used in the present embodiment;
FIG. 6 is a flow chart of an overall processing operation of the present embodiment;
FIG. 7 is a flow chart showing details of the self correction process of step s2 of FIG. 6;
FIG. 8 is a flow chart showing details of the clearance control information measurement process of step s5 of FIG. 7;
FIG. 9 is a flow chart showing details of the clearance measurement process of step s3 of FIG. 8 using the space loss method of Wallace spacing loss;
FIG. 10 is an explanatory diagram of measurement track for performing clearance measurement;
FIG. 11 is a block diagram of a circuit unit for detecting amplitudes of preamble read signals;
FIG. 12 is an explanatory diagram schematically showing head projection distance protrusion values accompanying heating of electric-power-distributed heater;
FIG. 13 is a graph diagram of clearance changed distances measured along with increase of electric power distribution amount of the heater and derivative values;
FIGS. 14A and 14B are flow charts of the clearance measurement process of step s3 of FIG. 8 using HRF method;
FIG. 15 is an explanatory diagram of measurement-dedicated track used in the HRF method;
FIG. 16 is a flow chart of the projection transition time measurement process of step 5 of FIG. 8;
FIGS. 17A to 17C are explanatory diagrams of variation of read signal amplitude and clearance changed distance with respect to frame position along with heater electric power distribution;
FIG. 18 is a flow chart of the recording current projection distance protrusion value measurement process of step s6 of FIG. 8;
FIG. 19 is a flow chart of temperature correction coefficient measurement process of step s7 of FIG. 8;
FIG. 20 is a graph diagram showing variation of clearance and heater projection sensitivity protrusion sensitivity with respect to device temperature;
FIG. 21 is a flow chart of the write clearance control process of step S6 of FIG. 6;
FIG. 22 is a flow chart of the read clearance control process of step S10 of FIG. 6;
FIG. 23 is an explanatory diagram of a track of an embodiment in which clearance is measured and recorded for each track;
FIGS. 24A and 24B are flow charts of a clearance measurement process in which clearance is measured and written in track unit;
FIG. 25 is a flow chart of a write clearance control process performed by reading clearance recorded in track; and
FIG. 26 is a flow chart of a read clearance control process performed by reading clearance recorded in track.
Patent Application
20070230014
