Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
192 words
A magnetic disc drive system comprising: a magnetic head (51); _ an actuator (52) for moving said magnetic head a control current detection circuit (55) for detecting a control current (ICNT) flowing through said actuator; a position signal generation circuit (56) for generating a position signal of said magnetic head; a speed control unit (57, 59, 62, 54) for effecting a seek control; a position control unit (58, 54) for effecting a fine position control after completion of said seek control; and means (18, 10, 11, 12, 13, 14), operatively connected to said speed control unit, said position control unit, said control current detection circuit and said position signal generation circuit, operable immediately upon receipt of a power supply and before receipt of a seek command, for measuring one or more position offset values along one or more cylinders on a magnetic disc by detecting said control current from said control current detection circuit when a position of said magnetic head is controlled under said fine position control, for calculating one or more corrections values and/for outputting said calculated offset correction values to said speed control unit and said position control unit.
Claim 2
Dependent Claim
192 words
A magnetic disc drive system comprising: a magnetic head (51); _ an actuator (52) for moving said magnetic head a control current detection circuit (55) for detecting a control current (ICNT) flowing through said actuator; a position signal generation circuit (56) for generating a position signal of said magnetic head; a speed control unit (57, 59, 62, 54) for effecting a seek control; a position control unit (58, 54) for effecting a fine position control after completion of said seek control; and means (18, 10, 11, 12, 13, 14), operatively connected to said speed control unit, said position control unit, said control current detection circuit and said position signal generation circuit, operable immediately upon receipt of a power supply and before receipt of a seek command, for measuring one or more position offset values along one or more cylinders on a magnetic disc by detecting said control current from said control current detection circuit when a position of said magnetic head is controlled under said fine position control, for calculating one or more corrections values and/for outputting said calculated offset correction values to said speed control unit and said position control unit.
Claim 3
Dependent Claim
57 words
A magnetic disc drive system according to claim 1, wherein after completion of said offset correction calculation, a seek control for a normal seek command is carried out by using said calculated offset correction values, and after completion of said normal seek control a fine position control is carried out by using said calculated offset correction values.
Claim 4
Dependent Claim
114 words
A magnetic disc drive system according to claim 1 or 2, further comprising means (16,10,11,12,13, 14) operatively connected to said speed control unit and said position signal generation circuit, for determining, after completion of said offset correction value calculation by said offset adjustment means, a speed control gain used in said speed control unit by seeking said magnetic head at a predetermined cylinder under application of said calculated offset values and by measuring a time for said seek which meets a requirement of a reference seek time, and after completion of said speed control gain adjustment, a seek control for a normal seek command being carried out by using said adjusted speed control gain.
Claim 5
Dependent Claim
60 words
A magnetic disc drive system according to claim 3, wherein said speed control gain adjustment means comprises a plurality of resistors connected in parallel by a plurality of switches each serially- connected to a corresponding resistor, said resistors having a predetermined relationship of respective resistance values, and a combination of resistances of said parallel-connected resistors defining said speed control gain.
Claim 6
Dependent Claim
26 words
A magnetic disc drive system according to claim 1, 2, 3, or 4 wherein said offset adjustment is carried out along a plurality of cylinder zones.