EP0249064A2 — Disk drive optimized channel circuit

Claim 1

Independent Claim 113 words

In a data storage device wherein data is stored in parallel tracks on a data storage media, a data channel including circuitry wherein a serial data read signal is verified for a true peak by determining that the read signal voltage has a minimum change during a given time (delta-V) which comprises means for generating a plurality of delta-V values and means for using one of said plurality of values of delta-V to verify a read signal read from one track on the surface of said media and a second of said plurality of values of delta-V to verify a read signal read from another track on the same surface of said media.

Claim 2

Dependent Claim 113 words

In a data storage device wherein data is stored in parallel tracks on a data storage media, a data channel including circuitry wherein a serial data read signal is verified for a true peak by determining that the read signal voltage has a minimum change during a given time (delta-V) which comprises means for generating a plurality of delta-V values and means for using one of said plurality of values of delta-V to verify a read signal read from one track on the surface of said media and a second of said plurality of values of delta-V to verify a read signal read from another track on the same surface of said media.

Claim 3

Dependent Claim 41 words

The data storage device of claim 1 wherein said means for generating a plurality of values for delta-V includes circuit means for respectively generating said plurality of values in response to the value of a signal received by said circuit means.

Claim 4

Dependent Claim 36 words

The data storage device of claim 2 wherein each of said plurality of values of delta-V includes a base value plus an incremental value that varies in accordance with said signal received by said circuit means.

Claim 5

Dependent Claim 15 words

The data storage device of claim 3 wherein one of said incremental values is zero.

Claim 6

Dependent Claim 37 words

The data storage device of claim 3 wherein said parallel tracks are divided into a plurality of contiguous bands of tracks and each said band uses a value of delta-V that can vary from band to band.

Claim 7

Dependent Claim 30 words

The data storage device of claim 5 including a plurality of media surfaces wherein a selected one of said plurality of delta-V values is used within each band of tracks.

Claim 8

Dependent Claim 56 words

The data storage device of claim 6 wherein delta-V is optimized for one band of tracks on each media surface and selected for the other bands of tracks on the media surfaces based on the optimized value for said one band and a predetermined set of values for other bands of tracks on the same surface.

Claim 9

Dependent Claim 54 words

The data storage device of claim 7 wherein the delta-V value is optimized for the innermost band of tracks on a disk surface and the delta-V value for other bands of tracks of greater radius is selected in accordance with a predetermined sequence of values based on said optimized value of said inner band.

Claim 10

Dependent Claim 25 words

The data storage device of claim 3 wherein said signal is received on a bus which provides binary signals to produce binary increments of delta-V.

Claim 11

Dependent Claim 61 words

The data storage device of claim 9 wherein said bus is a three bit bus with said circuit means generating binary increments of delta-V whereby delta-V has a base value when all bus lines are off and uniform added increments of 1 through 7 units in accordance with the binary signal on said bus when one or more lines are active.

Claim 12

Dependent Claim 288 words

In a rotating magnetic data storage device which uses a magnetic transducer head to write data to and read data from a moving magnetic media surface having parallel data tracks thereon and has plural selectable values of write current and uses a signal change per unit time (delta-V) read signal peak verification having a plurality of selectable values of delta-V, the method of enhancing transducer head read-write performance comprising writing a predetermined pattern of information on a selected track; reading the data on said selected track using an initial value of write current and recording the number of errors; incrementing said write current within said plurality of selectable values, reading data on said selected track and recording the number of errors; if the number of errors is fewer than the number recorded after the next previous reading, repeating the prior step of incrementing the write current and reading the selected track or if the present write current value is the final incremental value, setting the write current at the present value and if the number of errors exceeds the next previous recorded error count, setting the write current at the next prior write current value; reading said selected track and recording the number of delta-V errors; decrement delta-V and reread said selected track, recording the number of delta-v errors; if errors are less, repeat last step and if errors are more, increment delta-v, reread said selected track and record the number of delta-V errors; if errors are less than the previous sum, repeat step of incrementing delta-V and rereading; when retest produces an increased error sum, set delta-V at immediately preceding value or at the final value if fewer errors and current value is the final incremental value.

Claim 13

Dependent Claim 288 words

In a rotating magnetic data storage device which uses a magnetic transducer head to write data to and read data from a moving magnetic media surface having parallel data tracks thereon and has plural selectable values of write current and uses a signal change per unit time (delta-V) read signal peak verification having a plurality of selectable values of delta-V, the method of enhancing transducer head read-write performance comprising writing a predetermined pattern of information on a selected track; reading the data on said selected track using an initial value of write current and recording the number of errors; incrementing said write current within said plurality of selectable values, reading data on said selected track and recording the number of errors; if the number of errors is fewer than the number recorded after the next previous reading, repeating the prior step of incrementing the write current and reading the selected track or if the present write current value is the final incremental value, setting the write current at the present value and if the number of errors exceeds the next previous recorded error count, setting the write current at the next prior write current value; reading said selected track and recording the number of delta-V errors; decrement delta-V and reread said selected track, recording the number of delta-v errors; if errors are less, repeat last step and if errors are more, increment delta-v, reread said selected track and record the number of delta-V errors; if errors are less than the previous sum, repeat step of incrementing delta-V and rereading; when retest produces an increased error sum, set delta-V at immediately preceding value or at the final value if fewer errors and current value is the final incremental value.

Claim 14

Dependent Claim 65 words

The method of enhancing transducer head performance of claim 29 wherein the step of writing a predetermined pattern of information on a selected track comprises the steps of, writing old information on the selected track, writing new information on the selected track, and writing another information pattern on each track adjoining said selected track with each adjacent track information pattern offset toward said selected track.

Claim 15

Dependent Claim 29 words

The method of enhancing transducer head performance of claim 12 wherein said steps of reading and rereading said selected track comprises reading said track a predetermined number of times.

Claim 16

Dependent Claim 74 words

The method of enhancing transducer head performance of claim 13 wherein if the number of errors recorded after the first reading of said selected track exceeds a first pre-established number, the transducer head is failed and the test is terminated and if the number of errors recored at the final write current vaule setting is not less than a second pre-established number, the test is continued using successive decremented and incremented values of delta-V.

Claim 17

Dependent Claim 51 words

The method of enhancing transducer head performance of claim 14 wherein if the number of delta-V errors at the final incremental value is less than a third pre-established number, the head is passed as within specification and if the number of erros exceeds said third pre-established number, the head is failed.

Claim 18

Dependent Claim 157 words

In a rotating data storage device wherein data is written on and read from parallel tracks on a data disk storage media by a transducer, said device having means for reading and re-reading selected data tracks and means for shifting said transducer from the data track centerline position and using a data channel including circuitry wherein the serial data read signal is verified for a true peak by determining that the read signal voltage has a minimum change during a given time (delta-V) with means for altering the value of delta-V, an error recovery procedure invoked following identification of an error not correctable during real time processing of the serial data stream comprising re-reading the track on which the error occurred; shifting the transducer in one radial direction and re-reading said track; shifting the transducer in the opposite of said one radial direction and re-reading said track; and re-reading said track using an incremented value of delta-V.

Claim 19

Dependent Claim 157 words

In a rotating data storage device wherein data is written on and read from parallel tracks on a data disk storage media by a transducer, said device having means for reading and re-reading selected data tracks and means for shifting said transducer from the data track centerline position and using a data channel including circuitry wherein the serial data read signal is verified for a true peak by determining that the read signal voltage has a minimum change during a given time (delta-V) with means for altering the value of delta-V, an error recovery procedure invoked following identification of an error not correctable during real time processing of the serial data stream comprising re-reading the track on which the error occurred; shifting the transducer in one radial direction and re-reading said track; shifting the transducer in the opposite of said one radial direction and re-reading said track; and re-reading said track using an incremented value of delta-V.

Claim 20

Dependent Claim 39 words

The error recovery procedure of claim 16 wherein said re-reading with an incremented value of delta-V includes the steps of: incrementing the value of delta-V and re-reading said track and decrementing the value of delta-V and re-reading said track.

Claim 21

Dependent Claim 28 words

The error recovery procedure of claim 17 wherein said step of re-reading the track on which the error occurred comprises a plurality of successive re-readings of said track.

Claim 22

Dependent Claim 35 words

The error recovery procedure of claim 18 wherein the steps including shifting of the transducer include plural incerments of transducer shift in each radial direction and re-reading of said track at each shifted transducer position.

Claim 23

Dependent Claim 36 words

The error recovery procedure of claim 19 wherein the data recovery steps are sequentially invoked and the recovery procedure is terminated at the end of any step during which the detected error condition has been corrected.

Disk drive optimized channel circuit

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