Write power calibration utilizing least squares fit of read-back signals for moving media memory

Claim 3

A method as set forth in claim 1, wherein the recording media is a disk set for rotation in a disk drive unit, and the disk drive unit includes a microprocessor controller and a digital to analog converter for generating write signal power level, the method further comprising: applying digital to analog converter (DAC) settings from the microprocessor controller to the digital to analog converters, wherein the DAC settings are a sequence with uniform intervals between adjacent settings and each DAC setting corresponds to one write signal power level.

Claim 4

A method as set forth in claim 2, wherein the step of applying a plurality of write signal power levels includes: determining a sequence of uniformly spaced DAC settings; and applying, in response to microprocessor controller selection, the sequence to the digital to analog converter.

Claim 5

A method as set forth in claim 3, wherein the disk includes a plurality of tracks, and each track is radially divided into a plurality of sectors, the method further comprising the steps of: selecting one of the plurality of tracks as a calibration track; marking sectors of the calibration track with the test pattern, individual sectors being marked at a particular write signal power level; and writing at each write signal power level at least twice, at two mutually spaced sectors of the calibration track.

Claim 6

A method as set forth in claim 4, wherein the step of correlating measurements further includes: combining measurements associated with particular write signal power levels.

Claim 7

A method as set forth in claim 5, and further comprising the steps of: identifying a write power signal level correlated with the measurement of the read-back signal exhibiting the greatest amplitude; and determining the calibrated write signal power level by solving the parameter B 2 and B 3 using a selected subgroup of DAC settings adjacent and including the DAC settings providing the identified write signal power level.

Claim 8

A method as set forth in claim 6, wherein the disk drive unit is a magnetooptic drive unit and the marking source includes a laser to which the write signal power levels are applied.

Claim 9

A moving media memory for providing a maximum amplitude read-back signal, the moving media memory comprising: a moving recording media; means for marking the moving recording media; means for generating a read-back signal from the marks on the moving recording media; means for measuring the amplitude of the read-back signal; and means for selecting write signal power levels for application to the marking means, for correlating measurements of the amplitude of the read-back signal with the selected write signal power levels, and for determining an optimized write signal power level wherein the optimized write signal power level, W c , is determined by the solution of the relationship W.sub.c =W.sub.o -KB.sub.2 /2B.sub.3 where W o is an offset write signal power level, K is a step interval between adjacent write signal power levels, and B 2 and B 3 are parameters satisfying a least squares fit of a second order polynomial equation to data provided by correlated amplitude measurements and the selected write signal power levels.

Claim 10

A moving media memory for providing a maximum amplitude read-back signal, the moving media memory comprising: a moving recording media; means for marking the moving recording media; means for generating a read-back signal from the marks on the moving recording media; means for measuring the amplitude of the read-back signal; and means for selecting write signal power levels for application to the marking means, for correlating measurements of the amplitude of the read-back signal with the selected write signal power levels, and for determining an optimized write signal power level wherein the optimized write signal power level, W c , is determined by the solution of the relationship W.sub.c =W.sub.o -KB.sub.2 /2B.sub.3 where W o is an offset write signal power level, K is a step interval between adjacent write signal power levels, and B 2 and B 3 are parameters satisfying a least squares fit of a second order polynomial equation to data provided by correlated amplitude measurements and the selected write signal power levels.

Claim 11

A moving media memory as set forth in claim 8, wherein the moving media memory is a disk drive memory unit, the moving recording media is a disk set for rotation in the disk drive memory unit, and the selecting, correlating and determining means is a programmed microprocessor.

Claim 12

A disk drive memory unit as set forth in claim 9, and further comprising: digital to analog converter means responsive to the programmed microprocessor for applying write signal power levels to the marking means, wherein selection of write signal power levels is provided by selection of digital to analog converter settings applied to the digital to analog converter means.

Claim 13

A disk drive memory unit as set forth in claim 10, wherein the digital to analog converter settings include a sequence of uniformly spaced integers.

Claim 14

A disk drive memory unit as set forth in claim 11, and further comprising: a plurality of tracks on the disk; a plurality of radially divided sectors within each track; means for selecting one of the tracks as a calibration track; wherein a test pattern is marked in each of a plurality of sectors of the calibration track at a selected write signal power level; and wherein each write signal power level is used at least twice with respect to at least two spaced sectors of the calibration track.

Claim 15

A disk drive memory unit as set forth in claim 12, further comprising means for combining measurements of read-back signal amplitude at each selected write signal power level.

Claim 16

A disk drive memory unit as set forth in claim 13, and further comprising: means for identifying a measurement of the read-back signal, and its correlated write signal power level, exhibiting the greatest amplitude; and means for determining the calibrated write signal power level W c by solving for the parameters B 2 and B 3 using a selected subgroup of digital to analog converter settings and correlated amplitude measurements to and including the digital to analog converter setting for the identical measurement.

Claim 17

A disk drive unit as set forth in claim 14, wherein the disk drive memory unit is a magnetooptic disk drive unit and the marking means include a laser.

Claim 18

A data processing program product for maximizing the amplitude of a read-back signal in a drive memory unit, the drive memory unit including a moving media, a microprocessor, digital to analog means for converting digital to analog converter settings to write signals of various power levels, means responsive to the write signals for marking the moving media, means for generating a read-back signal from the marking of the moving media, and means for measuring the amplitude of the read-back signal, the data processing program product comprising a media storing: instruction means for selecting digital to analog converter settings; instruction means for correlating measurements of the amplitude of the read-back signal with the selected digital to analog converter settings; and instruction means for determining an optimized power level W c for the write signal to maximize the amplitude of the read-back signal by solution of the relationship W.sub.c =W.sub.o -KB.sub.2 /2B.sub.3 where W o is an offset power level for the write signal, K is a step interval between adjacent write signal power levels, and B 2 and B 3 are parameters satisfying a least squares fit of a second order polynomial equation to data provided by the instruction means for correlating measurements of the amplitude of the read-back signal and the digital to analog converter settings.

Claim 19

A data processing program product for maximizing the amplitude of a read-back signal in a drive memory unit, the drive memory unit including a moving media, a microprocessor, digital to analog means for converting digital to analog converter settings to write signals of various power levels, means responsive to the write signals for marking the moving media, means for generating a read-back signal from the marking of the moving media, and means for measuring the amplitude of the read-back signal, the data processing program product comprising a media storing: instruction means for selecting digital to analog converter settings; instruction means for correlating measurements of the amplitude of the read-back signal with the selected digital to analog converter settings; and instruction means for determining an optimized power level W c for the write signal to maximize the amplitude of the read-back signal by solution of the relationship W.sub.c =W.sub.o -KB.sub.2 /2B.sub.3 where W o is an offset power level for the write signal, K is a step interval between adjacent write signal power levels, and B 2 and B 3 are parameters satisfying a least squares fit of a second order polynomial equation to data provided by the instruction means for correlating measurements of the amplitude of the read-back signal and the digital to analog converter settings.

Claim 20

A data processing program product as set forth in claim 16, wherein the drive memory unit is a disk drive, the moving media is a disk set for rotation in the disk drive.

Claim 21

A data processing program product as set forth in claim 17, the media further storing: instruction means for providing a sequence of uniformly spaced integers as digital to analog converter settings.

Claim 22

A data processing program product as set forth in claim 18, wherein the disk drive further includes the disk having a plurality of tracks, each track having a plurality of radial sectors, the media further storing: instruction means for selecting one of the tracks as a calibration track; instruction means for marking each of a plurality of radial sectors at a selected digital to analog converter settings; and instruction means for causing each digital to analog converter setting to be used for at least two radial sectors.

Claim 23

A data processing program product as set forth in claim 19, the media further storing: instructions means for identifying the measurement of the read-back signal having the largest amplitude, and its correlated digital to analog converter setting; and instruction means for selecting a subgroup of digital to analog converter settings and correlated read-back signal amplitude measurements centered on and included the identified measurement and its correlated digital to analog converter setting.