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公开(公告)号：US3882540A
公开(公告)日：1975-05-06
申请号：US48007274
申请日：1974-06-17
Applicant: IBM
Inventor： OTTESEN HJALMAR H
CPC classification number: G11B20/10203 , G11B5/035 , G11B20/10037 , G11B20/1403
Abstract: Digital signal processing techniques enhance readback of digital signals from a magnetic recorder. Sampled signal amplitudes obtained at bit period boundaries and midpoints are converted to digital signal sets, which sets are processed for equalization, DC restoration, phase error detection, generation of timing signals, and amplitude compensation of the sampled signal amplitudes.
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公开(公告)号：CA1079848A
公开(公告)日：1980-06-17
申请号：CA252293
申请日：1976-05-11
Applicant: IBM
Inventor： OTTESEN HJALMAR H
Abstract: DISK STORAGE APPARATUS HAVING SIGNALS RECORDED IN A SPECIFIC FORMAT A record disk has a plurality of concentric record tracks divided into sectors of substantially equal lengths irrespective of the radius of the record track. In a preferred form, the record tracks are banded into radial groups, with the circumferential length of sectors in the radially inwardmost record track being equal in all of the bands. All trackidentifying signals (servo signals) are radially aligned in each of the groups of tracks for providing sector servoing of a head to a given track. In those embodiments employing a plurality of independently accessible disks, a tachometer is attached to the assembly with all of the disks being keyed to a tachometer index such that all locations on each of the disks have a specific format relationship to the key and the tachometer. Each disk is separately calibrated such that its format has a calibratable relationship to the tachometer index. Additionally, the specific format enhances radial positioning of a transducer for track selection. In a more specific form, the outermost band of tracks has the greatest radial extent for accessing stored data. The specific format is particularly adaptable to those data processing apparatus employing fixed block length storage blocks.
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公开(公告)号：FR2347742A1
公开(公告)日：1977-11-04
申请号：FR7634824
申请日：1976-11-12
Applicant: IBM
Inventor： DENNISON JAMES C , OTTESEN HJALMAR H
Abstract: RECORD TRACK FOLLOWING AND SEEKING An improved servo block pattern bands a plurality of parallel record tracks into a track seek and follow band. Servo block positions in the record tracks, plus the longitudinal duration of the signal bursts enable simultaneous track seeking and following within a band of tracks. Servo apparatus operable with such patterns adapt to amplitude variations of the servo readback signal to reduce the effect of amplitude variations on servo performance. The servo blocks may have differing frequencies or correlation patterns for enhancing track seek and follow functions.
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公开(公告)号：FR2332576A1
公开(公告)日：1977-06-17
申请号：FR7632451
申请日：1976-10-18
Applicant: IBM
Inventor： OTTESEN HJALMAR H
Abstract: A magnetic recorder employs a feedback phase equalizer for adjusting the readback signal to enhance detection capability. Phase errors are measured and used as criteria for dynamically and adaptively adjusting phase compensation of the read-back signal. In a preferred form, averaging phase errors over a predetermined signal characteristic of the readback signal controls adjustment of phase equalization.
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Patent Agency Ranking
公开(公告)号：CA2027992C
公开(公告)日：1994-11-29
申请号：CA2027992
申请日：1990-10-18
Applicant: IBM
Inventor： GLASER THOMAS W , GREENBERG RICHARD , OTTESEN HJALMAR H
Abstract: A data processing system is disclosed having a direct access storage device (DASD) subsystem comprising a number of separate physical housings, each housing having a number of disk supporting spindles mounted therein. The velocity of rotation of the spindles within a housing is synchronized, and the rotational position of the spindles may be locked into a fixed relationship. When number N of disk supporting spindles are provided, spindle rotation is synchronized, and mirrored data files are written out of phase by 360/N degrees, thereby providing reduced latency time during a subsequent read operation, while at the same time providing data integrity through the use of redundant data files.
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公开(公告)号：CA1268858A
公开(公告)日：1990-05-08
申请号：CA535597
申请日：1987-04-27
Applicant: IBM
Inventor： STICH MICHAEL C , RESMAN JOHN B , OTTESEN HJALMAR H , ANDERSON TODD B
Abstract: ADAPTIVE CONTROL TECHNIQUE FOR A DYNAMIC SYSTEM A controller for a voice coil motor driven disk file actuator is described. The device has an online adjustable gain characteristic for controlling movement of the actuator assembly and an estimator that estimates actuator velocity and bias. Forward gain is estimated from position and coil current measurements and compared with a nominal value to create an error signal used to adjust the controller and estimator gain characteristics. The control technique allows changes in the open loop system without changing the closed loop performance. By monitoring loop gain it is possible to alter compensator gains to maintain a constant closed loop performance.
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公开(公告)号：CA1079846A
公开(公告)日：1980-06-17
申请号：CA268527
申请日：1976-12-22
Applicant: IBM
Inventor： DENNISON JAMES C , OTTESEN HJALMAR H
Abstract: RECORD TRACK FOLLOWING AND SEEKING An improved servo block pattern bands a plurality of parallel record tracks into a track seek and follow band. Servo block positions in the record tracks, plus the longitudinal duration of the signal bursts enable simultaneous track seeking and following within a band of tracks. Servo apparatus operable with such patterns adapt to amplitude variations of the servo readback signal to reduce the effect of amplitude variations on servo performance. The servo blocks may have differing frequencies or correlation patterns for enhancing track seek and follow functions.
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公开(公告)号：CA1064615A
公开(公告)日：1979-10-16
申请号：CA266528
申请日：1976-11-24
Applicant: IBM
Inventor： OTTESEN HJALMAR H
Abstract: PHASE EQUALIZED READBACK APPARATUS AND METHODS A magnetic recorder employs a feedback phase equalizer for adjusting the readback signal to enhance detection capability. Phase errors are measured and used as criteria for dynamically and adaptively adjusting phase compensation of the readback signal. In a preferred form, averaging phase errors over a predetermined signal characteristic of the readback signal controls adjustment of phase equalization.
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