公开(公告)号：JPH10228737A

公开(公告)日：1998-08-25

申请号：JP2190398

申请日：1998-02-03

Applicant: IBM

Inventor： LOIS JOSEPH SELANO ,  MANTLE MAN-HON YU

IPC: G11B21/02 ,  G11B5/55 ,  G11B21/08

Abstract: PROBLEM TO BE SOLVED: To provide a system for determining the saturation time of a power amplifier in a computer hard disk drive. SOLUTION: In a hard disk drive, a head/actuator cyclically executes calibration seeking such that a power amplifier 32 for supplying energy to the head 26/actuator 28 is saturated. A predicted distance for moving the head during the calibration seeking is compared with an actual moving distance and a ratio between the two distances is used for deciding the saturation current of the power amplifier 32. In subsequent seeking, if the saturation current is smaller than a current required for the subsequent seeking, the saturation current is inputted to a head position prediction model. Other than that, the required current is used.

公开(公告)号：JP2000021105A

公开(公告)日：2000-01-21

申请号：JP16617699

申请日：1999-06-14

Applicant: IBM

Inventor： MARIO BROWN ,  WILLIAM JOHN CABELACK ,  LEWIS JOSEPH SERRANO ,  MANTLE MAN-HON YU

IPC: G11B5/596 ,  G11B5/012 ,  G11B5/82 ,  G11B20/18 ,  G11B21/10 ,  G11B27/30

Abstract: PROBLEM TO BE SOLVED: To provide a disk to be used in a dive drive and a method of manufacturing the same disk. SOLUTION: In the position error signal(PES) field of every track on the disk, encoded predetermined data, for example, servo data is written. In the preferred embodiment, a) data, for example, track number is mapped to the code word of error correcting code(ECC), b) code is encoded for further redundancy using a bit vector and c) unprocessed data written to the PES field is restricted and an analog signal characteristic used by the servo system for positioning is equalized. Therefore, this method enables that PES field can be used as the source of digital data recorded with resistance to trouble while it is used as in the prior art.

公开(公告)号：JP2000011565A

公开(公告)日：2000-01-14

申请号：JP16616599

申请日：1999-06-14

Applicant: IBM

Inventor： MARIO BROWN ,  WILLIAM JOHN CABELACK ,  LEWIS JOSEPH SERRANO ,  MANTLE MAN-HON YU

IPC: G11B5/596 ,  G11B20/18 ,  G11B21/10

Abstract: PROBLEM TO BE SOLVED: To provide error correcting and detecting method and device for retrieving prescribed data, servo data, for example, from a disk position error signal(PES) field in a data storage device. SOLUTION: In a preferable embodiment, PES data, a truck number, for instance, is mapped into a cord word of an error correcting coding(ECC), the cord word is further divided into one set of symbols, and these symbols are mapped into a second bit/vector group having a specified weight. A preferable encoding method is selected in order to equalize an analog signal characteristic of the PES field. As a result, the change in the conventional servo detector is made to a minimum, even if necessary, as this PES field is used as both of the analog information and digital information.

公开(公告)号：JPH10255417A

公开(公告)日：1998-09-25

申请号：JP3689298

申请日：1998-02-19

Applicant: IBM

Inventor： LEWIS JOSEPH SERRANO ,  MANTLE MAN-HON YU

IPC: G11B5/596 ,  G11B20/12 ,  G11B21/08 ,  G11B21/10 ,  G11B27/30

Abstract: PROBLEM TO BE SOLVED: To provide a method and device for writing the binary servo data in a servo burst incorporated on a storage medium of storage device. SOLUTION: Binary servo information contains a track discriminating information such as track number, cylinder number, head number, sector number, index and/or SID(sector identifier). A burst contains tn pieces of time slots (t0 -t7 ), and each slot is provided with a period of a servo burst frequency, and the written is servo data are provided with X pieces of bits of the binary data. Respective (1) bits of the servo data are expressed as the slots (t0 , t3 -t6 ) containing deformation, and respective (0) bits are expressed as empty, e.g. null slots (t1 , t2 , t7 ). By this method, a high bit efficiency system expressing the digital servo data is realized.

公开(公告)号：SG91860A1

公开(公告)日：2002-10-15

申请号：SG200002010

申请日：2000-04-10

Applicant: IBM

Inventor： JEFFREY JOSEPH DOBBEK ,  BRYAN SCOTT ROWAN ,  LOUIS JOSEPH SERRANO ,  MANTLE MAN-HON YU

IPC: G11B19/20 ,  G11B19/28 ,  G11B21/02 ,  G11B21/21 ,  H02P29/00

Abstract: Method and system aspects for controlling spindle motor speed during head loading in a disk drive are described. The aspects include inputting a time-varying reference velocity profile signal, and selecting a controller to control spindle motor speed. Further included is feeding forward control signals sufficient to precompensate for drag during a head loading event and maintain spindle motor speed within an operating tolerance.

公开(公告)号：SG86361A1

公开(公告)日：2002-02-19

申请号：SG1999005862

申请日：1999-11-22

Applicant: IBM

Inventor： WEI-MIN LU ,  ROGER WILLIAM WOOD ,  MANTLE MAN-HON YU

IPC: G11B20/00 ,  G05B19/29 ,  G11B33/00

Abstract: A method and apparatus for reducing track misregistration due to digital-to-analog converter quantization noise. In hard disk drive (HDD) servo control systems, quantization noises (or roundoff errors) due to the finite precision of the D/A converter (DAC) driving the VCM contribute a significant portion of the total track-misregistration (TMR). The present invention provides a quantization error feedback (QEF) technique to reduce TMR due to DAC quantization noises. The QEF technique according to the present invention offers a simple method of reshaping the spectrum of this noise to minimize its contribution to TMR. In the digital signal processor (DSP) implementation of the QEF schemes, the quantization error is monitored and accumulated in the DSP; when sufficient error has accumulated, the MSB feeding the DAC are modified such as to cancel the effect of the error. In addition, or alternatively, a state estimator may be driven with the most significant bits and a position error signal to reduce the power spectrum density function of the track misregistration at predetermined frequencies.