Dynamic magnetic information storage or retrieval – General processing of a digital signal – Address coding
Reexamination Certificate
2000-09-12
2004-01-06
Hudspeth, David (Department: 2651)
Dynamic magnetic information storage or retrieval
General processing of a digital signal
Address coding
C360S065000
Reexamination Certificate
active
06674591
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in mass data storage devices and methods for processing data in a read channel thereof, and more particularly to improvements in apparatuses and methods for detecting track identification indicia in accessing the data tracks of the device.
2. Relevant Background
Mass data storage devices include well known hard disk drives that have one or more spinning magnetic disks or platters onto which data is recorded for storage and subsequent retrieval. Hard disk drives may be used in many applications, including personal computers, set top boxes, video and television applications, audio applications, or some mix thereof. Many applications are still being developed. Applications for hard disk drives are increasing in number, and are expected to further increase in the future. Mass data storage devices may also include optical disks in which the optical properties of a spinning disk are locally varied to provide a reflectivity gradient that can be detected by a laser transducer head, or the like. Optical disks may be used, for example, to contain data, music, or other information.
In the past, typically the track identification pulses are well separated from each other to enable them to be properly detected. However, there has been considerable recent pressure on disk drive manufacturers to increase the density of the data written to a disk to increase the capacity of the drive. Much effort has been directed to data detection techniques to increase the density of the data that can be contained on the disk. For example, maximum likelihood sequence detection (MLSD) and partial response (PR) filtering techniques have been developed that allow adjacent data pulses to at least partially overlap and still be properly detected. Moreover, EPR4 filtering techniques and Viterbi algorithms have been developed that efficiently implement MLSD and enable the data to be written more closely.
However, to the best of my knowledge, such EPR4 techniques have not been applied to the detection of track identification information.
REFERENCES:
patent: 5737142 (1998-04-01), Zook
patent: 5822143 (1998-10-01), Cloke et al.
IEEE Journal of Solid State Circuits. Pai et al. “a 160-MHz Analog Front-End IC for EPR-IV PRML Magnetic Storage Read Channels”. Nov. 1996, vol.31, No. 11 pp. 1803-1816.*
Conway et al., “A CMOS 260Mbps Read Channel with EPRML Performance”, VLSI Circuits Conference in Hawaii, Jun. 10, 1998.
Nagaraj, et al., “A Median Peak Detecting Analog Signal Processor for Hard Disk Drive Servo”, IEEE J. S-S Cir., vol. 30, No. 4, pp. 461-70 4/95.
Pai, et al., “A 160-MHz Analog Front-End IC for EPR-IV PRML Magnetic Storage Read Channels”, IEEE J. S-S Cir., vol. 31, No. 11, pp.1803-1816, 11/96.
Shariatdoust, et al., “An Integrating Servo Demodulator for Hard Disk Drives”, IEEE 1993 Custom Integrated Circuits Conf., pp. 10.6-1-5, 1993.
SSI 32P4101A PRML Read Channel with EPR4, 16/17 90,6/8) ENDEC, 4-Burst Se “Total Solutions 99” Data CD-ROM, Texas Instruments Apr. 8, 1999 pp. 1-67 especially pp. 12-16.
Tuttle, et al., “A 130Mb/s PRML Read/Write Channel with Digital-Servo Detection”, IEEE Intntl Solid-State Circuits Conf., 1996, pp 64-65.
Tuttle, et al., “A 130Mb/s PRML Read/Write Channel with Digital-Servo Detection”, ISSCC Slide Suplement, 1996, pp 48-50.
Alini, et al., “A 200MSample/s Trellis-Coded PRML Read/Write Channel with Digital Servo”, IEEE Intntl Solid-State Circuits Conf., 1997, pp 318-319, and 478-9.
Brady W. James
Hudspeth David
Rodriguez Glenda
Swayze, Jr. W. Daniel
Telecky , Jr. Frederick J.
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