Abstract: An apparatus and method conducts a high-speed search on an optical medium having a plurality of tracks on which information is recorded. At least a first light spot and a second light spot are directed by the apparatus onto the optical medium. The light spots traverse across the tracks in one of a first direction and a second direction. A photodetector unit receives a reflected component of the first light spot to form a first electrical signal and a reflected component of the second light spot to form a second electrical signal. Digital shaping circuitry respectively converts the first electrical signal and the second electrical signal into a first digital signal and a second digital signal. A quadrature detector is configured to receive the first digital signal and the second digital signal. The first digital signal and the second digital signal are arranged in a quadrature relationship to each other.
Abstract: The disclosed device is directed towards an optical data storage system. The optical data storage system comprises an optical medium including a servo plane and at least one data plane. A first laser is positioned to generate a servo laser beam and address the servo plane with a first servo focus spot. A second laser is positioned to generate a read-write laser beam and address the data plane with a second read-write focus spot. A first servo system is associated with the first laser and is configured to provide focus and tracking error correction according to servo information associated with the servo plane. A second servo system is associated with the second laser and is configured to provide focus and tracking error correction according to servo information associated with the data plane.
Type:
Grant
Filed:
March 27, 2002
Date of Patent:
May 18, 2004
Assignee:
Research Investment Network, Inc.
Inventors:
James R. Amble, Herman A. Ferrier, LeRoy A. Volz, Andrew J. Diaber
Abstract: A pipeline video decoder and decompression system handles a plurality of separately encoded bit streams arranged as a single serial bit stream of digital bits and having separately encoded pairs of control codes and corresponding data carried in the serial bit stream. The pipeline system employs a plurality of interconnected stages to decode and decompress the single bit stream, including a start code detector. When in a search mode, the state code detector searches for a specific start code corresponding to one of multiple compression standards. The start code detector responding to the single serial bit stream generates control tokens and data tokens. A respective one of the tokens includes a plurality of data words. Each data word has an extension bit which indicates a presence of additional words therein. The data words are thereby unlimited in number.
Type:
Grant
Filed:
February 7, 2001
Date of Patent:
February 24, 2004
Assignee:
Discovision Associates
Inventors:
Adrian P Wise, Martin W Sotheran, William P Robbins, Anthony M Jones, Helen R Finch, Kevin J Boyd, Anthony Peter J Claydon
Abstract: The invention provides a single chip implementation of a digital receiver for multicarrier signals that are transmitted by orthogonal frequency division multiplexing. Improved channel estimation and correction circuitry are provided. The receiver has highly accurate sampling rate control and frequency control circuitry. BCH decoding of tps data carriers is achieved with minimal resources with an arrangement that includes a small Galois field multiplier. An improved FFT window synchronization circuit is coupled to the resampling circuit for locating the boundary of the guard interval transmitted with the active frame of the signal. A real-time pipelined FFT processor is operationally associated with the FFT window synchronization circuit and operates with reduced memory requirements.
Type:
Grant
Filed:
November 27, 2001
Date of Patent:
February 3, 2004
Assignee:
Discovision Associate
Inventors:
Peter A Keevill, Dawood Alam, John M. Nolan, Matthew J Collins, Thomas Foxcroft, David H. Davies, Jonathan Parker