Method and apparatus for performing DSV protection in an EFM/EFM+ encoding same

Patent 6778104 Issued on August 17, 2004. Estimated Expiration Date:

October 8, 2022. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Inventors

Assignee

Mediatek Inc.

Application

No. 10266781 filed on 10/08/2002

US Classes:

341/59, To or from run length limited codes341/69, Return-to-zero to or from NRZ (nonreturn-to-zero) codes369/59.23Having specific code or form generation or regeneration processing

Examiners

Primary: Williams, Howard L.

Attorney, Agent or Firm

Brinks Hofer Gilson & Lione

International Class

H03M 700

Abstract

An EFM/EFM+ encoding system is adapted to modulate a source symbol sequence into a modulated bit sequence that is further converted to a channel bit sequence, which is to be recorded on a recording medium and which has a cumulative Digital Sum Value (DSV), through NRZI conversion. An apparatus for performing DSV protection in the EFM/EFM+ encoding system includes a DSV calculation unit for calculating the DSV associated with the EFM/EFM+ modulated bit sequence, and a decision unit for adjusting at least a bit in the modulated bit sequence according to the result calculated by the DSV calculation unit such that the channel bit sequence from the NRZI conversion of the adjusted modulated bit sequence accumulates a relatively small DSV. A method of using the EFM/EFM+ encoding system to inhibit disc copying is also disclosed.