The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 2000
Filed:
Nov. 13, 1995
Ken Kutaragi, Kanagawa, JP;
Tetsuya Hirano, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A security system for preventing disc players from being used with unauthorized software is disclosed. The security code is stored through modulating an offset of the physical position of a plurality of data bits from a nominal track position. A two part optical read head provides an RF signal corresponding to the presence of a physical offset modulation. The RF signal is present when there is a physical offset of the data bits defining a first logical state and the absence of the RF signal defines a second logical state. A digital security code is encoded and decoded in this manner. A system for encoding a security code through modulating the physical offset of a plurality of data bits from a nominal track position is also disclosed.