CD-ROM with machine-readable I.D. code
AssigneeDigital Audio Disc Corporation
InventorsBarry A. Fite, Michael L. Mitchell, Russ A. Kunz, Clifford R. Brannon
Life of this patent
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Abstract
A machine-readable serial number is formed on a CD-ROM by using a laser to selectively remove a reflective layer from the CD-ROM. Removal of the reflective layer creates defects in addressable information storage locations on the CD-ROM. The serial number is read by detecting the defects. The serial number is used in a software distribution system in which many different software programs are distributed on a single CD-ROM and an access code based on the desired software program and the serial number of a particular CD-ROM is used to "unlock" the desired program on the particular CD-ROM.
Claims25
A method of forming a machine-readable code on an optical information storage disk, comprising the steps of:
- forming a disk shaped molded substrate which includes an information recording area in which information is represented by pits formed in said information recording area;
- applying a reflective coating to said information recording area of said substrate;
- and
- removing said reflective coating from selected portions of said information recording area to form a code pattern.
An apparatus for forming a machine-readable code pattern on a prerecorded compact disk that includes a reflective coating on an information bearing substrate, said information bearing substrate having an information recording area for storing information in recording tracks, the apparatus comprising:
- means for rotating said disk about a center of rotation of said disk;
- a laser for selectively emitting a cutting beam;
- means for directing said cutting beam to a point on said disk at a selected distance from said center of rotation of said disk;
- and
- means for controlling said laser and said means for directing so as to remove said reflective coating from selected portions of said information recording area of said information bearing substrate to form said machine-readable code.
An optical information storage disk in which a reflective coating is formed on a molded information bearing substrate, said information bearing substrate having an information recording area for storing information in recording tracks, and wherein said reflective coating is removed in a predetermined pattern from selected portions of said information recording area of said substrate to form a machine-readable code.
An optical information storage disk according to claim 22;
- wherein all of said bands are of substantially the same width.
A method of forming a machine-readable code on an optical information storage disk comprising the steps of:
- forming a plurality of addressable information storage locations on said disk, at least some of said locations containing program information;
- and
- creating defects in ones of said information storage locations in a predetermined pattern to form a machine-readable code.
Dependencies are inferred from the claim text.