CD-Rom with machine-readable I.D. code
First Claim
1. A method of sensing defects representing a machine-readable code formed on an optical information storage disk which includes a plurality of addressable information storage locations, the method comprising the steps of:
- examining selected ones of said plurality of addressable information storage locations;
determining as to each of said selected information storage locations whether said each location is defective; and
construing the presence and absence of defects in said selected information storage locations as a code.
0 Assignments
0 Petitions
Accused Products
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.
90 Citations
2 Claims
-
1. A method of sensing defects representing a machine-readable code formed on an optical information storage disk which includes a plurality of addressable information storage locations, the method comprising the steps of:
-
examining selected ones of said plurality of addressable information storage locations; determining as to each of said selected information storage locations whether said each location is defective; and construing the presence and absence of defects in said selected information storage locations as a code.
-
-
2. A method of reading a machine-readable code formed on an optical information storage disk which includes a plurality of addressable information storage locations, the method comprising the steps of:
-
examining selected ones of said plurality of addressable information storage locations; determining as to each of said selected information storage locations whether said each location is defective; recovering a code as a function of defective and non-defective information storage areas; and performing an encryption algorithm on the recovered code to produce an encrypted identifying code.
-
Specification