Method for controlling access to recorded data
Identification card and a method of producing same
Identification card with a visible authenticity feature and a method of manufacturing said card
Compact disc player capable of playing plural selections recorded on a compact disc in a preselected sequence
Security level identification method for computer based information
Method for affixing information on read-only optical discs Patent #: 4961077
ApplicationNo. 132709 filed on 10/06/1993
US Classes:369/275.5, Protection (e.g., preventing damage to medium, etc.)347/264, With record receiver or handling means therefor369/52.1, CONTROL STRUCTURE ON STORAGE MEDIUM SENSED BY OTHER THAN TRANSDUCER SUPPORT (E.G., CONDUCTIVE STRIP, NOTCHED EDGE SENSOR)369/53.21, For protection369/283, Layered (e.g., permanent protective layer)369/286, Laminated or unified discrete layers369/292MISCELLANEOUS
ExaminersPrimary: LaRoche, Eugene R.
Assistant: Nguyen, Tan T.
Attorney, Agent or Firm
Foreign Patent References
International ClassesG11B 023/30
AbstractA 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.