SpectraDisc Corporation today announced that it had been issued an additional US Patent #6,343,063 for ``Machine-Readable Optical Disc with Reading-Inhibit Agent.'' SpectraDisc is spin-out company of Spectra Systems Corporation that has developed a limited-play digital disc suitable for mass manufacturing and distribution. The limited-play disc consists of a DVD or CD that can only be read or played for a prescribed period of time after opening the package. The duration of play can be controlled from minutes to weeks by modifying the composition of the coating materials.

Nabil M. Lawandy, Ph.D., CEO of SpectraDisc stated, ``This patent was of particular importance to us because it both supports all methods relating to the use of the read out laser to affect the limited play mechanism as well as our approach to low cost packaging of the disc.'' The patent covers the use of a barrier layer that preserves the playability of the disc throughout the distribution chain. Once the consumer removes the barrier packaging, the limited duration in play time begins. SpectraDisc Corporation, headquartered in Providence, RI is spin-out subsidiary of Spectra Systems Corporation, with offices and laboratories in East Providence, Rhode Island. SpectraDisc is focused on the development of a limited-play CD, CD/ROM and DVD product for the entertainment, software and advertising industries.