| 摘要 |
<p>Optical storage media (10) with limited useful life include a substrate having a data storage portion (28) containing readable data. A reservoir (34) associated with the substrate retains possibly under a partial barrier layer a preselected chemical agent that interacts with the data storage portion to render it unreadable a preselected period of time after the chemical agent is activated. Use of the media is preferably prevented by a retainer (40) that cannot be removed without rupturing the reservoir (34), releasing the chemical agent, and starting the preselected time period. Instead, the optical storage medium may be stored under vacuum in an airtight container. Atmospheric pressure when the container is unsealed can then rupture the reservoir and release the chemical agent. Instead, the optical storage medium stored under vacuum may a flexible metallic lamina that can be deformed by atmospheric pressure when the container is unsealed. The lamina then completes a voltaic circuit from the data storage layer through the chemical agent to the lamina.</p> |
