Abstract: A limited-life storage medium comprises a flowable agent. In one example, the storage medium is an optical disc. In a ready-to-read condition, the center of mass of the disc does not coincide with the center of rotation. When the disc is read, the unbalanced rotation of the disc causes vibration that migrates the flowable agent into contact with a metal data-carrying layer, where the flowable agent interferes with the readability of the data so as to limit the useful life of the disc. The movement of the flowable agent improves the balance of the disc, and reduces the vibration.

Abstract: A limited-life storage medium comprises a flowable agent. The flowable agent comprises water and a hygroscopic substance. In one example, the flowable agent is a mixture of glycol and water with an acid or other corrosive active ingredient dissolved in it. In one example, the storage medium is an optical disc. When the disc is read, the rotation of the disc propels the flowable agent into contact with a metal data-carrying layer. In one example, the hygroscopic substance reduces any tendency of the flowable agent to dry out and cease to be flowable, and may tend to buffer the proportion of water in the flowable medium within a range.

Abstract: A limited-life storage medium comprises a flowable agent. In one example, the storage medium is an optical disc. In a ready-to-read condition, the center of mass of the disc does not coincide with the center of rotation. When the disc is read, the unbalanced rotation of the disc causes vibration that migrates the flowable agent into contact with a metal data-carrying layer, where the flowable agent interferes with the readability of the data so as to limit the useful life of the disc. The movement of the flowable agent improves the balance of the disc, and reduces the vibration.

Abstract: A storage medium contains information including a setup program comprising instructions for causing a computing device to install other parts of the information on the computing device. In normal use, reading the storage medium causes at least a selected part of the information on the storage medium to become unreadable within a predetermined time. The computing device reads the selected part of the information both before and after the predetermined time. The setup program installs the other parts of the information only if the selected part of the information is both readable before the predetermined time and unreadable after the predetermined time.

Abstract: An optical disc or other data storage medium has a substrate supporting a data storage region for storing readable data, and is caused to spin or is otherwise subjected to motion when read. A reservoir attached to the substrate and located in proximity to the data storage region stores a liquid reagent by liquid surface phenomena. When the medium is moved in order to read it, the centrifugal or other force causes the reagent to flow from the reservoir to interact with the data storage medium and interfere with the readability of the data.

Abstract: Optical storage media with limited useful life include a substrate having a data storage portion containing readable data. A reservoir associated with the substrate releasably retains 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 released. Alternatively, the invention includes an optical storage medium including a substrate supporting a metallic data storage layer for storing optically readable data, a reservoir located in proximity to the data storage layer for storing a chemical agent in contact with the data storage layer on a first side of the reservoir, and a flexible metallic lamina in contact with the chemical agent on an opposite side of the reservoir.