Abstract: A liquid piston Stirling engine electrical generator, the generator being a linearly reciprocating electrical generator that is powered by a Stirling engine having a liquid piston that is displaced by the cyclic contraction and expansion of a gas resulting from increases and decreases in temperature. The liquid piston and dynamic components of the linear generator are retained within a U-shaped tube or chamber, the tube being oriented in use to consist of a two upwardly extending, first and second vertical segments joining a horizontal segment. A liquid, such as oil or hydraulic fluid, is present in sufficient quantity to fill the horizontal segment and extend upward into the vertical segments.

Abstract: A liquid piston Stirling engine electrical generator, the generator being a linearly reciprocating electrical generator that is powered by a Stirling engine having a liquid piston that is displaced by the cyclic contraction and expansion of a gas resulting from increases and decreases in temperature. The liquid piston and dynamic components of the linear generator are retained within a U-shaped tube or chamber, the tube being oriented in use to consist of a two upwardly extending, first and second vertical segments joining a horizontal segment. A liquid, such as oil or hydraulic fluid, is present in sufficient quantity to fill the horizontal segment and extend upward into the vertical segments.

Abstract: A computer-readable medium having material at a select position therein and containing instructions for controlling an optical reader to cause the optical reader to re-read the position having the material one or more times to elicit a measurable parameter at such position.

Abstract: A method and system for providing copy-protected optical medium using transient optical state change security materials capable of changing optical state and software code to detect such change in optical state.

Abstract: A method and apparatus for preventing copying of data from optical disks. A locus on optical disk is initially read to produce a signal and is then re-read by a reader to produce a second signal. The signal detected upon re-reading is different from the signal that is detected upon initial sampling. A method and apparatus for controlling access to an optical disk, such as an optically readable disk. Light sensitive or other materials that are adapted to change state and affect reading of an optical disk are used to control access to data that may be stored on optical disk and/or to control use of the optical disk.

Abstract: A computer-readable medium having material at a select position therein and containing instructions for controlling an optical reader to cause the optical reader to re-read the position having the material one or more times to elicit a measurable parameter at such position.

Abstract: A method and apparatus for controlling access to a storage medium, such as an optically readable medium. Light sensitive or other materials that are adapted to change state and affect reading of a storage medium are used to control access to data that may be stored on optical medium and/or to control use of the medium.

Abstract: A device for preventing and controlling copying of data from an optical storage disc utilizing physical modifications in or on a storage capable optical disc. Also described is a method for authenticating and controlling reading or copying of information or data in or on optical discs as, for example, wherein a locus on or in the optical storage disc is initially read to produce a signal and is then re-read by a reader to produce a second signal. The signal detected upon re-reading is different from the signal that is detected upon initial sampling.

Abstract: A method and apparatus for controlling access to a storage medium, such as an optically readable medium. Light sensitive or other materials that are adapted to change state and affect reading of a storage medium are used to control access to data that may be stored on optical medium and/or to control use of the medium.