Abstract: A No-Fall-Through, FIFO memory includes a memory section comprising a plurality of locations for storing data words. Data words are written into the storage locations in response to a write clock input signal. Data words are read from the storage locations, in the same sequence as previously written, in response to a read clock signal. A write pointer maintains a write pointer value indicative of the number of data words which have been written. A read pointer maintains a read pointer value indicative of the number of data words which have been read. A comparator monitors the write pointer and read pointer values and detects differences between the two. The characteristics of the differences are utilized to control internal operations of the FIFO.

Abstract: An optical erasable thermally addressed, liquid crystal information storage and retrieval system is disclosed having an information density and the order of 10.sup.7 bits/cm.sup.2 while using liquid crystal cell thickness of relatively standard dimensions (.about.10 .mu.m). The system includes two substrates containing a smectic-A phase liquid crystal medium, and several thin filing attached to the substrates for establishing the proper conditions within the liquid crystal medium for creating a radiation scattering defect which is small in size (<1.0 .mu.m), and for performing erase functions in conjunction with an optical beam. A device according to the invention has an array of such defects in the liquid crystal medium representing information bits, with the array having a ratio of the shortest distance between individual defects to the thickness of the liquid crystal medium of less than 0.4, for a liquid crystal medium having thickness larger than 5 microns.

Abstract: A moving-coil type pickup cartridge comprises a vibration system including a stylus for tracing a sound groove of a record disc, at least one coil plate adapted to vibrate in response to vibration of the stylus of the vibration system, and an arrangement for producing magnetic fields with respect to the coil plate. The coil plate has at least one coil formed by thin film in a spirally-shaped pattern. The magnetic field producing arrangement has at least one permanent magnet for producing magnetic fields wherein are produced magnetic fluxes of mutually opposite directions respectively in regions of the coil resulting from substantially halving of the coil in the vibration direction thereof.