A computer memory system is disclosed which includes a randomly and electrically accessible semiconductor "page" memory. The semiconductor page memory is an array of memory units each of which includes an electrically accessible flip-flop for storing a binary information bit. In addition, each flip-flop is provided with a photodiode by which the flip-flop can be set in response to received light, and is provided with a liquid crystal light valve controlled by the electrical state of the flip-flop. The page array of memory units is constructed as a metal oxide semiconductor (MOS) integrated circuit. Each memory unit includes a flip-flop transistor having a drain which is extended over an area of opposite-conductivity material to form a photodiode. A liquid crystal material and a transparent electrode are positioned over the photodiode to form a light vale. The page array of memory units is used as a page-at-a-time electrical input-output unit for a great many pages of information stored optically on an erasable holographic storage medium.
A liquid crystal cell in which one of a pair of opposed spaced electrodes is circumscribed by a dielectric shield or mask having a hue, chroma and brightness substantially the same as the color of either the circumscribed electrode or of the scattered state of the liquid crystal material disposed between the electrodes.
A system for optical data storage and erasure, using a thermoplastic material and a plurality of heating elements associated therewith. A photosensitive switch series connected with each of the heating elements controls the flow of a heating current, for either writing-in or erasing a group of optical data in each storage area of the thermoplastic material.
In a liquid crystal matrix display panel for line-at-a-time driving at TV rate, an array of field effect transistor switches enable inputs to respective storage capacitors thereby providing storage of signals for a sufficient time for the liquid crystal material to respond. The transistor's drain pad also serves as one plate of the associated storage capacitor and a portion of its gate electrode is effectively the second plate, thereby minimizing the number of drive lines required and facilitating the fabrication of a practical device using state-of-the-art thin film transistor technology.
The invention relates to a method of making light dot distributions for the holographic storage of binary information with the aid of electronically controlled switching masks, characterized in that the individual elements of the switching mask are modulated in their path length through fading of the interference structure in the hologram associated with said elements.
Two electro-optical computer interface embodiments provide for one-way read only and two-way optical read and write. The two-way embodiment includes a main module having a shared memory, and a processor/controller and a main bus. A plurality of local processor modules each includes a local memory, a local processor, and a local bus. The processors are electrically joined by control conductors which provide for coordination and timing between local processors and the main processor. Each memory array has a film deposited on it by the Langmuir/Blodgett technique. The memory arrays are each illuminated by a pulsed laser or Q-switched laser. The film is responsive to the electric fields in the memory array cells for modulating the illumination light. The image is then read onto other memory arrays which are responsive to the illumination for transferring the data between memories.
