Selectively alterable optical data memory
AssigneeNEMATEL Dr, R. Eidenshink
InventorsMarkus Kreuzer, Rudolf Eidenschink
Life of this patent
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Abstract
A selectively alterable optical data memory (10) has a liquid crystal display (12) with a nematic medium (22), which consists of a nematic phase and a solid dispersed in it, a first voltage source (26), a second voltage source (30) and a modulable laser (32). With the first voltage source (26), the entire display can be converted into the homeotropic state by producing a forming voltage. With the laser (32), an orientation pattern can be produced in display 12 that can be erased or altered at least partially by the application of the threshold voltage and simultaneous irradiation with the laser (32).
Claims8
Selectively alterable optical data memory, having two plates, at least one of which is transparent, and which carry electrodes on internal surfaces thereof, a nematic medium between the plates comprising a nematic phase and a solid body dispersed in it, consisting essentially of highly-dispersed silicic acid, as well as a voltage source with which a voltage can be applied to the electrodes wherein the voltage source, when it is turned on, produces an auxiliary voltage which, by itself, cannot change the predetermined local orientation pattern of the data memory, and wherein a source of intense electromagnetic radiation is provided, which, when auxiliary voltage is applied, converts a predetermined local orientation pattern in the predetermined region of the data memory into another pattern.
Dependencies are inferred from the claim text.