The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 13, 1977
Filed:
Jul. 28, 1976
Donald D Boswell, Granada Hills, CA (US);
Hughes Aircraft Company, Culver City, CA (US);
Abstract
Methods and apparatus for erasing the stored scattering image in storage-type liquid crystal light valves. Erasure is accomplished by applying a signal from an erasing signal source across the liquid crystal cell where the signal is a voltage which is swept over the audio frequency range of 1 KHZ through 20 KHZ. In another embodiment, the erasing signal source supplies a precursor signal which has an initial frequency below the frequency threshold for scattering. This low frequency signal is maintained for a brief period of time to excite the entire liquid crystal cell into a uniform scattering state. The erasing signal is then swept over the audio frequency spectrum of 1 KHZ through 20 KHZ to cause the cell to return to the non-scattered, translucent state.