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:
Jul. 13, 1993
Filed:
Jan. 23, 1991
Robert R Birge, Manlius, NY (US);
Albert F Lawrence, San Diego, CA (US);
Syracuse University, Syracuse, NY (US);
Abstract
An electro optical random access memory uses a film of bacteriorhodopsin or similar photochromic substance which can change between two light absorbing states in response to light of each of two wavelengths. In one embodiment combined red and green laser beams are steered in two orthogonal directions to memory locations on the film. The relative amounts of the light of the two wavelength reflected from memory cell is sensed and discriminated to indicate '1' or '0'. A crowbar circuit holds one or the other of the two laser beams on to compensate for degradation that occurs in a read cycle. In another embodiment a single wavelength is employed for read and write operations, but at a much greater strength for the write operation.