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:
Oct. 09, 1990
Filed:
May. 24, 1989
Yuri Owechko, Newbury Park, CA (US);
Bernard H Soffer, Pacific Palisades, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
An associative memory system is provided which incorporates a spatial light modulator (SLM) and thresholding components. In the preferred embodiment, a Fourier transform hologram is used to convolve a reference beam with correlated input images and stored object images. An iteration and feedback loop is provided which is used to derive an enhanced reference beam for use in matching and enhancing the associative memory of the hologram with the object input plane image. The iteration loop of SLM and optical amplifying components comprises a liquid crystal light valve (LCLV) which receives the correlation plane image and provides that image in the form of a spatially phase-modulated and amplitude modulated signal to a polarizing thresholding analyzer device. The analyzer/polarizer is adjustable and threshold limits the data at fast rates and, is used in the preferred embodiment to threshold the data with reference to the greatest amplitude portion of the correlation spot provided to the LCLV. After the optical analyzer/polarizer threshold has processed the signal, an improved signal is provided to the writing photoconductor side of the LCLV. This processed signal is used to phase-modulate a projection light readout beam. A polarizing beam splitter converts the phase modulation of the readout beam to an amplitude modulation wherein an enhanced reference beam is derived which is processed back to the hologram for readout at the output plane of the system. In this manner a variable-gain fast response spatial light modulator component system is provided for use as an associative memory.