Patent Document ID: 5412755
Application ID: 08195737
Patent Flag: 1

Claim One:
1. An optical inner-product neural associative memory for retrieving the best match between an initial input two-dimensional N-tuple binary vector V and a number M of stored two-dimensional N-tuple binary vectors V.sub.i, where i=1,. .. ,M, each binary element of said two dimensional N-tuple binary vectors V and V.sub.i being represented by a binary optical value, comprising: a source of coherent light; a first optical storage means for storing said number M of two-dimensional N-tuple binary vectors V.sub.i at a first multiplication plane; a first spatial light modulator responsive to said coherent light for entering a vector image of said initial input two-dimensional N-tuple binary vector V in search of a best match with one of said number M of stored two-dimensional N-tuple binary vectors V.sub.i ; optical means at said first multiplication plane responsive to said initial input two-dimensional N-tuple binary vector and said number M of two-dimensional N-tuple binary vectors stored in said first optical storage means for forming an inner-product scalar .alpha..sub.i as a beam of light for each of said stored number M of two-dimensional N-tuple binary vectors; a second optical storage means at a second multiplication plane for storing said number M of two-dimensional N-tuple binary vectors as corresponding vectors; means at said second multiplication plane for weighting each of said number M of two-dimensional N-tuple binary vectors stored in said second optical storage means by multiplication of each of said number M of two-dimensional N-tuple binary vectors stored in said second optical storage means by said inner-product scalar beam of light to produce a number M of two-dimensional weighted vectors; a second spatial light modulator; means for detecting each of said number M of two-dimensional weighted vectors; means for entering a vector image of each of said number M of two-dimensional weighted vectors through said second spatial light modulator; means for optically summing said number M of two-dimensional weighted vectors and optically thresholding the sum of said number M of two-dimensional weighted vectors in order to produce a two-dimensional binary vector that is an approximation of one of said stored two-dimensional N-tuple binary vectors; and means for entering said two-dimensional binary vector produced as an approximation of one of said stored two-dimensional binary vectors by said means for optically summing and thresholding as an input binary vector into said optical inner-product neural associative memory through said first spatial light modulator to commence another iterative cycle corresponding to the same cycle of operations performed with said initial input two-dimensional N-tuple binary vector, and to recommence subsequent iterations until convergence is reached between said initial input two-dimensional N-tuple vector and a best match with one of said number M of two-dimensional N-tuple binary vectors stored in said first and said second optical storage means.