Abstract Image-bearing elements made of support material that transmits light longitudinally through its cross-section, in a plane parallel to its image-bearing surface, are disclosed for use in an information retrieval system. The retrieval code used in identifying each element is generated by modulating a directed beam of light transmitted longitudinally through the element's cross-section. Modulation of the directed beam is accomplished by, for example, placing opaque spots on a cross-sectional area of the element, punching holes in the element, or by placing a code mask at the end of the element from which the directed beam emanates. The code modulated beam is photoelectrically detected and the resulting electrical retrieval codes are used in the retrieval process.
In combination: a photographic support comprised of polyethylene terepthalate and capable of transmitting a beam of light through its cross-section in a plane parallel to its storage surface; illuminating means located adjacent to a first edge of said support for producing a beam of light directed through said support toward a second edge of said support; a code pattern recorded in the form of perforations which are selectively located along said second edge of said support for obstructing passage of such light and thereby optically modulating the directed light beam; and light-responsive signal generating means located adjacent to said second edge for converting the optically modulated beam emanating from said second edge into electrical signals.
Claim 2
Dependent Claim
115 words
In combination: a photographic support comprised of polyethylene terepthalate and capable of transmitting a beam of light through its cross-section in a plane parallel to its storage surface; illuminating means located adjacent to a first edge of said support for producing a beam of light directed through said support toward a second edge of said support; a code pattern recorded in the form of perforations which are selectively located along said second edge of said support for obstructing passage of such light and thereby optically modulating the directed light beam; and light-responsive signal generating means located adjacent to said second edge for converting the optically modulated beam emanating from said second edge into electrical signals.
Claim 3
Dependent Claim
83 words
The combination of claim 1 wherein (1) said second edge is opposite said first edge (2) said code pattern is recorded as a set of triangular notches, which notches are selectively located at positions along said second edge to obstruct emanation of beamed light at such positions, and (3) said light responsive signal generating means comprises a plurality of photodetectors, arranged to align with said positions on said support, for converting said optically modulated beam into electrical code signals representing said code pattern.