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Character Recognition Methods using Kinoforms

IP.com Disclosure Number: IPCOM000076202D
Original Publication Date: 1972-Jan-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Baxter, DW: AUTHOR [+3]

Abstract

Figs. 2 and 3 show systems for recognizing characters or other patterns by the use of kinoforms to detect individual features of each character, and optoelectronic transducers to convert each feature to a signal for recognition. Kinoforms are explained in L. B. Lesem et al, "The Kinoform: A New Wavefront Reconstruction Device", IBM J. Res. & Dev., Vol. 13, pp. 150-155 (March 1969), and their use as optical filters is presented in J. C. patau et al, "Incoherent Filtering Using Kinoforms", IBM J. Res. & Dev., Vol. 14, pp. 485-491, (Sept. 1970).

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Character Recognition Methods using Kinoforms

Figs. 2 and 3 show systems for recognizing characters or other patterns by the use of kinoforms to detect individual features of each character, and optoelectronic transducers to convert each feature to a signal for recognition. Kinoforms are explained in L. B. Lesem et al, "The Kinoform: A New Wavefront Reconstruction Device", IBM J. Res. & Dev., Vol. 13, pp. 150-155 (March 1969), and their use as optical filters is presented in J. C. patau et al, "Incoherent Filtering Using Kinoforms", IBM J. Res. & Dev., Vol. 14, pp. 485-491, (Sept. 1970).

Fig. 1 shows a stylized numeral "eight", 10. Bars 11 and 12 show the effect upon pattern 10 of kinoform filters designed to pass horizontal and vertical lines, respectively. Kinoform filters do not require illumination of pattern 10 by a source of coherent light.

In recognition system 20, Fig. 2, light from a pattern on document 21 is divided by beam splitter 22 into a plurality of separate rays 23, each directed toward a kinoform filter 24. Each filter 24 is designed to pass a selected feature of pattern 10, such as vertical lines or horizontal lines. An array of detectors 25 (or a single, scanned detector) for each filter 24 then produces signals indicating the positions at which each feature is present in pattern 10. These signals may be combined by conventional decision-tree or correlation circuits 26 to provide a signal indicating the identity of pattern 10.

In system 30, Fi...