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Photographic Process For Contrast Equalization

IP.com Disclosure Number: IPCOM000097825D
Original Publication Date: 1961-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Kay, RH: AUTHOR

Abstract

This photographic process for contrast equalization comprises applying to a typed document a fluorescent dye, exposing the treated document to ultraviolet light to cause the dye to fluoresce, and photo graphing the irradiated fluorescing document. The typed characters do not absorb the fluorescent dye. The camera photographs only the fluorescing and non-fluorescing areas of the document.

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Photographic Process For Contrast Equalization

This photographic process for contrast equalization comprises applying to a typed document a fluorescent dye, exposing the treated document to ultraviolet light to cause the dye to fluoresce, and photo graphing the irradiated fluorescing document. The typed characters do not absorb the fluorescent dye. The camera photographs only the fluorescing and non-fluorescing areas of the document.

The document is dyed with a mixture of a coumarin dye and acid yellow 7, blue and yellow green dyes, respectively. The dyes are dissolved in a solution of water soluble, polyvinyl alcohol and N-vinyl-2-pyrrolidone.

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