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Positive Display Screen for Film Negatives

IP.com Disclosure Number: IPCOM000094942D
Original Publication Date: 1965-Jul-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Damm, EP: AUTHOR

Abstract

A photographic film negative can be viewed as a temporary positive. This is effected by first exposing the negative on a transparency coated with photochromic or phototropic material which is, in turn, projected on a display screen.

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Positive Display Screen for Film Negatives

A photographic film negative can be viewed as a temporary positive. This is effected by first exposing the negative on a transparency coated with photochromic or phototropic material which is, in turn, projected on a display screen.

Negative film chip 1, which is supported in aperture card 2, is exposed by ultraviolet light from actinic source 3 on transparent strip 4 coated with a photochromic or phototropic material. The coating is preferably an organic phototropic compound of tri-phenyl hydrogen fulgide or 5-nitro 3, 6- dimethylquinoline. These materials change color and darken in response to actinic light and provide a relatively fast, reversible reaction. After exposure, strip 4 is moved along track 5 to a display station. Here it is illuminated by visible light source 6in a conventional manner such as with mirror 7 and display screen 8. Upon completion of viewing, strip 4 is moved to an erase station where infrared energy source 9 is activated to reverse the color change.

Coated strip 4 can be eliminated by alternatively coating screen 8 and using actinic light. This arrangement, however, lengthens exposure time because of lower light density.

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