US 4,057,345 AGranted

Additive lamphouse

AssigneeAnamorphic Ltd.

InventorsFranz F. Ehrenhaft, Seymour Rosin

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Abstract

Three component beams are taken off three sides of a single filament light source, individually attenuated, colored in respective ones of the three additive primary colors red, blue and green and recombined to form three superimposed component images of the filament light source. The three superimposed images of the filament light source are positioned at the light source location for the printing camera. Adjacent the light source the three component beams pass through three apertures spaced from the source far enough to be located at a position where the light field is uniform. Three superimposed real images of these apertures are formed down-path of the superimposed images of the filament light source and coincident with the plane of the transparency to be printed. The three superimposed real images of the filament light source are first brought into exact register and then, independently thereof, the three superimposed real images of the aperture are brought into exact register, utilizing first and second independent adjustment expedients.

Claims7

Dependent claims

An arrangement for providing color compensated light, comprising, in combination, a single filament light source;

means for deriving from the single filament light source three component beams and for transmitting those beams along three optical paths, including three light take-off means located at three different sides of the light source;
and means located in the three optical paths for attenuating the three component beams independently of one another, for coloring the three beams in the primary colors red, blue and green and for recombining the beams into a single beam of color compensated light, the means for attenuating, coloring and recombining comprising three attenuating means and a coloring means for coloring the three component beams in respective ones of the three primary colors red, green and blue, each of the three optical paths including one of the three attenuating means, with the attenuating means being located up-path of the coloring means, the coloring means being an optical element which both colors the three component beams in respective ones of the three primary colors red, green and blue and recombines the thusly colored component beams to form the single beam of color corrected light, the three optical paths at the portions thereof down-path of the three attenuating means extending in respective ones of three different directions, the first and second directions being opposite to each other, and the third direction being perpendicular to the first and second directions, the optical element being comprised of two dichroic mirrors, the two dichroic mirrors intersecting each other at an angle of 90.degree., each dichroic mirror standing in a plane which is oriented at an angle of 45.degree. to each of said first, second and third directions, one dichroic mirror transmitting only light of a first one of the three primary colors red, blue and green, the other dichroic mirror transmitting only light of a different second one of the three primary colors red, blue and green, the portions of the three optical paths located down-path of said optical element being coincident with one another.

An arrangement for providing color compensated light, comprising, in combination, a single filament light source;

means for deriving from the single filament light source three component beams and for transmitting those beams along three optical paths, including three light take-off means located at three different sides of the light source;
and means located in the three optical paths for attenuating the three component beams independently of one another, for coloring the three beams in the primary colors red, blue and green and for recombining the beams into a single beam of color compensated light, further including a printing camera for forming upon copying material located in the camera in a predetermined plane a real image of a transparency located in another predetermined plane with the transparency being illuminated by a light source occupying a predetermined position relative to the camera, the predetermined position being located down-path of the recombining means, the means for deriving, transmitting, attenuating, coloring and recombining the three component beams including three means, one in each of the three optical paths, for forming in register with one another at said predetermined position relative to the camera three superimposed real images of the filament light source in the three primary colors red, blue and green, whereby the superimposed real images of the filament light source serve as a color compensating light source for the printing camera, the means for deriving, transmitting, attenuating, coloring and recombining the three component beams including three means, one in each of the three optical paths, each defining an aperture through which the respective component beam passes, and three means, one in each of the three optical paths, for forming in register with one another in the plane of the transparency to be illuminated three superimposed real images of the aperture in the three primary colors red, blue and green, the means for deriving, transmitting, attenuating, coloring and recombining the three component beams including first adjusting means for adjusting the positions of the three real images of the filament light source independently of one another and second adjusting means for adjusting the positions of the three real images of the aperture independently of one another and independently of the three real images of the filament light source.

Dependencies are inferred from the claim text.