Process and device for copying photographic color images
AssigneeDurst AG. Fabrik Fototechnischer Apparate Bozen
InventorSiegfried Barbieri
Life of this patent
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Abstract
A blocking filter is used, in conjunction with the substractive filter method of copying photographic color images, to remove or substantially remove by greatly weakening wave lengths from the copying light in the range in which the filter characteristics of the blue and green color filters or the spectral sensitivity curves of photographic copying paper overlap each other, or more particularly in a 30 nm belt about a central wave length of approximately 500 nm.
Claims12
A process for copying or enlarging of photographic images in accordance with the substractive method in which substractive color filters are selectively interposed at variable depths in the path of the printing light, the process being characterized by substantially removing wave lengths from the copying light in the overlapping wave length range of the spectral sensitivity curves of photographic copying paper whereby disruptions caused by the reciprocal effect of filters in the overlapping wave lenths is minimized.
A device for filtering undesirable wave lengths from light used for copying photographic color images by the substractive method in which substractive color filter are selectively interposed at variable depths in the path of the printing light, comprising filter means, and the filter means being characterized by substantially filtering out wave lengths corresponding to the overlapping wave lengths of the spectral sensitivity curves of photographic copying paper.
Dependencies are inferred from the claim text.