Additive color photographic film assembly with diffraction grating

Abstract

This disclosure depicts a new low cost color photographic film assembly which is of the additive type but is of very high speed due to its extremely efficient utilization of available exposure light. The assembly includes a photosensitive layer actinic to light in the entire visible bandwidth of the exposure light for recording intensity variations in light incident thereon. It includes a spectral separation phase structure comprising a pattern of periodically repetitive, wavelength-sensitive phase elements effective to deflect incident light of predetermined different colors in different directions. The phase structure is supported adjacent to the photosensitive layer and spaced therefrom by a prescribed distance which is such that each element of an image formed on the assembly is analyzed into a number of color separation elements segregated on the photosensitive layer. The image is recorded in the layer as a dissected composite of interleaved color separation elements. In a preferred arrangement the spectral separation phase structure comprises at least two interlaced sets of periodically repetitive phase elements which are characterized by their unique capability of causing light of light of the same color to be recorded in substantially coincident relationship in the photosensitive layer whereby the available film area is shared and the light utilization efficiency of the assembly thereby greatly enhanced.