method for subtraktiven farbfilterung by diffraction, farbfiltervorrichtung for implementation of the procedure and use of such a farbfiltervorrichtung

摘要

A subtractive color filtering technique, suitable for the projection of color pictures, employs diffraction, rather than color dyes, for discriminatingly subtracting unwanted spectral wavelength portions of polychromatic illuminating light. The useful output light may consist of solely the zero-order diffraction output light or, alternatively, one or a certain combination of diffraction orders other than the zero diffraction order (such as the aggregate of all diffraction orders other than the zero diffraction order which corresponds to the complement of the zero-order diffraction output light).