(under subclass 885) Subject matter comprising two or more surfaces of different selectivity which are intended to sequentially affect a sensing element (which may be the human eye) at such a rate that their effects are combined in an optically additive way.
SEE OR SEARCH CLASS
352, Optics: Motion Pictures,
45, and 66+ for similar subject matter used in the motion picture art.
358, Facsimile,
41+, and 56+ for similar subject matter combined with generators or displays for color television.
