I just found this thread and it brought back some memories. Back in the mid 70's I believe it was, Popular Science ran an article on the color wheel principle but instead of using a spinning wheel it used a conveyor belt like film of plastic mounted vertically between two rollers and imprinted with RYB striping, in the middle between the two spinning rollers and the film was a another clear glass or plastic sheet with the b&w diagonal striping. Does anyone else recall this ?