SPECTRUM PRODUCING OPTICAL TEACHING AID

摘要

This invention discloses a novel teaching aid for demonstrating the component pure spectral colours of white light and the effect of selective recombination thereof. It utilizes the diffraction principle to produce a spectrum fro white light and selectively filters the spectrum. By splitting the filtered light prior to recombination, it is possible to project an image of the selective filter and the recombined selectively filtered light adjacent to each other on a projection screen. Thus, the effects of the variation of the filter is shown directly by a variation in the colour and intensity of the recombined light. This novel device provides a compact design of rather simple construction which clearly demonstrates the aforenoted principles and is an excellent teaching aid.