P-190: Method for Making Panels for Wedge Projection

Wedge projection displays can be made economically in small quantities by machining the wedge profile on a thick sheet of cast acrylic, machining a constant thickness on a thin sheet of cast acrylic, then index-matching the two together. The resulting panels can have smoothnesses almost as good as float glass and transparencies approaching that of plastic optical fibre. When used in reverse as a camera, panels have resolutions of 4 line pairs per millimetre and contrast ratios of 200:1.