Facetted Light Guide for Electrochromic Display
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-04
An electrochromic display is illuminated for projection via a wedgeshaped side light guide of the type shown in European Published Patent Application 55317-A1. The side light guide and an integral rectangular frame form a cell containing the display electrodes and electrochromic solution. The efficiency and uniformity of illumination of the display electrodes are improved by facetting the upper surface of the side light guide and also by facetting retro-reflective surfaces of the frame. As illustrated in the simplified side sectional drawing, the display cell is constructed from an integral transparent acrylic body comprising a wedge light guide 1 and a rectangular frame 2. A silicon chip 3, bearing an array of roughened silver display electrodes about 15 mm square, forms the base of the cell.