GB888255A - - Google Patents

Abstract

888,255. Illuminating instrument panels. KOLLSMAN INSTRUMENT CORPORATION. April 24, 1958 [Sept. 25, 1957], No. 13028/58. Class 75(4) [Also in Groups XVIII and XIX] An illuminating device for the indicating display of measuring-apparatus comprises a wedge 30 of transparent material in front of the display with a similar wedge 32 placed with its apex adjacent the base of the wedge 30 into which light is transmitted from a source 40, the base of the wedge 30 being provided with secondary light distributing means effective to redistribute at least a portion of the light from the source 40 entering the base of the wedge 30. These distributing means may be corrugations 34, 36, and 38, a roughened surface on the base or a reflecting material 48, 50, Fig. 3, on at least one of the faces of the wedge 30 near its base. Illumination of another display 22 placed near the base of the wedge 32 is improved by tapering this base and providing an auxiliary reflecting surface 66, Fig. 2a. If the display is circular, Fig. 5, two sources 88, 90 are provided and the upper part of the dial 80 is illuminated by rays returning up the wedge to be diffused by a reflecting surface 96 which may be sloped at the rear 100, Fig. 10 to enhance the effect. Adjacent faces of the wedges 30, 32 may be respectively concave and convex.