Abstract

Apparatus for providing higher contrast ratios at the face of a liquid crystal display operated in the light transmitting mode, using means for collecting and concentrating ambient light at the rear face of the display assembly for transmission therethrough. Optical fiber bundles have a larger bundle cross section area at an end which is exposed to ambient light and are brought down to a smaller cross section area over the rear face of a liquid crystal display. Another embodiment of the invention involves the use of a plurality of bundles of optical fibers spaced to receive ambient light from different directions and led to the rear face of a liquid crystal display where the fibers from the separate bundles are mixed to provide an evenly concentrated ambient light flux density across the rear face of the display. Another embodiment involves the use of reflecting surfaces to enhance the intensity of the ambient light impinging upon the rear of the liquid crystal display for transmission therethrough. The ambient light may be concentrated to impinge upon substantially the entire rear area of a liquid crystal display by the use of a rear mounted lens for focusing available ambient light energy on the rear of the display.