Method for fabricating thin panel illuminator

Abstract

A method for fabricating a thin-panel illuminator for uniform, high contrast lighting of large area graphic displays such as maps, photographs, charts, and the like. Light is introduced through one edge of a transparent substrate having front and back plane parallel opposed surfaces and thereby directed into the interior of the substrate. The back surface is textured with a multiplicity of shallow depressions such as grooves or dimples which have shallow sloped sides such that light is selectively directed from the interior of the substrate through a limited angle out of the substrate towards a display surface adjacent and coextensive with the back surface of the substrate and away from a viewer observing the display surface through the substrate. The diffusing surface is fabricated by roughening the back surface of the substrate to form relatively deep depressions which are then partially filled with an optically transparent liquid to thereby form relatively shallow depressions. The liquid within the depressions is then solidified.

Dependencies are inferred from the claim text.