Light guide structures
Publication Date: 2003-Jun-13
The IP.com Prior Art Database
Light guide structures (ID 611338)
Local out coupling of light from a light guide into a liquid display element is made adjustable by varying the degree of electrowetting of the liquid element on a surface element on one of the sides of a light guide or by fixing and containing a liquid element inside a switching unit that is present between the sides of a substrate (supporting member) of the liquid display element and the light guide that face each other. In one embodiment (Figure 1) the side of the supporting member is parallel- positioned with respect to the side of the light guide facing the supporting member and kept at a fixed distance by means of spacer elements, the spacer elements being positioned around a liquid element such that the liquid element becomes substantially confined within the volume enclosed by the spacer elements and the sides of the light guide and the supporting member. Preferably, the spacer elements are reflective. The surfaces of the spacer elements facing the liquid are at least moderately lyophobic (lyophobic = non wetting) towards the liquid. Preferably, at least part of the surfaces of the spacer elements facing the liquid element are conductive and in permanent electrical contact with the liquid, enabling their use as an electrode for imparting a voltage to the liquid element. The surface of the light guide side facing the liquid element is highly lyophobic with respect to the liquid. Electrowetting of a liquid element on the at least one moderately lyophobic surface element of the supporting member is enabled by providing a potential difference between the liquid element on the one hand and at least one electrode element, separated from the liquid ele...