US 6,304,365 B1Granted

Enhanced effective refractive index total internal reflection image display

AssigneeThe University of British Columbia

InventorLorne A. Whitehead

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Abstract

The invention provides an image display for viewing images in a preferred viewing direction. The display has parallel, macroscopically planar, structured surface, non-light absorptive light deflecting and reflecting portions which are longitudinally symmetrical in mutually perpendicular directions, both of which are perpendicular to the preferred viewing direction. A liquid containing a plurality of movable members contacts the light reflecting portion. A controller applies an electromagnetic force to selectively move the members into an evanescent wave region adjacent the light reflecting portion to frustrate TIR of light rays at selected points on the light reflecting portion. The structured surfaces on the light deflecting portion deflect light rays incident in the preferred viewing direction toward the light reflecting portion by imparting to the rays a directional component in the direction of longitudinal symmetry of the light reflecting portion. The structured surfaces on the light reflecting portion totally internally reflect the deflected light rays toward the light deflecting portion at points other than the selected points at which TIR is frustrated. Then, the structured surfaces on the light deflecting portion again deflect the totally internally reflected light rays, cancelling the directional component therefrom, such that the deflected totally internally reflected light rays emerge from the display in a direction substantially parallel to the preferred viewing direction.

Claims43

Dependent claims

An image display having a preferred viewing direction, said image display comprising:

(a) a substantially macroscopically planar light deflecting portion having longitudinal symmetry in a first direction substantially perpendicular to said preferred viewing direction;
(b) a substantially macroscopically planar light reflecting portion having longitudinal symmetry in a second direction substantially perpendicular to said first direction and substantially perpendicular to said preferred viewing direction, said light reflecting portion substantially parallel to said light deflecting portion;
(c) a liquid contacting said light reflecting portion;
(d) a plurality of movable members in said liquid;
(e) a controller for applying an electromagnetic force to said members to selectively move said members into an evanescent wave region adjacent said light reflecting portion to frustrate total internal reflection of light rays at selected points on said light reflecting portion;
wherein:
(i) said light deflecting portion is substantially non-light absorptive and has structured surfaces which deflect light rays incident upon said display in said preferred viewing direction toward said light reflecting portion by imparting to said incident light rays a directional component in said second direction;
(ii) said light reflecting portion is substantially non-light absorptive and has structured surfaces which totally internally reflect said deflected light rays toward said light deflecting portion at points other than said selected points;
and,
(iii) said light deflecting portion structured surfaces deflect said totally internally reflected light rays by cancelling said directional component from said totally internally reflected light rays, such that said deflected totally internally reflected light rays emerge from said image display in a direction substantially parallel to said preferred viewing direction.

7 more elements

Dependencies are inferred from the claim text.