Wide viewing angle reflective display
AssigneeThe University of British Columbia
InventorsLorne A. Whitehead, Michele Ann Mossman
Life of this patent
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Abstract
A reflective display having a plurality of approximately hemispherical high refractive index (η1) transparent hemi-beads substantially covering and protruding inwardly from a transparent sheet's inward surface. The transparent sheet, which has an outward viewing surface, has a refractive index (η2) which can be low (i.e. η1≈1.92 and η2≈1.59). A member is selectably moved into an intense evanescent wave region at the hemi-beads' inward side to selectably frustrate substantial total internal reflection of light rays. The member can be a plurality of light scattering particles suspended in a low refractive index (η3≈1.27) electrophoresis medium and electrophoretically moved into or out of the intense evanescent wave region.
Claims11
A reflective display, comprising:
- (a) a first transparent sheet having:
- (i) an inwardly protruding structure on an inward side of said first sheet, said structure having a refractive index greater than about 1.75;
- (ii) an outward viewing surface;
- (iii) an intense evanescent wave region at an inward side of said structure;
- (b) a second sheet spaced inwardly from said first sheet to define a reservoir between said first and second sheets;
- (c) an electrophoresis medium within said reservoir, said medium having a refractive index less than about 1.35;
- (d) a member within said medium;
- (e) a first electrode on said inward side of said structure;
- (f) a second electrode on an outward side of said second sheet;
- and,
- (i) a voltage source coupled between said electrodes to apply a voltage across said medium to selectably, electrophoretically move said member into or out of said intense evanescent wave region.
A method of making a reflective display, said method comprising:
- (a) partially embedding a plurality of approximately spherical high refractive index beads in one side of an elastomeric substrate;
- (b) removing portions of said beads which are not embedded in said substrate to produce a plurality of approximately hemispherical high refractive index hemi-beads embedded in said substrate, said hemi-beads having substantially flat, substantially coplanar faces;
- (c) transparently adhering said hemi-bead coplanar faces to a transparent substrate;
- and,
- (d) removing said elastomeric substrate.
Dependencies are inferred from the claim text.