Increased reflectance in total internal reflection-based image displays
AssigneeCLEARink Displays, Inc.
InventorsLorne A. Whitehead, Bram M. Sadlik, Graham F. Beales
Life of this patent
Estimating the term…
Abstract
Brightness in conventional total internal reflection image displays may decrease due to incident light passing through the dark pupil region in the white state. Adding sub-wavelength structures to the surface of the convex protrusions on the transparent front sheet may increase brightness in the white state. Control of the size, spacing, shape and refractive index of the sub-wavelength structures may lead to zeroth order reflection and enhanced brightness.
Claims19
A display front sheet, comprising:
- a transparent layer having a first surface and a second surface, the second surface positioned opposite the first surface, the second surface having a plurality of convex protrusions extending away from the first surface at least one protrusion having a dark pupil region;
- and
- structures positioned on the surface of the convex protrusions, the structures protruding away from a second surface of the transparent layer.
A reflective image display, comprising:
- a transparent layer having a first surface and a second surface, the second surface positioned opposite the first surface and the second surface having a plurality of convex protrusions extending away from the first surface, at least one protrusion having a dark pupil region;
- structures positioned on the surface of the convex protrusions, the structures protruding away from a second surface of the transparent layer;
- a substantially transparent front electrode layer positioned over the transparent layer;
- a dielectric layer disposed over the front electrode layer;
- a rear electrode positioned across the dielectric layer and forming a gap therebetween;
- and
- a plurality of electrophoretically mobile particles disposed in the gap.
A method to operate a reflective image display, the method comprising:
- conformally overlaying a front electrode over a transparent layer, the transparent layer having a plurality of protrusions, at least one protrusion further comprises a plurality of structures positioned thereon;
- positioning a rear electrode across from the dielectric layer to form a gap between the rear electrode and the dielectric layer;
- suspending a plurality of electrophoretically mobile particles in the gap formed between the dielectric layer and the rear electrode;
- and
- biasing the front electrode relative to the rear electrode at a first level to attract at least some of the plurality of electrophoretically mobile particles toward the front electrode.
Dependencies are inferred from the claim text.