Cogni Trax
Cogni Trax is a company related to hard edge occlusion for optical see through displays. It is based in Silicon Valley.
The technology is called Alpha Pix. It uses at least one SLM and quarter wave plate to cancel out light.[1]
Alpha Pix[edit]
Alpha Pix uses a catadioptric combiner in a thin form factor for AR smart glasses. Alpha Pix only shows the color black.
Alpha Pix controls per-pixel transparency in the virtual image plane, so it is possible to display virtual imagery in a black color. The black imagery can hard-edge occlude physical objects in the real background scene, making the generated black content visible even in direct sun-lit environments.
In total, it only consumes about 70mW of power.
The Alpha Pix CMOS display panel is designed like a smartphone camera, where the imaging lens is integrated directly on the CMOS panel. Alpha Pix uses a catadioptric combiner, which allows a compact folded optical path that enables very high optical efficiency between 25 percent and 75 percent.
Alpha Pix technology is patented in U.S. patent US10983355B2.