Optical Waveguide Plate Thickness Gradient for Near-Eye Displays

The patent applies local quality by designing the optical waveguide plate with non-uniform thickness distribution. The thickness varies across different regions of the waveguide plate, with specific thickness values at different locations. This local variation in thickness allows different regions to serve different optical functions, enabling both high light efficiency through total internal reflection and expanded viewing angle by controlling the optical path length and reflection angles in specific areas.

The patent implements local quality by creating a non-uniform thickness distribution where only specific regions have increased thickness. The optical waveguide plate has a first thickness in certain areas and a second, greater thickness in other areas. This localized thickness increase allows viewing angle expansion through enhanced total internal reflection in specific regions without uniformly increasing the entire waveguide volume, thus avoiding excessive light leakage while achieving the desired optical performance.

The patent applies parameter changes by modifying the thickness parameter of the optical waveguide plate. Specifically, the plate has a first thickness in certain regions and a second, greater thickness in other regions. This thickness parameter variation changes the optical path length and critical angle for total internal reflection, thereby reducing chromatic aberration and eliminating the rainbow effect while maintaining compact device volume. The non-uniform thickness distribution allows optimization of optical performance without sacrificing compactness.