Dichoptic Displays With Staggered Quantization for Reduced Banding
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Solution Overview
Problem
Waveguides in head-mounted displays exhibit low luminous efficiency and color and luminance non-uniformities, necessitating calibration that reduces bit-depth and results in abrupt transitions and quality limitations.
Innovation Solution
Implementing dichoptic displays with staggered quantization increments for each eye, leveraging binocular fusion to enhance perceived image quality by offsetting and staggering luminance and color quantization increments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If calibration is performed to compensate for waveguide non-uniformities, then color and luminance uniformity is improved, but bit-depth is reduced resulting in abrupt transitions and quality limitations
Solution Approach 1:
The patent divides the display system into separate dichoptic channels for each eye, with independent quantization increment sets. This segmentation allows each eye to receive images with different quantization characteristics, enabling the system to maintain higher effective bit-depth while still compensating for waveguide non-uniformities through the combination of both channels.
Solution Approach 2:
The patent applies different quantization increment sets to different visual channels (left eye vs. right eye). Each channel receives tailored quantization characteristics optimized for its specific requirements, allowing local optimization of image quality without compromising overall system performance or requiring uniform reduction of bit-depth across the entire display.
2Device complexity
If standard quantization increments are used in waveguide displays, then device complexity is reduced, but image quality suffers due to abrupt transitions and banding
Solution Approach 1:
The patent employs asymmetric quantization increment sets where the left eye and right eye receive different quantization characteristics. This asymmetry is deliberately introduced to exploit binocular fusion mechanisms, creating smoother transitions and eliminating banding artifacts while maintaining relatively simple device architecture. The offset between quantization sets provides the necessary variation to improve image quality without requiring complex additional hardware.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances perceived image quality by achieving higher bit-depth and reducing processing requirements, while mitigating color banding and form factor limitations.
Implementation Method 1
Once the light beams have been coupled into the waveguide, the light beams are 'guided' through the substrate, typically by multiple instances of total internal reflection (TIR) or by a coated surface(s).
Implementation Method 2
In some instances, an exit pupil expander, which can also take the form of an optical grating, is arranged in an intermediate stage between the input coupler and output coupler to receive light that is coupled into the waveguide by the input coupler, expand the light, and redirect the light towards the output coupler.
Data Source
AI summary
Dichoptic displays with staggered quantization increments produce enhanced perceived images through binocular fusion. Different luminances or intensities and/or different colors are displayed to different eyes using staggered quantization increments and a separate display for each eye in order to produce an improved perceived image compared to the quality of an image that can be produced by either of the individual displays. Offsetting and staggering the quantization increments for luminances and/or colors in a dichoptic display enables the leveraging of binocular fusion to take advantage of a “winner take all” (for luminance) or averaging (for colors or chromaticities) phenomenon in human vision. Using the techniques described herein, two n-bit displays that display different images to individual eyes using staggered quantization increments can be utilized to produce a perceived image having approximately 2n−1 bit-depth.