Waveguide Display Output Coupler Segmentation for Depth of Focus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Waveguide-type display apparatuses using parallel light rays suffer from an infinite depth position, making it difficult for individuals with normal eyesight to clearly view images.
Innovation Solution
The display apparatus incorporates an output coupler with a plurality of first diffraction grating elements arranged apart from each other, configured to diffract light into multiple directions, thereby increasing the depth of focus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If parallel light rays are used in waveguide display, then wide eye box is achieved, but depth of focus becomes infinite making images unclear for normal eyesight
Solution Approach 1:
The output coupler is segmented into multiple diffraction grating elements (first, second, and third diffraction grating elements) arranged in different regions. Each element diffracts light in specific directions to create virtual images at different depths, thereby segmenting the optical function to achieve finite depth of focus while maintaining wide eye box
Solution Approach 2:
Different regions of the output coupler are assigned different local optical properties. The first diffraction grating elements in the first region, second diffraction grating elements in the second region, and third diffraction grating elements in the third region each have distinct diffraction characteristics that collectively provide both wide eye box and appropriate depth of focus
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
The solution provides a waveguide-type display apparatus with an extended depth of focus, allowing users to clearly view images without the need for additional optical lenses, thus enhancing image sharpness and reducing the complexity of the display system.
Implementation Method 1
an output coupler on the waveguide, the output coupler being configured to output light traveling within the waveguide to an outside of the waveguide, wherein the output coupler includes a plurality of first diffraction grating elements arranged apart from each other, the plurality of first diffraction grating elements being configured to diffract a first light portion in a first wavelength band among the light traveling within the waveguide
Implementation Method 2
Light propagating within a waveguide by total reflection is output as parallel light rays while being diffracted by an output coupler
Data Source
AI summary
A display apparatus includes a waveguide; an input coupler on the waveguide and configured to introduce light containing an image into the waveguide; and an output coupler on the waveguide and configured to output light traveling in the waveguide to the outside of the waveguide, wherein the output coupler includes a plurality of first diffraction grating elements arranged apart from each other and configured to diffract a first light portion in a first wavelength band among the light traveling in the waveguide.