AR Optical Element With Multiplexed Index Structures for Uniform Luminance
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Solution Overview
Problem
Existing AR devices face issues with uneven luminance due to light rays entering at different angles, leading to reduced image quality and efficiency, and require multiple optical components, resulting in larger devices with crosstalk and lower light utilization.
Innovation Solution
An AR optical element with periodic structures of refractive index multiplexed at predetermined intervals and multiplicities, reflecting or transmitting light rays to achieve uniform intensity distribution and control observation direction, using a computer-generated hologram for manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a diffusion screen is used to reflect or transmit light rays from a projection device, then light can be displayed to users, but uneven luminance occurs because light is most easily observed in the direction of normal reflection and luminance decreases when deviating from this direction
Solution Approach 1:
The diffusion screen is segmented into multiple regions, each with different scattering properties. The screen includes a first region with first scatterers and a second region with second scatterers, allowing different portions of the screen to handle different angular ranges of reflected light, thereby achieving uniform luminance distribution across the entire screen surface
Solution Approach 2:
Different regions of the diffusion screen are赋予 different local qualities through varying scatterer distributions. The first region has scatterers configured for optimal performance in certain angular ranges, while the second region has scatterers optimized for other angular ranges, creating locally optimized light distribution that collectively achieves global uniformity
2Adaptability or versatility
If multiple projection devices and optical components (half mirror, lens array, lenticular lens, diffusion plate) are used to secure practical observation direction and area, then stereoscopic or directional images can be displayed, but the device size increases and crosstalk occurs between projection devices
Solution Approach 1:
Multiple optical functions are merged into a single diffusion screen structure. The screen integrates the functions of light diffusion, direction control, and area expansion that would traditionally require separate optical components, thereby reducing device complexity while maintaining the ability to control observation direction and area
Solution Approach 2:
The diffusion screen serves multiple functions simultaneously: it diffuses light from projection devices, controls the direction of reflected light, expands the observation area, and prevents crosstalk between adjacent projection devices. This multi-functionality eliminates the need for multiple specialized optical components
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 AR optical element provides high image quality, efficient light utilization, and a compact design by uniformly distributing light intensity and reducing crosstalk, enabling stereoscopic and directional image display.
Implementation Method 1
the AR optical element is configured to have periodic structures of refractive index multiplexed with a predetermined interval and a multiplicity, the periodic structures each having an optical normal in a different direction from a physical normal
Implementation Method 2
periodic structures of refractive index multiplexed with a predetermined interval and a multiplicity
Implementation Method 3
focus output light with an uniform intensity distribution on a desired observation area
Implementation Method 4
configured to reflect or transmit a group of light rays incident from a projection device and emits output light with a uniform intensity distribution
Data Source
AI summary
An AR optical element having high image quality, high efficiency of light utilization, and small-size is provided. The AR optical element has periodic structures of refractive index multiplexed with a predetermined interval and predetermined multiplicity, wherein each of the periodic structures of refractive index has an optical normal in a different direction from a physical normal orthogonal to a plane of a micro-region that reflects incident light.