Anamorphic Fresnel Lens for Compact AR Optical Control
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Solution Overview
Problem
Existing image generation devices for augmented reality head-up displays face challenges in achieving asymmetrical optical control and minimizing volume while maintaining optical performance.
Innovation Solution
The use of a plate-shaped anamorphic Fresnel lens with concentric oval grooves and a prism sheet, along with additional lenses and optical components, allows for independent adjustment of horizontal and vertical light paths, eliminating the need for a separate flat mirror.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional symmetrical Fresnel lens is used, then the structure is simple and easy to manufacture, but the optical path cannot be independently adjusted in horizontal and vertical directions for augmented reality applications
Solution Approach 1:
The patent applies asymmetry by designing an anamorphic Fresnel lens with different curvatures in the horizontal and vertical directions. The lens features a first curvature radius in the horizontal direction and a second curvature radius in the vertical direction, where these radii are different. This asymmetrical design enables independent optimization of optical paths for augmented reality displays, allowing the lens to handle the different magnification requirements in each direction while maintaining a single integrated structure rather than requiring multiple separate optical elements
2Reliability
If multiple separate optical elements are used to control optical paths, then optical performance can be optimized, but the device volume increases
Solution Approach 1:
The patent merges multiple optical functions into a single anamorphic Fresnel lens. By integrating the asymmetrical curvature design directly into the Fresnel lens structure, the invention combines the functions of optical path control in both horizontal and vertical directions, as well as focusing and collimation, into one compact element. This eliminates the need for multiple separate optical components that would increase device volume, while maintaining the optical performance needed for augmented reality applications
3Adaptability or versatility
If a separate flat mirror is used to reflect light, then the optical path can be adjusted, but the device volume increases and complexity increases
Solution Approach 1:
The patent extracts the optical path adjustment function from separate reflective components (flat mirrors) and integrates it directly into the Fresnel lens structure through the anamorphic design. By embedding the optical control capability within the lens itself through different curvature radii in orthogonal directions, the invention eliminates the need for external mirrors while maintaining full optical path adjustment capability for augmented reality displays
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
This configuration enhances optical performance and reduces the device's volume by allowing for precise optical path control, minimizing the need for additional reflective elements.
Implementation Method 1
The Fresnel lens may control the path of light between a light source and a display element
Implementation Method 2
a plurality of lenses disposed between the light source and the display element, in which the plurality of lenses may comprise a Fresnel lens with a plurality of oval grooves formed concentrically on one surface
Implementation Method 3
a prism sheet disposed between the plurality of lenses and the display element
Data Source
AI summary
An image generation device having a Fresnel lens, according to the present embodiment, comprises: a light source; a display element spaced apart from the light source; a plurality of lenses arranged between the light source and the display element; and a prism sheet arranged between the plurality of lenses and the display element, wherein the plurality of lenses comprise a Fresnel lens having, on one surface thereof, a plurality of oval grooves formed as concentric circles, the Fresnel lens can adjust the path of light between the light source and the display element, the one surface of the Fresnel lens has the plurality of oval grooves formed as concentric circles, the Fresnel lens has a first curvature in a first direction and a second curvature in a second direction, the first direction and the second direction are orthogonal to each other, and the first curvature and the second curvature can be different.