Four-Element Optical Lens for Compact Waveguide Displays and Thermal Stability
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Solution Overview
Problem
Existing head-mounted display devices face challenges in achieving high resolution, reduced size, and thermal stability while using optical lenses in waveguide displays, particularly due to design considerations of size, weight, and thermal drift.
Innovation Solution
An optical lens system comprising multiple lens elements with specific diopter configurations and materials, including glass and plastic, arranged along an optical axis to minimize thermal drift and reduce size, combined with a waveguide element to enhance image quality and brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional optical lens designs are used in waveguide displays, then the device can achieve basic imaging function, but the size and weight cannot be reduced sufficiently
Solution Approach 1:
The optical lens is divided into multiple lens elements (first lens element, second lens element, third lens element, fourth lens element) with different diopters and surface configurations. Each lens element contributes to specific optical functions, allowing the overall system to achieve high imaging quality while maintaining a compact form factor suitable for waveguide displays.
Solution Approach 2:
Different lens elements are assigned specific local optical properties: the first lens element has a concave light incident surface, the second lens element has a convex light exit surface with negative diopter, the third lens element has a convex light incident surface with positive diopter, and the fourth lens element has a concave light incident surface with positive diopter. This localized optimization of optical properties enables compact design while maintaining image quality.
2Weight of stationary object
If optical lens size is reduced for compact display, then device weight decreases, but thermal stability deteriorates
Solution Approach 1:
The optical lens system combines multiple lens elements made of different materials with distinct thermal properties. By composing the lens system with multiple elements having different diopters and material characteristics, the design achieves weight reduction while the composite structure provides thermal stability through compensatory effects among the different material components.
3Measurement precision
If multiple lens elements are added to improve image quality, then resolution increases, but device complexity increases
Solution Approach 1:
Each lens element in the four-element system is designed to perform multiple optical functions simultaneously. For example, the lens elements collectively address aberration correction, focal length control, and thermal drift compensation, thereby achieving high resolution without proportionally increasing system complexity.
Solution Approach 2:
The patent employs systematic variation of key optical parameters across the four lens elements, including diopter values (negative for second element, positive for third and fourth elements), surface curvatures (concave and convex configurations), and material properties. These parameter changes enable high-resolution imaging while maintaining manageable system complexity through structured design.
4Stability of the object's composition
If lens elements with specific diopter configurations are used to reduce thermal drift, then thermal stability improves, but manufacturing difficulty increases
Solution Approach 1:
The patent specifies concrete parameter ranges for the lens elements to balance thermal stability and manufacturability. The second lens element has a negative diopter with a convex light exit surface, while the third and fourth elements have positive diopters with specific surface configurations. These parameter choices achieve thermal drift compensation through well-established optical design principles that remain compatible with conventional manufacturing processes.
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 optical lens system achieves high resolution, reduced volume, and thermal stability, allowing for efficient image projection without the need for additional light-combining prisms, maintaining proper image quality across varying temperatures.
Implementation Method 1
The optical lens sequentially includes a first lens element, a second lens element, a third lens element, and a fourth lens element with diopters arranged along an optical axis from a light incident-side to a light exit-side. Each of the first lens element, the second lens element, the third lens element and the fourth lens element includes a light incident surface facing the light incident-side and allowing the image beam to pass through and a light exit surface facing the light exit-side and allowing the image beam to pass through.
Data Source
AI summary
An optical lens adapted to receive an image beam from an imaging element is provided. The optical lens includes a first lens element, a second lens element, a third lens element, and a fourth lens element with diopter arranged along an optical axis from a light incident-side to a light exit-side. The light incident surface of the first lens element is concave. The second lens element has negative diopter, and the light exit surface of the second lens element is convex. The third lens element has positive diopter, and the light incident surface of the third lens element is convex. The fourth lens element has positive diopter, and the light incident surface of the fourth lens element is concave. The image beam forms a stop on the light exit-side, and the image beam has the smallest beam cross-sectional area at the position of the stop.