Eyepiece Optical Assembly Stray Light Control
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Solution Overview
Problem
Existing eyepiece optical assemblies for head-mounted displays suffer from low image quality, distortion, and insufficient field-of-view angle, making it challenging to achieve high image resolution, low distortion, and visual comfort.
Innovation Solution
The eyepiece optical assembly consists of a sequence of optics groups, including a first lens group, a polarizer group, a waveplate group, a second lens group with a transflective surface, a third lens group, and another waveplate and polarizer group, optimized with specific focal lengths, thicknesses, and polarization control to improve image quality and reduce distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a catadioptric pancake optical system is adopted to improve processability, then manufacturing ease is improved, but stray light increases and contrast decreases
Solution Approach 1:
The patent introduces a polarizing beam splitter as an intermediary optical element between the lens groups. This component selectively transmits polarized light while blocking stray light, thereby reducing contrast degradation without compromising the pancake optical system's compact structure and manufacturability
Solution Approach 2:
The patent optimizes the optical parameters including focal lengths, curvature radii, and thicknesses of lens groups to control light paths and polarization states. By carefully adjusting these parameters, the system minimizes stray light while maintaining the simplified pancake structure for easy manufacturing
2Manufacturing precision
If a Fresnel optical face shape is used to achieve large field-of-view and high image quality, then optical performance is improved, but manufacturing complexity increases and mass production becomes difficult
Solution Approach 1:
The patent divides the optical system into multiple discrete lens groups (first lens group, second lens group, third lens group) with specific functions. Each group can be manufactured separately using standard optical machining processes, avoiding the need for complex Fresnel shaping while achieving comparable or superior image quality through optimized lens combinations
Solution Approach 2:
The patent specifies precise parameter ranges for focal lengths, curvatures, and thicknesses that can be achieved through conventional manufacturing. By selecting parameters within manufacturable ranges, the system attains high image quality without requiring difficult-to-produce Fresnel surfaces
3Manufacturing precision
If multiple lens combinations are used to achieve large field-of-view and high resolution, then optical performance is improved, but device volume and mass increase
Solution Approach 1:
The patent combines multiple lens groups and polarizing elements into a compact integrated assembly where the optical path folds back on itself. The first, second, and third lens groups are arranged in a space-efficient configuration that achieves high resolution and large field-of-view while minimizing overall volume and mass through careful spatial arrangement
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 image quality, reduces manufacturing complexity and cost, and provides a large field-of-view angle with low distortion, resulting in a more comfortable and high-definition visual experience.
Implementation Method 1
the iterative technology of polarization control material being more prominent
Implementation Method 2
The head-mounted display unit directs the video image light emitted by a miniature image display to a user's pupil through some optical imaging technologies
Implementation Method 3
the second optics group includes a second lens group and a transflective optical surface
Data Source
AI summary
The present invention relates to an eyepiece optical assembly, system and device. The assembly includes a first optics group, a second optics group and a third optics group arranged in sequence along an optical axis from a human eye viewing side to a miniature display. The first optics group includes a first lens group, a first polarizer group and a first waveplate group, the second optics group includes a second lens group and a transflective optical surface, and the third optics group includes a third lens group, a second waveplate group and a second polarizer group. Imaging light is emitted from the miniature display and is reflected and refracted back and forth between the first optics group and the second optics group, and finally exits from the first optics group close to the human eye viewing side into a human eye for imaging.