Virtual Image Display Device with Single Optical Path for HMDs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing virtual image display devices, such as HMDs, impose a significant physiological burden on users due to differences between perceived and actual virtual image distances, leading to fatigue, and have a narrow eyebox and high costs due to the need for separate optical systems for each eye.
Innovation Solution
A virtual image display device with a visual recognition distance detecting unit, virtual image light generating unit, and virtual-image-light transmitting and projecting unit that uses a single optical path for both eyes, allowing variable control of virtual image distance through luminance apportionment between long and short distance reference images to match actual visual recognition distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If binocular parallax method is used to adapt virtual image distance, then virtual image visual recognition distance can be adapted to actual space visual recognition distance, but physiological burden on user increases and user fatigue occurs during long-term use
Solution Approach 1:
The patent uses a single optical system to generate virtual images for both eyes simultaneously, creating identical visual recognition distances for binocular viewing. This eliminates the need for separate optical paths with different parallax settings, thereby removing the physiological burden caused by mismatched focal and perceived distances while maintaining distance adaptation capability.
Solution Approach 2:
The patent merges the left-eye and right-eye optical paths into a single optical system, allowing both eyes to receive light through the same optical components. This consolidation enables consistent virtual image distance presentation to both eyes without requiring separate adjustable optical paths, thus eliminating user fatigue while preserving adaptability.
2Adaptability or versatility
If separate optical systems are provided for left and right eyes to display different virtual images with binocular parallax, then virtual image visual recognition distance can be adapted, but device size and weight increase significantly
Solution Approach 1:
The patent combines the optical systems for left and right eyes into a single integrated optical path. By using shared optical components including lenses, mirrors, and display elements, the system achieves binocular parallax functionality without duplicating entire optical trains, thereby significantly reducing device weight and size.
Solution Approach 2:
The single optical system is designed to serve both eyes simultaneously, performing multiple functions with a single set of components. The optical elements are configured to direct light to both left and right eyes while maintaining the ability to present different virtual image positions, achieving multi-functionality without increasing component count.
3Adaptability or versatility
If separate optical systems are provided for left and right eyes to display different virtual images with binocular parallax, then virtual image visual recognition distance can be adapted, but device cost increases greatly
Solution Approach 1:
The patent merges the optical systems for left and right eyes into a single integrated optical path. By using shared optical components including lenses, mirrors, and display elements, the system achieves binocular parallax functionality without duplicating entire optical trains, thereby significantly reducing device weight and size.
Solution Approach 2:
The single optical system is designed to serve both eyes simultaneously, performing multiple functions with a single set of components. The optical elements are configured to direct light to both left and right eyes while maintaining the ability to present different virtual image positions, achieving multi-functionality without increasing component count.
4Adaptability or versatility
If binocular parallax is applied to adapt virtual image distance, then virtual image visual recognition distance can be adapted to actual space visual recognition distance, but viewpoint range (eyebox) becomes extremely narrow
Solution Approach 1:
The patent generates identical virtual images for both eyes through a single optical system, eliminating the need for precise binocular parallax alignment. This approach widens the acceptable viewpoint range because the system does not rely on maintaining specific parallax relationships between left and right eye images, thereby expanding the eyebox area.
Solution Approach 2:
The patent segments the virtual image generation into independent control for each eye while using a shared optical path. This allows flexible adjustment of virtual image positions without the constraints of rigid binocular parallax geometry, enabling a larger acceptable viewing area while maintaining distance adaptation capability.
Data Source
AI summary
A virtual image display device has a function of projecting a prescribed virtual image video within a visual field of a user and detects an actual visual recognition distance from the user to an object relating to a visually recognized object at which the user is gazing. A virtual image light generating unit has a function of generating a plurality of virtual image lights independent of each other and a virtual-image-light transmitting and projecting unit that has a function of transmitting and projecting the virtual image light to left and right eyes of the user through substantially the same optical path to allow a prescribed virtual image video to be visually recognized at a prescribed position within the visual field of the user. Additionally, a virtual-image visual recognition distance control unit that has a function of performing variable control of a visual recognition distance of a virtual image.