Dynamic Lens HMD for Multi-Depth AR Display
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Solution Overview
Problem
Conventional Head Mounted Displays (HMDs) are limited by their size, weight, field of view, and efficiency, particularly in presenting images and information across different depths and wider fields of view, which restricts their practical and leisure applications.
Innovation Solution
The use of dynamic lenses, such as tunable lenses and switchable lenses, integrated with control circuitry to adjust focal lengths and direct image light into different eyeward regions, allowing for the presentation of multiple images at varying depths and expanded fields of view without increasing the size of the display module or altering the optical combiner's focal length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional optical systems are used in HMDs, then the device structure is simple, but the field of view is limited and multiple depths cannot be displayed
Solution Approach 1:
The patent applies dynamic lenses that can change their focal length in real-time to display images at multiple depths. The optical system transitions from static to dynamic, allowing the same optical path to present images at different focal distances by adjusting lens parameters, thereby expanding field of view and depth capability without adding multiple fixed optical systems
Solution Approach 2:
The patent makes a single optical combiner serve multiple functions by integrating dynamic lenses that can switch between different focal lengths. This allows one optical system to handle both near-field and far-field image presentation, as well as accommodate different field of view requirements, eliminating the need for separate optical systems for each function
2Adaptability or versatility
If display module size is increased to expand field of view, then field of view is improved, but the 'bug eye' aesthetic and device bulk increase
Solution Approach 1:
The patent changes the optical parameters (focal length) of existing lenses dynamically to expand the effective field of view. By adjusting lens focal length rather than increasing display module size, the system achieves wider field of view coverage while maintaining a compact form factor and avoiding the 'bug eye' aesthetic associated with large display modules
3Adaptability or versatility
If fixed focal length optical combiner is used, then optical system is simple, but images at multiple depths cannot be displayed
Solution Approach 1:
The patent transforms the static optical combiner into a dynamic system by incorporating lenses with variable focal lengths. This allows the optical combiner to adapt its focusing capability to present images at multiple depths sequentially or simultaneously, enhancing versatility without requiring multiple fixed focal length combiners
Solution Approach 2:
The patent modifies the focal length parameter of the optical combiner lenses dynamically. By controlling lens curvature or refractive index changes, the system can shift focal points to accommodate different image depths, enabling multi-depth presentation while maintaining a single optical combiner structure
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
Enables the presentation of multiple images at different depths and expanded fields of view, enhancing the user's perception of augmented reality by allowing a wider range of information to be displayed without the 'bug eye' aesthetic, while maintaining transparency for external scene viewing.
Implementation Method 1
dynamic lenses, such as tunable lenses and switchable lenses, integrated with control circuitry to adjust focal lengths and direct image light into different eyeward regions
Data Source
AI summary
A Head Mounted Display (“HMD”) includes a display module to generate image light, an optical combiner, a stacked switchable lens, and control circuitry. The optical combiner combines the image light with external scene light. The optical combiner includes a reflective element coupled to receive the image light and direct the image light in an eye-ward direction. The stacked switchable lens is optically coupled to receive the image light. The stacked switchable lens includes at least a first switching optic and a second switching optic. The control circuitry is configured to selectively activate the first switching optic and the second switching optic. The first switching optic is configured to direct the image light toward a first eyeward region when activated by the control circuitry. The second switching optic is configured to direct the image light toward a second eyeward region when activated by the control circuitry.