Head-Mounted Image Display With Movable Optical Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image display devices struggle to maintain proper image projection onto the observer's pupil due to changes in the relative positional relationship between the pupil and the diffraction grating member, leading to improper image formation.
Innovation Solution
The image display device incorporates a light guide plate with a support substrate, first and second deflection units, and an optical member, along with a movement device that adjusts the relative positional relationship between the second deflection unit and the optical member by moving the support substrate in the X and Y directions, ensuring proper image projection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the relative positional relationship between the pupil and the diffraction grating member is fixed, then the image formation is stable, but the device cannot adapt to changes in the observer's wearing state
Solution Approach 1:
The patent applies the dynamics principle by making the support substrate movable relative to the light guide plate through a movement device. This allows the optical member mounted on the support substrate to dynamically adjust its position, enabling adaptation to different wearing states while maintaining a relatively simple overall structure. The movable configuration resolves the contradiction by introducing controlled mobility where needed rather than making the entire device complex.
Solution Approach 2:
The patent segments the device into distinct functional modules: the light guide plate with diffraction grating member, the support substrate, and the optical member. The support substrate acts as an independent movable platform that can be adjusted separately from other components. This segmentation allows the movement device to adjust only the necessary portion (support substrate and optical member) without complicating the entire device structure.
2Manufacturing precision
If the support substrate is made movable to adjust the relative position, then the image projection is optimized, but the device complexity increases
Solution Approach 1:
The movement device enables the support substrate to move in the optical axis direction, allowing dynamic adjustment of the relative position between the optical member and the light guide plate. This dynamic positioning capability ensures accurate image projection onto the pupil while adapting to different wearing conditions, achieving high manufacturing precision without requiring the entire device to be complex.
Solution Approach 2:
The movement device is configured to allow adjustment of the support substrate position, which can be done to optimize image projection for different observers or conditions. This self-adjustment capability enables the device to achieve precise image projection without requiring complex external adjustment mechanisms or multiple components.
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 allows for easy handling of changes in the observer's wearing state, ensuring consistent image projection onto the pupil by optimizing light intensity and maintaining image quality despite positional changes.
Implementation Method 1
light propagated inside the light guide plate by total reflection
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A display device includes: a frame to be mounted on a head of an observer; and an image display device attached to the frame. The image display device includes: an image forming device 110; a light guide plate 121; a support substrate 141; a first deflection unit 131; a second deflection unit 132; and an optical member 142 attached to the support substrate 141, in which light from the image forming device 110 is deflected at the first deflection unit 131, propagated inside the light guide plate 121 by total reflection, deflected at the second deflection unit 132, and incident on the optical member 142, and the optical member 142 emits the incident light toward a pupil 21 of an observer 20. The display device further includes a movement device 150 that moves the support substrate 141 with respect to the light guide plate 121 in order to change a relative positional relation between the second deflection unit 132 and the optical member 142.