Virtual Image Display Device Frame with Optical Member Limiting Part
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing virtual image display devices face challenges in achieving a balance between reducing weight and enhancing support strength while maintaining image quality and field of view, often resulting in complex structures that increase weight and compromise support.
Innovation Solution
A virtual image display device with a frame unit that includes a limiting part to mechanically restrict the displacement of an optical member, reducing excessive stress and deformation, and allowing for thermal expansion, while also using a metal frame and resin optical member for high accuracy and stiffness, and incorporating a prism-like light guide for improved field of view and see-through functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the coupling member is provided separately from the frame to support the image display unit, then the image display unit can be supported, but the structure becomes complicated and weight increases
Solution Approach 1:
The patent merges the coupling member function into the frame structure itself. The frame includes a holding part that directly holds the image display unit, eliminating the need for a separate coupling member. This integration reduces structural complexity and weight while maintaining support strength through the frame's own mechanical design.
2Strength
If the support strength for the image display unit by the coupling member is increased, then the image display unit is better supported, but the weight increases
Solution Approach 1:
The frame serves dual functions as both the structural framework and the coupling member for supporting the image display unit. This eliminates the need for additional weight-bearing components while maintaining adequate support strength through optimized frame geometry and material selection.
Solution Approach 2:
The patent removes the separate coupling member from the system, extracting its supporting function and assigning it to the frame structure. This reduction in components directly reduces weight while the frame's holding part provides the necessary support capability.
3Weight of moving object
If the weight of the coupling member is reduced, then weight decreases, but the support strength of the image display unit is liable to be lower
Solution Approach 1:
The frame is designed to perform both structural support and image display unit coupling functions. By integrating these roles, the system achieves adequate support strength without requiring heavy dedicated coupling components, as the frame itself provides the necessary mechanical support.
4Stability of the object's composition
If the optical member is completely fixed to the frame unit, then displacement is prevented, but thermal expansion differences cause distortion and deformation
Solution Approach 1:
The patent employs a dynamic fixing mechanism where the optical member is held by the holding part but can expand and contract freely in response to temperature changes. The frame's holding structure allows controlled movement or expansion gaps, enabling the optical member to accommodate thermal expansion without causing distortion or deformation, while maintaining positional stability during normal operation.
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 solution effectively improves support strength, reduces weight, and enhances durability and thermal stability, allowing for a more compact and reliable virtual image display device with improved image quality and field of view.
Implementation Method 1
an optical member that directs a light from the image element toward an eye of an observer for visual recognition of an image
Implementation Method 2
the frame unit has a limiting part that mechanically limits displacement of the optical member partially fixed to the frame unit
Implementation Method 3
even when there is a difference in coefficient of thermal expansion between the optical member and the frame unit, the expansion or the like of the optical member with respect to the frame unit is allowed and distortion, deformation, breakage of the optical member may be prevented more reliably
Data Source
AI summary
A limiting part limits displacement of an optical member partially fixed to a frame unit, and excessive stress applied on the optical member and deformation of the optical member may be prevented. That is, support strength of the optical member may be improved by supplementarily using the limiting part. Note that the optical member is partially fixed to the frame unit, and fastening parts and the number of parts are reduced and downsizing becomes easier and reduction in weight of the virtual image display device is easier. Further, the optical member is partially fixed to the frame unit, and thus, even when there is a difference in coefficient of thermal expansion between the optical member and the frame unit, the expansion or the like of the optical member with respect to the frame unit is allowed and distortion, deformation, breakage of the optical member may be prevented more reliably.