Eyeglass Light Guide Optics for Face Clearance and Retinal Focus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image projection devices attached to spectacle-type frames often lack sufficient clearance from the user's face, leading to interference and reduced image quality due to proximity and protrusion issues.
Innovation Solution
An image projection device with a light guide member formed of glass material having multiple reflection surfaces, including a concave curved surface, that converges light beams at a convergence point in the eye, allowing for sufficient clearance and improved image quality by using a configuration where some beams pass through and others are reflected by a half-mirror surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the image projection device is attached to a spectacle-type frame, then the device can be worn on the user's face, but the clearance between the device and the user's face becomes small
Solution Approach 1:
The patent extends the optical path in the lateral direction by using a light guide member that travels from the temple toward the front of the eye, rather than placing all optical components directly in front of the eye. This dimensional change allows sufficient clearance from the face while maintaining proper optical path length for image quality
2Volume of moving object
If the optical components are placed close to the eye for compact design, then the device size is reduced, but image quality deteriorates due to insufficient optical path length
Solution Approach 1:
The light guide member acts as an intermediary that carries the image light beam from the scanning unit at the temple to the eye. This mediator allows the optical components to be positioned at the temple (reducing device volume) while maintaining sufficient optical path length through the light guide member to preserve image quality
Solution Approach 2:
The patent changes the optical path configuration from a direct front-to-back arrangement to a lateral arrangement following the temple-to-front path. This dimensional change enables longer optical path length within a compact device volume, resolving the contradiction between size and image quality
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
Secures sufficient clearance from the face while maintaining high-quality image projection by optimizing beam convergence and reducing interference with the user's face.
Implementation Method 1
a light guide member that is attached to the frame and disposed in front of an eye of the user, is formed of a glass material through which a plurality of image light beams emitted from the scanning unit at different times pass, has a plurality of reflection surfaces that reflect the plurality of image light beams
Implementation Method 2
converges the plurality of image light beams reflected by the plurality of reflection surfaces at a first convergence point in the eye of the user
Implementation Method 3
a second optical member that is disposed at the second convergence point and causes each of the plurality of image light beams to enter a last reflection surface, which reflects the plurality of image light beams last among the plurality of reflection surfaces included in the light guide member, as diffusion light
Data Source
AI summary
An image projection device incudes a scanning unit that two-dimensionally scans a light beam emitted from a light source, a light guide member that is formed of a glass material through which light beams emitted from the scanning unit at different times pass, has reflection surfaces reflecting the light beams, converges the light beams reflected by the reflection surfaces at a first convergence point in the eye of the user, and then irradiates a retina of the user with the converged light beams, a first optical member that converges the light beams emitted from the scanning unit at a second convergence point before the light guide member and then causes the light beams to enter the light guide member, and a second optical member that is disposed at the second convergence point and causes the light beams to enter a last reflection surface as diffusion lights.