Light Guide Reflecting Surface Layout for Blind Spot Visibility
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Solution Overview
Problem
Existing blind spot assistance devices suffer from reduced recognition and visibility of the scene in the blind spot area due to periodic streaks caused by light shielding layers and reflecting surfaces, which increase eye-attractiveness and hinder visual processing.
Innovation Solution
An optical member with a light guide that includes an incident surface, first and second reflecting surfaces, exit portions, and rough surfaces, where the first reflecting surface is inclined to satisfy a specific angle inequality, reducing the eye-attractiveness by tilting the streaks and enhancing the visibility of the blind spot area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a semi-transmissive mirror and light shielding layers are used in the blind spot assistance device, then the light guidance function is achieved, but periodic streaks are generated that reduce scene recognition and visibility
Solution Approach 1:
The patent extracts and removes the light shielding layers and semi-transmissive mirrors from the optical system. Instead, it uses a light guide with total internal reflection at interfaces between regions of different refractive indices, eliminating the components that generate harmful periodic streaks while maintaining the light guidance function
Solution Approach 2:
The patent replaces the mechanical/optical system using mirrors and light shielding layers with a refractive index-based system. By creating regions with different refractive indices within the light guide, it achieves light guidance through optical refraction and total internal reflection rather than through reflective surfaces, thereby eliminating streak generation
2Ease of operation
If multiple reflecting surfaces and light shielding layers are arranged periodically, then light is guided to the viewer, but eye-attractiveness increases and visual processing is hindered
Solution Approach 1:
The patent changes the fundamental optical parameter from reflectivity to refractive index. By varying the refractive index continuously or in steps within the light guide material, it guides light without creating the periodic reflective surfaces that cause eye-attractiveness issues. The light guidance is achieved through gradual or stepped changes in refractive index rather than discrete reflective interfaces
3Reliability
If a semi-transmissive mirror is used in the blind spot assistance device, then light reflection is achieved, but device complexity and cost increase
Solution Approach 1:
The patent merges the light guidance function and the light reflection function into a single integrated light guide structure. The light guide itself performs both functions by using total internal reflection at its internal interfaces, eliminating the need for separate semi-transmissive mirrors and light shielding layers, thereby reducing device complexity and cost
Solution Approach 2:
The light guide is designed to perform multiple functions simultaneously: it guides light from the blind spot area, reflects light internally through total internal reflection, and presents a uniform surface without periodic streaks. This multi-functional design eliminates the need for multiple specialized components, reducing overall system complexity
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 optical member effectively suppresses the deterioration in recognition of the scene in the blind spot area by reducing eye-attractiveness and improving visibility, while also potentially reducing the cost by eliminating the need for a semi-transmissive mirror.
Implementation Method 1
a first reflecting surface configured to reflect light from the incident surface
Implementation Method 2
a second reflecting surface configured to reflect light reflected by the first reflecting surface
Implementation Method 3
a first rough surface cross-connected with the incident surface, the first reflecting surface, and the second reflecting surface; and a second rough surface cross-connected with the first reflecting surface and the second reflecting surface
Data Source
AI summary
An optical member includes a light guide. An inclination angle of a first reflecting surface of the light guide with respect to a first direction perpendicular to a normal direction of the first reflecting surface is defined as γr in a rotational direction about an axis extending in the normal direction. A line segment is defined by connecting the viewer and the light guide in a cross section perpendicular to the first direction. An inclination angle of the line segment with respect to a second direction perpendicular to the normal direction and the first direction is defined as β in a rotational direction about an axis extending in the first direction. The first reflecting surface is formed so as to satisfy Inequation of 10°≤arctan(tan γr×sin β)≤90°.