Light Guide Turn Signal Mirror With Defined Emission Profile
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Solution Overview
Problem
Existing exterior rear view mirror designs with turn signal indicators suffer from diffuse light emission due to the use of reflectors, which complicates light path and increases costs, while also failing to provide a well-defined lighting profile.
Innovation Solution
A design featuring a garnish element that fixes a light guide in the housing with openings for clear light emission, where a second LED is placed at the vertex of the mirror to improve forward light emission and define the angle of light emission, and a printed circuit board blocks light from the light guide to enhance the lighting profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If reflectors are used to concentrate light in the turn signal indicator, then light emission intensity is improved, but light path becomes complex and light emission becomes diffuse
Solution Approach 1:
The patent removes the reflector component from the turn signal indicator assembly, extracting the problematic element that caused diffuse light emission and complex light paths. The solution uses only a light guide and LED without any reflective surfaces, simplifying the overall structure while maintaining effective light transmission.
Solution Approach 2:
The patent introduces a light guide as an intermediary component between the LED and the lens. This light guide mediates light transmission by conducting light from the LED through its internal structure to the lens, providing a controlled and direct light path without requiring reflectors to concentrate or redirect light.
2Illumination intensity
If reflectors are used to concentrate light, then light emission is enhanced, but manufacturing cost increases
Solution Approach 1:
The patent eliminates the reflector component from the assembly, reducing the number of parts that need to be manufactured, assembled, and quality-checked. This extraction of the unnecessary component directly lowers manufacturing complexity and cost while achieving the same light emission enhancement through the simplified light guide structure.
3Illumination intensity
If a light guide is used without blocking elements, then light transmission is maximized, but light emission profile becomes undefined
Solution Approach 1:
The patent applies local quality by strategically placing blocking elements at specific locations within the light guide structure. These blocking elements are positioned to control light emission in certain directions while allowing light transmission in others, creating a defined lighting profile with specific angular characteristics that meet regulatory requirements.
Solution Approach 2:
The patent uses the blocking elements to control the angular distribution of light emission, effectively creating different emission patterns. By blocking light in certain directions and allowing it in others, the system achieves a defined emission profile with specific angular characteristics, analogous to how color filters define spectral characteristics.
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 solution provides a clear and defined lighting profile for the turn signal indicator, meeting regulatory requirements for light emission angle and intensity without the need for reflective elements, thus improving the overall efficiency and cost-effectiveness of the design.
Implementation Method 1
The use of reflectors was state of the art at this time... The light emitted via reflectors is at least reflected backwards from lens structure once... The reflected part is first reflected by the lens and than by the reflector
Implementation Method 2
With the availability of LEDs as light sources for turn signal indication devices these indicators also included light guides
Data Source
AI summary
The invention is related to an exterior rear view mirror assembly with a mirror base and a mirror head comprising at least one of the following features as mirror glass, mirror glass actuator, power fold actuator, lighting elements, indicators and at least one opening for a turn signal indicator light module. The assembly comprises a housing covered by a lens, at least one light guide with a first LED feeding light into the cross sectional area of the light guide, and at least a second LED placed apart the light guide, wherein a decorative, none reflective garnish is fixed between none reflective housing and transparent lens.