In-Vehicle Headlight Asymmetric LED Optical Path
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Solution Overview
Problem
Existing in-vehicle headlights using LEDs face challenges in achieving a compact, cost-effective, and efficient light distribution that maintains clear light and dark boundaries, as previous solutions either require complex configurations or increased component costs.
Innovation Solution
A projector-type headlight design utilizing an LED with a linearly formed light-emitting edge, two convex lenses, and a transparent light distribution member with a reflection face to form a cut-off line, allowing for effective light projection and reduced component complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional spheroidal mirror reflector is used with LED to form real image for light distribution control, then light distribution can be adjusted, but device complexity and size increase
Solution Approach 1:
The patent extracts the light distribution control function from the complex spheroidal mirror reflector system and implements it through a simpler optical path using LED's inherent directional emission properties combined with a projection lens, eliminating the need for real image formation and complex reflector geometry
Solution Approach 2:
Instead of using the conventional approach of forming a real image of the light source and then controlling light distribution, the patent inverts the approach by directly using the LED's directional emission and controlling light distribution through the projection lens optical path, achieving the same effect with simpler components
2Loss of energy
If auxiliary lens is added to recover widely-spread light from LED, then light-beam utilization rate increases, but device size and opening portion increase
Solution Approach 1:
The patent applies local quality by optimizing the LED emission characteristics in the specific direction needed for headlight illumination, using the LED's inherent directional emission properties to concentrate light where it is needed without requiring additional optical elements that would increase device size
Solution Approach 2:
The LED's inherent directional emission properties are utilized to self-concentrate light in the forward direction, eliminating the need for external auxiliary lenses to recover and redirect light, thereby maintaining high light-beam utilization rate without increasing device opening portion
3Volume of moving object
If projection lens aperture is reduced to compact device size, then device becomes more compact, but sufficient brightness cannot be achieved
Solution Approach 1:
The patent employs asymmetric optical design where the projection lens aperture is optimized for the specific LED emission pattern, creating an asymmetric light path that maximizes light collection efficiency within a compact form factor, allowing sufficient brightness with reduced lens aperture
Solution Approach 2:
The patent optimizes key optical parameters including the distance between LED and projection lens, the focal length of the projection lens, and the LED emission angle to achieve maximum brightness output from a compact lens aperture, balancing device size and illumination intensity through parameter optimization
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 design results in a compact, cost-effective headlight that achieves sufficient brightness with clear light and dark boundaries, optimizing light distribution and reducing power consumption.
Implementation Method 1
a convex projection lens is used and the light emitted by an optical source is refracted by the projection lens so as to go out ahead of the vehicle
Implementation Method 2
a light distribution member that is placed between the LED and the projection lens, that is formed using a transparent material and that has, on its inner surface, a reflection face for reflecting the light emitted by the LED
Data Source
AI summary
In a headlight for in-vehicle use, an LED serving as an optical source is provided in which one edge side of its light-emitting face is formed into a linear portion and placed at a side of an optical axis so that the center of the light-emitting face is displaced from the optical axis. A projection lens is constituted by a radiation-side convex lens and an LED-side convex lens that are arranged in a direction of the optical axis. Between the LED and the projection lens, a light distribution member is placed that is formed using a transparent material and has, on its inner surface, a reflection face for reflecting light emitted by the LED.