Automotive Solid-State Headlamp Reflector Optics
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Solution Overview
Problem
Current solid-state headlamps for vehicles face challenges in meeting the standardized specifications for low beam and high beam performance as per ECE Addendum 36: Regulation No. 37, particularly due to issues with light distribution and thermal management, which are not adequately addressed by existing LED retrofit lamps.
Innovation Solution
A solid-state headlamp design featuring a reflector optics system with a first and second reflector optic portion, where the first reflective surfaces are annularly arranged around the longitudinal axis to direct light onto the second reflector optic portion, allowing for homogeneous light distribution and improved heat dissipation, enabling compliance with ECE standards for luminous flux and external dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If solid-state light sources are arranged on a support member at the rear base portion, then thermal management is improved, but light distribution uniformity deteriorates due to Lambertian radiation pattern
Solution Approach 1:
The reflector optics is divided into multiple reflective surfaces (first reflective surface, second reflective surface, third reflective surface) with different orientations. Each surface segment reflects light from the LED array in a specific direction to achieve uniform illumination on the road, compensating for the Lambertian radiation pattern of the LED sources.
Solution Approach 2:
Different regions of the reflector optics are designed with different reflective properties and orientations. The first reflective surface has a specific inclination angle for directing light upward, the second reflective surface directs light forward, and the third reflective surface directs light downward, creating locally optimized light distribution across the entire system.
2Illumination intensity
If multiple light sources are positioned closely to achieve required luminous flux, then light output is improved, but thermal management deteriorates
Solution Approach 1:
Instead of positioning multiple LED sources closely in three-dimensional space (which would cause thermal issues), the invention uses a single planar array of LED light sources mounted on a support member. The reflector optics then distributes light from this two-dimensional array across the road space, achieving required luminous flux without thermal management problems.
3Manufacturing precision
If conventional halogen headlamp reflector design is used, then standardized specifications are met, but adaptability to solid-state light sources deteriorates
Solution Approach 1:
The reflector optics parameters (inclination angles, surface orientations, geometric configuration) are specifically optimized for solid-state LED light sources with Lambertian radiation patterns. This differs from conventional halogen headlamp reflector designs, enabling the system to meet ECE standards while being adapted to solid-state technology.
4Illumination intensity
If support member geometry is optimized for light distribution, then illumination uniformity is improved, but device complexity increases
Solution Approach 1:
The support member and the first reflective surface are merged into a single integrated component. This eliminates the need for separate support structures and simplifies the overall device geometry while maintaining the ability to distribute light uniformly across the road surface.
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 design achieves a luminous flux of at least 1500 lumens with test voltage variations, meeting ECE standards for H7 and H11 type headlamps, while maintaining compact dimensions and efficient heat management, thus suitable for use in high beam, low beam, and daytime running lights.
Implementation Method 1
The first reflector optic portion is configured to receive light emitted from the solid-state light sources and emit the light toward the second reflector optic portion
Implementation Method 2
The second reflector optic portion is configured to receive the light reflected from the first reflector optic portion and emit the light through the light-transmissive housing
Implementation Method 3
A plurality of solid-state light sources arranged on the support member at the rear base section are operated by a drive circuitry
Data Source
AI summary
In an embodiment an automotive solid-state headlamp includes a lamp body extending in a longitudinal direction, the lamp body having a rear base portion and a front portion and including a support member disposed in a light-transmissive housing, a plurality of solid-state light sources arranged on the support member at the rear base portion of the lamp body, and a drive circuitry electrically coupled to the light sources and arranged at the rear base portion of the lamp body and configured to operate the plurality of light sources when energized, wherein the plurality of light sources, when energized, are configured to cause the solid-state lamp to emit, through the light-transmissive housing (a) a luminous flux of at least 1500 lumens +/−10% when energized with a 13.2 Volt test voltage, or of at least 1750 lumens +/−10% when energized with a 28 Volt test voltage, or (b) a luminous flux of at least 1350 lumens +/−10% when energized with a 13.2 Volt test voltage, or of at least 1600 lumens +/−10% when energized with a 28 Volt test voltage.