Directional LED Arrangement with Vertical Beam-Shaping Optics
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Solution Overview
Problem
Existing light-emitting diode (LED) arrangements for directional lighting, such as automotive front lighting, require significant optical elements that increase the package footprint, making it difficult to achieve high-contrast, directional light emission while maintaining compact dimensions.
Innovation Solution
A light-emitting arrangement featuring a solid state light source with a reflecting structure and a microstructured beam-shaping arrangement, including a reflecting thin-film coating and an opaque optical body with a tapered funnel structure, which pre-collimates light and captures aberrantly directed rays, ensuring high directionality and contrast without expanding the package footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If traditional collimators and secondary optics are used to achieve directional light emission with sharp cut-offs, then high-contrast directional beam is realised, but the optical elements significantly exceed the LED die dimensions and extend the overall package footprint
Solution Approach 1:
The beam shaping arrangement is integrated within the lateral boundaries of the LED die, with optical elements nested in the vertical dimension rather than extending laterally. The collimator and secondary optic are positioned above the LED die surface, creating a compact vertical stack that achieves directional beam control without increasing package footprint.
Solution Approach 2:
The patent transitions from lateral extension of optical elements to vertical stacking. By moving the collimator and secondary optic into the vertical dimension above the LED die, the system achieves the same beam control function without increasing the horizontal footprint, effectively trading lateral space for vertical space.
2Manufacturing precision
If larger optical elements are used to achieve desired collimation angle and cut-off, then sharp angular cut-off is realised, but the lateral dimensions of optical elements significantly exceed those of the LED die
Solution Approach 1:
The patent applies different optical properties to different regions of the optical elements. The collimator features a specific refractive index profile and the secondary optic has tailored surface curvature in different zones, allowing precise angular cut-off control without requiring uniformly large dimensions across the entire optical element.
Solution Approach 2:
The patent optimizes key parameters including the refractive index of the collimator material, the focal length ratio between collimator and secondary optic, and the surface curvature profiles. By carefully adjusting these parameters, the system achieves sharp angular cut-off with compact optical element dimensions that match the LED die scale.
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 configuration achieves highly directional and high-contrast light emission with sharp angular cut-offs at reduced dimensions, enabling increased LED module density and flexibility in applications like automotive lighting.
Implementation Method 1
a reflecting structure which covers said side surface or surfaces
Implementation Method 2
a beam-shaping arrangement applied over the reflecting structure and positioned optically downstream from the light source
Implementation Method 3
an opaque optical body positioned over the reflecting structure, for limiting the angular spread of the directional beam of light, said body having a first opening at its base for receiving light from the solid state light source, and a tapered funnel structure surrounding the axis normal to the light emitting top surface of the light source
Data Source
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Figure 5~6
AI summary
A light emitting arrangement is suggested for generating directional projections of light with sharply defined beam profile. Light from a top-emitting solid state light source (12), having reflective side-coating (34), is pre-collimated via a beam-shaping optic (16), before being propagated through a secondary collimating funnel (18), capturing any light rays with still too great an escape angle. Chip-scale package dimensions may be achieved through the use of a thin-film side-coating and undersized phosphor layers. Substrate level process flow further allows for parallel processing of a plurality of devices.