LED Sealing Member Curved Surface Light Distribution
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Solution Overview
Problem
Conventional light-emitting diodes used in vehicular lamps experience a rapid decrease in luminance with increasing divergence angle from the optical axis, leading to insufficient light distribution and efficiency issues, particularly when used in lamps with large lenses or oblique directions.
Innovation Solution
A light-emitting diode with a transparent sealing member featuring a curved surface structure, including a concave curve near the optical axis and convex curves on both sides, which diffuses light at small divergence angles and converges light at larger angles, ensuring a more uniform luminance distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional light-emitting diode with a spherical sealing member is used, then the structure is simple and easy to manufacture, but the luminance rapidly decreases with increasing divergence angle from the optical axis
Solution Approach 1:
The sealing member employs a curved surface with specific radii of curvature (R1 for the first curved surface, R2 for the second curved surface) to control light propagation. The curved surfaces refract light at different angles, transforming the luminance distribution from rapidly decreasing to gradually decreasing, thereby improving illumination uniformity while maintaining a manufacturable curved geometry.
2Illumination intensity
If a lens is added to control light distribution, then the luminance distribution can be improved, but the device complexity increases
Solution Approach 1:
The light distribution control function is merged into the sealing member itself by incorporating curved surfaces with specific radii of curvature. This integration eliminates the need for separate lens components, achieving improved luminance distribution while reducing device complexity. The sealing member simultaneously provides both protective sealing and optical control functions.
3Area of moving object
If a large lens is used to secure sufficient light-emitting area, then the light-emitting area is improved, but the lens efficiency decreases due to wide incident angles at the perimeter
Solution Approach 1:
The sealing member employs different radii of curvature for different regions: R1 for the first curved surface and R2 for the second curved surface. This local variation in optical properties ensures that light at different positions (center and perimeter) is refracted at appropriate angles, maintaining efficient light extraction across the entire large light-emitting area while preventing energy loss at the perimeter.
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 enhances light distribution by maintaining luminance across a wider angle range, improving lens efficiency and providing uniform illumination, even in large or narrow lens configurations, thus addressing the limitations of conventional light-emitting diodes.
Implementation Method 1
a curved surface portion, and the cross-sectional shape of the curved surface portion taken along a first plane that includes the optical axis is formed in the shape of an undulating curve that has a concave curve positioned near the optical axis and convex curves positioned on both sides of the concave curve
Data Source
AI summary
A light-emitting diode including a curved surface portion 14aA formed in the front face of a sealing member 14 with the cross-sectional shape of the curved surface portion being in the shape of an undulating curve that has a concave curve C1 near the optical axis and convex curves C2 on both sides of concave curve C1, thus allowing the light emitted from a light-emitting chip 12 at a small divergence angle centered on the optical axis Ax to reach the concave curve C1 and to be directed forward as diffused light deflected from the optical axis and further allowing the light emitted at a large divergence angle centered on the optical axis Ax to reach the convex curves C2 and to be directed forward as light deflected toward line L positioned at the divergence angle θ.