LED with Segmented Reflector for High Luminance
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Solution Overview
Problem
Conventional surface-mount, top-firing light-emitting diodes face challenges in achieving high luminance and narrow directivity, making them unsuitable for flashlights and portable terminals where bright, focused illumination is required.
Innovation Solution
The design includes a substrate with a light-emitting diode device, a metal line for electrical connection, a translucent sealing resin portion that forms an independent convex projection, and a reflector with an inclined surface surrounding the resin portion, reducing light loss and increasing luminance while allowing for narrow directivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a scattering effect material is used for the opaque reflection case, then the angle of beam spread is wide, but the luminance is low
Solution Approach 1:
The reflector is divided into two distinct regions: a specular reflection region (first region) and a diffuse reflection region (second region). This segmentation allows each region to perform its specific function - the specular region concentrates light for high luminance, while the diffuse region spreads light for wide beam angle, resolving the contradiction between these two opposing requirements.
Solution Approach 2:
Different regions of the reflector are assigned different optical properties. The first region (central area) has specular reflection properties to concentrate light and increase luminance, while the second region (outer area) has diffuse reflection properties to spread light and widen the beam angle. This local differentiation of quality allows simultaneous achievement of high luminance and wide beam spread.
2Reliability
If the sealing resin portion completely fills the recessed portion, then the light-emitting diode device is sealed, but the amount of resin is large and cost increases
Solution Approach 1:
The sealing resin portion is extracted from completely filling the recessed portion and is instead configured to cover only the essential components (light-emitting diode device and metal line) that require sealing. This reduces the resin amount and cost while maintaining sealing effectiveness for the critical elements.
Solution Approach 2:
Instead of completely filling the recessed portion with resin (excessive action), the sealing resin is applied only to the necessary extent of covering the light-emitting diode device and metal line (partial action). This partial sealing approach achieves the required reliability without the excess material consumption and cost associated with complete filling.
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 enhances light output, achieving higher luminance and narrower directivity, suitable for flashlights and portable terminals, while also reducing the amount of resin needed and lowering production costs.
Implementation Method 1
a light-emitting diode device 16 arranged on main surface 15u
Implementation Method 2
a reflector 19 arranged on main surface 15u so as to surround an outer perimeter of sealing resin portion 18 with an inclined surface 19f
Data Source
AI summary
A light-emitting diode includes a substrate having a main surface, a light-emitting diode device arranged on the main surface, a translucent sealing resin portion sealing the light-emitting diode device so that the light-emitting diode device is implemented as an independent convex portion projecting from the main surface, and a reflector arranged on the main surface so as to surround an outer perimeter of the sealing resin portion with an inclined surface at a distance from the outer perimeter.