Light Transmissive Member Geometry for Uniform LED Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light emitting devices face challenges in efficiently extracting and directing light output while maintaining structural integrity and reducing luminance variations due to misalignment and light leakage.
Innovation Solution
A light emitting device design featuring a light transmissive member with a larger lower surface area than the light emitting elements, bonded with a reflective member that covers lateral surfaces, ensuring efficient light extraction and reduced luminance variations through precise alignment and minimal light loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the light transmissive member has a larger lower surface area than the light emitting element, then light extraction efficiency is improved, but the device complexity increases due to precise alignment requirements
Solution Approach 1:
The patent introduces a mounting board as an intermediary component between the light emitting element and the light transmissive member. The mounting board provides a standardized mounting surface with positioning features that facilitate precise alignment during assembly, thereby reducing the complexity of direct alignment between the light emitting element and the larger light transmissive member while maintaining high light extraction efficiency
2Loss of energy
If the light reflective member covers lateral surfaces of the light transmissive member, then light leakage is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies that the light reflective member covers the lateral surfaces of the light transmissive member with a controlled gap distance (e.g., 0.1-2mm) between the reflective member and the light transmissive member. This parameter change allows for easier manufacturing while still effectively preventing light leakage through the lateral surfaces, as the reflective member redirects light that would otherwise escape
3Stability of the object's composition
If the upper surface area of the light transmissive member is smaller than the lower surface area, then luminance uniformity is improved, but the device complexity increases
Solution Approach 1:
The patent employs an asymmetric design where the light transmissive member has a larger lower surface area than upper surface area. The lower surface is designed to match the larger area of the light emitting element for optimal light extraction, while the upper surface is smaller to concentrate and uniformize the emitted light. This asymmetric geometry inherently improves luminance uniformity without requiring additional complex structural components
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 enhances light extraction efficiency, maintains consistent luminance, and extends illumination distance with high luminance, suitable for automotive headlights and various lighting applications.
Implementation Method 1
The light transmissive member has an upper surface and a lower surface, and allows light from the one or more light emitting elements to be incident on the lower surface of the light transmissive member and to be output from the upper surface of the light transmissive member
Implementation Method 2
The light reflective member covers surfaces of the light transmissive member and lateral surfaces of the one or more light emitting elements
Data Source
AI summary
A light emitting device includes light emitting element(s). A light transmissive member is on an upper surface of the light emitting element(s). An upper surface area of the light transmissive member is smaller than a lower surface area of the light transmissive member. The upper surface area of the light transmissive member is smaller than a sum of upper surface areas of each light emitting element(s). The lower surface area of the light transmissive member is larger than the sum of the upper surface areas of each light emitting element(s). A light reflective member is provided having a first light reflective member and an underfill. The first light reflective member covers surfaces of the light transmissive member and lateral surfaces of the light emitting element(s) to expose the upper surface of the light transmissive member. The underfill covers the lateral and lower surfaces of each light emitting element(s).