Shaped Bonding Member for LED Light Extraction and Color Uniformity
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Solution Overview
Problem
Existing light emitting devices face challenges in optimizing the placement and shape of light-transmissive members to enhance light extraction efficiency and color reproduction in liquid crystal display backlights.
Innovation Solution
A light emitting device design that includes a light-transmissive member, a bonding member, and a light-reflective member, where the bonding member covers the upper surface and lateral surfaces of the light emitting element, and the light-reflective member covers the bonding and light-transmissive members, with the bonding member's surface being flush and inclined to facilitate efficient light extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a light-transmissive member is bonded onto a light emitting element using a conventional bonding method, then the bonding process is simple, but the light extraction efficiency on the lateral side is insufficient
Solution Approach 1:
The bonding member is designed with a circular-arc shape at its lateral surface that contacts the light emitting element. This curved geometry increases the contact area and improves light extraction efficiency by redirecting lateral light emissions more effectively than a flat bonding surface would.
Solution Approach 2:
The bonding member has different geometries at different locations: a circular-arc shape at the lateral surface for improved light extraction, and a flat upper surface for bonding to the light-transmissive member. This local differentiation optimizes both light extraction and bonding functions.
2Device complexity
If the bonding member covers only the upper surface of the light emitting element, then the bonding structure is simple, but the light extraction efficiency and positioning accuracy are insufficient
Solution Approach 1:
The circular-arc shaped lateral surface of the bonding member provides better contact with the light emitting element, improving positioning accuracy and ensuring consistent light extraction across the bonding interface.
Solution Approach 2:
The bonding member extends from a two-dimensional upper surface bonding to a three-dimensional structure that wraps around the lateral surface of the light emitting element, adding vertical dimension control for improved positioning accuracy.
3Illumination intensity
If the bonding member has an irregular shape to improve light extraction, then the light extraction efficiency improves, but the manufacturing precision and alignment become difficult
Solution Approach 1:
The circular-arc shape provides a mathematically defined geometry that is easier to manufacture with precision compared to irregular shapes, while still achieving improved light extraction through increased contact area and optimized light redirection.
Solution Approach 2:
The bonding member combines different geometric features (circular-arc lateral surface and flat upper surface) in a single component, achieving both improved light extraction and manufacturability through composite geometry rather than irregular shaping.
4Device complexity
If the light-transmissive member is positioned without a specialized bonding member shape, then the device structure is simple, but the color reproduction and light uniformity are insufficient
Solution Approach 1:
The circular-arc shaped bonding member improves the coupling between the light emitting element and light-transmissive member, enhancing light extraction efficiency and producing more uniform color distribution across the device output.
Solution Approach 2:
The bonding member's specialized geometry at the lateral surface creates localized optimization of light extraction, which contributes to overall improved color reproduction and light uniformity without requiring complex modifications throughout the entire device structure.
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 allows for improved light extraction efficiency and color reproduction, enabling a more uniform and efficient light emitting device with enhanced contrast and distinguishability between light-emitting and non-light-emitting regions.
Implementation Method 1
a light-transmissive member containing a fluorescent material is bonded onto a light emitting element by a light-transmissive bonding member
Implementation Method 2
The light-reflective member covers the bonding member and a lateral surface of the light-transmissive member
Implementation Method 3
an inclined surface that is inclined so as to extend toward the light-transmissive member
Data Source
AI summary
A light emitting device includes a light emitting element, a light-transmissive member, a bonding member and a light-reflective member. The bonding member is disposed between the light emitting element and the light-transmissive member, with the bonding member covering an upper surface of the light emitting element and at least a part of a lateral surface of the light emitting element. The light-reflective member covers the bonding member and a lateral surface of the light-transmissive member. The bonding member includes a surface that is flush with the lateral surface of the light-transmissive member, and an inclined surface that is inclined so as to extend toward the light-transmissive member.