Light Emitting Device Covering Member Refraction
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Solution Overview
Problem
Existing light emitting devices face challenges in achieving efficient light extraction and uniform brightness distribution, particularly when light sources are spaced far apart, leading to brightness unevenness.
Innovation Solution
A method of manufacturing a light emitting device involving a substrate with a light source, an underfill material applied in a circular or rectangular shape around the source, and a covering member with a recess portion above the source, formed to refract light and enhance external extraction without hitting the substrate, achieving a batwing light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If light sources are spaced far apart to reduce crowding, then device area is reduced, but brightness unevenness increases
Solution Approach 1:
The patent applies local quality by creating a convex light-guiding structure with varying curvature at different positions. The curvature radius is specifically designed to be smaller at the center and larger at the edges, creating localized optical properties that redirect light from densely spaced LEDs to uniformly illuminate the entire surface, thereby resolving brightness unevenness while maintaining compact device area.
Solution Approach 2:
The patent transitions from a flat two-dimensional light-emitting surface to a three-dimensional convex light-guiding structure. This dimensional change allows light to be guided through the curved surface, redirecting light paths and achieving uniform illumination distribution across the display surface without increasing device area or LED spacing.
2Ease of manufacture
If a flat light-emitting surface is used, then manufacturing is simple, but light extraction efficiency is low
Solution Approach 1:
The patent replaces the flat light-emitting surface with a convex light-guiding structure having a specific curvature radius. This curvature enables light extracted from the LED to be guided along the curved surface, increasing the path length and improving light extraction efficiency. The curved structure is manufactured by forming a convex pattern on the light-guiding layer, which can be achieved through standard semiconductor fabrication processes.
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 method results in improved light extraction efficiency and reduced brightness unevenness, even when light sources are spaced 20 mm or more apart, by optimizing the shape and material properties of the covering member and underfill material.
Implementation Method 1
a covering member having a recess portion is provided above the light source
Data Source
AI summary
A method of manufacturing a light emitting device includes providing a substrate on which a light source is disposed. An underfill material is ejected from a nozzle onto the substrate substantially around the light source in a circular shape, a shape of a letter ‘C’, or a rectangular shape. A covering member having a recess portion is provided above the light source.