LED Light-Extraction Structures for Wider Off-Center Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LED devices face challenges in achieving high light emission efficiency and desired emission patterns due to limitations in light extraction and internal reflection, which hinder the development of high-quality lighting applications.
Innovation Solution
Incorporation of light-extraction films with internal cavities and angled sidewalls to direct light emissions off-center, enhancing the LED devices' ability to emit light at wider angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional LED structures are used, then manufacturing is simple, but light extraction efficiency is limited due to internal reflection
Solution Approach 1:
The light extraction film is segmented into multiple discrete light extraction elements (cones, pyramids, or hemispheres) distributed across the film surface. Each element acts as an independent light directing unit with internal cavities that shape and redirect light emissions, breaking the uniform surface into functional segments that collectively improve light extraction efficiency while managing structural complexity through modular design
Solution Approach 2:
The patent introduces three-dimensional light extraction elements with internal cavities into the traditionally two-dimensional flat light extraction film. The elements feature angled inner sidewalls and varying depths, creating vertical and angular dimensions that enable light to be directed at specific off-center angles, transforming the light extraction from a planar process to a volumetric one that overcomes internal reflection limitations
2Adaptability or versatility
If light extraction elements with internal cavities are added, then emission angle control is improved, but manufacturing complexity increases
Solution Approach 1:
The patent controls emission angles by varying key geometric parameters of the light extraction elements, including the angle of inner sidewalls (which determine light direction), element height, base diameter, and cavity depth. By adjusting these parameters during manufacturing, different emission patterns can be achieved without changing the fundamental element structure, enabling versatile angle control while maintaining manufacturing feasibility through parameter optimization rather than structural redesign
3Illumination intensity
If multiple light extraction elements are used, then light emission pattern is enhanced, but device complexity increases
Solution Approach 1:
Multiple light extraction elements are merged into a single integrated light extraction film, where all elements are formed as one cohesive component rather than separate parts. This merging approach enables complex emission patterns to be achieved through the collective arrangement of multiple elements within a unified structure, enhancing illumination quality while avoiding the complexity of assembling numerous discrete 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 light-directing structures effectively promote light exit at desired emission angles, improving light extraction efficiency and enabling wider angle emissions, thus overcoming conventional limitations.
Implementation Method 1
Light-extraction elements and corresponding internal cavities are shaped to direct light emissions off center to provide LED devices with wider angle emissions
Implementation Method 2
Angled shapes of the inner sidewalls and/or further angled shapes of outer sidewalls of light-extraction elements may effectively promote light to exit the LED chip at desired emission angles
Data Source
AI summary
Solid-state lighting devices including light-emitting diodes (LEDs) and more particularly light-directing structures in LED devices and related methods are disclosed. Exemplary light-directing structures include light-extraction films having one or more light-extraction elements with internal cavities for shaping emissions. Light-extraction elements and corresponding internal cavities are shaped to direct light emissions off center to provide LED devices with wider angle emissions. Internal cavities may be at least partially embedded within light-extraction films. Internal cavities may be bounded by angled inner sidewalls. Angled shapes of inner sidewalls and/or further angled shapes of outer sidewalls of light-extraction elements may effectively promote light to exit the LED chip at desired emission angles. Exemplary LED devices include LED chips and LED packages.