Light Emitting Device Groove Scattering External Light
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large-scale display devices and traffic signals using light emitting devices suffer from indirect glare and reduced contrast due to external light reflection, particularly when the encapsulant outside the recessed portion of the package reflects external light.
Innovation Solution
A light emitting device design featuring a package with a recessed portion, a light-transmissive encapsulant, and a groove on the top surface with surface irregularities, where the encapsulant covers the groove's depressed portions, scattering external light and reducing reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the encapsulant is supplied in the recessed portion and spreads out from the recessed portion, then the light emitting device is protected and light transmission is maintained, but external light is reflected by the encapsulant located outside the recessed portion causing indirect glare and decreased display contrast
Solution Approach 1:
The groove is provided only in specific regions where the encapsulant tends to spread outward, creating localized light scattering zones. The groove surface includes depressed portions and projecting portions that generate light scattering only in the peripheral regions where external light reflection is problematic, while maintaining smooth encapsulant coverage over the light emitting element for optimal light transmission.
Solution Approach 2:
The groove acts as an intermediary structure between the encapsulant and the external environment. It modifies the encapsulant surface in peripheral regions to scatter external light before it can cause harmful reflections, while allowing the encapsulant to maintain its protective and light-transmissive functions over the light emitting element.
2Object-affected harmful factors
If a dark color layer is added to cover the encapsulant overflowing from the recessed portion to reduce external light reflection, then display contrast is improved, but the device structure becomes more complex
Solution Approach 1:
The invention replaces the chemical/optical approach of using a dark color layer with a mechanical surface structure approach. The groove with depressed portions and projecting portions creates light scattering through its physical geometry, eliminating the need for additional dark color layers or coatings while achieving the same contrast improvement effect.
Solution Approach 2:
The invention changes the surface parameters of the groove (creating depressed portions and projecting portions) to alter light interaction. This geometric parameter modification enables light scattering without requiring material composition changes or additional layers, thereby reducing device complexity.
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 design effectively minimizes indirect glare and contrast reduction caused by external light reflection, maintaining display quality while using a simple and efficient structural approach.
Implementation Method 1
A surface of the groove includes depressed portions and projecting portions. The encapsulant covers at least a part of the surface of the groove, and a portion of the encapsulant that covers the surface of the groove includes a surface irregularity.
Data Source
AI summary
Alight emitting device includes a package, alight emitting element, and a light-transmissive encapsulant. The package has a top surface and a recessed portion formed with an opening at the top surface. The light emitting element is located on a bottom surface of the recessed portion. The light-transmissive encapsulant is supplied in the recessed portion. The package is provided with a groove formed in the top surface and surrounding the opening. A surface of the groove includes depressed portions and projecting portions. The encapsulant covers at least a part of the surface of the groove, and a portion of the encapsulant that covers the surface of the groove includes a surface irregularity.