Light Emitting Device With Partial Reflective Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light emitting devices face challenges in maintaining luminous intensity and efficiently directing excitation light, with limitations in wavelength conversion and light extraction efficiency.
Innovation Solution
A light emitting device configuration featuring a package with a recess, a light emitting element, a sealing member with a fluorescent material, and a first film on the sealing member's surface, where the first film reflects a portion of the light while allowing most to pass through, optimizing light extraction and wavelength conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If microparticles are attached to the entire surface of the silicone resin to reduce luminous intensity decrease, then luminous intensity is maintained, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts the light extraction function from the entire surface treatment and concentrates it to a specific region (the first film positioned at the light output surface). This selective placement maintains luminous intensity while simplifying the overall structure by eliminating the need for comprehensive surface treatment.
Solution Approach 2:
Instead of applying microparticles to the entire surface, the patent applies a first film with light reflecting properties to a specific local region (the light output surface). This local quality approach maintains luminous intensity where it is most needed while reducing overall device complexity.
2Productivity
If a first film is provided on part of the light output surface to reflect light, then light extraction efficiency is enhanced, but manufacturing precision requirements increase
Solution Approach 1:
The first film serves multiple functions: it reflects light to enhance extraction efficiency, and its positioning at the light output surface allows it to work effectively with the curved surface geometry. This multi-functionality justifies the precision requirement by delivering compound benefits.
Solution Approach 2:
The patent utilizes the curved (concave) shape of the light output surface and positions the first film to work with this curvature. The curved geometry naturally directs reflected light, reducing the precision burden on the film's exact positioning while maintaining high light extraction efficiency.
3Adaptability or versatility
If fluorescent material is used to convert wavelength, then color adjustment is enabled, but thermal discoloration and soldering heat resistance issues occur
Solution Approach 1:
The first film acts as an intermediary between the light emitting element and the fluorescent material. By reflecting and redirecting light through this intermediate layer, the system optimizes the interaction between excitation light and fluorescent material, enhancing color conversion efficiency while reducing thermal stress on the fluorescent material.
Solution Approach 2:
The first film is positioned to reflect light before it reaches the fluorescent material, pre-optimizing the light path and distribution. This preliminary action ensures efficient excitation of the fluorescent material while minimizing unnecessary thermal generation, thereby improving heat resistance.
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 enhances light extraction efficiency, maintains luminous intensity, and allows for fine adjustment of color while reducing thermal discoloration and soldering heat resistance issues.
Implementation Method 1
The sealing member includes a light-transmissive material containing a fluorescent material to convert a wavelength of the light emitted from the light emitting element
Implementation Method 2
The first film is provided on a part of the light output surface of the sealing member to reflect a part of the light emitted from the light emitting element
Data Source
AI summary
A light emitting device includes a package having a recess including an opening, a bottom surface, and an inner lateral surface extending from the bottom surface. A covering member covers at least one of the bottom surface or the inner lateral surface. A light emitting element is mounted on the bottom surface and has a light emitting surface. A sealing member is provided in the recess to cover the light emitting surface and has a light output surface having a concave shape. The sealing member includes a light-transmissive material containing a fluorescent material. A first film is provided on a part of the light output surface of the sealing member to reflect a part of the light emitted from the light emitting element, another part of the light emitted from the light emitting element being configured to pass through the first film.