Light-emitting apparatus with UV-reflecting filter
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Solution Overview
Problem
Conventional light-emitting apparatuses using quantum dots suffer from low extraction efficiency of desired white light, leading to increased power consumption and reduced light emission brightness, as well as unwanted emission of lights other than white, such as ultraviolet and blue light.
Innovation Solution
A light-emitting apparatus configuration that includes a light source emitting ultraviolet or near-ultraviolet light, a conversion member converting this light to white light, and a first filter member that reflects the ultraviolet light and transmits the white light, ensuring only desired light is emitted by arranging these components in a specific order from the light source to the light-emitting surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a quantum dot sheet is used to convert LED light to white light, then color purity and color gamut are improved, but extraction efficiency of white light becomes low and power consumption increases
Solution Approach 1:
The invention divides the light conversion function into multiple quantum dot layers, each layer containing quantum dots of specific sizes that convert specific wavelengths. This segmentation allows for more efficient wavelength conversion and reduces energy loss, thereby improving white light extraction efficiency while maintaining color purity.
Solution Approach 2:
The invention optimizes the size distribution and composition of quantum dots to change the conversion parameters. By adjusting quantum dot size, shape, and material composition, the conversion efficiency from blue LED light to white light is improved, reducing power consumption while maintaining high color purity and gamut.
2Illumination intensity
If a quantum dot sheet is used to convert LED light to white light, then color gamut is enlarged, but unwanted light (ultraviolet, blue light) is emitted and extraction efficiency of white light becomes low
Solution Approach 1:
The invention segments the quantum dot conversion process into multiple layers with different quantum dot size distributions. Each layer targets specific wavelength conversion, ensuring complete absorption of blue LED light and conversion to the full spectrum of white light. This eliminates unwanted blue light transmission while maintaining enlarged color gamut.
Solution Approach 2:
The invention introduces intermediate quantum dot layers that act as mediators in the light conversion process. These intermediate layers with specific size distributions serve as transition stages, efficiently converting blue light to intermediate wavelengths that are then converted to the complete white light spectrum, preventing direct transmission of unwanted blue light.
3Productivity
If multiple quantum dot layers are added to improve white light extraction efficiency, then device complexity increases
Solution Approach 1:
The invention merges multiple quantum dot layers into a single integrated light conversion element. By combining the light conversion function of multiple quantum dot layers with the diffusion function of optical sheets into one integrated component, the device achieves high white light extraction efficiency while minimizing structural complexity and ease of installation.
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 effectively prevents the emission of unwanted light, enhances the extraction efficiency of white light, reduces power consumption, and increases display brightness by converting and filtering out ultraviolet light, thereby improving the overall performance of the light-emitting apparatus.
Implementation Method 1
a quantum dot sheet that converts the light from the LED to white light. The quantum dot sheet is a sheet (film)-like member that has the quantum dot as a phosphor (fluorescent material). Light that causes excitation of the phosphor is referred to as 'excitation light'
Implementation Method 2
a first filter member configured to reflect the first light and transmit the second light
Data Source
AI summary
A light-emitting apparatus according to the present invention is a light-emitting apparatus configured to emit light from a light-emitting surface, and includes: a light source configured to emit first light that is ultraviolet light or near-ultraviolet light; a conversion member configured to convert the first light to second light that is white light; and a first filter member configured to reflect the first light and transmit the second light, wherein the light source, the conversion member, and the first filter member are provided in an order of the light source, the conversion member, and the first filter member in a direction from the light source toward the light-emitting surface.