White Light Emitting Device With Specific Phosphor Chromaticity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional white light source modules for liquid crystal display backlights face challenges in achieving high color reproducibility and uniformity due to the spacing of red, green, and blue LEDs, which complicates circuit configurations and increases costs, while alternatives using blue LEDs and phosphors suffer from low light intensity and poor color representation.
Innovation Solution
A white light emitting device comprising a blue LED chip with a dominant wavelength of 443 to 455 nm, excited by red and green phosphors with specific color coordinates, dispersed or formed as films within a resin encapsulant, to produce white light with enhanced color reproducibility and uniformity, reducing the need for multiple LEDs and simplifying circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If red, green, and blue LEDs are arranged on a circuit board to produce white light, then color reproducibility is improved, but device complexity and manufacturing cost increase due to spaced arrangement and multiple LEDs required
Solution Approach 1:
The patent combines multiple LED chips (red, green, blue) into a single integrated package structure, merging what would otherwise be separate components requiring complex circuit board arrangements into one unified device that can be directly mounted on the circuit board, thereby simplifying the overall system complexity while maintaining color reproduction capabilities
Solution Approach 2:
The patent segments the white light generation function into distinct wavelength components by using separate LED chips for different color ranges (red, green, blue), with each chip contributing specific wavelength bands to the overall spectrum, allowing optimized color reproduction without requiring all LEDs to be spaced apart on a board
2Illumination intensity
If red, green, and blue LEDs are arranged on a circuit board to produce white light, then color reproducibility is improved, but manufacturing cost increases due to multiple LEDs and packages required
Solution Approach 1:
The patent combines multiple LED chips (red, green, blue) into a single integrated package structure, merging what would otherwise be separate components requiring complex circuit board arrangements into one unified device that can be directly mounted on the circuit board, thereby simplifying the overall system complexity while maintaining color reproduction capabilities
Solution Approach 2:
The integrated LED package serves multiple functions simultaneously: it generates multiple wavelength components (red, green, blue), provides structural consolidation, and enables direct mounting as a single component, replacing what would otherwise require multiple separate components and complex assembly procedures
3Device complexity
If blue LED and yellow phosphor are used to implement white light source module, then circuit configuration is simplified and cost is reduced, but color reproducibility deteriorates due to low light intensity at long wavelength
Solution Approach 1:
The patent applies local quality by using different LED chip types for different wavelength regions within the same package: red LEDs for long wavelengths, green LEDs for intermediate wavelengths, and blue LEDs for short wavelengths, allowing each region to be optimized for its specific function while maintaining overall system simplicity
Solution Approach 2:
The patent uses a composite approach by combining multiple LED chip materials and types (red, green, blue) within a single package structure, creating a multi-component system that leverages the strengths of each material type to achieve broad spectrum coverage and improved color reproduction while maintaining circuit simplicity
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 solution achieves superior color reproducibility and uniformity across a large color coordinate space, reducing manufacturing costs and the complexity of circuit configurations, while maintaining high light efficiency and environmental friendliness.
Implementation Method 1
a blue light emitting diode (LED) chip having a dominant wavelength of 443 to 455 nm
Implementation Method 2
a red phosphor disposed around the blue LED chip, the red phosphor excited by the blue LED chip to emit red light
Implementation Method 3
a green phosphor disposed around the blue LED chip, the green phosphor excited by the blue LED chip to emit green light
Data Source
AI summary
A white light emitting device including: a blue light emitting diode chip having a dominant wavelength of 443 to 455 nm; a red phosphor disposed around the blue light emitting diode chip, the red phosphor excited by the blue light emitting diode chip to emit red light; and a green phosphor disposed around the blue light emitting diode chip, the green phosphor excited by the blue light emitting diode chip to emit green light, wherein the red light emitted from the red phosphor has a color coordinate falling within a space defined by four coordinate points (0.5448, 0.4544), (0.7079, 0.2920), (0.6427, 0.2905) and (0.4794, 0.4633) based on the CIE 1931 chromaticity diagram, and the green light emitted from the green phosphor has a color coordinate falling within a space defined by four coordinate points (0.1270, 0.8037), (0.4117, 0.5861), (0.4197, 0.5316) and (0.2555, 0.5030) based on the CIE 1931 color chromaticity diagram.