Backlight Module Using Mixed Chromaticity LED Spectra
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Solution Overview
Problem
The existing backlight modules for LCD devices face challenges in achieving even chromaticity and luminance due to limitations in phosphor coating processes, leading to increased production costs and reduced usability of white LEDs with spectra outside desired regions.
Innovation Solution
A backlight module design incorporating an optical film set and multiple light source sets, where each set includes a first and second light source with distinct chromaticity spectra that mix to form a harmonious light, expanding the usable chromaticity range and improving color uniformity, using LEDs or other light sources with varying phosphor densities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If white LEDs with the same chromaticity (spectrum in region 50) are chosen to fulfill even chromaticity requirement, then color uniformity is improved, but production cost increases due to dropping LEDs with spectrum outside region 50
Solution Approach 1:
The patent changes the chromaticity parameter acceptance range by mixing LEDs with different chromaticities (region 50 and region 51) to achieve uniform chromaticity output, thereby utilizing a broader range of LEDs and reducing production costs while maintaining color uniformity
Solution Approach 2:
The patent creates a composite light source system by combining LEDs with different chromaticity characteristics (region 50 and region 51) to produce a harmonious mixed light with uniform chromaticity, similar to how composite materials combine different properties to achieve desired performance
2Productivity
If white LEDs with spectrum outside region 50 are used, then production cost is reduced, but chromaticity uniformity deteriorates due to uneven colors and luminance
Solution Approach 1:
The patent modifies the chromaticity distribution parameters by intentionally mixing LEDs from region 50 and region 51, transforming the chromaticity characteristics to achieve uniform output while expanding the usable LED range and reducing costs
3Ease of manufacture
If phosphor coating process is used to create white LEDs, then light emission is achieved, but chromaticity control ability is limited resulting in uneven colors
Solution Approach 1:
The patent applies different chromaticity characteristics to different LED groups (region 50 and region 51), allowing each group to contribute its specific spectral properties to the overall mixed light, thereby achieving better chromaticity control through spatial distribution of quality
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 approach reduces production costs and enhances the range of usable chromaticity, achieving more even light distribution and improved color uniformity by mixing light sources with different spectral distributions, thereby optimizing the backlight module's performance.
Implementation Method 1
The first chromaticity light and the second chromaticity light mix in the space between the light source sets and the optical film group to form a harmonious light
Data Source
AI summary
A backlight module includes an optical film set and a plurality of light source sets having a first light source and a second light source. The first light source generates a first chromaticity light while the second light source generates a second chromaticity light. The first chromaticity light mixes with the second chromaticity light in the space between the light source sets and the optical film set and then enters the optical film set. The first chromaticity light and the second chromaticity light have their own spectrum and both spectra fall into a first color region of the CIE 1931 color space. Within the first color region, the spectrum of the first chromaticity light is close to a second color region while the spectrum of the second chromaticity light is close to a third color region.