Quantum Dot Backlight Module for Luminance and Chroma Control
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Solution Overview
Problem
The existing liquid crystal display technologies face issues with lower luminance, color saturation deviation, and chroma offset due to the use of phosphor in backlight modules, which are prone to heat-related problems and inefficiencies.
Innovation Solution
A backlight module is designed with a fluorescent layer comprising quantum dots (CdSe, ZnSe, and CdS) on a diffuser plate, where the light-emitting chip is separate from the fluorescent layer to excite the quantum dots, utilizing an aluminum substrate for heat dissipation and enhancing luminance and color saturation, while avoiding chroma offset.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If phosphor is used in the fluorescent layer, then the backlight module can be manufactured with existing technology, but luminance is reduced and color saturation deviates
Solution Approach 1:
The patent changes the material parameter of the fluorescent layer from conventional phosphor to quantum dot materials (CdSe, ZnSe, CdS), which fundamentally alters the light emission characteristics to achieve higher luminance and color saturation while maintaining manufacturability through established quantum dot synthesis and coating techniques
Solution Approach 2:
The patent uses composite quantum dot materials comprising multiple types (CdSe, ZnSe, CdS) in specific ratios to optimize both luminance and color saturation properties, creating a composite fluorescent layer that overcomes the limitations of single-material phosphor systems
2Device complexity
If phosphor is used in the fluorescent layer, then the structure can be simplified, but chroma offset occurs
Solution Approach 1:
The patent changes the material composition parameter from phosphor to quantum dots with precise size and composition control, enabling accurate chroma reproduction without the chroma offset problems inherent in phosphor-based systems, while maintaining a similarly simple layered structure
3Device complexity
If light-emitting chip is integrated with phosphor, then device complexity is reduced, but heat dissipation becomes ineffective causing lower luminance
Solution Approach 1:
The patent segments the light-emitting chip and fluorescent layer into separate components, allowing independent optimization of heat dissipation for the chip and light emission for the quantum dot layer, thereby maintaining high luminance while managing thermal effects that would otherwise degrade phosphor performance
Solution Approach 2:
The patent introduces a reflective layer as an intermediary between the light-emitting chip and the fluorescent layer, which helps manage heat distribution and improves light extraction efficiency, thereby maintaining high luminance output while separating the thermal management function from the light emission function
4Device complexity
If light-emitting chip is integrated with phosphor, then assembly is simplified, but heat affects phosphor causing color saturation deviation
Solution Approach 1:
The patent segments the heat-generating light-emitting chip and the temperature-sensitive fluorescent layer into separate components with thermal management structures, preventing heat transfer that would cause color saturation deviation in phosphor while maintaining relatively simple assembly through standardized mounting interfaces
Solution Approach 2:
The patent introduces thermal management structures as intermediaries between the light-emitting chip and fluorescent layer, including reflective layers and heat dissipation pathways, that allow the components to remain separated for thermal protection while enabling controlled interaction for optimal optical performance and color accuracy
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 increases luminance and color saturation, reduces chroma offset, and saves energy by separating the light-emitting chip from the quantum dot material, ensuring uniform light emission and a thinner module.
Implementation Method 1
the light-emitting chip comprising UV LED chip and/or blue LED chip
Implementation Method 2
the light-emitting chip being disposed between the substrate and the fluorescent layer for irradiating on the fluorescent layer to excite the quantum dots to emit light
Implementation Method 3
the substrate being a aluminum substrate for dissipating heat of the light-emitting chip
Data Source
AI summary
The present invention provides a backlight module and liquid crystal display device. The backlight module includes diffuser plate, substrate, fluorescent layer and light-emitting chip. The fluorescent layer is disposed on a light-entering surface of diffuser plate, and the fluorescent layer includes quantum dot (QD). The light-emitting chip is disposed on the substrate and the light-emitting chip is between substrate and fluorescent layer for irradiating on the fluorescent layer to excite the quantum dots to emit light to form white backlight source. The present invention uses quantum dots to effectively increase luminance, color saturation and avoid chroma offset. The quantum dots can emit uniform light and reduce thickness of the backlight module.