Stacked Light Guide Plates for High Contrast Edge Backlight
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Solution Overview
Problem
Current display technologies, such as liquid crystal display modules, face challenges in achieving high contrast and color saturation while maintaining a thin and lightweight design, especially in miniaturized devices like laptops, due to the limitations of direct backlight modules and the expense and heat sensitivity of quantum dot films.
Innovation Solution
An edge backlight module utilizing a light guide plate stack structure with region-based light emission control, where light guide plates are divided into longitudinal and lateral regions, and light emitting devices are strategically placed to achieve high dynamic range and saturation, with white and high saturation light emitters controlled based on frame content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a direct backlight module is used to achieve high contrast, then the contrast between different regions is improved, but the overall thickness and weight of the display apparatus increase
Solution Approach 1:
The backlight module is segmented into multiple independent light guide plates (LGPs) stacked in layers, with each LGP divided into multiple longitudinal regions. This segmentation allows different regions to emit light independently, achieving high contrast without requiring a bulky direct backlight structure.
Solution Approach 2:
The patent transitions from a planar backlight structure to a three-dimensional stacked configuration of multiple LGPs. By stacking LGPs in the vertical dimension and controlling light emission from different layers, the system achieves high contrast while maintaining a thin overall profile.
2Illumination intensity
If quantum dot film is used to render high saturation, then the color saturation is improved, but the cost increases and non-active regions form in high temperature and humidity environments
Solution Approach 1:
The patent replaces expensive quantum dot film with a more stable alternative implementation using light guide plates with specific optical structures. This approach achieves high color saturation without the reliability issues and high cost associated with quantum dot materials.
3Illumination intensity
If blue light LED is used to excite quantum dot, then high saturation effect is achieved, but blue light leaking regions form in active regions
Solution Approach 1:
The patent extracts and eliminates the quantum dot layer that causes blue light leakage. By using an alternative light guide plate structure with embedded light emitting devices, the system achieves high saturation without the harmful blue light leakage effect.
4Object-generated harmful factors
If LCM board size is increased to avoid blue light leaking region, then blue light leakage is prevented, but narrow board design becomes unachievable
Solution Approach 1:
The patent replaces the quantum dot-based solution with an alternative light guide plate structure that inherently prevents blue light leakage without requiring increased board size, enabling narrow board designs.
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 solution enables the display apparatus to achieve high dynamic contrast and color saturation, facilitating improved visual experience while maintaining a slim and lightweight design, and preventing light leakage in varying environmental conditions.
Implementation Method 1
the light is reflected at the reflecting regions of the corresponding LGPs and emitted from the emitting regions of the corresponding LGPs
Data Source
AI summary
An edge backlight module, a display apparatus and a backlight controlling method thereof are provided. Each light guide plate (LGP) is divided into longitudinal region(s) in the same direction. The LGPs are arranged in a stacked manner. Each two adjacent LGPs are arranged as upper LGP being completely overlapped with the longitudinal region(s) of lower LGP. The longitudinal region overlapped with adjacent upper LGP is defined as a reflecting region. The longitudinal region not overlapped with adjacent upper LGP is defined as an emitting region. Each LGP has one emitting region. Each reflecting film is sandwiched between two adjacent LGPs. Light from a light emitting device is emitted from the emitting region. Combing with lighting control at lateral region(s) separately, an array region is formed. The light emitting device further includes a high saturation light emitter to render an effect with a high dynamic range and high saturation.