Glass Light Guide Plate with Microstructured Polymeric Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional liquid crystal display (LCD) light guide plates face limitations in brightness, contrast ratio, and viewing angle, particularly due to the use of plastic materials which introduce color shift and reliability issues when attempting to incorporate microstructures for enhanced local dimming efficiency.
Innovation Solution
The use of glass light guide plates with a polymeric film comprising microstructures, such as lenticular lenses, disposed on the light emitting surface, which are designed to minimize color shift and reliability issues by controlling the aspect ratio, spacing, and refractive index difference between the glass substrate and the polymeric film, allowing for efficient light confinement and local dimming capabilities similar to back-lit configurations while maintaining a thickness comparable to edge-lit systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plastic LGPs with microstructures are used to enhance local dimming efficiency, then light confinement and dynamic contrast are improved, but color shift and reliability issues occur
Solution Approach 1:
The patent changes the material parameter from plastic to glass for the LGP substrate, eliminating color shift while maintaining microstructure functionality. The glass substrate has superior optical stability and does not suffer from the color shift problems inherent in plastic materials, thus resolving the reliability issue while preserving local dimming efficiency through the microstructures.
Solution Approach 2:
The patent uses a composite structure combining glass substrate with polymeric microstructures. The glass provides optical stability and eliminates color shift, while the polymeric microstructures maintain light confinement capability. This composite approach resolves the contradiction by assigning different functions to different materials.
2Reliability
If glass LGPs are used to overcome plastic material limitations, then low light attenuation and high mechanical strength are achieved, but microstructure fabrication becomes difficult
Solution Approach 1:
The patent uses a polymeric release layer as an intermediary between the glass substrate and the microstructures. This release layer facilitates the fabrication process by allowing easy separation of the microstructured surface from the mold, thus making microstructure fabrication on glass feasible without compromising the glass material properties.
Solution Approach 2:
The patent changes the processing temperature parameter to accommodate glass fabrication. By controlling the processing temperature to be below the glass transition temperature, the glass substrate can be processed with microstructures without deforming, thus enabling fabrication while maintaining material integrity.
3Productivity
If direct-lit BLU is used to achieve improved dynamic contrast, then local brightness adjustment is enhanced, but display thickness increases
Solution Approach 1:
The patent transitions from a planar light source arrangement to an edge-lit configuration where light sources are positioned at the edges of the display. This dimensional change allows light to travel through the glass substrate and emerge at the opposite edge, enabling local dimming control while maintaining a thin overall display structure.
Solution Approach 2:
The patent changes the light source positioning parameter from behind the panel (direct-lit) to edge-positioned (edge-lit). This parameter change enables the light to propagate through the glass substrate with controlled path length, achieving local brightness adjustment without increasing the display thickness.
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 improved local dimming efficiency, reduced color shift, and enhanced reliability by using glass substrates with microstructured polymeric films, enabling glass light guide plates to match the performance of back-lit systems while maintaining the thickness of edge-lit configurations, thus addressing the limitations of plastic materials.
Implementation Method 1
glass light guide plates may offer various improvements over plastic LGPs, e.g., in terms of their low light attenuation
Implementation Method 2
providing one or more microstructures on the LGP surface that may confine the light from each LED within a narrow band
Implementation Method 3
controlling the aspect ratio, spacing, and refractive index difference between the glass substrate and the polymeric film
Data Source
AI summary
Disclosed herein are light guide plates comprising a glass substrate having an edge surface and a light emitting surface and a polymeric film comprising a plurality of microstructures disposed on the light emitting surface. At least one light source may be coupled to the edge surface of the glass substrate. The light guides disclosed herein may exhibit reduced light attenuation and/or color shift. Display and lighting devices comprising such light guide plates are further disclosed.