Light Diffusion Member with Pyramid Structure for Wide Viewing Angle
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Solution Overview
Problem
Current light diffusion sheets and optical compensation films used in liquid crystal display devices have a narrow viewing angle range for high contrast displays, limiting the angular range for effective viewing.
Innovation Solution
A light diffusion member comprising a light diffusion film, a polarizing film, and a retardation film, where the light diffusion film has a light shielding layer and a light diffusion portion with a specific geometry, and the polarizing film and retardation film are aligned to enhance light distribution and contrast, allowing for a wider viewing angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light diffusion sheet with V-shaped groove and light absorptive layer is used, then light diffusion is achieved, but the viewing angle range for high contrast display remains narrow
Solution Approach 1:
The patent combines multiple functional layers (light diffusion film with pyramid structure, polarizing film, and retardation film) into a single integrated light diffusion member. This merging of functions allows the component to simultaneously achieve light diffusion, polarization control, and viewing angle expansion, resolving the contradiction between light diffusion performance and viewing angle range
Solution Approach 2:
The patent introduces a pyramid-shaped three-dimensional structure on the light diffusion film surface, adding geometric dimensionality to control light propagation. The pyramid structure with specific inclination angles (45-60 degrees) creates multiple light reflection paths, expanding the viewing angle in the horizontal direction while maintaining contrast performance
2Reliability
If an optical compensation film with discotic liquid crystal compound is used, then contrast is improved, but the viewing angle range for high contrast display remains narrow
Solution Approach 1:
The patent changes the optical parameters of the system by introducing a retardation film with specific birefringence properties (Δn×d = 100-200 nm) and a polarizing film with specific transmission axis orientation. These parameter changes enable the system to maintain high contrast across a wider viewing angle range by compensating for liquid crystal orientation effects at different viewing angles
Solution Approach 2:
The patent creates a composite light diffusion member combining materials with different optical properties: the light diffusion film (with pyramid structure), the polarizing film (with dichroic dye or PVA), and the retardation film (with discotic liquid crystal compound). This composite structure achieves both improved contrast and expanded viewing angle through synergistic interaction of the different material properties
3Reliability
If multiple separate components (light diffusion sheet and optical compensation film) are used, then light diffusion and contrast are achieved, but the overall structure becomes complex and the viewing angle improvement is limited
Solution Approach 1:
The patent merges the light diffusion sheet and optical compensation film into a single integrated light diffusion member with stacked layers. This consolidation reduces the number of separate components and simplifies the overall device structure while maintaining or improving display quality through the synergistic interaction of the combined functional layers
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 enables a liquid crystal display device with a wider angular range for high contrast viewing, improving light distribution and reducing light leakage, thereby enhancing display quality.
Implementation Method 1
A portion of light which has been vertically incident to the light diffusion layer is totally reflected by a wall surface of the groove
Implementation Method 2
a retardation layer which is formed from a birefringence body which has optically-negative uniaxiality and is provided on the first surface of the third substrate, and in which an alignment direction of the birefringence body is different in a thickness direction
Implementation Method 3
a polarization layer which has a transmission axis and an absorption axis which are provided on a first surface of the second substrate
Data Source
AI summary
According to an aspect of the present invention, there is provided a light diffusion member which includes a light diffusion film, a polarizing film, and a retardation film. The light diffusion film includes a first substrate, a light diffusion portion, and a light shielding layer. The polarizing film includes a second substrate and a polarization layer. The retardation film includes a third substrate and a retardation layer. The retardation layer is formed from a birefringence body which has optically-negative uniaxiality. An alignment direction of the birefringence body is different in a thickness direction thereof. A slow axis of the retardation layer is positioned at azimuth between a transmission axis and an absorption axis of the polarization layer.