Optical Laminate With Dichroic Layers for Viewing-Angle Tint Control
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Solution Overview
Problem
Image display devices with viewing angle switching functions experience significant tinting issues that degrade display quality, particularly when used in public settings where privacy is a concern.
Innovation Solution
An optical laminate comprising a first and second light absorption anisotropic layer, each containing a dichroic substance, with specific alignment and alignment degree requirements, is integrated with a liquid crystal cell to suppress tinting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a liquid crystal cell is used as the refractive index anisotropic layer for viewing angle switching, then the viewing angle switching function is achieved, but the tint of the display screen deteriorates
Solution Approach 1:
The patent changes the parameters of the light absorption anisotropic layer by specifying precise requirements: alignment degree of 0.95 or higher, transmittance central axis angle of 0°-40°, and specific wavelength-dependent alignment characteristics. These parameter optimizations allow the layer to maintain consistent optical properties across different viewing angles while minimizing tint, thereby resolving the contradiction between viewing angle switching capability and display tint quality.
Solution Approach 2:
The patent employs composite material structures by combining the optimized light absorption anisotropic layer with the liquid crystal cell in a multi-layer optical laminate. This composite structure integrates the viewing angle switching function of the liquid crystal cell with the tint suppression capabilities of the specially designed light absorption layer, achieving both functions simultaneously without compromise.
2Object-affected harmful factors
If the alignment degree of the light absorption anisotropic layer is increased to suppress tinting, then the tinting is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent establishes specific parameter ranges for the light absorption anisotropic layer, including alignment degree of 0.95 or higher, transmittance central axis angle of 0°-40°, and controlled wavelength-dependent alignment variations. By defining these precise parameters, the patent provides clear manufacturing targets that balance high alignment degree requirements with achievable manufacturing precision, preventing excessive tinting while maintaining realistic production standards.
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 optical laminate effectively reduces tinting in image display devices with viewing angle switching functions, enhancing privacy and display clarity in public use scenarios.
Implementation Method 1
at least one of the first light absorption anisotropic layer or the second light absorption anisotropic layer is a specific light absorption anisotropic layer satisfying all of the following requirements 1 to 3, Requirement 1: Contain a dichroic substance
Implementation Method 2
a liquid crystal cell; and a second light absorption anisotropic layer, in which the refractive index anisotropic layer is a liquid crystal cell (for example, an electrically birefringent switchable TN liquid crystal cell)
Implementation Method 3
an electrically birefringent switchable TN liquid crystal cell
Data Source
AI summary
An optical laminate and an image display device that can suppress tinting of a display screen when being used in an image display device having a viewing angle switching function. The optical laminate includes in the following order, a first light absorption anisotropic layer; a liquid crystal cell; and a second light absorption anisotropic layer, in which at least one of the first or second light absorption anisotropic layers is a specific light absorption anisotropic layer satisfying all of the following requirements 1: contain a dichroic substance, 2: an angle between a transmittance central axis of a light absorption anisotropic layer and a normal direction of a surface of a light absorption anisotropic layer is 0° or more and 40° or less and 3: a difference in alignment degrees of a light absorption anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm is 0.025 or less.