Optical Element with Inclined Anisotropic Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical elements with nonlinearly changing local optical axis directions suffer from varying in-plane diffraction efficiency due to different incidence angles, leading to regions with decreased diffraction efficiency.
Innovation Solution
An optical element comprising multiple optically anisotropic layers with continuous and rotational in-plane alignment patterns, where the orientations of optical axes change by 180°, and at least one layer is inclined with varying inclination angles, ensuring consistent diffraction efficiency across different regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single optically anisotropic layer with nonlinearly changing local optical axis directions is used, then the device structure is simple, but the in-plane diffraction efficiency varies significantly across different regions
Solution Approach 1:
The optical element is divided into multiple optically anisotropic layers (typically two or more layers), each contributing to the overall diffraction function. This segmentation allows the diffraction efficiency to be distributed and averaged across layers, reducing the variation in in-plane diffraction efficiency that would occur in a single layer with nonlinearly changing optical axis directions.
Solution Approach 2:
The patent employs composite structures by combining multiple optically anisotropic layers with different optical axis orientation patterns. Each layer may have different characteristics (e.g., different pitch variations, different orientation rotation directions), and their composite effect produces a more uniform in-plane diffraction efficiency across the entire optical element.
2Adaptability or versatility
If light is incident at different incidence angles depending on the region, then the optical element can handle various light directions, but the in-plane diffraction efficiency decreases in certain regions
Solution Approach 1:
By dividing the optical element into multiple layers, each layer can be optimized to contribute to diffraction efficiency across different incidence angle ranges. The cumulative effect of multiple layers averages out the efficiency variations that would occur in any single layer exposed to varying incidence angles.
Solution Approach 2:
Each optically anisotropic layer can have locally optimized optical axis orientations and pitch variations tailored to compensate for the incidence angle variations in different regions. This local optimization across multiple layers ensures that the overall diffraction efficiency remains relatively uniform even when handling light from different directions.
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 averages in-plane diffraction efficiency, improving overall diffraction performance by minimizing variations in light emission intensity across different incidence angles.
Implementation Method 1
an optical element comprising a plurality of optically anisotropic layers, each of which has an in-plane alignment pattern in which orientations of optical axes derived from a liquid crystal compound change continuously and rotationally
Implementation Method 2
each of which has an in-plane alignment pattern in which orientations of optical axes derived from a liquid crystal compound change continuously and rotationally
Implementation Method 3
at least one of the plurality of optically anisotropic layers is an inclined optically anisotropic layer having a region where a plurality of pairs of bright lines and dark lines derived from the orientations of the optical axes
Data Source
AI summary
Provided are an optical element, including a plurality of optically anisotropic layers, each of which has an in-plane alignment pattern in which orientations of optical axes derived from a liquid crystal compound change continuously and rotationally along at least one in-plane direction, in a thickness direction, in which the optically anisotropic layers each have regions where lengths over which the orientations of the optical axes rotate by 180° in the one direction are different from each other, and at least one of the plurality of optically anisotropic layers is an inclined optically anisotropic layer having a region where a plurality of pairs of bright lines and dark lines in a cross-sectional image are present and the pairs of the bright lines and the dark lines are inclined at inclination angles which are different from each other with respect to a normal line of an interface of the optically anisotropic layer.