Fail-Safe Electro-Active Lenses Using Cholesteric Liquid Crystals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electro-active lenses face challenges in achieving fail-safe operation, insensitivity to polarization, minimizing electrical power consumption, reducing the number of electrical connections, and maintaining high visual acuity, particularly due to the polarization sensitivity of liquid crystalline materials and the need for multiple layers or high operating voltages.
Innovation Solution
The development of an electro-active lens using a cholesteric liquid crystal material with a nematic liquid crystal host, which is polarization insensitive and operates at low voltages, integrated with a substrate having a diffractive relief structure, allowing for a crossover wavelength in the blue light spectrum and requiring only two electrical connections, ensuring fail-safe operation and high diffraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional liquid crystalline materials are used in electro-active lenses, then the lens can change optical power, but the lens becomes sensitive to polarization which reduces visual acuity
Solution Approach 1:
The patent uses a homogeneous nematic liquid crystal host material that is isotropic in its optical properties, making the refractive index independent of polarization direction. This eliminates the polarization sensitivity problem while maintaining the ability to adjust optical power through voltage-controlled refractive index changes.
Solution Approach 2:
The patent changes the fundamental optical parameter of the liquid crystal material from birefringent (conventional) to isotropic (nematic host), allowing the refractive index to be modified by voltage without creating polarization-dependent optical paths that would degrade visual acuity.
2Reliability
If multiple layers or high voltages are used to achieve fail-safe operation, then reliability improves, but device complexity and power consumption increase
Solution Approach 1:
The patent extracts the fail-safe functionality from a multi-layer complex structure and achieves it through a single-layer nematic liquid crystal design. The inherent properties of the nematic material provide fail-safe operation without requiring additional layers or complex architectural arrangements.
Solution Approach 2:
The patent changes the operating voltage parameter to low voltage ranges, enabling fail-safe operation through simple voltage control rather than complex multi-layer structures. The nematic liquid crystal's response to low voltages provides reliable optical power adjustment with inherent fail-safe characteristics.
3Adaptability or versatility
If conventional liquid crystal materials are used, then optical power can be adjusted, but electrical power consumption increases due to high operating voltages
Solution Approach 1:
The patent changes the electrical operating parameter from high voltage to low voltage, significantly reducing power consumption. The nematic liquid crystal material's electrical-optical response characteristics enable effective optical power adjustment at low voltage levels, eliminating the high power requirements of conventional materials.
4Adaptability or versatility
If conventional electro-active lens designs are used, then optical functionality is achieved, but the number of electrical connections increases
Solution Approach 1:
The patent merges the electrical connection requirements into a minimal configuration, using a single continuous electrode structure that provides both ground and voltage application functions. This consolidation reduces the number of separate electrical connections while maintaining full optical functionality through the nematic liquid crystal's response to the applied electric field.
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 provides a fail-safe electro-active lens that focuses all incident light, operates at low power consumption, and maintains high visual acuity by using a cholesteric liquid crystal material with a nematic host, addressing the limitations of polarization sensitivity and power requirements in existing technologies.
Implementation Method 1
When electrical energy is applied to the electro-active material by means of the electrodes, the electro-active material's index of refraction can be altered thereby changing an optical property of the electro-active element
Implementation Method 2
The substrate has a diffractive relief structure and, an electro-active material in optical communication with the substrate
Data Source
AI summary
A fail-safe electro-active lens is presented in which the lens includes a substrate having a diffractive relief surface and an electro-active material in optical communication with the substrate. The electro-active material can include a nematic liquid crystal host. The refractive index of the substrate is equal to the average refractive index of the liquid crystal at a wavelength in the blue light spectrum.