Rapid Switching Optical Shutter Using Liquid Crystal Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical shutters fail to rapidly and efficiently switch between transmitting visible and near-infrared radiation, limiting their application in devices that require alternating between these spectral regions for image capture and depth sensing.
Innovation Solution
An optical shutter comprising a wavelength selective polarizing filter and a liquid crystal polarization modulator that switches between polarization states to alternately transmit and block visible and near-infrared radiation, utilizing a broadband polarizer and specific polarizing filters to achieve high contrast and energy throughput in both wavelength regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional optical shutters are used to switch between visible and near-infrared transmission, then the switching speed is limited, but the structural complexity increases when attempting to improve switching speed
Solution Approach 1:
The patent combines a wavelength-selective polarizing filter with a liquid crystal polarization modulator into a single integrated optical shutter unit. The polarizing filter and liquid crystal modulator work together in close optical association to achieve rapid switching between visible and near-infrared transmission states, eliminating the need for separate mechanical shutters for different wavelength regions.
Solution Approach 2:
The invention replaces conventional mechanical optical shutters with an electro-optical system using liquid crystal technology. The liquid crystal polarization modulator uses electrical control signals to switch between polarization states, enabling rapid electronic switching without mechanical moving parts, thereby achieving high switching speeds while maintaining simple structure.
2Use of energy by moving object
If rapid switching between visible and near-infrared transmission is implemented, then the energy throughput improves, but the contrast ratio deteriorates
Solution Approach 1:
The patent utilizes the wavelength-dependent optical properties of the liquid crystal material and polarizing filter combination. By changing the wavelength parameter of incident radiation between visible and near-infrared regions, the system achieves high contrast ratios in both regions through the specific design of the wavelength-selective polarizing filter and liquid crystal polarization modulator parameters.
3Adaptability or versatility
If a broadband polarizing filter is used to cover both visible and near-infrared regions, then the adaptability improves, but the manufacturing precision requirements increase
Solution Approach 1:
The patent segments the optical filtering function into two distinct components: a broadband polarizing filter that provides initial polarization across both visible and near-infrared regions, and a liquid crystal polarization modulator that provides wavelength-selective control. This segmentation allows each component to be optimized independently, reducing overall manufacturing precision requirements while maintaining broad wavelength coverage.
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 rapid switching between visible and near-infrared transmission states, providing high radiation energy throughput and contrast ratios, suitable for high-resolution color and depth image acquisition in digital cameras, with improved viewing angles and optical performance across the visible and near-infrared spectrum.
Implementation Method 1
The wavelength selective polarizing filter is constructed to impart a polarization state to incident radiation and transmit polarized radiation within at least the visible wavelength region of the electromagnetic spectrum
Implementation Method 2
The liquid crystal polarization modulator is positioned to receive incident radiation for internal propagation through the liquid crystal polarization modulator and is responsive to a first value and a second value of an applied control signal to switch the internally propagating radiation to, respectively, a first polarization state and a second polarization state
Implementation Method 3
The guest-host liquid crystal mixture, depending on an orientation of the liquid crystal director determined by one of the first and second polarization states to which the internally propagating radiation is switched, exhibits variable absorption of different radiation wavelength regions to produce the optical shutter output radiation in different wavelength regions of the electromagnetic spectrum
Data Source
AI summary
An optical shutter (10) includes a wavelength selective polarizing filter (12) in optical association with a liquid crystal polarization modulator (14) to rapidly switch between optical states to alternately transmit visible radiation and near infrared radiation. The wavelength selective polarizing filter is constructed to impart a polarization state to incident radiation and transmit polarized radiation within at least the visible wavelength region of the electromagnetic spectrum. The liquid crystal polarization modulator is positioned to receive incident radiation for internal propagation through the liquid crystal polarization modulator and is responsive to a first value and a second value of an applied control signal (32) to switch the internally propagating radiation to, respectively, a first polarization state and a second polarization state. The switching between the first and second polarization states produces, in cooperation with the wavelength selective polarizing filter, optical shutter output radiation in different wavelength regions of the electromagnetic spectrum.