LCOS Spatial Light Modulator Driving for Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal spatial light modulating elements in optical node devices experience flickering due to their driving mechanisms, which are based on conventional video signal frequencies, leading to power variations and increased flickering at higher temperatures, necessitating the use of thermal electric cooling elements that increase equipment size and power consumption.
Innovation Solution
The optical node device employs a spatial light modulating element with a driving mechanism that switches pixels at a frequency higher than video frequencies, using a LCOS element with a specific circuitry that alternates polarity voltages and reduces the active surface area to minimize flickering and power variations, eliminating the need for thermal electric cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If liquid crystal spatial light modulating elements are driven at conventional video signal frequencies, then the device structure remains simple, but flickering occurs and power variations increase
Solution Approach 1:
The patent applies periodic action by driving the liquid crystal spatial light modulating element at a high frequency that is a multiple of the vertical scanning frequency (e.g., 120Hz, 240Hz, or higher). This high-frequency periodic driving eliminates flickering by ensuring that the liquid crystal pixels are updated faster than the human eye can detect, while maintaining a structured and predictable driving pattern that simplifies control circuit design.
2Reliability
If liquid crystal spatial light modulating elements are driven at higher frequencies to reduce flickering, then flickering is reduced, but power consumption increases
Solution Approach 1:
The patent utilizes periodic action with alternating polarity voltages applied to the liquid crystal pixels. By periodically switching the voltage polarity (positive, negative, zero) at high frequency, the system achieves flicker-free operation while the periodic nature of the waveform allows for optimized power consumption through symmetric positive-negative cycles that minimize net power demand.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the driving voltage parameters including polarity alternation and frequency multiplication. The driving waveform parameters (voltage amplitude, polarity, frequency) are optimized to achieve the minimum power consumption required for flicker-free operation, rather than using constant high power driving.
3Temperature
If thermal electric cooling elements are added to reduce temperature-induced flickering, then temperature stability is improved, but equipment size and power consumption increase
Solution Approach 1:
The patent eliminates the need for thermal electric cooling elements by using high-frequency periodic driving of the liquid crystal pixels. This periodic high-frequency operation inherently compensates for temperature-induced variations in liquid crystal response, maintaining stable optical performance across a range of temperatures without requiring active cooling systems.
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
This approach significantly reduces flickering and power variations, enabling a compact and low-power optical node device that maintains stability across varying optical attenuations without requiring cooling elements, even at elevated temperatures.
Implementation Method 1
a chromatic dispersion device that scatters spatially the signal beam depending on the wavelength of the signal beam
Implementation Method 2
an optical coupler that focuses, onto a two-dimensional plane, beams dispersed by the chromatic dispersion device
Implementation Method 3
A control method wherein a phase diffraction grating (Optical Phased Array, sometimes termed "OPA") is formed through a phase modulating function and the diffraction phenomenon is used
Implementation Method 4
a phase diffraction grating (Optical Phased Array, sometimes termed "OPA") is formed through a phase modulating function and the diffraction phenomenon is used
Data Source
AI summary
An optical node device includes a light receiving/emitting portion having an input port into which a signal beam is incident and an output port that emits a signal beam of a selected wavelength, a chromatic dispersion device that scatters spatially the signal beam depending on the wavelength of the signal beam, an optical coupler that focuses, onto a two-dimensional plane, beams dispersed by the chromatic dispersion device, a spatial light modulating element arranged so as to receive incident light deployed on an xy plane made up of an x-axis direction deployed according to wavelength and a y-axis direction orthogonal to the x-axis direction, and having numerous pixels arranged in a lattice on the xy plane, and a spatial light modulating element driving portion that drives electrodes of the individual pixels arranged in the xy axial directions in the spatial light modulating element.