Synchronized ROIC Modulation and Demodulation for Image Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional filtering techniques for infrared signals are susceptible to interference and noise, leading to non-optimal performance in real-world scenarios due to environmental factors and limitations in existing filtering mechanisms.
Innovation Solution
Implementing a system that modulates and demodulates optical signals using a read-out integrated circuit (ROIC) to filter out excess noise, such as random telegraph noise (RTS), by modulating the input optical signal at a frequency higher than the noise knee frequency and demodulating it within each pixel, combined with digital signal processing to enhance image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional filtering techniques are used for infrared signals, then the filtering mechanism is simple, but the signal clarity is poor and the system is susceptible to interference and noise
Solution Approach 1:
The patent modulates the infrared signal by changing its frequency parameter to a frequency above the noise knee frequency. This parameter change transforms the signal into a frequency range where noise is minimal, allowing for effective noise reduction while maintaining signal integrity. The modulation converts the original low-frequency signal susceptible to noise into a high-frequency signal that can be easily distinguished from low-frequency noise components.
Solution Approach 2:
The patent employs periodic modulation of the infrared signal at a specific frequency above the noise knee frequency. This periodic action creates a characteristic frequency signature that distinguishes the signal from random noise. The demodulation process then uses synchronized periodic detection to extract the signal while rejecting non-synchronized noise components, achieving superior signal clarity compared to conventional filtering.
2Reliability
If the input optical signal is modulated at a frequency higher than the noise knee frequency, then excess noise is reduced, but the system complexity increases due to modulation and demodulation requirements
Solution Approach 1:
The patent integrates multiple functions into the ROIC, including modulation, detection, and demodulation capabilities within a single integrated circuit. This multi-functionality reduces the need for separate discrete components for each function, thereby managing system complexity while achieving effective noise reduction through frequency modulation above the noise knee frequency.
Solution Approach 2:
The patent replaces complex mechanical modulation mechanisms with electronic modulation implemented in the ROIC. Instead of using mechanical choppers or moving parts to modulate the signal, the system uses electronic frequency modulation, which achieves the same noise reduction effect with fewer moving parts and reduced mechanical complexity.
3Measurement precision
If demodulation is performed within each pixel in the ROIC, then signal-to-noise ratio is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent divides the demodulation function into individual pixel operations within the ROIC array. Each pixel independently performs demodulation on its received signal, which segmenting the processing load across many pixels reduces the precision requirements for any single pixel. The collective effect of many pixels achieving moderate precision produces the high overall signal-to-noise ratio.
Solution Approach 2:
Each pixel in the ROIC performs its own demodulation operation independently, making the system self-sufficient at the pixel level. This self-service approach means that pixels do not require highly precise external synchronization mechanisms, as each pixel autonomously recovers the signal from noise using the modulation frequency information embedded in the signal itself, reducing manufacturing precision requirements.
Data Source
AI summary
A system, method and device for filtering noise from image data is disclosed. The method includes: (a) obtaining an input optical signal input to an optical system, (b) modulating the input optical signal to obtain a modulated image signal, wherein the input optical signal is modulated according to a predefined frequency, (c) demodulating, by a read-out integrated circuit (ROIC), the modulated image signal to obtain a filtered image signal in which at least part of 1/fn noise is filtered from the image data, wherein the modulated image signal is demodulated based at least in part on a synchronizer signal, and (d) providing the filtered image signal.