Two-Channel CMOS Sensor for Low-Light Full-Color Imaging
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Solution Overview
Problem
Current low-light image sensors, such as CCD and CMOS cameras, face challenges in low-light conditions due to high power consumption, noise, and reduced light sensitivity, as they rely on three light channels which filter out significant amounts of incoming light and are difficult to manufacture.
Innovation Solution
A two-light-channel system is developed, where an array of photosensitive pixels generates electrical signals in response to incident light, using only two light channels to produce full-color images, reducing noise and increasing light availability, allowing for accurate color identification in low-light conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a three-light-channel system (RGB CFA) is used, then color information can be captured, but significant amounts of incoming light are filtered out, reducing light sensitivity in low-light conditions
Solution Approach 1:
The patent extracts only two specific wavelength bands from the full spectrum (e.g., blue-green and red-infrared) rather than using three overlapping RGB channels. This extraction approach allows more total light to reach the sensor while still capturing sufficient color information for full-color image reconstruction through computational methods.
Solution Approach 2:
The patent changes the parameters of the light channels by selecting specific wavelength bands with optimal transmission properties rather than using traditional RGB filters. This parameter optimization allows the two channels to capture more light while maintaining color discrimination capability through spectral differences.
2Object-affected harmful factors
If CCD technology is used, then high light sensitivity and low noise are achieved, but power consumption increases up to 100 times compared to CMOS sensors
Solution Approach 1:
The patent replaces the charge transfer mechanism of CCDs with a static CMOS sensor architecture where each pixel has its own readout circuitry. This substitution eliminates the need for charge transfer across the sensor, dramatically reducing power consumption while maintaining low noise through on-pixel signal processing and the two-channel spectral separation approach.
3Illumination intensity
If CCD technology is used, then high light sensitivity is achieved, but the device takes up more space than comparable non-CCD sensors
Solution Approach 1:
The patent removes the charge transfer infrastructure required by CCDs and retains only the essential photosensitive elements and readout circuits in a CMOS architecture. The two-channel wavelength extraction approach also reduces the need for complex filter arrays, allowing for a more compact sensor design with higher pixel density.
Solution Approach 2:
The patent merges multiple functions into each pixel element: photosensitivity, wavelength filtering, charge amplification, and analog-to-digital conversion all occur at or near the pixel level in the CMOS architecture. This integration eliminates the need for separate charge transfer pathways and external conversion circuits, reducing overall sensor area.
4Illumination intensity
If a two-light-channel system is used, then light availability increases and noise is reduced, but color differentiation must be achieved with fewer channels
Solution Approach 1:
The patent introduces computational algorithms as an intermediary between the two-channel spectral data and the final color image. These algorithms use the spectral signatures captured in the two wavelength bands, combined with reference color data and interpolation techniques, to reconstruct full-color images with accurate color differentiation despite the reduced number of optical channels.
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 two-light-channel system enables effective color differentiation and increased dynamic range, allowing for accurate color identification and image generation in low-light environments, such as security cameras and medical endoscopy, with improved power efficiency and reduced manufacturing complexity.
Implementation Method 1
An array of photosensitive pixels generates electrical signals in response to incident light from a scene
Data Source
AI summary
Full-color images of low-light scenes are generated by the systems and methods described herein using only two light channels. An array of photosensitive pixels includes two sets of pixels, the first sensitive only to light associated with a first light channel, the second only to light associated with a second light channel. Thus the first set of pixels generate a first set of electrical signals in response to incident light within the first light channel, and the second set of pixels generate a second set of electrical signals in response to incident light within the second light channel. An image processor receives the first and second sets of electrical signals and generates a full-color image of the scene by processing only signals generated by the first and second sets of pixels.