Image Sensor Pixel Sub-pixel Segmentation Dynamic Range
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Solution Overview
Problem
Image sensing devices face challenges in improving dynamic range, sensitivity, and Signal-to-Noise Ratio (SNR) due to miniaturization, which deteriorates these performance metrics.
Innovation Solution
The image sensing device incorporates a unit pixel structure with sub-pixels of different colors and a white sub-pixel, where the row control block manages exposure times and outputs signals sequentially, and an image process block processes these signals to generate image data, compensating for sensitivity and SNR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If miniaturization is applied to reduce pixel size, then device integration is improved, but dynamic range deteriorates
Solution Approach 1:
Each pixel is divided into multiple sub-pixels with different colors (R, G, B, W). The white sub-pixel captures a broader spectrum including infrared, while colored sub-pixels capture specific wavelength ranges. This segmentation allows the system to maintain small pixel size while achieving extended dynamic range through spectral diversity.
Solution Approach 2:
The patent extends the dynamic range by adding a spectral dimension rather than increasing spatial size. The white sub-pixel provides sensitivity to wavelengths beyond the visible spectrum (including infrared), creating an additional dimension of light detection that compensates for miniaturization effects.
2Volume of moving object
If miniaturization is applied to reduce pixel size, then device integration is improved, but sensitivity deteriorates
Solution Approach 1:
The pixel is segmented into multiple specialized sub-pixels, each optimized for specific wavelength ranges. The white sub-pixel provides enhanced sensitivity to infrared and broad-spectrum light, compensating for the reduced size of individual photodetectors through spectral specialization.
Solution Approach 2:
Different sub-pixels within the same pixel unit have different spectral sensitivities tailored to their function. The white sub-pixel is optimized for broad-spectrum and infrared detection, while colored sub-pixels are optimized for specific visible wavelengths, allowing each miniaturized element to maintain high sensitivity for its designated purpose.
3Volume of moving object
If miniaturization is applied to reduce pixel size, then device integration is improved, but Signal-to-Noise Ratio deteriorates
Solution Approach 1:
By segmenting the pixel into multiple sub-pixels with specialized functions, the system can process different spectral bands separately. This allows for targeted noise filtering and signal enhancement for each sub-pixel type, improving overall SNR despite miniaturization.
Solution Approach 2:
The patent employs multiple exposure times and combines signals from different sub-pixels with varying exposure durations. Longer exposure on white sub-pixels captures more signal for infrared/broad-spectrum detection, while shorter exposure on colored sub-pixels reduces saturation. This feedback-based multi-exposure strategy improves SNR by optimizing signal capture for each sub-pixel's spectral characteristics.
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 enhances dynamic range and SNR, minimizing motion artifacts and improving image quality by using image data with varied exposure times and leveraging the white sub-pixel signal for sensitivity compensation.
Implementation Method 1
a pixel array including a plurality of pixels arranged in a matrix, each pixel including a photodiode
Data Source
AI summary
An image sensing device includes a unit pixel including one or more first sub-pixels of a white color and a plurality of second sub-pixels of a color other than the white color in a matrix, a row control block suitable for controlling the first and second sub-pixels to output sequentially first and second pixel signals during one row unit time, and an image process block suitable for processing the first and second pixel signal's.