Local Binning Image Sensor for Low Light Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional high-sensitivity image sensors face a trade-off between sensitivity and spatial resolution, as existing binning methods that enhance sensitivity often deteriorate image quality by applying binning over the entire image area, leading to reduced resolution in well-lit areas.
Innovation Solution
The image sensor employs a local binning technique that selectively applies binning only to low illumination areas, using a column readout circuit to determine and store low illumination information, allowing for adaptive binning in the charge, analog, or digital domain, thereby preserving spatial resolution in non-low illumination areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional binning is applied over the entire image area to enhance sensitivity, then sensitivity is improved, but spatial resolution deteriorates
Solution Approach 1:
The patent applies binning selectively only to low illumination areas rather than uniformly across the entire image. The column readout circuit identifies regions with low light levels and performs binning operations only on those specific areas, while preserving full resolution in well-lit regions. This local application of binning resolves the contradiction by enhancing sensitivity where needed without sacrificing spatial resolution where not needed.
Solution Approach 2:
The image processing is divided into two distinct pathways: one for low illumination areas that applies binning, and another for normal illumination areas that maintains full resolution. The column readout circuit segments the image processing based on illumination conditions, allowing different processing strategies to be applied to different regions of the image simultaneously.
2Reliability
If binning is applied to enhance sensitivity in dark areas, then image quality in low light is improved, but overall image resolution is reduced
Solution Approach 1:
The system applies different processing qualities to different regions: binning is applied locally only to dark areas where it improves image quality, while bright areas maintain their original high resolution. This localized approach ensures that image quality enhancement in low light does not come at the cost of overall image resolution.
3Reliability
If conventional binning methods are used, then sensitivity enhancement is achieved, but image quality is deteriorated due to resolution loss
Solution Approach 1:
The patent implements local binning that preserves image quality by applying sensitivity enhancement only where necessary. The column readout circuit identifies low illumination regions and applies binning selectively, maintaining high resolution in well-lit areas while enhancing sensitivity only in dark regions, thus avoiding overall image quality deterioration.
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 sensitivity in low illumination areas while maintaining high spatial resolution in well-lit areas, extending the dynamic range and preventing loss of image quality, thus achieving high-quality images without sacrificing spatial resolution.
Implementation Method 1
a photodiode to receive light and create photocharges
Data Source
AI summary
Disclosed are an image sensor and a local binning method in which binning is applied selectively. For example, binning is applied to pixels having low illumination and binning is not applied to non-low illumination pixels. Information on pixels having low illumination for a first image frame may be stored and used to perform binning with respect to areas of a second image frame corresponding to low illumination pixel areas determined with respect to the first image frame.