Image Sensor Color Filter Array for Reduced Parallax Errors
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Solution Overview
Problem
Conventional image sensors suffer from low sensitivity and color resolution due to the distance between nearest kernels of the same color, leading to misalignment of monochromatic and colored information and parallax errors in complex scenes.
Innovation Solution
A color filter array with 4x4 kernels, each containing four quadrants of three monochrome pixels and one color pixel, arranged in patterns like RGGB, RGBE, RYYB, CYYM, or CYGM, combined with an image processor that includes a fusion unit to align and combine signals from monochrome and color pixels, producing high-resolution images with improved color representation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional colour filter array with 4x4 kernels containing 12 monochrome pixels and 4 colour pixels of one colour only is used, then manufacturing simplicity is maintained, but sensitivity and colour resolution are low due to large distance between nearest kernels of the same colour
Solution Approach 1:
The patent divides each 4x4 kernel into four quadrants, where each quadrant contains three monochrome pixels and one colour pixel. This segmentation allows colour pixels of different types to be distributed more evenly across the kernel, reducing the distance between nearest colour kernels and improving colour resolution while maintaining manageable structural complexity
Solution Approach 2:
The patent employs asymmetric colour filter arrangements where the four quadrants have different colour compositions (e.g., RGGB pattern). This asymmetric distribution optimizes the spacing between colour pixels of the same type across different quadrants, improving sampling rate and colour resolution without requiring symmetric complex structures
2Reliability
If monochrome pixels and colour pixels are acquired in different image sensors, then separate optimization is possible, but misalignment of monochromatic and colored information occurs leading to parallax errors
Solution Approach 1:
The patent merges monochrome pixels and colour pixels into a single integrated image sensor with a unified colour filter array structure. This consolidation ensures that monochromatic and colored information are captured at the same physical location, eliminating misalignment and parallax errors while simplifying the overall sensor configuration
Solution Approach 2:
The patent introduces an intermediary colour filter array structure that mediates between monochrome and colour sensing requirements. The colour filter array serves as an intermediary layer that allows both monochrome and colour information to be captured simultaneously from the same pixel location, resolving the alignment issue without requiring separate sensors
3Illumination intensity
If conventional colour filter array is used, then device simplicity is maintained, but chroma is not spread optimally resulting in insufficient light capture
Solution Approach 1:
The patent applies local quality by assigning different colour filter characteristics to different quadrants within each 4x4 kernel. Each quadrant has optimized colour filtering tailored to its specific position and function, allowing optimal light capture and chroma distribution across the entire sensor array without requiring complex overall restructuring
Data Source
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AI summary
A colour filter array for an image sensor comprises a plurality of monochrome pixels and colour pixels arranged in one or more kernels. The one or more kernels includes four quadrants, and each quadrant of the one or more kernels includes three monochrome pixels and one colour pixel. The four quadrants in each kernel of the colour filter array may for example be arranged in an RGGB pattern.