CMOS Pixel Structure With Optical Isolation for Crosstalk Reduction
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Solution Overview
Problem
CMOS image sensors distort high-resolution images, affecting image quality due to crosstalk noise and the need for pixel rearrangement technology when color filters of adjacent pixel units are the same.
Innovation Solution
A pixel structure with adjacent pixel units arranged in an array, featuring a first optical partition wall between them and a microlens assembly above, where each pixel unit includes a color filter, pixel microlens, and photoelectric conversion layer, with different colors for adjacent pixel units to prevent image distortion and reduce crosstalk noise, and the pixel microlens is positioned under the color filter to enhance light concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pixel rearrangement technology is used to output high-resolution images, then image resolution is improved, but image distortion occurs and image quality deteriorates
Solution Approach 1:
The patent applies local quality by assigning different colors to color filters of adjacent pixel units, creating local differentiation that eliminates the need for pixel rearrangement. This local variation in color filter configuration allows direct high-resolution output without distortion, resolving the contradiction between image resolution and image quality.
2Ease of manufacture
If adjacent pixel units have the same color filter, then manufacturing is simplified, but crosstalk noise increases and image quality deteriorates
Solution Approach 1:
By making adjacent pixel units have different color filter colors, the patent creates local differentiation that reduces crosstalk noise between pixels. This approach maintains manufacturing feasibility while significantly improving image quality by minimizing optical interference between adjacent pixel units.
3Reliability
If pixel microlens is positioned under the color filter, then light concentration is improved and optical performance is enhanced, but structural complexity increases
Solution Approach 1:
The patent inverts the conventional microlens positioning by placing the pixel microlens under the color filter rather than above it. This inverted configuration effectively concentrates light onto the photoelectric conversion layer while maintaining manufacturing feasibility, resolving the contradiction between optical performance and structural complexity.
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 configuration improves image quality by avoiding technical compromises from pixel rearrangement, reducing crosstalk noise, and enhancing optical performance, resulting in better image quality for high-resolution outputs without the need for complex lens structures.
Implementation Method 1
each of the pixel units includes a color filter, a pixel microlens, and a photoelectric conversion layer arranged successively from top to bottom, and colors of color filters of the adjacent pixel units are different
Implementation Method 2
the pixel microlens is arranged under the color filter, which can help the pixel unit to better concentrate light
Implementation Method 3
The Complementary Metal-Oxide-Semiconductor (CMOS) image sensor has the characteristics of high integration, low power consumption, high speed, and low cost
Implementation Method 4
a first optical partition wall is arranged between the adjacent pixel units, so that crosstalk noise between pixels can be reduced
Data Source
AI summary
A pixel structure and an image sensor are provided. The pixel structure includes: a plurality of pixel units adjacent to each other and are arranged in an array. A first optical partition wall is arranged between the adjacent pixel units. The pixel structure further includes a microlens assembly. The microlens assembly is located on an upper side of all the pixel units and is opposite to all the pixel units. Each of the pixel units includes a color filter, a pixel microlens, and a photoelectric conversion layer arranged successively from top to bottom. Colors of color filters of the adjacent pixel units are different.