Image Sensor Color Filter Thickness for Uniform Pixel Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image sensors often face challenges in achieving uniform sensitivity across pixels, leading to variations in image quality due to differences in color filter thickness and shape, which affects the consistency of light detection and signal processing.
Innovation Solution
The image sensor design incorporates a substrate with a grid pattern and color filters of varying thickness and shape, where center pixels have a concave-shaped color filter with reduced thickness, and edge pixels have convex-shaped filters with greater thickness, ensuring uniform sensitivity by minimizing crosstalk and optimizing light detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If color filters of uniform thickness are used across all pixels, then manufacturing is simplified, but pixel sensitivity becomes non-uniform due to crosstalk and light detection variations
Solution Approach 1:
The patent applies local quality by varying the thickness of color filters according to their specific location within the pixel array. Edge pixels receive thicker color filters while center pixels receive thinner color filters, optimizing each region's light detection characteristics to compensate for position-dependent crosstalk and sensitivity variations.
Solution Approach 2:
The patent changes the physical parameter of color filter thickness based on spatial position. By adjusting this parameter locally rather than maintaining uniform thickness, the patent optimizes light detection and reduces crosstalk effects at different positions in the array, achieving more uniform pixel sensitivity.
2Reliability
If color filter thickness is increased to reduce crosstalk, then signal quality improves, but light detection efficiency decreases
Solution Approach 1:
The patent applies local quality by differentiating color filter thickness between edge pixels and center pixels. Edge pixels, which experience more crosstalk, receive thicker filters for better signal quality, while center pixels receive thinner filters to maintain light detection efficiency, thus optimizing each region's performance 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 design enhances the uniformity of pixel sensitivity, leading to improved image quality by reducing variations in light detection and signal processing across the image sensor array.
Implementation Method 1
a first pixel including a first photoelectric conversion element and a first color filter, and a second pixel including a second photoelectric conversion element and a second color filter
Implementation Method 2
The photodiode may convert incident light into electrical signals
Data Source
AI summary
An image sensor that provides a uniform sensitivity for pixels having color filters of the same color to increase the image quality is provided. The image sensor includes a substrate, a first grid pattern disposed on the substrate and including a first side wall and a second side wall opposite to the first side wall, a first pixel including a first photoelectric conversion element and a first color filter, and a second pixel including a second photoelectric conversion element and a second color filter. The first color filter contacts the first side wall and the second color filter contacts the second side wall. The first color filter and the second color filter are color filters of same color, and a first thickness of the first color filter is greater than a second thickness of the second color filter.