Image Sensor Edge Electrode Layout for Optical Black Integrity
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Solution Overview
Problem
The edge portion of the photoelectric conversion layer in imaging devices with organic semiconductor materials is often damaged during processing, leading to electric charges entering the optical black region and hindering its functionality.
Innovation Solution
The implementation of a common photoelectric conversion layer for both effective pixel and optical black regions, with an outer edge electrode positioned to face the photoelectric conversion layer via an insulating layer, ensuring that electric charges generated at the edge are prevented from entering the optical black region by applying a potential with the same or opposite sign to the outer edge electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common photoelectric conversion layer is used for both effective pixel region and optical black region, then manufacturing complexity is reduced, but edge portion damage during processing causes electric charges to enter the optical black region and hinder its functionality
Solution Approach 1:
An outer edge electrode is introduced as an intermediary component between the common photoelectric conversion layer and the optical black region. This electrode applies a potential barrier that prevents electric charges generated at the edge portion from entering the optical black region, thus protecting the optical black region's functionality while maintaining the simplicity of the common photoelectric conversion layer structure.
2Ease of manufacture
If the photoelectric conversion layer edge is left exposed, then manufacturing is simpler, but electric charges generated at the edge enter the optical black region and degrade image quality
Solution Approach 1:
The outer edge electrode serves as a protective intermediary that can be applied after the photoelectric conversion layer is formed. This approach maintains the simplicity of photoelectric conversion layer processing while the electrode itself acts as a barrier to prevent charge leakage into the optical black region, effectively addressing the edge integrity issue without complicating the manufacturing process.
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 effectively prevents electric charges from entering the optical black region, thereby maintaining its functionality and improving imaging quality by reducing kTC noise and random noise.
Implementation Method 1
signal charges generated by photoelectric conversion
Data Source
AI summary
An imaging device includes: an effective pixel region that includes a plurality of imaging elements-A, amplifies signal charges generated by photoelectric conversion, and reads the signal charges into a drive circuit; and an optical black region that includes a plurality of imaging elements-B, surrounds the effective pixel region, and outputs optical black that serves as the reference for black level. In the imaging device, the photoelectric conversion layer forming the plurality of imaging elements-A and the plurality of imaging elements-B is a common photoelectric conversion layer, the common photoelectric conversion layer is located on an outer side of the optical black region, and extends toward an outer edge region surrounding the optical black region, and an outer edge electrode is disposed in the outer edge region.