Photoelectric Conversion Apparatus Black-Level Correction
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Solution Overview
Problem
The existing technique for black-level correction in photoelectric conversion apparatuses, as described in Japanese Patent Laid-Open No. 2012-156334, has low accuracy, which affects the image quality by not effectively increasing the quality of signals resulting from black-level correction.
Innovation Solution
A photoelectric conversion apparatus is designed with a configuration that includes charge generation and storage regions in a semiconductor layer, where a dielectric region is located above the charge generation region and surrounded by an insulator layer, and light-shielding layers are used to control light exposure, with specific openings and coverage areas to enhance light utilization and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light-shielding film is disposed between the optical waveguide and the photoelectric conversion unit in the OB pixel region, then light shielding is achieved, but the accuracy of black-level correction is insufficient
Solution Approach 1:
The light-shielding layer is divided into multiple segments: a first light-shielding layer covering the charge storage region and a second light-shielding layer covering the charge generation region in OB pixels. This segmentation allows precise control of light exposure for different functional regions, improving black-level correction accuracy while maintaining manageable structural complexity through modular design
Solution Approach 2:
Different regions of the photoelectric conversion apparatus are provided with different light-shielding configurations. Effective pixels have openings in the light-shielding layer to allow light exposure, while OB pixels are fully covered. This local differentiation optimizes each region's function and achieves accurate black-level correction without unnecessarily complicating the entire structure
2Object-affected harmful factors
If the light-shielding layer covers the charge storage region, then noise is reduced, but light utilization efficiency decreases
Solution Approach 1:
The light-shielding layer is segmented with openings positioned precisely over the charge generation regions while maintaining coverage over the charge storage regions. This segmentation allows light to reach the charge generation regions for efficient photoelectric conversion while blocking light from the charge storage regions to prevent noise, thereby resolving the contradiction between noise reduction and light utilization efficiency
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 the accuracy of black-level correction and enhances the quality of signals by effectively managing light exposure and noise reduction, leading to improved image quality.
Implementation Method 1
a charge generation region disposed in a semiconductor layer... the first unit is configured so that the charge generation region of the first unit is able to receive light through the opening of the first light-shielding layer
Implementation Method 2
a dielectric region located above the charge generation region and surrounded by an insulator layer
Data Source
AI summary
A photoelectric conversion apparatus includes a plurality of units each including a charge generation region disposed in a semiconductor layer. Each of a first unit and a second unit of the plurality of units includes a charge storage region configured to store charges transferred thereto from the charge generation region, a dielectric region located above the charge generation region and surrounded by an insulator layer, and a first light-shielding layer covering the charge storage region that is located between the insulator layer and the semiconductor layer, and the first light-shielding layer having an opening located above the charge generation region. The charge generation region of the first unit is able to receive light through the opening of the first light-shielding layer. The charge generation region of the second unit is covered with a second light-shielding layer.