Amplification Image Sensor Shutter Control for Charge Overflow
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Solution Overview
Problem
Conventional amplification-type solid-state image capturing apparatuses with shared charge detection sections suffer from image quality impairment due to overflow phenomena when capturing high-luminance subjects, resulting in horizontal stripe patterns and whitened appearances in captured images.
Innovation Solution
Incorporating an additional shutter operation for pixel sections that have not performed the original shutter operation or have previously completed a reading operation, to discharge accumulated signal charge and prevent overflow into the shared charge detection section.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple pixel sections share a single charge detection section to reduce device complexity, then device complexity is reduced, but image quality deteriorates due to overflow phenomena and horizontal stripe patterns when capturing high-luminance subjects
Solution Approach 1:
The pixel sections are divided into multiple groups, with each group sharing a dedicated charge detection section. This segmentation approach maintains the benefits of charge detection sharing while limiting overflow effects to within each group, preventing horizontal stripe patterns across the entire image sensor.
Solution Approach 2:
An additional shutter operation is performed on pixel sections that have not yet completed their reading cycle, before they can cause overflow into the shared charge detection section. This preliminary discharge of accumulated charge prevents the overflow phenomenon and resulting image quality degradation.
2Productivity
If signal charge is accumulated in pixel sections over multiple scan periods to improve productivity, then productivity is improved, but harmful overflow phenomena occur in the shared charge detection section
Solution Approach 1:
The additional shutter operation discharges accumulated signal charge from pixel sections before they can overflow into the shared charge detection section during subsequent reading operations, preventing the harmful overflow effect while maintaining the extended accumulation period for improved productivity.
Solution Approach 2:
The system maintains continuous signal charge accumulation across multiple scan periods for improved productivity, while the additional shutter operation ensures continuous prevention of overflow by periodically discharging excess charge from pixel sections before they can harm the shared charge detection section.
3Productivity
If the shutter period is extended to allow more pixel sections to complete reading operations, then productivity is improved, but horizontal stripe patterns become more prominent due to overflow from earlier pixel sections
Solution Approach 1:
The additional shutter operation is timed to discharge accumulated charge from pixel sections that completed their reading operation in previous scan periods, before they can cause overflow into the shared charge detection section during the extended shutter period, thereby preventing horizontal stripe patterns.
Solution Approach 2:
The system monitors the reading operation completion status of different pixel section groups and applies additional shutter operations selectively to those groups that have completed reading, creating a feedback-controlled mechanism that prevents overflow-related horizontal stripes while maintaining extended productivity.
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 approach effectively suppresses the generation of horizontal stripes, allowing for accurate signal reading from currently-read pixel sections and maintaining image quality by managing signal charge overflow.
Implementation Method 1
a photoelectric conversion element for receiving light of a subject and performing a photoelectric conversion on the light of the subject
Data Source
AI summary
An amplification-type solid-state image capturing apparatus according to the present invention, having a plurality of pixel sections each including a photoelectric conversion element for receiving light of a subject and performing a photoelectric conversion on the light of the subject and a transfer section capable of transferring signal charge from the photoelectric conversion element to a charge detection section, the plurality of pixel sections connected to each charge detection section, and the amplification-type solid-state image capturing apparatus amplifying and reading potential at the charge detection section as signal data for each of the pixel sections, includes: when one of the plurality of pixel sections which share the charge detection section performs an original shutter operation, a shutter control section for performing an additional shutter operation on the remaining pixel sections which share the charge detection section with the one pixel section and have not performed the original shutter operation yet.