CMOS Image Sensor Differential Readout With Fewer Vertical Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Differential amplification CMOS image sensors face challenges in further performance improvements, particularly in reducing the number of vertical signal lines to enable miniaturization and efficient multi-row readout operations.
Innovation Solution
The proposed solution involves a differential amplification solid-state imaging apparatus with a configuration that includes switch transistors, multiple pixels with amplification transistors, and shared reset and current supply lines to reduce the number of vertical signal lines, allowing for miniaturization and efficient multi-row readout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a differential amplification CIS is used to increase gain and conversion efficiency, then performance is improved, but the number of vertical signal lines increases, preventing miniaturization
Solution Approach 1:
The patent merges the reset function for multiple pixels into a single shared reset line, and combines multiple current supply functions into shared current supply lines. This reduces the number of vertical signal lines while maintaining the differential amplification functionality, thereby resolving the contradiction between performance improvement and device miniaturization.
Solution Approach 2:
The shared reset line and current supply lines serve multiple pixels simultaneously, making these signal lines universal resources. This multi-functionality approach reduces the total number of vertical signal lines needed, enabling miniaturization while preserving the high conversion efficiency of differential amplification CIS.
2Ease of operation
If more vertical signal lines are provided for each pixel, then individual pixel control is improved, but pixel size increases, reducing readout efficiency
Solution Approach 1:
The patent combines the control of multiple pixels through shared reset lines and current supply lines, reducing the total number of vertical signal lines. This merging approach maintains sufficient control capability while reducing pixel size and improving readout efficiency by enabling faster multi-row readout operations.
3Area of moving object
If the number of vertical signal lines is reduced for miniaturization, then pixel size decreases, but control capability over multiple pixels is reduced
Solution Approach 1:
The shared reset line and current supply lines are designed to serve multiple pixels universally, maintaining control capability across reduced pixel sizes. This universal control approach allows miniaturization while preserving the ability to control and read out multiple rows efficiently through the reduced set of vertical signal lines.
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 reduces the number of vertical signal lines, enabling pixel miniaturization and improving readout efficiency, thereby enhancing the performance of differential amplification CMOS image sensors.
Implementation Method 1
a first pixel including a first photoelectric converter
Data Source
AI summary
A light detecting device includes: one or more switch transistors, a first pixel including a first floating diffusion region coupled to a first photoelectric converter through a first transfer transistor, and a first amplification transistor coupled to the first floating diffusion region, a second pixel including a second floating diffusion region coupled to a second photoelectric converter through a second transfer transistor, and a second amplification transistor coupled to the second floating diffusion region, and a third pixel including a third floating diffusion region coupled to a third photoelectric converter through a third transfer transistor, and a third amplification transistor coupled to the third floating diffusion region. A pixel signal is differentially amplified by the first and third amplification transistors. The first and second floating diffusion regions are selectively connected to each other via one of the one or more switch transistors.