Image Sensor Pixel Array Dual Conversion Gain Capacitor Layout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image sensing devices face challenges in efficiently adjusting sensitivity without increasing pixel size or introducing noise-causing capacitors, limiting their dynamic range and adaptability to varying light conditions.
Innovation Solution
The image sensing device incorporates a pixel array with dual conversion gain (DCG) capacitors and strategically arranged photoelectric conversion elements, allowing for adjustable sensitivity by changing the layout structure of pixels, enabling both high and low sensitivity modes without increasing pixel size or using noise-inducing capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a capacitor is introduced to adjust sensitivity, then the dynamic range is improved, but noise is generated
Solution Approach 1:
The patent extracts the harmful capacitor component from the pixel structure while retaining the sensitivity adjustment function. By removing the capacitor that causes noise, the invention achieves dynamic range adjustment through alternative means (pixel layout configuration) that do not introduce harmful electrical noise into the signal path.
Solution Approach 2:
The pixel structure is designed to perform multiple functions: sensitivity adjustment, noise reduction, and signal generation all within the same pixel unit. The pixel can operate in different modes (high sensitivity, low sensitivity, linear mode) by configuring the photoelectric conversion elements and readout circuitry, eliminating the need for separate capacitor-based adjustment mechanisms.
2Adaptability or versatility
If pixel size is increased to improve sensitivity adjustment, then the dynamic range is enhanced, but the pixel area increases
Solution Approach 1:
The patent implements dynamic sensitivity adjustment through software-controlled pixel configuration rather than physical hardware changes. The pixel array can be dynamically reconfigured between different sensitivity modes (high, low, linear) by controlling the readout circuitry and photoelectric conversion element configuration, allowing sensitivity adjustment without increasing physical pixel area.
Solution Approach 2:
The invention changes operational parameters (photoelectric conversion element configuration, readout mode, gain settings) rather than physical dimensions to achieve sensitivity adjustment. By modifying electrical and operational parameters, the system achieves a 4x or greater dynamic range adjustment capability while maintaining constant pixel physical size.
3Measurement precision
If more photoelectric conversion elements are added to increase sensitivity, then the sensitivity is improved, but the pixel complexity increases
Solution Approach 1:
The patent segments the pixel array into independently controllable units that can be configured in different sensitivity modes. Rather than adding more conversion elements to each pixel, the system segments the array and uses readout circuitry configuration to achieve sensitivity adjustment, reducing per-pixel complexity while maintaining overall system capability.
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 solution allows the image sensing device to acquire the necessary capacitance for low sensitivity modes without increasing pixel size or using capacitors that could cause noise, thereby enhancing its dynamic range and adaptability to different light conditions.
Implementation Method 1
one or more photoelectric conversion elements structured to generate photocharges in response to incident light
Data Source
AI summary
An image sensing device includes a pixel array configured to include a first pixel belonging to a first row and a first column, and a second pixel belonging to a second row adjacent to the first row and a second column adjacent to the first column; and a dual conversion gain (DCG) capacitor coupled between the first pixel and the second pixel, and a first DCG transistor for selectively connecting the DCG capacitor to or disconnecting the DCG capacitor from a first floating diffusion region of the first pixel; and the second pixel includes a second floating diffusion region and a second DCG transistor for selectively connecting the DCG capacitor to or disconnecting the DCG capacitor from a second floating diffusion region of the second pixel.