Pixel Circuit Potential Boost for Avalanche Image Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image sensors face a trade-off between resolution and photosensitivity, with reduced pixel area leading to lower photosensitivity and decreased signal-to-noise ratio, especially under low illuminance conditions.
Innovation Solution
An imaging device is developed that generates a higher potential within the pixel using a circuit structure incorporating transistors and capacitors, enabling the operation of an avalanche photodiode without a high voltage power source, thereby enhancing sensitivity and resolution while reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pixel area is reduced to increase resolution, then the resolution is improved, but the photosensitivity is lowered
Solution Approach 1:
The invention changes the electrical parameters within the pixel by generating a time-varying potential that includes a reset potential and an avalanche multiplication potential. This allows the photoelectric conversion device to operate with high gain without requiring a larger pixel area, thus maintaining resolution while improving photosensitivity.
Solution Approach 2:
The invention applies a reset potential to the photoelectric conversion device before the imaging operation to initialize the pixel and prevent saturation. This preliminary action enables the device to quickly respond to incoming light signals, improving the effective photosensitivity without increasing the physical pixel area.
2Use of energy by moving object
If a dedicated power supply circuit is used to generate high voltage for avalanche multiplication, then the photosensitivity is improved, but the device complexity increases
Solution Approach 1:
The invention merges the high voltage generation function with the existing pixel circuit by using the pixel's own transistors and capacitors to generate the required potentials. This eliminates the need for a separate dedicated power supply circuit, reducing device complexity while maintaining high photosensitivity through avalanche multiplication.
Solution Approach 2:
The pixel circuit serves itself by generating the high voltage potential required for avalanche multiplication using its own components (transistors and capacitors). This self-service approach eliminates external power supply requirements and reduces overall device complexity.
3Use of energy by moving object
If a dedicated power supply circuit is used for high voltage generation, then the photosensitivity is improved, but the power consumption increases
Solution Approach 1:
The invention combines the high voltage generation with the pixel's existing operational cycles, using the same transistors and capacitors that are already part of the pixel circuit. This eliminates the continuous power consumption associated with dedicated power supply circuits while maintaining the high photosensitivity needed for low-light imaging.
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
The imaging device achieves high sensitivity and resolution with low power consumption, enabling fast and reliable image capture by generating a reset potential and adding potentials to the pixel, thus overcoming the trade-off between resolution and photosensitivity.
Implementation Method 1
a pixel including a first circuit and a second circuit, the second circuit includes a photoelectric conversion device
Implementation Method 2
A solution to the above problem is to use a photoelectric conversion device utilizing an avalanche multiplication effect, which has high photosensitivity
Data Source
AI summary
An imaging device that generates, in a pixel, a potential higher than a potential to be supplied to the pixel is provided. The imaging device includes a pixel including a first circuit and a second circuit; the second circuit includes a photoelectric conversion device; the first circuit is electrically connected to the second circuit; the first circuit has a function of adding a first potential and a second potential to generate a third potential; and the second circuit has a function of generating data in the photoelectric conversion device to which the third potential is applied and has a function of outputting the data.