Pixel Potential Generation for Avalanche Imaging Sensors
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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
The imaging device employs a pixel circuit that generates a higher potential using a combination of transistors and capacitors, allowing for the operation of an avalanche photodiode without a high voltage power source, thereby increasing 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 patent changes the electrical potential parameter by generating a higher potential (e.g., 20V or higher) within the pixel circuit to enable avalanche multiplication in the photoelectric conversion device. This parameter change allows the device to operate in an avalanche mode that provides high gain and improved photosensitivity even with reduced pixel area, thus resolving the trade-off between resolution and photosensitivity
Solution Approach 2:
The patent introduces a potential generation circuit as an intermediary component within the pixel circuit that combines multiple potentials (e.g., V1 and V2) to generate a higher potential. This intermediary mechanism enables the photoelectric conversion device to achieve avalanche multiplication without requiring an external high voltage power source, thereby improving photosensitivity while maintaining high resolution
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 patent merges the potential generation function directly into the pixel circuit by combining multiple potential sources (V1 and V2) within the same circuit structure. This integration eliminates the need for a separate dedicated power supply circuit, thereby reducing device complexity while still achieving the high voltage required for avalanche multiplication and high photosensitivity
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 enables high-resolution imaging with improved photosensitivity and low power consumption, allowing for efficient image capture under various lighting conditions.
Implementation Method 1
a second circuit having a function of generating data in the photoelectric conversion device to which the third potential is applied
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.