Photodetector Pixel Sensitivity Layout for Wider Dynamic Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing photodetection devices for time of flight distance measurement systems face challenges in widening the dynamic range without increasing the number of photoelectric converters, which leads to larger chip sizes and higher power consumption.
Innovation Solution
The photodetection device incorporates a plurality of photoelectric converters per pixel, including at least one first photoelectric converter with high sensitivity and one or more second photoelectric converters with lower sensitivity, allowing for adjustable voltage settings and varying opening ratios to achieve a stepwise decrease in sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of photoelectric converters per pixel is increased to widen the dynamic range, then the dynamic range is improved, but the chip size and power consumption increase
Solution Approach 1:
The patent applies local quality by assigning different sensitivity characteristics to different photoelectric converters within the same pixel. Specifically, it uses a combination of high-sensitivity photoelectric converters (for detecting weak reflected light from distant objects) and low-sensitivity photoelectric converters (for detecting strong light from nearby objects). This local differentiation of sensitivity allows the system to handle a wide dynamic range without increasing the total number of converters, thereby avoiding increased chip size.
Solution Approach 2:
The patent employs parameter changes by varying the sensitivity parameter of photoelectric converters through different design configurations. It changes physical parameters such as the active area size, quantum efficiency, or coupling strength of the photoelectric converters to create distinct sensitivity levels. This allows the system to achieve multiple sensitivity ranges using the same number of converters, thus widening the dynamic range without increasing chip size.
2Adaptability or versatility
If the number of photoelectric converters per pixel is increased to widen the dynamic range, then the dynamic range is improved, but the power consumption increases
Solution Approach 1:
The patent applies local quality by assigning different sensitivity characteristics to different photoelectric converters within the same pixel. Specifically, it uses a combination of high-sensitivity photoelectric converters (for detecting weak reflected light from distant objects) and low-sensitivity photoelectric converters (for detecting strong light from nearby objects). This local differentiation of sensitivity allows the system to handle a wide dynamic range without increasing the total number of converters, thereby avoiding increased power consumption.
Solution Approach 2:
The patent employs parameter changes by varying the sensitivity parameter of photoelectric converters through different design configurations. It changes physical parameters such as the active area size, quantum efficiency, or coupling strength of the photoelectric converters to create distinct sensitivity levels. This allows the system to achieve multiple sensitivity ranges using the same number of converters, thus widening the dynamic range without increasing power consumption.
3Adaptability or versatility
If photoelectric converters with different sensitivities are used, then the dynamic range is widened without increasing chip size, but the device complexity increases
Solution Approach 1:
The patent applies merging by combining photoelectric converters with different sensitivity characteristics into a single integrated pixel structure. Multiple converters with varying sensitivities are arranged within one pixel and their outputs are combined through signal processing circuits. This merging approach allows the system to achieve wide dynamic range while maintaining a compact structure and minimizing the increase in device complexity.
Solution Approach 2:
The patent applies universality by designing a multi-functional pixel that can detect light across a wide dynamic range using a single integrated structure. The pixel incorporates multiple photoelectric converters with different sensitivities that can be selectively activated or combined based on the input light conditions. This universal design allows the same pixel structure to handle both weak and strong light signals, reducing the need for separate specialized components and thereby limiting the increase in device complexity.
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 enables the widening of the dynamic range without increasing the number of photoelectric converters, resulting in improved distance measurement performance and reduced chip size and power consumption.
Implementation Method 1
a first avalanche photodiode... photoelectrically convert incident light
Implementation Method 2
each of the first photoelectric converters includes a first avalanche photodiode
Data Source
AI summary
There is provided a photodetection device capable of widening a dynamic range without increasing the number of photoelectric converters. The photodetection device according to an embodiment of the present disclosure includes a plurality of photoelectric converters arranged in one of pixels and configured to photoelectrically convert incident light. The plurality of photoelectric converters includes at least one first photoelectric converter and at least one second photoelectric converter having a lower sensitivity to the incident light than the first photoelectric converter.