Light-Receiving Element Counter Saturation Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-receiving elements with counter circuits are prone to saturation when faced with high background light levels, which affects the accuracy of photon detection and counting.
Innovation Solution
A light-receiving element with a control processing circuit that manages multiple counter circuits and sensing circuits, allowing for dynamic switching and alternation of counter values to prevent saturation, and includes a histogram creator to monitor and adjust counter values based on predetermined upper limit values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single counter circuit counts photons for each pixel, then the counting function is simple and the device structure is compact, but the counter circuit becomes saturated under high background light conditions
Solution Approach 1:
The patent divides a single counter circuit into multiple sub-counters (first counter and second counter) that operate in different modes. The first counter counts photons during a first period when the sensing circuit is active, and the second counter counts photons during a second period when the sensing circuit is inactive. This segmentation prevents saturation by distributing the counting load across multiple circuits and time periods, while maintaining overall system functionality.
2Measurement precision
If the sensing circuit continuously counts photons, then the photon detection capability is maintained, but the counter circuit saturates under high background light
Solution Approach 1:
The patent implements periodic switching between two counting modes: a first mode where the sensing circuit is active and the first counter counts photons, and a second mode where the sensing circuit is inactive and the second counter counts photons. This periodic alternation allows the system to maintain photon detection capability while preventing counter saturation by resetting one counter while the other is actively counting.
3Reliability
If multiple counter circuits are used to prevent saturation, then counter saturation is suppressed, but the device complexity increases
Solution Approach 1:
The patent combines multiple counter circuits (first counter and second counter) into a single integrated counter unit that can switch between different counting modes. The control circuit manages the switching between the first counter and second counter based on the operating mode, effectively merging their functions into one cohesive system. This approach achieves saturation suppression while minimizing the increase in device complexity through unified control.
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 solution effectively suppresses counter circuit saturation, even in high background light conditions, thereby maintaining accurate photon detection and counting, and allows for extended dynamic range without compromising resolution.
Implementation Method 1
a sensing circuit that allows detection of incidence of a photon... provided with, for every pixel, a sensing circuit including a single-photon avalanche diode (SPAD) that detects the presence or absence of a photon
Data Source
AI summary
Provided is a light-receiving element and an electronic apparatus capable of suppressing saturation of a counter circuit. The present disclosure provides a light-receiving element including a plurality of pixels, in which each of the plurality of pixels includes a sensing circuit that allows detection of incidence of a photon, and a counter circuit that counts a pulse output from the sensing circuit, and in a first mode, at least one first counter circuit among a plurality of counter circuits included in the plurality of pixels counts on the basis of an output value of a second counter circuit different from the first counter circuit among the plurality of counter circuits.