Photodetector Edge Detection Circuit for Smaller Pulse-Counting Layouts
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Solution Overview
Problem
Existing photodetection devices and systems require a large circuit area, necessitating a reduction in circuit size for more efficient and compact designs.
Innovation Solution
The implementation of a photodetection device and system that includes multiple light-receiving sections, edge detectors, and adders, utilizing latches and combination circuits to process pulse signals, allowing for the detection of edges and calculation of pulse numbers, thereby reducing circuit area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional photodetection devices use traditional edge detection circuits, then detection accuracy is maintained, but circuit area becomes large
Solution Approach 1:
The patent combines multiple edge detection functions into a single integrated edge detection circuit that processes signals from multiple light receiving sections simultaneously. The circuit merges the detection of rising edges and falling edges into unified detection logic, and combines results from multiple photodetectors through an adder unit, thereby reducing the total circuit area while maintaining detection accuracy
Solution Approach 2:
The edge detection circuit is designed to perform multiple functions: detecting rising edges, detecting falling edges, processing signals from multiple light receiving sections, and generating both first detection signals and second detection signals. This multi-functional design eliminates the need for separate detection circuits for each function, reducing overall circuit area while preserving all detection capabilities
2Measurement precision
If multiple light receiving sections are used to improve detection capability, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The patent merges the processing of signals from multiple light receiving sections into a single edge detection circuit. The circuit accepts input signals from multiple photodetectors and processes them simultaneously through unified detection logic, combining multiple detection functions into one integrated unit that reduces overall device complexity
Solution Approach 2:
The device is segmented into distinct functional modules: multiple light receiving sections for parallel signal acquisition, a unified edge detection circuit for centralized processing, and an adder unit for result aggregation. This modular segmentation allows each component to perform its function efficiently while maintaining low overall complexity through clear functional separation
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 a more compact photodetection system with improved efficiency in detecting light pulses, reducing circuit size while maintaining accurate distance measurements.
Implementation Method 1
a light-receiving element, and is configured to generate a pulse signal including a pulse corresponding to a result of light reception by the light-receiving element
Data Source
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AI summary
A photodetection device according to the present disclosure includes a plurality of light-receiving sections that each generates a pulse signal including a pulse corresponding to a result of light reception, a plurality of edge detectors that each generates a detection signal by detecting an edge of the pulse in the pulse signal generated by a corresponding light-receiving section, and an adder that generates a detection value indicating number of the pulses on the basis of a plurality of the detection signals. The edge detectors each include a first latch circuit that generates a first signal by latching the pulse signal on the basis of a first clock signal, a second latch circuit that generates a second signal by latching the first signal on the basis of a second clock signal that is an inverted signal of the first clock signal, a combination circuit that generates a third signal on the basis of the pulse signal, the first signal, and the second signal, and a third latch circuit that generates the detection signal by latching the third signal on the basis of the first clock signal.