Differential Comparator LiDAR Timing for Accurate Amplitude Estimation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Time-of-flight systems face challenges in precise amplitude estimation due to the limitations of digitization and thresholding techniques, which are either expensive or imprecise and prone to pulse pileup issues.

Innovation Solution

A differential comparator-based system that includes a signal delay component, differential comparator, and a processor to generate distance and amplitude data from LiDAR signals using time-delayed waveforms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If digitization (high-speed ADC) is used for waveform detection, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:

Improvewaveform detection precisionVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/electronic digitization system (high-speed ADC) with an optical-based differential comparator system. The differential comparator uses optical signal processing to directly compare the received waveform with a reference waveform, extracting timing and amplitude information without requiring high-speed digital conversion. This substitution reduces device complexity while maintaining measurement precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If thresholding is used for waveform detection, then device complexity is reduced, but amplitude estimation precision deteriorates due to information loss

Engineering Contradiction:

Improvesystem complexityVSAvoidamplitude estimation precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces a differential comparator as an intermediary between the received waveform and the detection process. This intermediary component compares the received signal with a time-delayed reference signal, preserving amplitude information through the differential comparison process. The intermediary enables accurate amplitude estimation while keeping the system simple, avoiding the information loss inherent in direct thresholding.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If thresholding is used for waveform detection, then device complexity is reduced, but measurement precision deteriorates due to pulse pileup issues

Engineering Contradiction:

Improvesystem complexityVSAvoidmeasurement reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces the thresholding mechanism with a differential comparison mechanism. The differential comparator continuously compares the received waveform with a reference waveform, enabling it to distinguish between genuine signal returns and pulse pileup events. This substitution improves measurement reliability by correctly identifying and rejecting pulse pileup, while maintaining system simplicity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12474452B2System and method for differential comparator-based time-of-flight measurement with amplitude estimation

Publication Date: 2025.11.18 LG INNOTEK CO LTD

AI summary

A system including a first unit configured to: receive a LiDAR output signal, compare a time-delayed LiDAR output signal to the LiDAR output signal, and provide a digital output signal, and a second unit configured to generate LiDAR data including a distance and an amplitude based on the digital output signal.