Time-of-Flight Demodulation Circuitry Chopping Tap Mismatch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Time-of-flight (ToF) depth measurement devices face challenges with tap mismatches and noise in indirect ToF methods, which affect accuracy and frame rate, and existing solutions either decrease frame rate or increase measurement time.
Innovation Solution
The implementation of time-of-flight demodulation circuitry that applies modulation signals to two signal paths and transfers them after a predetermined period, reducing tap mismatches and noise through chopping operations, allowing for increased frame rate and improved accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If modulation signals are applied to multiple signal paths simultaneously in conventional iToF, then depth measurement can be performed, but tap mismatches and noise occur which reduce measurement accuracy
Solution Approach 1:
The patent implements periodic switching of modulation signals between signal paths using a chopper circuit. The modulation signal is alternately applied to different signal paths in periodic intervals, which eliminates tap mismatches and reduces noise by ensuring that each signal path receives the modulation signal under consistent periodic conditions, thereby improving both measurement accuracy and reliability
Solution Approach 2:
The patent introduces a chopper circuit as an intermediary component between the modulation signal source and the signal paths. This intermediary periodically switches and transfers modulation signals between different signal paths, acting as a mediator that balances the signal distribution and eliminates systematic errors caused by direct simultaneous application to multiple paths
2Measurement precision
If existing solutions are used to reduce tap mismatches, then measurement accuracy may be maintained, but frame rate decreases or measurement time increases
Solution Approach 1:
The periodic switching mechanism allows the system to rapidly alternate between signal paths within each measurement frame, enabling multiple measurements to be completed in the time it would take for a single measurement in conventional systems. This periodic action maintains high frame rates while eliminating tap mismatches through the systematic periodic switching of modulation signals
Solution Approach 2:
The patent maintains continuous operation by seamlessly switching modulation signals between signal paths without interruption to the overall measurement process. The chopper circuit ensures continuous transfer of modulation signals, allowing the measurement process to proceed without idle periods, thereby maintaining high productivity and frame rates
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 enhances the accuracy of depth measurements by reducing tap mismatches and noise, enabling higher frame rates and improved performance in short-wave infrared measurements while maintaining a wide detector bias range.
Implementation Method 1
reducing tap mismatches and noise through chopping operations
Data Source
AI summary
The present disclosure generally pertains to time-of-flight demodulation circuitry, configured to: apply, for a predetermined time period, a first modulation signal to a first signal path including a first light detection element; apply, for the predetermined time period, a second modulation signal to a second signal path including a second light detection element; and after the predetermined time period, transfer the first modulation signal from the first signal path to the second signal path and transfer the second modulation signal from the second signal path to the first signal path.