ToF Sensor ECC Pixel Signals for Long-Range Accuracy
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Solution Overview
Problem
Time-of-Flight (ToF) sensors face challenges due to low signal-to-noise ratios, especially at long distances, leading to incorrect region code decisions and significant errors in decoded distances.
Innovation Solution
Incorporating additional pixel signals to generate an error correcting code (ECC) within the ToF sensor, which reduces the probability of region code decision errors and enhances the accuracy of decoded distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional pixel signals are added to generate ECC, then measurement precision and reliability are improved, but device complexity increases
Solution Approach 1:
The sensor array is segmented into different functional regions: some pixels generate ToF pixel signals for distance measurement while other pixels generate ECC pixel signals for error correction. This segmentation allows the system to achieve improved measurement precision through ECC without requiring every pixel to perform both functions, thus managing device complexity.
Solution Approach 2:
The patent implements multi-functionality by enabling pixels to serve dual purposes - generating both ToF pixel signals and ECC pixel signals. The processing circuitry is designed to handle both signal types, allowing the sensor to achieve both distance measurement and error correction capabilities within a unified device structure, thereby improving measurement precision while controlling complexity increase.
2Reliability
If ECC pixel signals are generated using additional pixels, then reliability of region code decision is improved, but the quantity of pixel signals increases
Solution Approach 1:
The sensor array is segmented into different functional regions: some pixels generate ToF pixel signals for distance measurement while other pixels generate ECC pixel signals for error correction. This segmentation allows the system to achieve improved measurement precision through ECC without requiring every pixel to perform both functions, thus managing device complexity.
Solution Approach 2:
The patent uses additional pixels to create copies of the ToF measurement signals specifically for error correction purposes. These ECC pixel signals are generated by the same light reception mechanism but are dedicated to creating redundant copies that can detect and correct errors in the region code decisions, thereby improving reliability while accepting an increase in the total quantity of pixel signals.
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 use of ECC significantly improves the accuracy of distance calculations and extends the operating range of ToF sensors by reducing errors associated with noise and low signal levels.
Implementation Method 1
charge is collected in a photoelectric conversion device of the pixel circuit as a result of impinging light
Implementation Method 2
an infrared light-emitting diode (LED) is used as the light source
Data Source
AI summary
Time-of-Flight (ToF) sensors, methods, and non-transitory computer-readable media. In one example of the present disclosure, a ToF sensor includes an array of pixels and processing circuitry. The processing circuitry is configured to generate a plurality of ToF exposure control signals that control at least one pixel of the array of pixels to generate a plurality of ToF pixel signals, generate a plurality of error correcting code (ECC) exposure control signals that control the at least one pixel to generate a plurality of ECC pixel signals, and determine a distance from an object based on the plurality of ToF pixel signals and the plurality of ECC pixel signals.