Distance Image Sensor Threshold Validation for Accuracy
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Solution Overview
Problem
Existing distance image measuring apparatuses generate false distance information when targets are outside the measurement range, leading to degraded accuracy in distance information.
Innovation Solution
A distance image measuring apparatus with a light source generating pulsed light, controlled by a light source control means, and a pixel circuit with multiple charge readout regions and control electrodes, where charge transfer control means apply control pulses to transfer charge and voltage detection means read out signals, allowing for repeated distance calculations based on signal components exceeding a threshold value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If multiple charge readout regions are used to expand measurement range, then distance measurement range is improved, but false distance information is generated when target is outside measurement range
Solution Approach 1:
The pixel circuit is divided into multiple charge readout regions (first, second, third charge readout regions) that correspond to different distance ranges. Each region independently accumulates charge for its specific range, allowing the system to measure distances across a wide range while maintaining accuracy by selecting the appropriate region's data for validation
Solution Approach 2:
The system calculates distance values from multiple charge readout regions and uses a determination unit to validate which distance value is correct based on feedback from the measurement results. This feedback mechanism identifies false distance information and selects only valid measurements, resolving the accuracy issue while maintaining expanded measurement range
2Length of stationary object
If multiple calculations are performed for the same target, then distance measurement range is expanded, but it becomes difficult to determine which distance information is true
Solution Approach 1:
A determination unit is provided that receives distance values from multiple charge readout regions and automatically determines which value represents the true distance. This feedback-based validation system simplifies the complexity by providing an automated decision-making mechanism rather than requiring manual validation of multiple calculations
Solution Approach 2:
The system performs preliminary distance calculations in parallel across multiple charge readout regions before final validation. By pre-calculating all possible distance values and then validating them systematically, the system reduces the complexity of determining true distance information while maintaining expanded measurement capability
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 enables the generation of highly accurate distance images regardless of the target's position by validating distance calculations and filtering out invalid data, thereby improving measurement accuracy.
Implementation Method 1
a photoelectric conversion region configured to convert light into charge
Implementation Method 2
a sensor device that generates an image signal including distance information using a time of flight of light
Data Source
AI summary
A distance image sensor includes a light source, a light source control means for controlling the light source, a pixel circuit including a photoelectric conversion region, charge readout regions, and control electrodes, a charge transfer control means for sequentially applying a control pulse to the control electrodes, and a distance calculation means for reading voltages of the charge readout regions as detection signals and repeatedly calculating a distance on the basis of the detection signals, and the distance calculation means calculates a sum value of signal components of charge generated from the pulsed light other than background light among the detection signals, calculates a distance from the detection signals using a predetermined equation when the sum value exceeds a first threshold value, and invalidates the calculation of the distance when the sum value does not exceed the first threshold value.