ToF Camera Protective Part Defect Detection for Stable Ranging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Time-of-flight cameras are susceptible to measurement interference from dirt, scratches, water droplets, fog, or other objects on the protective part, which can cause damage in applications like personnel safety detection, without compromising the waterproof and dustproof structure.
Innovation Solution
A time-of-flight camera system with a detection method that uses separate light sources for measurement and inspection, allowing detection of interference without affecting the camera's protective structure, by emitting a second light to inspect the protective part and analyzing luminous intensity distributions to determine defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective part (glass or plastic) is added to protect internal components and circuits from water and dust, then waterproof and dustproof protection is improved, but the protective part may accumulate dirt, scratches, water droplets, or fog that interfere with light transmission and affect measurement results
Solution Approach 1:
The patent applies preliminary action by introducing a detection light unit that continuously monitors the protective part for dirt, scratches, water droplets, or fog before they significantly affect measurement accuracy. The system performs defect detection on the protective part itself, enabling early warning and preventive maintenance, thus resolving the contradiction between maintaining protective coverage and ensuring measurement precision.
2Measurement precision
If a detection system is added to detect dirt, scratches, water droplets, or fog on the protective part, then measurement precision is improved, but the device complexity increases due to additional light sources and detection mechanisms
Solution Approach 1:
The patent applies universality by designing a detection light unit that uses the same receiving unit (photoelectric converter) as the main ToF measurement system. The detection light unit shares the optical path and signal processing infrastructure with the main light source, enabling the system to perform both protective part inspection and distance measurement functions without proportionally increasing complexity. This multi-functional approach resolves the contradiction between detection accuracy and device complexity.
3Measurement precision
If the detection light unit illuminates the protective part to detect defects, then detection accuracy is improved, but the receiving unit may be directly illuminated causing false signals and reducing measurement reliability
Solution Approach 1:
The patent applies local quality by configuring the detection light unit with specific illumination angles and directions that target only the protective part surface for inspection. The detection light is directed at oblique angles to illuminate potential defects (dirt, scratches, water droplets) on the protective part while the receiving unit is positioned to detect reflected light from defects rather than direct illumination. This spatial differentiation resolves the contradiction between defect detection accuracy and measurement reliability by creating distinct optical paths for detection and measurement functions.
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
Accurately detects interference on the protective part without disrupting the camera's waterproof and dustproof integrity, ensuring reliable distance measurements and preventing potential hazards in applications like human-machine collaboration.
Implementation Method 1
a receiving unit, disposed in the case, configured to receive a first feedback light generated by the first light, and configured to receive a second feedback light generated by the second light incident on the protective part
Implementation Method 2
a receiving unit, disposed in the case, configured to receive a first feedback light generated by the first light
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A time-of-flight camera includes: a case; a protective part, disposed on the case; a main light source unit, disposed at a first position of the case, and configured to emit a first light during a first period; a detection light unit, disposed at a second position of the case, and configured to emit a second light during a second period; a receiving unit, disposed in the case, configured to receive a first feedback light generated by the first light, and configured to receive a second feedback light generated by the second light incident on the protective part and generate a luminous intensity distribution; a storage unit, electrically connected to the receiving unit, and configured to store the luminous intensity distribution; and a processing unit, electrically connected to the receiving unit and the storage unit, and configured to determine whether the protective part has a defect based on the luminous intensity distribution.