TOF Sensor Diffuser Breakage Detection via Transparent Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current distance measurement apparatuses, such as TOF sensors, face challenges in reliably detecting diffuser breakage, which can lead to unsafe laser beam exposure if not addressed.
Innovation Solution
Incorporating a light source section that modulates a laser beam using a pulsed wave and a breakage detection section with a transparent electrode to detect reflected waves, allowing for reliable detection of diffuser breakage without compromising transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a diffuser is used to diffuse a high output laser beam, then user safety is improved by reducing beam intensity, but the system becomes vulnerable to breakage that can cause harmful laser exposure
Solution Approach 1:
The patent applies preliminary action by integrating a transparent electrode and breakage detection circuitry into the diffuser before deployment. The electrode is pre-formed on the diffuser surface, and the detection system is pre-configured to monitor the electrode's electrical continuity. This allows the system to proactively detect diffuser integrity issues before they result in harmful laser exposure, enabling preventive shutdown of the laser source.
Solution Approach 2:
The transparent electrode serves as an intermediary element that performs dual functions: it maintains optical transparency for laser beam diffusion while simultaneously providing electrical conductivity for breakage detection. This intermediary component bridges the optical function (diffusion) and the safety monitoring function (integrity detection), allowing the system to monitor diffuser health without compromising its primary optical purpose.
2Reliability
If a transparent electrode is added to the diffusion member for breakage detection, then detection reliability is improved, but device complexity increases
Solution Approach 1:
The transparent electrode exemplifies multi-functionality by serving both optical and electrical functions simultaneously. Optically, it remains transparent to allow laser beam diffusion. Electrically, it conducts signals to enable breakage detection through continuity monitoring. This dual functionality eliminates the need for separate detection components, thereby reducing overall device complexity while maintaining high detection reliability.
Solution Approach 2:
The patent utilizes parameter changes in the electrode's electrical properties to detect diffuser breakage. By monitoring changes in electrical continuity (resistance/infinity transition) of the transparent electrode, the system can reliably detect breakage events. This parameter-based detection approach simplifies the monitoring mechanism compared to more complex sensing systems.
3Object-affected harmful factors
If the light source section is halted to protect users from laser beam, then user safety is improved, but measurement functionality is lost
Solution Approach 1:
The patent implements feedback control by continuously monitoring the transparent electrode's electrical continuity and using this information to control the laser source operation. When the electrode shows signs of breakage (changing from continuous to discontinuous electrical path), the system provides feedback to halt the laser source. This feedback mechanism ensures user safety while maintaining measurement functionality during normal operation, as the laser only stops when actual breakage is detected.
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
Enables effective detection of diffuser breakage, ensuring user safety by halting laser beam emission when a breakage is detected, while minimizing impact on transmittance and detection accuracy.
Implementation Method 1
detects a reflected wave that occurs at a released end
Data Source
AI summary
The present disclosure relates to a distance measurement apparatus and a detection method that allow for reliable detection of diffuser breakage. Provided is a distance measurement apparatus that includes a light source section and a breakage detection section. The light source section emits a laser beam. The breakage detection section detects breakage of a diffusion member that diffuses the laser beam emitted from the light source section. The light source section modulates the laser beam on the basis of a pulsed wave generated by a pulse generator and emits the modulated laser beam. The breakage detection section feeds the pulsed wave to one end of a transparent electrode formed in a predetermined pattern on the diffusion member, detects a reflected wave that occurs at a released end that is another end, and detects breakage of the diffusion member on the basis of a detection result of the reflected wave. The technology according to the present disclosure is applicable, for example, to a distance image sensor using a TOF technique.