Projector Diffuser Monitoring for Pinhole Defect Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing projection systems fail to accurately distinguish between safe and unsafe operating conditions of a diffuser due to undetected minor damages like pinhole defects, leading to potential eye damage from unsafe laser light levels.
Innovation Solution
A system that monitors the state of a diffuser by sampling and analyzing the light distribution in the exit pupil using a sampler and detectors to generate alarm signals when anomalies are detected, allowing for precise differentiation between safe and unsafe operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor detects reflected light from a diffuser to shut off laser power, then safety is improved, but the detection precision is insufficient to distinguish minor damages like pinhole defects
Solution Approach 1:
The detection system is segmented into multiple independent photodetectors arranged in a matrix, each monitoring specific angular ranges. This segmentation allows the system to detect localized light concentration patterns caused by pinhole defects while maintaining overall safety monitoring coverage.
Solution Approach 2:
The invention transitions from single-point intensity detection to angular distribution detection by arranging photodetectors to measure light intensity across different angles. This dimensional change enables detection of pinhole defects that concentrate light in specific angular directions without affecting overall intensity.
2Device complexity
If a single detector monitors reflected light intensity, then device complexity is reduced, but the ability to detect and measure diffuser damages is insufficient
Solution Approach 1:
The detection system is divided into multiple photodetectors, each responsible for monitoring specific angular sectors. This segmentation enables comprehensive damage detection while keeping individual detector complexity low and manageable.
Solution Approach 2:
The photodetector matrix serves multiple functions: detecting pinhole defects, monitoring diffuser detachment, identifying cracks, and tracking light source position drift. This multi-functionality reduces the need for separate detection systems for each failure mode.
3Illumination intensity
If highlight projection concentrates light at specific positions, then illumination intensity is improved, but the risk of eye damage from undetected pinhole defects increases
Solution Approach 1:
The photodetector matrix provides real-time feedback on light distribution patterns. When a pinhole defect is detected through abnormal angular light concentration, the system immediately triggers safety shutdown, preventing eye damage while allowing high-intensity highlight projection during normal operation.
Solution Approach 2:
The system performs preliminary detection of potential hazards (pinhole defects) before they can cause harm. By monitoring angular light distribution continuously, the system identifies and neutralizes dangerous conditions proactively, enabling safe high-intensity projection.
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
Effectively detects minor diffuser damages, preventing unsafe laser light exposure by generating alarm signals to shut down or reduce laser power, ensuring safety and reducing the risk of eye damage.
Implementation Method 1
a diffuser (11) illuminated by a light source (100), at least one light beam (16i) comprising at least one bundle of rays of light (16i) exiting the diffuser (11)
Implementation Method 2
a sampler that samples the light beam exiting the diffuser and re-directs it towards a detection apparatus
Implementation Method 3
The one or more detectors can include photosensors, photodiodes, photoresistors, phototransistors or similar and drive electronics to monitor these photosensors
Data Source
AI summary
The invention provides an optical apparatus configured to monitor a state of a diffuser illuminated by a light source, at least one light beam comprising at least one bundle of rays of light exiting the diffuser being for illumination of a transmissive or reflective spatial light modulator of a projector, further comprising a sampler that samples the light beam exiting the diffuser and re-directs the light beam sample towards a detection system, wherein the detection system is coupled to an analyzer that generates a signal when an anomaly is detected in the distribution of the light intensity in a cross-section of the sample of the light beam. It also provides a method of monitoring a state of a diffuser illuminated by a coherent light source.