Waveguide Grating Light Projection Safety Feedback
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Solution Overview
Problem
Current light projecting technologies, particularly those using lasers, lack adequate safety mechanisms to prevent excessive light from spilling into the environment in case of device damage or malfunction, potentially causing eye damage due to uncontrollable laser emission.
Innovation Solution
A light projecting system comprising a waveguide with grating structures that undergo total internal reflection, a detector to measure the remainder beam, and a processor to adjust the light source's emission based on threshold conditions, ensuring eye safety by reducing light intensity when dangerous conditions are detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If powerful lasers are used for light projection, then the light projection effectiveness is improved, but the risk of eye damage from uncontrollable laser spill increases
Solution Approach 1:
The patent implements a feedback mechanism where a detector continuously monitors the remainder beam that undergoes total internal reflection within the waveguide. When the detected light intensity exceeds a predetermined threshold, the system automatically adjusts the light source emission to reduce intensity, thereby preventing eye damage while maintaining effective light projection during normal operation.
Solution Approach 2:
The patent introduces a waveguide as an intermediary component between the light source and the external environment. The waveguide confines the powerful laser light through total internal reflection, directing it precisely toward the target while preventing uncontrollable spill into the environment. The grating structures act as controlled out-coupling points, further regulating light emission.
2Object-affected harmful factors
If multiple lasers are used to ensure safety, then the eye safety protection is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
Instead of using multiple lasers, the patent employs a single light source equipped with a feedback control system. The detector monitors the remainder beam and provides real-time information to adjust the light source emission, achieving safety protection through active control rather than redundant hardware components.
Solution Approach 2:
The system performs self-monitoring and self-regulation through the feedback mechanism. The detector continuously checks the light beam conditions, and the system automatically adjusts the light source emission without requiring external intervention or complex safety systems, thereby simplifying the overall device structure.
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 system effectively mitigates the risk of eye damage by automatically reducing light intensity when unsafe conditions are detected, providing enhanced eye safety protection without the need for multiple lasers and reducing manufacturing costs and device size.
Implementation Method 1
the waveguide is configured to guide the in-coupled light beam to undergo total internal reflection between the first surface and the second surface
Implementation Method 2
each of the first grating structures is configured to disrupt the total internal reflection to cause at least a portion of the in-coupled light beam to couple out of the waveguide
Implementation Method 3
a detector configured to receive and measure the remainder beam and to cause the in-couple beam to at least decrease in strength
Data Source
AI summary
A light projecting system comprises: a waveguide comprising a first surface, a second surface, and a fourth surface, at least one of the first surface or the second surface comprising a first plurality of grating structures; a light source coupling light into the waveguide to form an in-coupled light beam, wherein: each of the first grating structures is configured to disrupt the total internal reflection to cause at least a portion of the in-coupled light beam to couple out of the waveguide, and a remainder beam of the in-coupled light beam undergoing the total internal reflection being coupled out of the waveguide after the out-coupling at each of the first grating structures; a detector configured to receive and measure the remainder beam; and a processor coupled to the detector and configured to determine if a dangerous condition occurs based on the measured remainder beam.