Optical Element Sensing Circuit for Laser Displacement Safety
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Solution Overview
Problem
Existing optical devices face challenges in safely detecting and preventing displacement of optical elements, which can lead to excessive light emission that exceeds eye safety thresholds, potentially causing retinal damage.
Innovation Solution
A sensing circuit is integrated within the control integrated circuit to monitor the electrical trace of the optical element, using resistive voltage dividers and comparator circuits to detect any displacement or improper coupling, thereby disabling the laser light source to prevent unsafe light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an optical element is added to increase total power transmission, then the power transmission capability is improved, but the risk of retinal damage from displacement increases
Solution Approach 1:
The patent applies preliminary action by implementing a sensing circuit that proactively detects the presence and proper positioning of the optical element before the laser is activated. The circuit includes a conductive trace on the optical element that forms an electrical circuit when properly positioned, allowing the system to verify correct placement in advance and prevent harmful radiation exposure before it can occur.
2Reliability
If a sensing circuit with conductive trace is implemented to detect displacement, then the safety detection capability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the sensing function with the existing optical element structure by integrating a conductive trace directly onto the optical element itself. This approach combines multiple functions (optical transmission and presence detection) into a single component, reducing overall device complexity while maintaining reliable safety detection capability.
Solution Approach 2:
The optical element serves multiple functions: it acts as both the optical transmission component and the sensing element through its integrated conductive trace. This multi-functionality eliminates the need for separate sensing components, thereby reducing device complexity while improving reliability through consistent safety monitoring.
3Power
If the laser light source emits high optical power, then the light emission capability is improved, but the eye safety threshold is exceeded
Solution Approach 1:
The patent implements feedback control by using the sensing circuit to continuously monitor the position and presence of the optical element, and automatically controlling the driver circuit to enable or disable the laser based on the detected conditions. This closed-loop feedback system ensures that high-power laser emission only occurs when the optical element is properly positioned, maintaining both high emission capability and eye safety.
Data Source
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AI summary
An optical element is positioned in a holder over a laser light source. The optical element includes an electrical trace that is coupled between first and second pads. A sensing circuit that is also coupled to the first and second pads performs a voltage/current sensing operation to detect displacement of the optical element and control enablement of the laser light source.