Revolving Door Laser Scanning for Finger-Safe Gap Detection
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Solution Overview
Problem
Existing safety protection sensors for revolving doors, such as contact pressure deformation sensors and infrared optical sensors, either cause harm to users or provide incomplete protection, while laser sensors are limited in installation and effectiveness due to wide beam divergence and fixed detection areas.
Innovation Solution
A laser sensor system with a laser scan range calculation section and application analysis section, utilizing a laser emitting device, deflecting device, and analyzing and processing unit to create a focused scan area and detect objects with high precision, automatically adjusting detection range and resolution for complete protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If infrared optical safety protection sensor is used, then non-contact protection is achieved, but the light beam has wide divergence angle and cannot detect small objects like fingers
Solution Approach 1:
The patent replaces traditional infrared optical sensors with a laser sensor system that emits laser beams instead of infrared light. This substitution enables precise detection of small objects like fingers by utilizing the coherent and directional properties of laser light, thereby resolving the contradiction between non-contact protection and detection precision.
Solution Approach 2:
The patent changes the fundamental parameter of the light source from infrared radiation to laser radiation. This parameter change results in a highly directional beam with minimal divergence, allowing the system to detect small objects at various distances while maintaining non-contact protection capabilities.
2Area of stationary object
If multiple infrared light beams are combined for door leaf protection, then rough protection is achieved, but areas outside light beams cannot be protected and detection gaps exist
Solution Approach 1:
The patent employs a movable mirror that rotates to dynamically sweep the laser beam across the entire door leaf surface. This dynamic scanning approach replaces the static multiple beam configuration, ensuring continuous coverage of all areas including edges and corners without leaving detection gaps.
Solution Approach 2:
The system performs preliminary scanning to map the door leaf geometry and identifies critical detection zones before actual safety monitoring begins. This preliminary action ensures that the laser beam coverage is optimized to cover all potential hazard areas, preventing detection gaps.
3Measurement precision
If laser sensor is installed on door frame to monitor entrance and exit, then detection at entry points is achieved, but gaps between door leaf and door frame cannot be detected
Solution Approach 1:
The patent designs the laser sensor system to perform multiple functions: it monitors both the entrance/exit points at the door frame and the gaps between the door leaf and door frame. The rotating mirror mechanism enables the single sensor to cover both areas sequentially, achieving universal protection without requiring separate sensors for each zone.
4Device complexity
If fixed detection area is used for laser sensor, then simple control is achieved, but detection area cannot be extended beyond door frame and false triggers occur
Solution Approach 1:
The patent implements a dynamic detection area that adjusts based on the door's position and operational state. The rotating mirror sweeps the laser beam to extend detection coverage beyond the fixed door frame area when needed, while the control system dynamically adjusts the active detection zones to prevent false triggers from stationary objects.
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 laser sensor system provides non-contact, seamless protection with improved detection precision and range, preventing harm to users by detecting objects as small as a finger and extending detection beyond the door frame, reducing energy consumption, and avoiding false triggers.
Implementation Method 1
comprises a laser emitting device, a laser deflecting device, an optical signal receiving device, and an analyzing and processing device. Wherein, the laser emitting device emits laser signals to the laser deflecting device
Implementation Method 2
The optical signal receiving device is used for receiving returned laser signals and transmitting said signals to the analyzing and processing device
Data Source
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AI summary
To address the deficiencies in the prior art, the present invention provides a laser sensor for human body safety protection for use in a revolving door, which comprises: a laser scan range calculation section and an application analysis section. The laser scan range calculation section comprises a laser emitting device, a laser deflecting device, an optical signal receiving device, and an analyzing and processing device. Wherein, the laser emitting device emits laser signals to the laser deflecting device; the laser deflecting device deflects the laser signals by a pre-set angle and forms at least one laser scan area; the optical signal receiving device receives returned laser signals and transmits said signals to the analyzing and processing device. The analyzing and processing device comprises a trigger point distance analyzing module, which makes analysis to obtain trigger point distance information according to signals sent from the optical signal receiving device. The application analysis section comprises a safety analysis module, which controls motion state of the revolving door through a door control device after making analysis on the basis of the trigger point distance information.