Light-Detecting Safety Barrier Using Camera Image Comparison

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional photo-electric safety barriers are vulnerable to misalignments and tampering due to divergent light beams and have a large footprint, which limits their effectiveness and safety in detecting intrusions in potentially hazardous areas.

Innovation Solution

A safety barrier featuring a flexible, light-emitting tube with a camera system that uses a controlled, variable light signal and image comparison to detect intrusions, with positioning markers and a band-pass filter to enhance accuracy and resistance to tampering, and optional dual light-emitting tubes for improved detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional photo-electric barriers use divergent light beams from LEDs, then the barrier can tolerate small misalignments between columns, but the system becomes vulnerable to tampering and accidental displacements

Engineering Contradiction:
Improvealignment toleranceVSAvoidanti-tampering capability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The light source is divided into multiple independent LEDs arranged in a specific geometric pattern rather than using a single divergent beam. Each LED acts as an independent detection zone, and the control unit analyzes the specific pattern of interruptions to distinguish between misalignment and tampering attempts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control unit continuously monitors the light beam interruption patterns and compares them against expected patterns. When deviations are detected that suggest tampering rather than simple misalignment, the system generates alarm signals. This feedback mechanism enables the system to adapt and respond to abnormal conditions while maintaining tolerance for normal alignment variations.

Inventive Principle:
Principle #23Feedback

2Area of stationary object

If conventional photo-electric barriers use two bulky columns arranged within the gate, then the light beams can cover the detection area, but the available transit area is considerably narrowed

Engineering Contradiction:
Improvedetection coverageVSAvoidtransit area availability
Core Design Contradiction:
Area of stationary objectVSEase of operation

Solution Approach 1:

The system transitions from a two-column three-dimensional structure to a planar arrangement where LEDs are mounted on a flat surface (gate frame or wall). This dimensional change projects the detection planes into the gate area without requiring physical columns to occupy space within the transit zone, thus maintaining detection coverage while preserving transit area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Instead of using physical columns that occupy space, the invention uses optical projections and light patterns that replicate the detection functionality. The light beams create virtual detection planes that can be positioned within the gate area without requiring physical structures, effectively copying the detection function without the spatial burden.

Inventive Principle:
Principle #26Copying

3Reliability

If the light beams are made more collimated to reduce tampering vulnerability, then anti-tampering capability improves, but the tolerance for misalignment decreases

Engineering Contradiction:
Improveanti-tampering capabilityVSAvoidalignment tolerance
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

Different regions of the detection system use light beams with different characteristics. LEDs positioned at corners or edges may use more collimated beams for tampering detection, while central LEDs use broader beams for general intrusion detection. Each local zone is optimized for its specific function, and the control unit integrates information from all zones to make overall security assessments.

Inventive Principle:
Principle #3Local quality

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 solution provides enhanced resistance to accidental displacements and tampering, with a smaller footprint and improved detection accuracy, allowing for precise monitoring of the gate area and reducing false alarms.

Implementation Method 1

a flexible, light-emitting tube (14) arranged along two adjacent sides of the periphery of the gate (12), and a camera (18), which is arranged on the periphery of the gate at the opposite corner with respect to the light-emitting tube

Methodology Applied
Scientific EffectLight emission and detection: Light

Implementation Method 2

Camera 18 is provided with a band-pass light filter 24 which is compatible with the radiation emitted by the light-emitting tube and is adapted to limit the susceptibility of the camera to external light interferences.

Methodology Applied
Scientific EffectBand-pass filtering: Filter (optical)

Data Source

PatentEP2224266B1Light-detecting safety barrier
Publication Date: 2015.03.18 REER
  • EP2224266B1 patent drawingFigure 1~4

AI summary

The barrier is installable in a gate (12) leading to a potentially dangerous area, and comprises a light-emitting tube (14) arranged along a portion of the periphery of the gate (12), as well as a camera (18) substantially arranged on the periphery of the gate (12) in front of the light-emitting tube (14) for detecting its image. A control unit (22) is programmed to compare, instant by instant, the current image detected by the camera (18) with a reference image representing the light-emitting tube in a clear condition, and to generate an alarm signal each time the reference image differs from the current image by a predetermined, minimum number of pixels.