Light Curtain Alignment Using Shaped Infrared Beams

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The alignment of light curtains is challenging due to the use of infrared light beams, which are invisible, making it difficult for operators to visually verify the alignment of transmitters and receivers, thereby requiring additional design efforts for visible alignment transmitters and markings.

Innovation Solution

The use of light beams with different beam profiles, emitted by transmitters, to align the light curtain, where the alignment quality is determined by analyzing the received signal levels, allowing for precise alignment without additional design effort, using existing infrared transmitters and receivers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If infrared light beams are used for object detection, then the detection function is achieved, but the alignment operation becomes difficult because the light beams are invisible

Engineering Contradiction:
Improveobject detection capabilityVSAvoidalignment operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the parameter of beam profile (from circular to non-circular shapes such as rectangular, triangular, or trapezoidal) of the infrared light beams. This allows the invisible infrared beams to carry identifiable shape information that can be detected by the receivers, enabling alignment verification without switching to visible light.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces beam profiles as an intermediary carrier of alignment information. Instead of using visible light as a mediator, the system uses the shape characteristics of infrared beams themselves to convey alignment status, allowing operators to indirectly observe alignment through signal pattern analysis.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If alignment transmitters and markings are added to enable visual alignment, then the alignment operation becomes easier, but the device complexity and design effort increase considerably

Engineering Contradiction:
Improvealignment operationVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent makes the existing infrared transmitters and receivers multi-functional. The transmitters not only emit detection beams but also emit alignment beams with specific profiles. The receivers not only detect object beams but also analyze beam profiles for alignment verification. This eliminates the need for separate alignment transmitters and markings.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The light curtain system performs its own alignment function using its existing components. The transmitters and receivers generate and analyze beam profiles without requiring external alignment equipment, markings, or additional visible light sources. The system is self-aligning through signal pattern recognition.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If multiple light beams with different beam profiles are used for alignment, then the alignment precision is improved, but the signal processing complexity increases

Engineering Contradiction:
Improvealignment precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the alignment verification process by using multiple light beams with different beam profiles (e.g., rectangular, triangular, trapezoidal) emitted at different angles. Each beam profile provides independent alignment information for different spatial dimensions, allowing precise multi-dimensional alignment verification through separate signal channels.

Inventive Principle:
Principle #1Segmentation

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

Enables simple and precise alignment of the light curtain by visualizing misalignments through signal level analysis, eliminating the need for additional alignment transmitters and markings, thus reducing design complexity and cost.

Implementation Method 1

an arrangement of transmitters (4) emitting light beams (3) and receivers (6) receiving light beams (3)

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

the transmitters typically emit light beams in the infrared range, i.e., in the non-visible wavelength range

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 3

receivers (6) receiving light beams (3)

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4279792B1Light curtain
Publication Date: 2024.04.24 LEUZE ELECTRONIC GMBH & CO KG
  • EP4279792B1 patent drawingFigure 1
  • EP4279792B1 patent drawingFigure 2
  • EP4279792B1 patent drawingFigure 3~4

AI summary

The invention relates to a light curtain (1) for detecting objects in a monitoring area, comprising an arrangement of light beams (3) emitting transmitters (4) and light beams (3) receiving receivers (6). When the monitoring area is clear, the light beams (3) from the transmitters (4) pass through the monitoring area and are each directed to an associated receiver (6). When an object enters the monitoring area, the beam path of the light beams (3) from at least one transmitter (4) is at least partially interrupted. In an evaluation unit, an object detection signal is generated based on the received signals from the receivers (6). According to the invention, light beams (3) with different beam profiles are provided, and in an alignment mode, received signals from the receivers (6) are determined as a measure of the alignment accuracy of the light curtain (1).