Light Curtain Digital Switching for Transmitter Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing light curtains require high component expenditure for monitoring analog signals, increasing production costs and complexity, particularly in safety applications where reliable transmitter control is crucial.

Innovation Solution

Implementing a digital switching mechanism for each transmitter, allowing for binary control signals to activate or deactivate transmitters, reducing design effort and enhancing error security through direct status signal evaluation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If analog signal monitoring is used to control transmitters, then transmitter activation control is achieved, but component expenditure and production costs increase significantly

Engineering Contradiction:
Improvetransmitter activation control reliabilityVSAvoidcomponent expenditure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the analog signal monitoring system with a digital switching mechanism. Instead of using analog current monitoring to control transmitters, the invention employs digital switching elements (such as solid-state switches) that are controlled by digital signals. This substitution of analog control with digital control reduces component complexity and production costs while maintaining or improving reliability through direct digital status signal evaluation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If analog signal monitoring is used to control transmitters, then transmitter activation control is achieved, but production costs increase

Engineering Contradiction:
Improvetransmitter activation control reliabilityVSAvoidproduction costs
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the analog signal monitoring system with a digital switching mechanism. Instead of using analog current monitoring to control transmitters, the invention employs digital switching elements (such as solid-state switches) that are controlled by digital signals. This substitution of analog control with digital control reduces component complexity and production costs while maintaining or improving reliability through direct digital status signal evaluation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If digital switching mechanism is implemented for each transmitter, then component costs and complexity are reduced, but transmitter monitoring effort increases

Engineering Contradiction:
Improvecomponent expenditureVSAvoidmonitoring efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent merges the control and monitoring functions into a single integrated digital switching mechanism. Each digital switch is configured to both control transmitter activation and generate status signals that indicate its operational state. This merging of control and monitoring functions eliminates the need for separate monitoring components, reducing overall system complexity while maintaining efficient monitoring through the digital status signals generated by the switches themselves.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If digital switching mechanism is implemented for each transmitter, then error security is enhanced, but control unit complexity increases

Engineering Contradiction:
Improveerror securityVSAvoidcontrol unit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the control system into independent digital switching mechanisms, with each switch handling a single transmitter. This segmentation allows each digital switch to operate independently and generate its own status signal, simplifying the control unit's task to primarily reading and evaluating these discrete status signals. The segmentation approach enhances error security by isolating failures to individual switches while keeping the overall control unit architecture relatively simple through modular design.

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

This approach significantly reduces component costs and complexity while ensuring robust and reliable transmitter activation control, enabling efficient error checking and immediate response to object interference or internal errors, ensuring safe machine operation.

Implementation Method 1

a transmitting unit (2) having a number of transmitters (5) emitting light beams (4)

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

a receiving unit (3) having a number of receivers (11) receiving light beams (4)

Methodology Applied
Scientific EffectLight reception: Photoelectric Effect

Data Source

PatentEP3246732B1Method to operate a light curtain and light curtain
Publication Date: 2019.06.19 LEUZE ELECTRONIC GMBH & CO KG
  • EP3246732B1 patent drawingFigure 1
  • EP3246732B1 patent drawingFigure 2
  • EP3246732B1 patent drawingFigure 3a~3f

AI summary

The invention relates to a method for operating a light curtain (1), wherein the light curtain is used to detect objects within a monitoring area. The light curtain (1) has a transmitter unit (2) at a first edge of the monitoring area, comprising a number of light beams (4) emitting transmitters (5), and a receiver unit (3) at a second edge of the monitoring area. The receiver unit (3) has a number of receivers (11) receiving light beams (4) and an evaluation unit (12) in which an object detection signal is generated depending on the received signals from the receivers (11). A control unit (6) is provided in the transmitter unit (2) for controlling the transmitters (5), and a digital switching circuit (7) is assigned to each transmitter (5).The digital switching circuits (7) are sequentially supplied with control signals generated in the control unit (6), which activate or deactivate the transmitters (5) assigned to the digital switching circuits (7). Each digital switching circuit (7) generates a binary status signal, the signal states of which indicate whether the transmitter (5) has been activated by the control signals or not. The binary status signals of all digital switching circuits (7) are read back to the control unit (6) sequentially and compared there with setpoint values.