Optoelectronic Sensor Parallel Operation Modulation
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Solution Overview
Problem
Existing optoelectronic sensor arrangements with multiple light transmitters face increased response times and interference issues when operated in parallel, particularly due to the interleaving of codes over time, which affects their interference immunity and reliability.
Innovation Solution
Assigning unique basic modulation frequencies to each light transmitter, allowing light receivers to distinguish between signals and preventing interference, while using evaluation devices to generate object detection signals without increasing response time, even when multiple light grids or barriers are operated in parallel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple light transmitters are operated in parallel with time-interleaved codes, then the monitoring coverage is increased, but the response time increases due to code interleaving
Solution Approach 1:
The patent applies periodic action by assigning each light transmitter a unique periodic modulation frequency. Instead of time-interleaved codes where transmitters operate sequentially, all transmitters operate simultaneously with their own characteristic frequencies (e.g., 1kHz, 2kHz, 3kHz). The receiver detects objects by analyzing the modulation frequency of received light signals, enabling parallel operation without response time penalties.
2Area of stationary object
If multiple light transmitters operate simultaneously with different codes, then the monitoring coverage is increased, but interference between transmitters increases
Solution Approach 1:
The patent applies local quality by giving each light transmitter a unique local characteristic - its own modulation frequency. This allows the receiver to distinguish between light from different transmitters through frequency discrimination. For example, light from transmitter 1 modulated at 1kHz can be differentiated from light from transmitter 2 modulated at 2kHz, eliminating mutual interference while maintaining simultaneous operation and expanded coverage.
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 enhances the interference immunity and maintains fast response times for optoelectronic sensor arrangements by ensuring that light transmitters can be differentiated based on their modulation frequencies, preventing mutual interference and allowing for reliable operation with overlapping monitoring areas.
Implementation Method 1
several light transmitters emit at least one light signal each into a monitoring area
Implementation Method 2
the at least one light signal emitted by a light transmitter has a basic modulation frequency assigned to the respective light transmitter
Implementation Method 3
The at least one light signal from a light transmitter is received by at least one light receiver assigned to the light transmitter
Data Source
Figure 1~2
Figure 3~5a
Figure 5b~6
AI summary
The method involves transmitting a light signal into a monitoring area by light transmitters (12), where the transmitted light signal is provided with a base modulation frequency associated to one of the transmitters. The base modulation frequency is different from a base modulation frequency of the light signal of the other transmitter. The transmitted light signal is received by light receivers (14). A received signal of the receivers is evaluated by an evaluation device. An object detection signal is produced by the evaluation unit based on the received signal. An independent claim is also included for an optoelectronic sensor arrangement comprising comparators.