Light Grid Distance Measurement With Variable Intensity And Amplification

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Solution Overview

Problem

Existing light grids for object detection, such as those used in elevator doors, are costly and lack differentiated monitoring capabilities.

Innovation Solution

A light grid system with qualified and unqualified transmitter and receiver elements, controlled by a device to determine distance values through varying intensities and amplifications, allowing for dynamic process tracking and cost-effective operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If all transmitter and receiver elements are designed as qualified elements with multiple intensity and amplification levels, then measurement precision and distance determination accuracy are improved, but device complexity and cost increase

Engineering Contradiction:
Improvedistance determination accuracyVSAvoidcomplexity of light grid
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The light grid is segmented into two functional groups: qualified transmitter and receiver elements (which perform distance measurement through intensity/amplification variations) and simple transmitter and receiver elements (which perform basic object detection). This segmentation allows the system to achieve precise distance measurement without requiring all elements to be complex qualified elements, thereby reducing overall device complexity while maintaining measurement accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the light grid are assigned different functional qualities: qualified elements are equipped with multiple intensity and amplification levels for precise distance determination, while simple elements use fixed intensity and amplification for basic detection. This local differentiation optimizes the system by applying complex functionality only where needed for measurement, rather than uniformly across all elements.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If qualified transmitter and receiver elements are used with varying intensities and amplifications, then distance determination capability is improved, but cost of the light grid increases

Engineering Contradiction:
Improvedistance determination capabilityVSAvoidcost of light grid
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The system segregates the expensive qualified elements (with multiple intensity/amplification capabilities) from the inexpensive simple elements. Only a subset of transmitter and receiver elements are manufactured as qualified elements, while the rest are produced as simple elements. This reduces the overall bill of materials cost while preserving distance determination capability through the qualified elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

High-quality components with variable intensity and amplification are applied locally only to the qualified elements needed for distance measurement, rather than equipping all elements with such capabilities. This localized application of high-quality components achieves the required measurement precision while minimizing the total cost of the system.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If sequential control of combinations is used to determine distance values, then measurement precision is improved, but loss of time increases due to periodic sequencing

Engineering Contradiction:
Improvedistance value accuracyVSAvoidtime for distance determination
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The control device operates in periodic cycles, sequentially activating different combinations of qualified transmitter and receiver elements with varying intensities and amplifications. Each cycle completes a full set of measurements required for accurate distance determination. This periodic sequencing ensures all necessary data points are collected for precise measurement while maintaining a regular, predictable timing structure that allows for efficient processing.

Inventive Principle:
Principle #19Periodic action

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 precise object detection with optimized resolution and cost savings by using a combination of elements with different functionalities, ensuring consistent accuracy across varying distances and allowing wireless transmission of data for independent evaluation.

Implementation Method 1

a transmitter bar (21) with one or more transmitter elements (31, 33) which emit radiation with a specific intensity

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

a receiver bar (22) with one or more receiver elements (32, 34) which receive the radiation of an associated transmitter element (31, 33)

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4307018B1Light grid with distance measurement
Publication Date: 2025.09.10 CEDES AG
  • EP4307018B1 patent drawingFigure 1
  • EP4307018B1 patent drawingFigure 2a~2c
  • EP4307018B1 patent drawingFigure 3~5

AI summary

Light grid for determining the distance between transmitter and receiver strips, comprising a transmitter strip with one or more transmitter elements emitting radiation of a specific intensity, a receiver strip with one or more receiver elements receiving the radiation from an associated transmitter element, and a control device for controlling the transmitter elements and/or the receiver elements and for evaluating the receiver elements, wherein the transmitter element and the receiver element, or at least one of the transmitter elements and/or at least one of the receiver elements, are configured as qualified transmitter and receiver elements, wherein the qualified transmitter element or elements are configured to emit different intensities and/or the qualified receiver element or elements are configured toto apply different amplifications and output an intensity value for the received and amplified radiation, and the control device is designed to control different combinations of intensities and amplifications of the qualified transmitter and/or receiver elements and to determine a distance value depending on the sum of the resulting intensity values ​​of the controlled combinations,