Optoelectronic Sensor Decoupling Optical and Electronic Modules

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Solution Overview

Problem

Conventional laser scanners face challenges with complex electronics that hinder miniaturization, increase power consumption, and sensitivity to electromagnetic interference, while internal reference targets are prone to scattered light and limited field of view due to restricted angular ranges.

Innovation Solution

Decoupling optical and electronic components by using an optics module with a movable deflection unit and a separate electronics module connected via optical fibers, allowing for miniaturization and robustness against electromagnetic interference, with a reference optical waveguide providing a reference signal for evaluation without scattered light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If optical and electronic components are integrated in one housing, then the device structure is compact, but the device cannot be miniaturized and experiences increased power consumption and heat generation

Engineering Contradiction:
Improvedevice sizeVSAvoidpower consumption
Core Design Contradiction:
Volume of moving objectVSUse of energy by moving object

Solution Approach 1:

The device is divided into two separate modules: an optical module containing optical components (transmitter, receiver, deflection unit) and an electronic module containing electronic components (evaluation electronics, power supply). This segmentation allows independent optimization of each module, enabling miniaturization of the optical module while distributing power consumption across separate units.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electronic components are extracted from the optical module and placed in a separate electronic module. This extraction removes the heat-generating and power-consuming electronic components from the optical module, enabling the optical module to be miniaturized without the burden of integrated electronics.

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If electronic components are increased to meet integration demands, then network integration capability improves, but sensitivity to electromagnetic interference increases

Engineering Contradiction:
Improvenetwork integration capabilityVSAvoidelectromagnetic interference sensitivity
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

Optical fibers serve as an intermediary communication medium between the optical module and electronic module. This optical connection replaces electrical cables, providing galvanic isolation that protects the sensitive optical components from electromagnetic interference while maintaining network integration capabilities through the electronic module.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a contiguous angular range is used for reference target measurement, then functional testing is enabled, but the field of view is restricted

Engineering Contradiction:
Improvefunctional testing capabilityVSAvoidfield of view
Core Design Contradiction:
ReliabilityVSArea of moving object

Solution Approach 1:

Instead of using a physical reference target that occupies angular space, a virtual reference target is created by optically coupling a reference optical waveguide directly to the transmitter. This copying approach provides reference measurement functionality without requiring a physical object in the scanning path, thus preserving the full 360° field of view.

Inventive Principle:
Principle #26Copying

4Measurement precision

If an internal reference target system is used for functional testing, then error-free distance measurement can be checked, but scattered light problems arise

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidscattered light
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The reference measurement function is copied from a physical reference target to an optical waveguide-based virtual reference target. This eliminates scattered light issues because the reference signal is delivered through the optical fiber without requiring reflection from a physical target surface, while still providing the necessary reference for distance measurement accuracy verification.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The mechanical/optical reference target system is replaced with an optical fiber-based reference signal delivery system. This substitution eliminates the scattered light problem inherent in physical targets while maintaining the functional testing capability for distance measurement precision.

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

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 full 360° scanning, reduced electronic complexity, increased robustness, and miniaturization of laser scanners, enhancing reliability and adaptability for various applications including safety and network integration.

Implementation Method 1

transmitting and receiving optical waveguides (16, 18) for coupling light into and out of the optics module (12)

Methodology Applied
Scientific EffectLight transmission through optical waveguide: Optical Fibre

Implementation Method 2

a light beam generated by a laser periodically sweeps over a monitored area with the aid of a deflection unit

Methodology Applied
Scientific EffectLight reflection and deflection: Reflection

Implementation Method 3

The light is reflected on objects in the monitored area and evaluated in the scanner

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Implementation Method 4

at least one reference optical waveguide (68) which supplies at least part of the transmission signal as a reference signal to the light receiver (38)

Methodology Applied
Scientific EffectLight transmission through optical waveguide: Optical Fibre

Implementation Method 5

a light beam generated by a laser periodically sweeps over a monitored area

Methodology Applied
Scientific EffectLaser light generation: Laser

Implementation Method 6

the distance of the object from the laser scanner is also deduced from the time of flight using the speed of light

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP3208636B1Optoelectronic sensor and method for detecting objects
Publication Date: 2018.01.24 SICK AG
  • EP3208636B1 patent drawingFigure 1
  • EP3208636B1 patent drawingFigure 2
  • EP3208636B1 patent drawingFigure 3

AI summary

An optoelectronic sensor (10), in particular a laser scanner, is described, comprising a light emitter (20) for emitting a scanning beam (26) into a monitoring area (30), a light receiver (38) for generating a received signal from the scanning beam (32) reflected by objects in the monitoring area (30), a movable deflection unit (28) for periodically deflecting the scanning beam (26, 32) in order to scan the monitoring area (30) during movement, an evaluation unit (42) configured to detect objects in the monitoring area (30) based on the received signal, and a transmitting optical waveguide (16, 52) for transmitting the scanning beam (26) from the light emitter (20) to the deflection unit (28), and/or a receiving optical waveguide (18, 52) for transmitting the reflected scanning beam (32) from the deflection unit (28) to the light receiver. (38) to direct.The sensor (10) comprises an optical module (12) with the movable deflection unit (28) and a separate electronic module (14) with the light transmitter (20) and/or the light receiver (38) as well as the evaluation unit (42), and the transmitting optical waveguide (16, 52) and/or the receiving optical waveguide (18) connects the two modules (12, 14) together.