Optoelectronic Sensor Miniaturization via Angled Transmitter-Receiver Axis

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Solution Overview

Problem

Existing optoelectronic sensors based on the triangulation principle face limitations in miniaturization due to the arrangement of the transmitter, receiver, and evaluation unit on a common circuit board, which restricts their size reduction and versatility.

Innovation Solution

The sensor design features a transmitter-receiver axis angled relative to the housing longitudinal axis, with the transmitter at the axis intersection, allowing for a compact and cost-effective miniaturization. The receiver and evaluation unit are adjacent, with short connecting lines to minimize interference, and a metallic shield enhances electromagnetic compatibility. The transmitter and receiver lenses are aligned within a one-piece tube for precise alignment, and a soldering adapter board provides connections without increasing width.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the transmitter, receiver and evaluation unit are arranged on a common circuit board, then the device complexity is reduced and manufacturing is simplified, but the sensor size cannot be sufficiently miniaturized

Engineering Contradiction:
Improvedevice complexityVSAvoidsensor size
Core Design Contradiction:
Device complexityVSVolume of moving object

Solution Approach 1:

The transmitter-receiver axis is arranged at an angle to the longitudinal axis of the housing, creating a three-dimensional configuration that reduces the sensor width while maintaining functional separation of components on a common circuit board

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The receiver is positioned asymmetrically relative to the longitudinal axis of the sensor housing, with the transmitter-receiver axis intersecting the longitudinal axis at an angle, allowing compact arrangement without symmetric constraints

Inventive Principle:
Principle #4Asymmetry

2Ease of operation

If the receiver is arranged centrally on the longitudinal axis for optimal optical alignment, then the optical adjustment is simplified, but the sensor width increases and miniaturization is limited

Engineering Contradiction:
Improveoptical alignmentVSAvoidsensor width
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The receiver is deliberately positioned asymmetrically, offset from the central longitudinal axis, with the transmitter-receiver axis intersecting the longitudinal axis at an angle between 5° and 30°, reducing sensor width while maintaining adequate optical alignment

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The optical alignment requirements are localized to the transmitter-receiver axis intersection point, allowing the rest of the sensor to be optimized for compactness with the receiver positioned at the optimal location for miniaturization

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the receiver and evaluation unit are positioned far apart to reduce interference, then electromagnetic compatibility improves, but the sensor width increases

Engineering Contradiction:
Improveelectromagnetic interferenceVSAvoidsensor width
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

A metallic shield is introduced as an intermediary element between the receiver and evaluation unit, providing electromagnetic shielding that allows close positioning of components without compromising signal quality, thus enabling miniaturization while maintaining immunity to interference

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design significantly reduces sensor size, enhances sensitivity, and improves measurement accuracy by minimizing external interference, while allowing for easier mechanical alignment and increased range, making the sensor more versatile and efficient.

Implementation Method 1

at least one transmitter (2) for emitting transmitted light (48) in the direction of a monitoring area

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

a receiver (5) with at least two receiving elements (12) arranged on a transmitter-receiver axis (22) for the output of at least two received signals

Methodology Applied
Scientific EffectPhotodetection: Photoelectric Effect

Implementation Method 3

A transmitting lens is arranged in front of the transmitter to focus the transmitted light

Methodology Applied
Scientific EffectOptical focusing: Lens

Implementation Method 4

A receiving lens is arranged in front of the receiver in order to focus the received light onto the receiver

Methodology Applied
Scientific EffectOptical focusing: Lens

Data Source

PatentEP2040097B1Optoelectronic sensor
Publication Date: 2011.04.20 SICK AG
  • EP2040097B1 patent drawingFigure 1
  • EP2040097B1 patent drawingFigure 2~3
  • EP2040097B1 patent drawingFigure 4~5

AI summary

The sensor (1) has an evaluating device (7) for determining whether an object lies in a front or a rear of the sensor. The evaluating device, a transmitter (2) and a receiver (5) are accommodated in a common printed circuit board (18), where the receiver and the evaluating device are arranged adjacent to each other. A transmitter-receiver axis (22) is arranged at an angle to a longitudinal axis (20) of a housing, and the transmitter is arranged in an intersection point (24) of the axes, or the axis (22) runs parallel to the axis (20) and at a distance to the axis (20).