Optical Sensor Paint Jet Width Measurement

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Solution Overview

Problem

Existing measurement systems for paint jets in conformal coating processes are inaccurate and time-consuming, leading to positioning errors and high paint consumption due to the need to move the curtain nozzle during calibration, which results in inefficiencies and increased costs.

Innovation Solution

A painting device equipped with an optical sensor having a wide field of view that allows for simultaneous measurement of paint jet width and symmetry without moving the sensor relative to the paint jet, utilizing two operating modes to output signals corresponding to the width and central position of the paint jet, enabling quick and precise calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the curtain nozzle is moved during calibration to measure paint jet width, then measurement can be performed with a narrow sensor field of view, but measurement time increases and positioning errors occur

Engineering Contradiction:
Improvepaint jet width measurement accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent transitions from a one-dimensional measurement approach (moving sensor or nozzle along a single axis) to a two-dimensional solution by providing the sensor with a wide field of view that covers the entire expected paint jet width. This allows simultaneous measurement of the entire paint jet cross-section without movement, resolving the contradiction between measurement precision and calibration time.

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

2Productivity

If the curtain nozzle is moved during calibration, then measurement can be performed, but positioning errors lead to reduced manufacturing precision

Engineering Contradiction:
Improvecalibration speedVSAvoidpaint jet positioning accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical movement system (moving the curtain nozzle or sensor during calibration) with an optical solution. The sensor is equipped with a wide field of view that optically captures the entire paint jet width simultaneously, eliminating mechanical positioning requirements and associated errors while maintaining high productivity.

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

3Device complexity

If a narrow sensor field of view is used, then sensor cost and complexity are reduced, but the sensor must be moved relative to the paint jet requiring complex positioning mechanisms

Engineering Contradiction:
Improvesensor positioning system complexityVSAvoidsensor field of view width
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent merges multiple measurement capabilities into a single stationary sensor unit. By integrating a wide field of view that can simultaneously capture the entire paint jet width, the sensor combines what would otherwise require multiple sensors or a moving measurement system, thereby reducing overall device complexity while maintaining a sufficiently large field of view.

Inventive Principle:
Principle #5Merging (Combining)

4Measurement precision

If the curtain nozzle is moved during calibration, then measurement is possible, but paint consumption increases due to continuous paint supply during movement

Engineering Contradiction:
Improvepaint jet width measurement capabilityVSAvoidpaint consumption
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The patent implements a stationary measurement approach where the sensor continuously monitors the paint jet at a fixed position. This periodic, stationary measurement eliminates the need for continuous paint supply during movement, reducing paint consumption while maintaining measurement precision through ongoing monitoring at the calibration position.

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

This solution enables fast, accurate, and cost-effective measurement and calibration of paint jets, reducing paint consumption and eliminating the need for manual adjustments, thereby improving the precision and efficiency of the conformal coating process.

Implementation Method 1

the receiver does not receive the light emitted by the transmitter directly, but rather as light reflected from an object

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

The optical sensor consists of an essentially point-shaped light source 3A and a receiver 3B, for example a photodiode

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP3449207B1Device and method for measuring a paint jet for coating circuit boards
Publication Date: 2024.03.06 REHM THERMAL SYST GMBH
  • EP3449207B1 patent drawingFigure 1~2
  • EP3449207B1 patent drawingFigure 3~4
  • EP3449207B1 patent drawingFigure 5~6

AI summary

The invention relates to devices and methods for measuring a paint jet for a painting process for electronic subassemblies. Said devices and methods allows the width and symmetry of the paint jet to be determined without performing any relative movement between the paint jet and the sensor.