Preform Optical Inspection Using Multi-Orientation Sensing

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Solution Overview

Problem

Existing methods for preform quality assurance in stretch blow molding require multiple sensors and cameras, leading to a complex and costly test setup that is difficult to maintain and optimize.

Innovation Solution

A single optical sensor system with a holding device and evaluation unit is used to inspect preforms in multiple orientations, allowing comprehensive testing of geometry-related and material-related criteria by determining sensor data at different angles and positions, including indirect detection through mirrors if necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple sensors and cameras are used to inspect preforms, then measurement precision and reliability of quality assurance is improved, but device complexity and maintenance effort increase

Engineering Contradiction:
Improvequality inspection accuracyVSAvoidtest setup complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple sensors (optical sensor, camera, laser sensor) into a single integrated testing device that can perform multiple measurement functions simultaneously. The holding device integrates positioning, rotation, and measurement capabilities in one unit, reducing the number of separate components needed while maintaining comprehensive inspection capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The testing device is designed with multi-functional capabilities where a single device can perform various measurement tasks including optical inspection, dimensional measurement, and surface quality assessment. The holding device can rotate preforms to multiple orientations and position them for different types of measurements, making one device replace multiple specialized sensors.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple sensors are deployed to cover all preform surfaces, then inspection completeness is improved, but ease of operation and maintenance difficulty worsen

Engineering Contradiction:
Improveinspection completenessVSAvoidtest setup operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The holding device incorporates dynamic rotation capabilities that allow the preform to be rotated to multiple predetermined orientations during inspection. This dynamic positioning enables a single sensor to capture data from all surfaces of the preform by rotating it through different angles, eliminating the need for multiple fixed sensors positioned around the preform.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The holding device acts as an intermediary between the preform and the sensor, facilitating comprehensive inspection by rotating and positioning the preform relative to the sensor. This mediator approach allows one sensor to effectively perform the work of multiple sensors by manipulating the object's orientation rather than adding more sensing elements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single optical sensor is used to reduce complexity, then device complexity and maintenance effort are reduced, but measurement precision and inspection completeness may worsen

Engineering Contradiction:
Improvesensor system complexityVSAvoidmulti-criteria measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces the dimension of time and motion by rotating the preform through multiple orientations during inspection. Instead of adding more sensors in space, the system uses temporal sequencing and rotational movement to capture comprehensive data from all surfaces. This transforms a spatial problem (needing multiple sensors) into a temporal problem (taking multiple measurements over time).

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

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 reduces sensor complexity, improves reliability, and ensures high-quality inspections by covering the entire preform surface efficiently, while minimizing maintenance efforts and optimizing the test process.

Implementation Method 1

an optical sensor is assigned to the test device, wherein the optical sensor is configured to determine sensor data of the preform

Methodology Applied
Scientific EffectOptical detection: Photoelectric Effect

Data Source

PatentEP4563325B1Test device for testing at least one preform, stretch blow molding machine and method for testing a preform
Publication Date: 2026.03.25 KHS GMBH
  • EP4563325B1 patent drawingFigure 1~2
  • EP4563325B1 patent drawingFigure 3
  • EP4563325B1 patent drawingFigure 4

AI summary

The invention relates to a testing device (102) for testing at least one preform (101), a method, and a stretch blow molding system (131). The testing device (102) has an optical sensor (103), an evaluation unit (109) with a data input (111) and a data output (113), wherein the evaluation unit (109) is connected to the optical sensor (103) via the data input (111) for exchanging sensor data, and a holding device (105) assigned to the testing device (102), which is designed to hold the preform (101) and guides the preform (101) to a first position (121) at a first time in a first predefined orientation of the preform (101) and to a second position (123) at a second time in a second predefined orientation of the preform (101).wherein the testing device (102) is configured to determine first sensor data of the preform (101) at the first time by means of the optical sensor (103) and to send them to the evaluation unit (103) via the data input (111), and to determine second sensor data of the preform (101) at the second time by means of the optical sensor (103) and to send them to the evaluation unit (109) via the data input (111), wherein the evaluation unit (109) is configured to determine compliance with a first test criterion based on the first sensor data and to determine compliance with a second test criterion based on the second sensor data.