Diffuse Light Source for Hollow Body Inner Diameter Measurement

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Solution Overview

Problem

Current methods for measuring the internal diameter of hollow objects, such as bottles, are limited in their ability to accurately assess the diameter at various sections along the axis of revolution, making it difficult to ensure proper corking and uncorking, and are not suitable for rapid industrial checks due to the need for object immobilization and time-consuming rotation for multiple diameter measurements.

Innovation Solution

A method and device using a diffuse light source with defined luminous borders on either side of the object, coupled with a camera system, allows for precise measurement of internal diameters at any height along the axis of revolution by analyzing light transitions in images, enabling measurement of diameters at different sections without the need for object movement or extensive rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a collimated laser beam is used to illuminate the transparent tube at an inclined angle, then the internal diameter can be measured through light refraction analysis, but only the diameter at the height of the light source line can be measured, requiring additional relative movement to measure other sections

Engineering Contradiction:
Improveinternal diameter measurementVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from a line-shaped light source to an extended planar light source, adding a vertical dimension to the illumination. This allows simultaneous measurement of internal diameters at multiple heights along the tube axis, eliminating the need for mechanical movement to capture different sections.

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

Solution Approach 2:

The extended light source is divided into multiple luminous segments or lines at different vertical positions. Each segment independently illuminates a specific cross-section of the tube, enabling parallel measurement of multiple diameters without mechanical movement.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If scanning with a finely collimated light source is used to measure internal diameter, then measurement can be performed, but the object must be immobilized during complete scanning of the transverse section, which is not suitable for rapid industrial checks

Engineering Contradiction:
Improveinternal diameter detection accuracyVSAvoidmeasurement speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The extended light source enables continuous simultaneous measurement of multiple cross-sections without interruption. The entire measurement process occurs in a single exposure, eliminating the need for sequential scanning and object immobilization, thereby enabling rapid industrial inspection.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

By extending the light source in the vertical dimension, the system captures multiple measurement planes simultaneously in a single shot, transforming a time-consuming sequential process into an instantaneous parallel operation.

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

3Manufacturing precision

If rotation of the object around its axis is performed to measure several diameters of the same section, then comprehensive dimensional control is achieved, but a rotation by increments with stop between each increment takes significant time of analysis

Engineering Contradiction:
Improvedimensional controlVSAvoidmeasurement time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The extended light source illuminates the entire vertical extent of the tube simultaneously, capturing all necessary diameter measurements in a single static image. This eliminates the need for incremental rotation and stopping, reducing measurement time while maintaining comprehensive dimensional control.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent adds vertical extension to the light source, transforming the measurement from a single-plane rotational process into a multi-plane simultaneous capture, thereby eliminating mechanical rotation entirely.

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

4Measurement precision

If a diffuse light source is used with defined luminous borders, then internal diameters at any height can be measured by analyzing light transitions, but the light source configuration becomes more complex

Engineering Contradiction:
Improveinternal diameter measurement at multiple heightsVSAvoidlight source configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent utilizes optical contrast transitions (analogous to color changes) where the diffuse light source creates distinct light-dark boundaries at the tube walls. These luminous borders provide clear detection signals for diameter measurement without requiring complex mechanical or electronic systems.

Inventive Principle:
Principle #32Color changes

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 quick and precise measurement of internal diameters at multiple heights and sections, improving dimensional control and suitability for industrial applications by reducing measurement time and error.

Implementation Method 1

a camera system, allows for precise measurement of internal diameters at any height along the axis of revolution by analyzing light transitions in images

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

coupled with a camera system, allows for precise measurement of internal diameters at any height along the axis of revolution by analyzing light transitions in images

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2742320B1Optoelectronic method and device for measuring the inner diameter of a hollow body
Publication Date: 2017.11.15 TIAMA SOCIETE ANONYME
  • EP2742320B1 patent drawingFigure 1~2
  • EP2742320B1 patent drawingFigure 3

AI summary

The invention relates to a method for measuring the inner diameter of a hollow body (2). According to the invention: the hollow body (2) is illuminated, on one side thereof, by a diffuse light source (9) having two light boundaries (91, 92) spaced apart along the axis of measurement (x) so as to produce, in one image, two diametrically opposed light transitions that are spaced apart from one another; the light rays reflected and refracted by the hollow body (2) are recovered from the side of the hollow body opposite the illuminated side, so as to form at least one image which contains at least the two light transitions; and the image is processed in order to determine the distance between the two light transitions, with a view to determining the measurement of the inner diameter of the hollow body.