Cap Slit Inspection Using Convergent Sidewall Illumination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cap inspection technologies are inefficient and lack precision in detecting slits or recesses on caps, leading to reduced production speed and potential defects.

Innovation Solution

An apparatus and method utilizing an illuminator to illuminate the cap's lateral surface, combined with a conveyor and multiple cameras to capture high-contrast images of the slits, enhanced by a collimator and diffuser to improve image clarity, and a control unit to process the data for accurate inspection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual inspection methods are used to detect slits in caps, then the inspection process is simple and quick, but the method is unreliable and cannot detect slits smaller than the human eye can resolve

Engineering Contradiction:
Improveslit detection precisionVSAvoidinspection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces human visual inspection with an automated optical inspection system that uses cameras and image processing algorithms. This substitution enables detection of slits at the micro-scale level that are imperceptible to the human eye, significantly improving measurement precision while maintaining operational simplicity through automation.

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

Solution Approach 2:

The patent creates digital copies (images) of the cap surfaces and analyzes these copies using image processing software. By working with digital representations rather than directly manipulating the physical caps, the system achieves high precision in detecting subtle slit defects without requiring complex physical measurement apparatus.

Inventive Principle:
Principle #26Copying

2Reliability

If traditional inspection methods are used, then the inspection process is fast, but defects are missed leading to product recalls and brand damage

Engineering Contradiction:
Improvedefect detection reliabilityVSAvoidinspection speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements continuous imaging and analysis of cap surfaces during the manufacturing process. The optical inspection system operates continuously without interrupting production, maintaining high inspection speed while improving reliability through consistent, uninterrupted detection of slit defects at multiple stages of cap formation.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system provides real-time feedback about detected defects to the manufacturing process, enabling immediate corrective action. By continuously monitoring and providing feedback on slit detection, the system ensures high reliability in defect identification while maintaining production throughput through automated, real-time inspection.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If caps are inspected after sealing to ensure quality, then product quality is maintained, but production time is extended and productivity decreases

Engineering Contradiction:
Improvecap seal qualityVSAvoidinspection time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs optical inspection of the cap body and sealing surface before the sealing operation. By detecting potential slit defects in advance, the system prevents defective caps from proceeding to sealing, eliminating the need for post-sealing inspection and reducing production time while maintaining seal quality through preventive rather than corrective inspection.

Inventive Principle:
Principle #10Preliminary 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

Ensures precise and efficient inspection of slits on caps, allowing for real-time detection and correction of placement, thereby improving production quality and speed.

Implementation Method 1

an optical inspection system to inspect the cap body and the sealing surface of the cap before the sealing operation

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4581352B1Apparatus and method for inspecting a slit on a cap
Publication Date: 2026.05.13 SACMI COOPERATIVA MECCANICI IMOLA SOC COOP ARL
  • EP4581352B1 patent drawingFigure 1~2
  • EP4581352B1 patent drawingFigure 3A~3B
  • EP4581352B1 patent drawingFigure 3C~4

AI summary

An apparatus (1) for inspecting a slit (I) made on a lateral surface (SL) of a plastic cap (T) comprises: a conveyor (11) for transporting the cap (T) along a path (P); an illuminator (10), configured to illuminate the lateral surface (SL) of the cap (T) placed at an inspection position, wherein the cap (T), at the inspection position, is aligned with an inspection axis (I), the inspection axis (I) being oriented vertically and transversely to the path (P); a plurality of cameras (12) surrounding the inspection axis (I) and configured to capture image data representing a plurality of images of the lateral surface (SL) of the cap (T) at the inspection position; a control unit, configured to receive the image data and process them to derive therefrom information relating to the slit, the apparatus being characterized in that the illuminator (10) includes a side wall (101) extending around the inspection axis (I) to illuminate all of the lateral surface (SL) of the cap (T) with rays that converge towards the inspection axis (I), the side wall (101) delimiting an internal space and including an inlet opening (103) and an outlet opening (104) to allow for passage of the cap (T) into and out of the internal space, respectively.