Converting Machine Calibration for Printed Image Register Control
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Solution Overview
Problem
Converting machines struggle to accurately position pre-printed images on sheets, leading to inconsistent placement of creased and cut lines relative to the image, resulting in variable positioning of the image on finished boxes.
Innovation Solution
A calibration system for converting machines that includes an image sensor to capture the actual image of an indicia, a memory to store optimal reference points, and a control unit to calculate deviations and execute correction programs for transfer drives to adjust the sheet position, ensuring consistent image placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If pre-printed sheets are fed into the converting machine, then the machine can process externally printed materials, but the position of the printed pattern becomes unknown and inconsistent
Solution Approach 1:
The system performs preliminary detection of the printed pattern position on the sheet before the die-cutting operation. The optical detection device scans the sheet to locate the printed pattern and calculates the actual position deviation, then pre-adjusts the die-cutting tool position to compensate for this deviation, ensuring accurate cutting relative to the printed pattern.
Solution Approach 2:
The system implements a feedback mechanism where the optical detection device continuously monitors the position of the printed pattern on the sheet, compares it with the predetermined reference position, and automatically adjusts the die-cutting tool position based on the detected deviation. This closed-loop control ensures consistent positioning despite variations in pre-printed sheets.
2Device complexity
If register control systems use front leading edge of sheet as reference, then the control system is simple, but the accuracy of cuts in relation to the image deteriorates when processing pre-printed sheets
Solution Approach 1:
The system introduces an optical detection device as an intermediary between the sheet feeding mechanism and the die-cutting tool. This intermediary detects the actual position of the printed pattern on the sheet and provides real-time position information to the control system, enabling accurate positioning without significantly increasing overall system complexity.
Solution Approach 2:
The system replaces the traditional mechanical reference method (using the front leading edge of the sheet) with an optical detection method. The optical detection device uses light to locate the printed pattern position, providing more accurate and flexible positioning information compared to mechanical reference points.
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
The system ensures that the printed image is placed at a consistent position on all boxes, improving accuracy and reducing errors in the production of folding or flat-packed boxes.
Implementation Method 1
an image sensor configured to capture an actual image of an indicia on a sheet passing through the converting machine
Data Source
AI summary
The present invention relates to a calibration system (30) and a calibration method for a converting machine (20) provided with a die-cutting tool (18′) and at least one transfer unit (25) for transporting a sheet (1) along a travel path in a direction of conveyance (D) through the converting machine. The calibration system comprising a first image sensor (33), a memory (36) and a control unit (34). The calibration system is configured to detect an actual position of an indicia (42) on the sheet (1) and compare with a reference position of the indicia (42) stored in the memory (36). A correction program stored in the memory is executed when at least one of the longitudinal displacement (Δxi) and the lateral displacement (Δyi) of the indicia exceeds a predetermined tolerance threshold (Txi, Tyi).