Automated Color Registration via Vision-Based Mark Detection

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Solution Overview

Problem

Existing plate element printing machines require time-consuming and costly manual adjustments for color registration, consuming ink and discarding sheets, with limited precision due to reliance on edge detection and multiple registration marks, which reduces accuracy and increases waste.

Innovation Solution

A method involving printing and detecting pairs of registration marks of different colors at distant locations on the sheet, using a vision system and calculation unit to determine position deviations and generate adjustment signals for automatic registration, reducing the need for multiple marks and improving precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual color registration adjustment is performed using traditional methods with multiple registration marks, then color registration can be achieved, but the process becomes time-consuming and increases ink consumption and sheet waste

Engineering Contradiction:
Improvecolor registration precisionVSAvoidadjustment time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical adjustment with an automated vision-based system. A camera captures images of registration marks, and a processing unit automatically calculates position deviations and generates adjustment signals, eliminating the need for operators to manually measure and adjust plate positions, thereby reducing adjustment time while maintaining precision

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

Solution Approach 2:

The patent uses optical copies (images) of registration marks captured by a camera to determine position deviations. Instead of direct mechanical measurement, the system creates digital representations of the marks and processes these copies to calculate alignment errors, enabling faster automated registration

Inventive Principle:
Principle #26Copying

2Measurement precision

If multiple registration marks are printed on sheets for manual detection, then color registration can be determined, but ink consumption and sheet waste increase

Engineering Contradiction:
Improveregistration error detection accuracyVSAvoidink consumption and sheet waste
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The patent replaces manual visual detection with an automated optical detection system. A camera captures images of registration marks, and software automatically processes these images to determine position deviations, eliminating the need for operators to physically examine each sheet and reducing the number of sheets required for registration

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

Solution Approach 2:

The system enables self-service registration by automatically capturing images of registration marks, processing them to calculate alignment errors, and generating adjustment signals without operator intervention. This automation reduces the number of sheets needed for registration since the system can process images digitally without requiring physical inspection of multiple sheets

Inventive Principle:
Principle #25Self-service

3Ease of operation

If registration marks are placed in margin areas of sheets, then color registration can be monitored, but the distance from edges reduces measurement accuracy

Engineering Contradiction:
Improveregistration mark detectionVSAvoidposition deviation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent uses image processing algorithms to detect registration marks regardless of their position on the sheet. The system captures images and uses software to calculate positions relative to sheet edges, compensating for the reduced physical distance between marks and edges through computational methods rather than relying solely on geometric distance

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

4Productivity

If automated vision systems are implemented for color registration, then adjustment time is reduced, but system complexity increases

Engineering Contradiction:
Improveregistration speedVSAvoidvision system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions into a single automated registration system. The vision system performs mark detection, image processing, deviation calculation, and adjustment signal generation all through one integrated system, eliminating the need for separate manual operations and reducing overall system complexity despite the advanced capabilities

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

Solution Approach 2:

The system implements automatic feedback by capturing images of registration marks, calculating position deviations, and generating adjustment signals that are applied to the printing press. This closed-loop feedback mechanism automates the registration process, increasing speed while managing complexity through systematic control

Inventive Principle:
Principle #23Feedback

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 method allows for rapid, precise automatic color registration with reduced ink consumption and sheet waste, simplifying operator tasks and minimizing downtime during job changes.

Implementation Method 1

Many known reading devices or vision systems make it possible to detect and read these marks printed on the sheets scrolling in front of a light source

Methodology Applied
Scientific EffectOptical detection: Light

Data Source

PatentEP2619012B1Method and arrangement for registering colors for a printing machine
Publication Date: 2014.08.20 BOBST MEX SA
  • EP2619012B1 patent drawingFigure 1~3
  • EP2619012B1 patent drawingFigure 4~7

AI summary

The invention relates to a method for registering at least two colors for a machine for printing on plate elements (1), provided with at least two printer groups (4, 6, 7, 8, 9), wherein said method comprises the steps of: printing, on a first plate element (13), a first mark (29) with a first color using the first printer group (4), printing a second mark (32) spaced apart from the first mark (29) with the first color and using the first printer group (4), printing a third mark (35) with a second color using a second printer group (6), wherein a theoretical position between the first and third marks (29, 35) is known, and printing a fourth mark (36) spaced apart from the third mark (35) with the second color and using the second printer group (6), wherein a theoretical position between the second and fourth marks (32, 36) is known; detecting the first and third marks (29, 35) and the second and fourth marks (32, 36), determining the deviations in the positions between the first and third marks (29, 35) and comparing the deviations with the theoretical position between the first and third marks (29, 35), as well as determining the deviations in the positions between the second and fourth marks (32, 36) and comparing the deviations with the theoretical position between the second and fourth marks (32, 36), and generating an adjustment signal for the second printer group (6) in accordance with the determined deviations in order to register the second color relative to the first color.