Color Profile Adjustment in Sheet-Fed Offset Printing Press

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Solution Overview

Problem

Sheet-fed offset printing presses face significant challenges in quickly and economically switching between printing processes, resulting in high waste and unproductive machine time due to uneven ink distribution and the need for extensive ink adjustment, especially when using high-priced substrates.

Innovation Solution

The method involves iteratively setting a color profile by using pre-printed waste and unprinted good sheets, with a detection device recognizing and processing only good sheets to adjust ink zones, reducing waste and minimizing the number of high-priced sheets required to achieve the desired color profile.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional ink adjustment methods are used to switch between printing processes, then the printing press can be converted from one printing process to another, but significant waste of high-priced substrates and unproductive machine time occur due to uneven ink distribution

Engineering Contradiction:
Improveability to switch between printing processesVSAvoidwaste of high-priced substrates
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The system performs preliminary detection and classification of sheets during the changeover process. By using detection devices to identify good sheets versus waste sheets in advance, the system can selectively process only the valuable good sheets for color profile adjustment, preventing waste of high-priced substrates during the transition between printing processes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The printing press system uses its own detection devices and control units to automatically identify and classify sheets, eliminating the need for manual inspection. The system serves itself by automatically detecting uneven ink distribution, classifying sheets as good or waste, and adjusting the color profile accordingly, thereby reducing waste without requiring external intervention.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If traditional ink adjustment methods are used to switch between printing processes, then the printing press can be converted from one printing process to another, but significant unproductive machine time is lost due to extensive ink adjustment

Engineering Contradiction:
Improveability to switch between printing processesVSAvoidunproductive machine time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system implements a feedback mechanism where detection devices continuously monitor the ink distribution on sheets during the changeover process. The control unit receives this feedback information and automatically adjusts the color profile based on the detected conditions, significantly reducing the time required for manual ink adjustment and enabling faster switching between printing processes.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces manual mechanical ink adjustment with an automated optical detection and control system. Detection devices using optical principles identify ink distribution patterns, and the control unit automatically adjusts printing parameters, eliminating the time-consuming manual intervention required in traditional methods and enabling rapid process switching.

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

3Measurement precision

If all sheets are processed for color profile adjustment, then comprehensive color data is collected, but the number of high-priced good sheets required increases

Engineering Contradiction:
Improvecolor profile accuracyVSAvoidconsumption of high-priced good sheets
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The system extracts and separates good sheets from waste sheets using detection devices during the changeover process. By taking out only the valuable good sheets for color profile adjustment and excluding waste sheets, the system maintains comprehensive color data collection from appropriate sources while minimizing the consumption of high-priced substrates.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system applies different processing treatments to different sheets based on their quality. Good sheets are selected for color profile adjustment while waste sheets are excluded. This local quality approach ensures that color measurement precision is maintained using only suitable sheets, thereby reducing the overall consumption of high-priced good sheets required for adjustment.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3921164B1Method for adjusting a colour profile in a sheet-fed offset printing press using preprinted faulty sheets
Publication Date: 2023.01.04 KOENIG & BAUER AG
  • EP3921164B1 patent drawingFigure 1
  • EP3921164B1 patent drawingFigure 2
  • EP3921164B1 patent drawingFigure 3

AI summary

The invention relates to a method for setting a colour profile in a sheet-fed offset printing press (01), in which method: the preprinted waste sheets and unprinted good sheets are used in the event of a changeover following a job change or in the event of a proof print from the relevant sheet-fed offset printing press (01); repeatedly, after each of several sets of waste sheets, at least one good sheet is passed through the sheet-fed offset printing press (01) and the waste sheets and good sheet(s) are each inked by means of at least one inking unit (04) having a plurality of ink zones each; the inked good sheets are detected as such in the sheet-fed offset printing press (01) as a result of a manual input on a control device (19) entered by an operator of the sheet-fed offset printing press (01) or automatically; and the colour profile is set by means of an ink regulator (24), wherein the colour profile is set by means of the ink regulator (24) after detection and evaluation of the inking of exclusively the good sheets. A metal sheet is preferably used as the waste sheet and/or as the good sheet.