Duplex Printing Elasticity Adjustment via Cue Mark Detection

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Solution Overview

Problem

Conventional printing apparatuses face difficulties in accurately setting elasticity information for duplex printing due to elongation or contraction in the transport direction of long printing paper, requiring tedious trial and error processes and visual measurement of register shifts, which is challenging and inefficient.

Innovation Solution

A printing apparatus that includes cue marks for indicating printing start positions, a detector for cue mark detection, a page interval calculator, a difference computing unit, and a setting unit to calculate and adjust elasticity information based on differences between page intervals and image sizes, allowing for optimal elasticity information setting without manual visual measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual measurement of register marks is used to measure misregister, then measurement can be performed, but measurement precision deteriorates due to difficulty in accurately measuring shifts of 50μm or 0.1mm

Engineering Contradiction:

Improvemisregister measurement precisionVSAvoiddifficulty of visual measurement

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces the mechanical/visual measurement system with an optical detection system. The detector automatically detects the positions of register marks on the printing medium and calculates misregister amounts, eliminating the need for manual visual measurement and significantly improving measurement precision while reducing operator burden.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If trial and error process is used to set elasticity information, then optimal elasticity information can be obtained, but productivity deteriorates due to repeated test printing and measurement

Engineering Contradiction:

Improveoptimal elasticity informationVSAvoidprinting efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements an automatic feedback mechanism where the detector measures the actual misregister amount, the controller calculates the difference from the target value, and automatically adjusts the elasticity information based on this feedback. This eliminates the manual trial-and-error process while ensuring optimal elasticity information is obtained, significantly improving productivity.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of elasticity information using the detected misregister data. The controller automatically revises the elasticity information without requiring operator intervention for manual adjustment, making the system self-sufficient and eliminating repeated test printing cycles.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If manual adjustment of elasticity information is performed, then elasticity information can be modified, but ease of operation deteriorates due to complex adjustment process

Engineering Contradiction:

Improveelasticity information adjustmentVSAvoidoperation simplicity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system automatically adjusts elasticity information based on detected misregister amounts without requiring manual operator intervention. The controller performs the adjustment autonomously, making the operation simple while maintaining the ability to adapt elasticity information to different printing conditions.

Inventive Principle:

Principle #25Self-service

4Productivity

If tension is applied in transport direction for long printing paper, then printing can be performed, but manufacturing precision deteriorates due to elongation or contraction in transport direction

Engineering Contradiction:

Improveprinting capabilityVSAvoidregistration accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent uses feedback from the detector that measures actual misregister caused by paper elongation or contraction under tension. The controller automatically adjusts the elasticity information based on this feedback, compensating for the deformation and maintaining registration accuracy despite the applied tension during transport.

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP3854598B1Printing apparatus

Publication Date: 2023.08.23 SCREEN HOLDINGS CO LTD

Figure 1
Figure 2(a)~2(c)
Figure 3(a)~3(b)

AI summary

After printing cue marks and front surface images on the front surface of web paper WP by a printing station 21, an image data elongation-contraction processor 57 creates corrected back surface image data based on elasticity information, and a printing station 35 prints back surface images based on the corrected back surface image data, on the back surface of the printing medium. At this time, a page interval calculator 61 calculates a page interval from an interval between the cue marks detected by a detector 33, and a difference computing unit 63 calculates differences between the page interval and image size in a transport direction of the corrected back surface image data. Since these differences indicate shifts of the correction based on the elasticity information, optimal elasticity information can be set by revising the elasticity information with these differences through a setting unit 71. Consequently, the operator of the apparatus can easily set optimal elasticity information based on the differences.