Print Apparatus Test Medium Positioning and Alignment Control

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Solution Overview

Problem

Existing print apparatuses face challenges in accurately positioning a test medium with a size different from the normal printing medium, which is required for precise alignment control of the print head.

Innovation Solution

The print apparatus includes a position indication section to adjust the test medium to a specific position corresponding to the print head, allowing the test pattern to be printed even when the sizes of the normal printing medium and the test medium differ. Additionally, a pattern detection section is used to detect the test pattern and determine any alignment shift of the print head.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a test medium different from the normal printing medium is used for printing a test pattern, then the test pattern can be printed on a more suitable medium, but the position of the test medium must be accurately positioned which increases operational complexity

Engineering Contradiction:
Improvemedium compatibilityVSAvoidpositioning accuracy
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

A position indication section (marks or indicators) is introduced as an intermediary element on the test medium to facilitate accurate positioning. These marks serve as reference points that guide the operator or automated system to correctly position the test medium relative to the print head, thereby reducing operational complexity while maintaining medium versatility

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces manual positioning judgment with automated optical detection. A pattern detection section uses optical reading to automatically detect the position indication marks and determine the test medium's position, substituting manual mechanical positioning with automated optical measurement to improve both accuracy and ease of operation

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

2Measurement precision

If alignment control is performed by optically reading line segments of a test pattern, then alignment can be detected, but the process requires precise positioning of the test medium which complicates the operation

Engineering Contradiction:
Improvealignment detection accuracyVSAvoidtest medium positioning
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

Position indication marks are pre-defined and pre-positioned on the test medium before printing occurs. These marks are placed at known locations that correspond to specific print head positions, allowing the system to automatically calculate alignment based on detecting these pre-established reference points rather than requiring complex real-time positioning

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pattern detection section provides feedback by optically reading the position indication marks and comparing the detected positions with expected positions. This feedback mechanism automatically determines both the test medium's position and any alignment shifts, eliminating the need for manual positioning judgment and simplifying operation while maintaining high measurement precision

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 solution enables accurate detection and correction of print head alignment shifts, maintaining high print quality even when using different-sized media, and reduces the operational load on the operator.

Implementation Method 1

the alignment control is performed by optically reading line segments of a test pattern formed on a medium

Methodology Applied
Scientific EffectOptical reading: Reflection

Data Source

PatentEP3798011B1Print apparatus, method for controlling the same, and storage medium
Publication Date: 2025.01.29 SEIKO EPSON CORP
  • EP3798011B1 patent drawingFigure 1
  • EP3798011B1 patent drawingFigure 2
  • EP3798011B1 patent drawingFigure 3

AI summary

A printer includes an ink ejection unit (81) configured to eject ink to a print medium (W), a transport belt (4) on which the print medium is mounted, a driving section (141) configured to transport the print medium by moving the transport belt, a specifying section (S12) configured to specify a print head (90A) to be adjusted using a test pattern, markers configured to indicate a position of the print medium when the test pattern is printed on the print medium, and a driving controller (100) configured to control the driving section. The driving controller controls the driving section in accordance with the print head to be adjusted specified by the specifying section so as to adjust a position of the print medium.