Inspecting Chart for Printing Misregister Correction

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Solution Overview

Problem

Current printing apparatuses require excessive time and complexity to determine and correct misregister issues caused by skew or serpentine transportation of printing sheets, affecting printing quality.

Innovation Solution

A printing apparatus that prints an inspecting chart with reference and deviation patterns, allowing for rapid visual detection of misregister corrections by utilizing a control unit to operate printing heads and transport the print medium, enabling quick identification of correction amounts through visual density differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If evaluation patterns are printed on multiple printing sheets and visually determined using magnifying glass or special measuring instrument, then color misalignment amount can be determined, but the process becomes complicated and requires much time to obtain correction amount

Engineering Contradiction:
Improvecolor misalignment amount determinationVSAvoidtime required for obtaining correction amount
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The inspecting chart is divided into multiple line segment groups (first line segment group, second line segment group, third line segment group) with different orientations. Each group contains line segments printed by different printing heads, allowing separate measurement of misregister in different directions (orthogonal to transportation direction and in transportation direction) to be performed independently and efficiently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary measurement method using line segment groups with different orientations. Instead of direct visual inspection of color alignment, the system uses the positional relationship between line segments printed by different printing heads as an intermediary indicator. The misregister amount is derived from the deviation of these line segments, which can be measured more quickly and accurately than direct color pattern inspection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If conventional inspection methods are used to determine correction amount for skew or serpentine transportation, then misregister can be corrected, but the determination process is complicated and time-consuming

Engineering Contradiction:
Improvemisregister correctionVSAvoidcomplexity of determining correction amount
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The inspection chart is segmented into multiple line segment groups oriented in different directions. The first line segment group has line segments extending in the transportation direction, the second line segment group has line segments extending orthogonal to the transportation direction, and the third line segment group has line segments extending in another direction. This segmentation allows independent measurement of misregister components in different directions, simplifying the overall correction determination process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds an additional dimensional aspect to the inspection by incorporating line segment groups with different orientations (0 degrees, 90 degrees, and other angles relative to transportation direction). This multi-dimensional approach transforms a complex two-dimensional misregister measurement into simpler one-dimensional measurements along different axes, reducing the overall complexity of the determination process.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If multiple line segment groups with different orientations are printed in the inspecting chart, then misregister in different directions can be measured independently, but the inspecting chart becomes more complex

Engineering Contradiction:
Improvemisregister measurement in different directionsVSAvoidinspecting chart structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The inspecting chart is segmented into distinct line segment groups, each dedicated to measuring misregister in a specific direction. The first line segment group measures misregister in the transportation direction, the second line segment group measures misregister orthogonal to the transportation direction, and the third line segment group provides additional directional measurement. This segmentation enables independent and precise measurement in each direction without interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each line segment group serves multiple functions: it acts as a reference for measuring misregister in its specific direction, provides a visual indicator of alignment quality, and can be used to verify the effectiveness of correction adjustments. The line segments themselves serve as both the measurement target and the reference standard, eliminating the need for separate reference markers.

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

Data Source

PatentEP2944474B1Inspecting chart and printing apparatus
Publication Date: 2020.06.17 RICOH CO LTD
  • EP2944474B1 patent drawingFigure 1
  • EP2944474B1 patent drawingFigure 2
  • EP2944474B1 patent drawingFigure 3

AI summary

Disclosed is an inspecting chart including a reference pattern containing a first line segment group and a second line segment group, a first-side deviation pattern, and a second-side deviation pattern. The first line segment group is formed by a plurality of first line segments printed by a reference printing head at a first given interval. The second line segment is formed by second line segments printed by a printing head on a center between two adjacent first line segments or a center of each of the first line segments, the printing head being spaced away from the reference printing head in a the transportation direction of a print medium. The first-side deviation pattern and the second-side deviation pattern are printed with various deviations.