Printing Apparatus with Opposite Head Orientation for Color Consistency

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Solution Overview

Problem

The use of a printing apparatus with printing heads arranged in opposite orientations leads to color differences between areas printed by the left and right heads, resulting in lower image quality due to different ink application orders.

Innovation Solution

The printing apparatus divides the print medium into areas where only one head is used, and a shared area where both heads print, with specific distribution patterns and multi-pass printing methods to ensure consistent ink application across the entire medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If printing heads are arranged in opposite orientations to shorten printing time, then productivity is improved, but manufacturing precision deteriorates due to color differences

Engineering Contradiction:
Improveprinting timeVSAvoidcolor consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by making the right-side printing head have a different discharge port arrangement than the left-side printing head. Specifically, the right-side printing head discharges in the order of yellow, magenta, cyan, black from upper to lower, while the left-side printing head discharges in the order of black, cyan, magenta, yellow. This local differentiation in discharge sequences ensures that both printing heads apply ink in the same relative order to their respective areas, eliminating color differences while maintaining the productivity benefit of opposite orientation arrangement.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If identical printing heads are used in opposite orientations to lower production cost, then ease of manufacture is improved, but manufacturing precision deteriorates due to color differences

Engineering Contradiction:
Improveproduction costVSAvoidcolor consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent implements local quality by configuring the discharge ports of the right-side printing head in reverse order compared to the left-side printing head. The right-side printing head has discharge ports arranged as yellow, magenta, cyan, black from upper to lower, while the left-side printing head has black, cyan, magenta, yellow. This localized adjustment in discharge sequence allows identical printing head models to be used on both sides, maintaining ease of manufacture while achieving color consistency across the print medium.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If different ink application orders are used to match printing head orientations, then ease of operation is improved, but manufacturing precision deteriorates due to color differences in different areas

Engineering Contradiction:
Improveprinting operationVSAvoidcolor uniformity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies local quality by establishing different local discharge sequences for the left and right printing heads. The left-side printing head discharges ink in the order of black, cyan, magenta, yellow from upper to lower, while the right-side printing head discharges in the order of yellow, magenta, cyan, black. This local differentiation ensures that despite the opposite orientations of the printing heads, the ink application order relative to the print medium is consistent, thereby maintaining color uniformity while preserving operational simplicity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3330092B1Printing apparatus and printing method
Publication Date: 2021.05.05 CANON KK
  • EP3330092B1 patent drawingFigure 1
  • EP3330092B1 patent drawingFigure 2A~2B
  • EP3330092B1 patent drawingFigure 3

AI summary

A printing apparatus uses a printing unit on which a right and a left printing heads are mutually arranged in opposite orientations in a predetermined direction to execute multi-pass printing.