Symmetrical Head Unit for Liquid Discharging Apparatus

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Solution Overview

Problem

Existing liquid discharging apparatuses face issues with printing quality due to varying discharge sequences of colors and individual differences between heads when moving relative to a medium in different directions, leading to reduced print quality.

Innovation Solution

A head unit configuration with multiple heads for each color, arranged symmetrically across the body, ensures consistent discharge sequences regardless of movement direction, distributing color discharge across multiple heads to mitigate individual head differences and streak formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If all nozzles for a single color are formed in only a single head, then the device complexity is reduced, but the printing quality deteriorates due to varying discharge sequences and individual head differences

Engineering Contradiction:
Improvehead configurationVSAvoidprinting quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent divides the nozzle rows for each color into multiple segments distributed across multiple heads. Specifically, for each color, nozzle rows are arranged in a first region and a second region of the body, with each region containing multiple heads. This segmentation allows the system to maintain consistent discharge sequences while reducing the impact of individual head differences on printing quality.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the head unit moves relative to the medium in different directions, then the adaptability is improved, but the printing quality deteriorates due to different discharge sequences of colors

Engineering Contradiction:
Improvemovement direction flexibilityVSAvoidprinting quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent employs asymmetric arrangement of nozzle rows within each head, combined with symmetric distribution across multiple heads. The nozzle rows in the first region and second region are arranged asymmetrically within each region, but the overall configuration creates symmetry in the discharge sequence when viewed from both movement directions. This allows the head unit to maintain consistent color discharge sequences regardless of the direction of relative movement between the head unit and the medium.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3354471B1Head unit and liquid discharging apparatus
Publication Date: 2021.04.21 SEIKO EPSON CORP
  • EP3354471B1 patent drawingFigure 1
  • EP3354471B1 patent drawingFigure 2
  • EP3354471B1 patent drawingFigure 3

AI summary

A head unit includes a plurality of heads each including a nozzle row including a plurality of nozzles that discharge liquid onto a medium and is arranged along a first direction, and a body in which the plurality of the heads are arranged along a second direction intersecting with the first direction. In a case in which a region on one side of a center of the body in the second direction as a first region and a region on another side of the center of the body in the second direction is taken as a second region, two or more of the plurality of the heads each including the nozzle row corresponding to a first color are provided in each of the first region and the second region. In a case in which one side of the body in the second direction is taken as a first side and another side of the body in the second direction as a second side, a color corresponding to the nozzle row at an nth position from the first side is the same as a color corresponding to the nozzle row at an nth position from the second side, with n being a positive integer.