Conveyor Roller Spacing for Inkjet Head Protection

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Solution Overview

Problem

In ink-jet recording apparatuses, smaller recording media can curve and come into contact with the inkjet head, causing treatment liquids to coagulate and clog nozzles, leading to ejection failures.

Innovation Solution

The design includes a conveyor system with multiple conveying portions spaced apart to prevent smaller recording media from reaching the inkjet head, using a first liquid to apply an image-quality enhancement liquid and a second liquid to prevent coagulation with the head's surface, ensuring the liquids do not attach and cause clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If two roller pairs are disposed to sandwich the head therebetween in the conveyance direction, then the recording medium can be conveyed through the head region, but smaller recording media stop at the head position and curve to contact the ejection surface, causing treatment liquid to attach to the head

Engineering Contradiction:

Improveconveyance of recording mediumVSAvoidnozzle ejection function

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The conveyor is divided into multiple conveying portions (first, second, and third conveying portions) with different spacing characteristics. The first conveying portion has smaller spacing between rollers to provide support, while the second conveying portion has larger spacing to allow passage without contact, segmenting the conveyance path to solve the contradiction between supporting small media and preventing contact with the head.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the conveyor are given different local qualities in terms of roller spacing. The region upstream of the head (first conveying portion) has tighter roller spacing for support, while the region at the head level (second conveying portion) has wider spacing to prevent contact, creating localized structural characteristics that address different functional requirements along the conveyance path.

Inventive Principle:

Principle #3Local quality

2Volume of moving object

If the distance between roller pairs is reduced to accommodate smaller media, then compactness is improved, but smaller media may not be properly supported and may contact the ejection surface

Engineering Contradiction:

Improveapparatus compactnessVSAvoidprevention of treatment liquid attachment

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The conveyor structure is segmented into multiple portions with different roller spacings. The first conveying portion uses smaller roller spacing to maintain compactness, while the second conveying portion uses larger spacing to prevent media contact with the head, allowing the apparatus to be compact overall while maintaining reliability for small media.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The solution transitions from a uniform one-dimensional roller spacing approach to a multi-dimensional approach where different regions have different spacing characteristics. By creating a three-dimensional conveyor structure with varying roller positions in the conveyance direction, the system achieves both compactness and reliability simultaneously.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 configuration effectively prevents the treatment liquid from attaching to the inkjet head, avoiding nozzle clogging and maintaining ink ejection functionality, even with smaller media sizes, while allowing for a more compact apparatus design.

Implementation Method 1

one of the first liquid and the second liquid acts on the other of the first liquid and the second liquid, causing one of coagulation and precipitation of a component of the other of the first liquid and the second liquid

Methodology Applied

Scientific EffectCoagulation: Coagulation

Implementation Method 2

Methodology Applied

Scientific EffectPrecipitation: Precipitation

Data Source

PatentUS9004671B2Image forming apparatus

Publication Date: 2015.04.14 BROTHER KOGYO KK

AI summary

An image forming apparatus comprises a conveyor to convey a recording medium in a conveyance direction; first and second applicators to respectively apply first and second liquids to the recording medium, the second applicator being disposed downstream of the first applicator. One of the first and second liquids causes coagulation or precipitation of a component of the other liquid. The conveyor comprises a first pair of rollers; a second pair of rollers; and at least one third pair of rollers. The second applicator is disposed between the first and second pair of rollers. The first pair of rollers and the at least one third pair of rollers constitute a plurality of upstream-side pairs of rollers disposed upstream of the second pair of rollers, and a distance between adjacent two of the upstream-side pairs of rollers is larger than a distance between the first and second pair of rollers.