Inkjet Head Replacement With Liquid-Level Pipe Detection

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Solution Overview

Problem

Inkjet printing apparatuses face issues with ink ejection failure due to solidification or other reasons, leading to printing failures and ink spillage during head replacement, as users often improperly connect pipes, and existing detection methods require actual printing to identify pipe connection abnormalities.

Innovation Solution

A method and system for detecting pipe connection abnormalities in inkjet printing apparatuses by monitoring ink liquid levels in supply and collection tanks during head replacement, ensuring proper pipe connections are made without requiring actual printing, using connectors and a controller to determine connection states based on liquid level positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If head replacement is manually performed by a user, then the head can be replaced, but pipe connection abnormalities may occur due to improper connection

Engineering Contradiction:

Improvehead replacement operationVSAvoidpipe connection reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system continuously monitors ink liquid levels in both the supply tank and collection tank, and provides feedback to the controller. When an abnormal change in liquid level is detected, the system automatically identifies the problematic head and notifies the user, enabling real-time detection and correction of pipe connection issues without requiring manual inspection or test printing.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces manual visual inspection and test printing with an automated sensor-based detection system. Liquid level sensors automatically monitor ink levels, and the controller processes this data to identify pipe connection abnormalities, substituting mechanical/manual verification methods with automated electronic detection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If printing is performed to detect pipe connection abnormalities, then abnormalities can be identified, but ink spillage and printing failures occur

Engineering Contradiction:

Improvepipe connection abnormality detectionVSAvoidink spillage and printing failure

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system performs preliminary detection of pipe connection abnormalities by monitoring ink liquid levels before actual printing occurs. By detecting abnormal liquid level changes that indicate poor pipe connections during ink circulation, the system identifies problematic heads in advance, allowing users to correct connection issues before printing, thereby preventing ink spillage and printing failures.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If ink circulation is resumed after head replacement, then printing can continue, but pipe connection abnormalities cause ink mixing and printing failures

Engineering Contradiction:

Improveprinting continuityVSAvoidprinting quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The monitoring system provides continuous feedback on ink liquid levels in both tanks during ink circulation. If an abnormal change is detected after head replacement, the system immediately identifies the problematic head and alerts the user, enabling real-time detection of pipe connection issues during circulation without requiring test printing, thus maintaining both productivity and reliability.

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

Enables detection of pipe connection issues without printing, preventing ink spillage and ensuring high-quality printing by confirming correct pipe connections post-head replacement.

Implementation Method 1

Ink flows from the supply tank to the collection tank via the head according to a difference (differential pressure) between the air pressure in the supply tank and the air pressure in the collection tank

Methodology Applied

Scientific EffectPressure difference (differential pressure): Pressure Gradient

Data Source

PatentEP4338968B1Head replacement method, inkjet printing apparatus, and head replacement support program

Publication Date: 2025.10.08 SCREEN HOLDINGS CO LTD

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AI summary

The head replacement method includes: a pipe connection step (S15) of performing, by a user, pipe connection of a new head; an ink circulation start step (S400) of starting circulation of ink in a circulation flow path; and a connection state determination step (S410, S500, S600, S610, S700, S800) of determined, based on an ink liquid level position representing a height of an ink liquid level in at least one of a collection tank and a supply tank, whether a pipe connection, including a connection between an ink discharge pipe and a collection branch pipe and a connection between an ink inflow pipe and a supply branch pipe, is properly made.