Print Head Wiping via Temperature-Dependent Fluid Control

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Solution Overview

Problem

Current methods for cleaning fluid ejection devices, such as print heads in 2D and 3D printing, are inefficient in removing cured or spilled printing fluid, particularly when the device temperature is below a certain threshold, leading to excessive treatment fluid consumption and potential overflow.

Innovation Solution

A method that controls the application of treatment fluid based on the temperature of the fluid ejection device, using a controller and temperature sensor to adjust the amount of treatment fluid applied, ensuring efficient removal of crusted printing fluid without excess consumption, by applying more fluid when the temperature exceeds a threshold and reducing or eliminating fluid application when below it.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If treatment fluid is applied continuously to clean the fluid ejection device, then cleaning coverage is maintained, but treatment fluid consumption increases excessively

Engineering Contradiction:
Improvecleaning coverageVSAvoidtreatment fluid consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system changes the parameter of treatment fluid application from continuous to temperature-dependent variable application. The controller adjusts the amount of treatment fluid applied based on real-time temperature sensor readings, applying more fluid when temperature exceeds the threshold (indicating cured printing fluid) and reducing or stopping application when temperature is within normal range, thereby optimizing fluid consumption while maintaining cleaning effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements a feedback control mechanism where the temperature sensor continuously monitors the temperature of the fluid ejection device and feeds this information back to the controller. The controller uses this feedback to dynamically adjust the treatment fluid application rate, creating a closed-loop system that responds to actual cleaning needs rather than applying fluid continuously, thus reducing waste while ensuring thorough cleaning when necessary

Inventive Principle:
Principle #23Feedback

2Productivity

If treatment fluid is applied in large amounts to remove crusted printing fluid, then cleaning efficiency improves, but fluid overflow risk increases

Engineering Contradiction:
Improvecleaning efficiencyVSAvoidfluid overflow
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically changes the application parameter of treatment fluid from fixed high-volume application to variable volume application based on temperature conditions. When the temperature sensor detects that the temperature exceeds the threshold (indicating presence of cured printing fluid), the controller applies treatment fluid at a higher rate to ensure effective cleaning. When temperature is within normal range, the controller reduces or stops fluid application, thereby preventing overflow while maintaining high cleaning efficiency when actually needed

Inventive Principle:
Principle #35Parameter changes

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 approach reduces treatment fluid consumption, enhances cleaning efficiency by tailoring fluid application to the device's temperature, preventing overflow, and optimizing the wiping process for fluid ejection devices.

Implementation Method 1

a temperature sensor to measure a temperature of the print head

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

determining, in view of the temperature signal, the amount of treatment fluid to be ejected... to dissolve and remove crusted printing fluid

Methodology Applied
Scientific EffectThermal dissolution:

Data Source

PatentEP3746302B1Wiping a print head
Publication Date: 2024.04.10 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3746302B1 patent drawingFigure 1~3
  • EP3746302B1 patent drawingFigure 4~5
  • EP3746302B1 patent drawingFigure 6

AI summary

Methods to wipe a print head are described. In an example of a method, an amount of treatment fluid is determined based on a temperature of the print head and the print head is wiped with the determined amount of treatment fluid and a wiping medium.