Inkjet Printer Ink Pump Degradation Monitoring

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Solution Overview

Problem

Inkjet recording apparatuses with ink circulation systems face issues where a decrease in ink pump ejection performance due to aging can lead to overflow or supply errors, causing the printer to stop during operation, resulting in wasted prints and requiring maintenance before resuming use.

Innovation Solution

An inkjet printer with an ink circulation type inkjet head, including a supply side sub tank, a discharge side sub tank, and an ink pump that feeds ink from the discharge side to the supply side based on detection mechanisms, maintaining ink circulation and alerting users to potential performance degradation through monitoring and error processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an ink circulation type inkjet head is used to maintain ink flow and prevent clogging, then the printing reliability is improved, but the system complexity increases due to the need for pumps and detection mechanisms

Engineering Contradiction:
Improveprinting reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs detection mechanisms that monitor ink levels in both the supply side sub tank and discharge side sub tank, providing feedback to the control unit. The control unit adjusts pump operation based on this feedback, creating a closed-loop system that maintains reliable ink circulation while automating the management of complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The ink circulation system is designed to automatically monitor and regulate ink flow without requiring manual intervention. The detection mechanisms and control unit work together to self-regulate the ink levels and pump operation, making the system maintain itself during operation.

Inventive Principle:
Principle #25Self-service

2Duration of action of moving object

If pump ejection performance decreases due to aging, then the feeding amount of ink is reduced, but this leads to overflow errors in the discharge side sub tank or supply errors in the supply side sub tank, causing the printer to stop

Engineering Contradiction:
Improvepump service lifeVSAvoidprinting continuity
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The detection mechanisms continuously monitor ink levels in advance before overflow or supply errors occur. When abnormal conditions are detected, the system can take preliminary actions such as adjusting pump operation or alerting the user, preventing printing stops before they happen.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit receives continuous feedback from detection mechanisms about ink levels in both sub tanks. This feedback enables real-time adjustment of pump operation to compensate for performance degradation, maintaining printing continuity even as the pump ages.

Inventive Principle:
Principle #23Feedback

3Ease of repair

If the printer stops during printing due to ink pump performance degradation, then maintenance can be performed, but subsequent printing cannot be performed and the medium being printed becomes waste

Engineering Contradiction:
Improvemaintenance accessibilityVSAvoidwasted print medium
Core Design Contradiction:
Ease of repairVSLoss of substance

Solution Approach 1:

The detection mechanisms provide advance warning of pump performance issues before they cause printing stops. This allows users to schedule maintenance at convenient times rather than being forced to stop during printing, preventing waste of print medium.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit monitors pump performance through detection mechanisms and provides feedback about the pump's condition. This enables predictive maintenance scheduling based on actual pump status rather than fixed intervals, optimizing the timing of maintenance to prevent printing stops.

Inventive Principle:
Principle #23Feedback

4Reliability

If detection mechanisms are added to monitor ink levels in both sub tanks, then the reliability of ink supply is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveink supply reliabilityVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The detection mechanisms serve multiple functions: monitoring ink levels, detecting abnormal conditions, and providing feedback for pump control. This multi-functionality justifies the added complexity by delivering multiple benefits from a single system addition.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The detection mechanisms create a feedback loop that enables automatic pump control and early warning of problems. The reliability gains from continuous monitoring and automatic response outweigh the complexity of adding the detection system.

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

Prevents printer stops by maintaining consistent ink flow and allowing users to address ink pump degradation before it causes operational failures, thereby reducing waste and downtime.

Implementation Method 1

A negative pressure inside the discharge side sub tank is a negative pressure larger than a negative pressure inside the supply side sub tank, and the ink moving from the supply side sub tank to the discharge side sub tank through the inkjet head causes the ink inside the inkjet head to circulate

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP3616928B1Inkjet printer and control method for inkjet printer
Publication Date: 2022.11.02 MIMAKI ENGINEERING CO LTD
  • EP3616928B1 patent drawingFigure 1
  • EP3616928B1 patent drawingFigure 2
  • EP3616928B1 patent drawingFigure 3

AI summary

In an inkjet printer, when an amount of ink in a supply side sub tank is an appropriate amount and an amount of ink in the discharge side sub tank is an appropriate amount, the ink is supplied from the discharge side sub tank to the supply side sub tank at a constant flow rate by an ink pump. Furthermore, the inkjet printer acquires at a predetermined time interval a first pump driving speed, which is the driving speed of the ink pump at this time, compares it with a predetermined reference speed, and executes a predetermined error processing when the first pump driving speed exceeds a reference speed.