Inkjet Printer Air Circulation Path Segmentation for Pressure Stability

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Solution Overview

Problem

Inkjet printers with air pump-driven ink circulation systems experience unstable air flow volume at low drive rates, leading to pressure fluctuations in the inkjet head, which results in decreased print quality.

Innovation Solution

An inkjet printer design incorporating a main connection path and an adjustment path with a narrower air passage, along with a changeover device and controller to adjust air flow volume without altering the air pump's drive rate, maintaining preset pressures in the pressurized and depressurized spaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the air pump is driven at a low drive rate to maintain preset pressures, then energy consumption is reduced and fine pressure adjustment is achieved, but the air flow volume becomes unstable causing pressure fluctuation and decreased print quality

Engineering Contradiction:
Improveenergy consumptionVSAvoidprint quality
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The invention changes the physical parameter of the air passage (width/size) to control air flow volume. By providing multiple air passages with different widths and selectively opening them based on operational requirements, the system can adjust air flow without changing the air pump's drive rate, thereby maintaining stable air flow volume even at low drive rates and preventing pressure fluctuations that would degrade print quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces dynamic switching between different air passages based on operational conditions. The air passage switching mechanism dynamically selects appropriate air passages to open, allowing the system to adapt air flow volume to current needs while maintaining stability. This dynamic adjustment capability ensures that during maintenance operations, the appropriate air passage is selected to provide stable air flow and prevent pressure fluctuations.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If the air pump drive rate is reduced for fine pressure adjustment, then pressure control precision is improved, but air flow volume stability deteriorates causing nozzle pressure fluctuation

Engineering Contradiction:
Improvepressure control precisionVSAvoidair flow volume stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The invention changes the physical parameter of the air passage (width/size) to control air flow volume. By providing multiple air passages with different widths and selectively opening them based on operational requirements, the system can adjust air flow without changing the air pump's drive rate, thereby maintaining stable air flow volume even at low drive rates and preventing pressure fluctuations that would degrade print quality.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If a single wide air passage is used in the main connection path, then air flow volume is sufficient for pressure generation, but pressure fluctuation increases during maintenance operations

Engineering Contradiction:
Improveair flow volumeVSAvoidpressure stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The invention segments the single air passage into multiple air passages with different widths. Instead of using one large air passage, the system provides several smaller passages that can be selectively opened. During maintenance operations, appropriate smaller passages are selected and opened, which provides sufficient air flow volume while reducing pressure fluctuations compared to using a single wide passage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces dynamic switching between different air passages based on operational conditions. The air passage switching mechanism dynamically selects appropriate air passages to open, allowing the system to adapt air flow volume to current needs while maintaining stability. This dynamic adjustment capability ensures that during maintenance operations, the appropriate air passage is selected to provide stable air flow and prevent pressure fluctuations.

Inventive Principle:
Principle #15Dynamics

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 stabilizes nozzle pressure and prevents print quality degradation by adjusting air flow volume independently of the air pump's drive rate, reducing pressure fluctuations in the inkjet head.

Implementation Method 1

an air pump arranged in the portion of the main connection path and configured to send air from the depressurized space to the pressurized space

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP3354464B1Ink jet printing apparatus
Publication Date: 2020.05.27 RISO KAGAKU CORP
  • EP3354464B1 patent drawingFigure 1
  • EP3354464B1 patent drawingFigure 2
  • EP3354464B1 patent drawingFigure 3

AI summary

An inkjet printer includes: a pressurized space and a depressurized space for circulation of ink along a circulation path; a main connection path and an adjustment path connecting the pressurized space and the depressurized space to each other; an air pump configured to send air from the depressurized space to the pressurized space though the main connection path or the adjustment path; a changeover device configured to change over between the main connection path and the adjustment path; and a controller. The controller drives the air pump with the main connection path being set to generate preset pressures respectively in the pressurized space and the depressurized space and then controls the air pump with the adjustment path being changed over to maintain pressures in the pressurized space and the depressurized space respectively at the preset pressures.