Liquid Ejecting Apparatus Pressure Reducing Operation

Solution Overview

Problem

Liquid ejecting apparatuses, such as ink jet printers, face instability in ink ejection after a discharging operation, leading to unpredictable ink behavior during subsequent printing due to elevated pressure in the liquid ejecting unit.

Innovation Solution

A liquid ejecting apparatus with a pressurizing mechanism, a wiping mechanism, and a pressure reducing operation that stabilizes the pressure in the liquid ejecting unit after a discharge stopping operation, allowing for a finishing wiping operation to prevent gas-liquid interface collapse and ensure stable ink ejection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a discharging operation is performed by supplying pressurized liquid to the liquid ejecting unit, then liquid can be discharged from the nozzle, but the pressure in the liquid ejecting unit remains high after discharge stops, causing unstable liquid ejection

Engineering Contradiction:

Improveliquid discharge capabilityVSAvoidliquid ejection stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by performing a pressure reducing operation before the finishing wiping operation. The pressure reducing operation reduces the pressure in the liquid ejecting unit to a predetermined level before wiping, ensuring that the meniscus is properly formed and positioned in the nozzle. This preliminary pressure reduction prevents unstable liquid ejection during subsequent printing operations.

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If a finishing wiping operation is performed immediately after discharge stops, then the nozzle surface can be cleaned, but the high pressure causes the meniscus to collapse and liquid ejection becomes unstable

Engineering Contradiction:

Improvenozzle cleaningVSAvoidmeniscus stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by performing a pressure reducing operation before the finishing wiping operation. The pressure reducing operation reduces the pressure in the liquid ejecting unit to a predetermined level before wiping, ensuring that the meniscus is properly formed and positioned in the nozzle. This preliminary pressure reduction prevents unstable liquid ejection during subsequent printing operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic action through a multi-step maintenance sequence: discharging operation, discharge stopping operation, pressure reducing operation, and finishing wiping operation. This periodic sequence ensures that pressure is reduced to appropriate levels at each stage, maintaining meniscus stability while performing necessary cleaning operations.

Inventive Principle:

Principle #19Periodic action

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

The solution effectively suppresses unstable ink ejection by reducing pressure in the liquid ejecting unit, maintaining a stable meniscus within the nozzle, and preventing interface collapse during wiping operations, thereby ensuring reliable ink flow and improved printing performance.

Implementation Method 1

a pressurizing mechanism that pressurizes the liquid in the liquid supply flow path

Methodology Applied

Scientific EffectPressurization: Pressurisation

Implementation Method 2

a wiping mechanism that wipes a nozzle surface on which the nozzle is formed

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Data Source

PatentUS10442187B2Liquid ejecting apparatus and maintenance method for liquid ejecting apparatus

Publication Date: 2019.10.15 SEIKO EPSON CORP

AI summary

A liquid ejecting apparatus sequentially performs a discharging operation of discharging pressurized liquid from a nozzle, a discharge stopping operation of stopping the discharging operation, a pressure reducing operation of reducing the pressure in a liquid ejecting unit, and a wiping operation of wiping a nozzle surface.