Liquid Discharge Apparatus Bubble Removal via Bypass and Deaerator

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Solution Overview

Problem

Liquid discharge apparatuses with circulation paths often experience poor discharge due to bubbles, leading to discharge failure and curved discharge, as the meniscus in nozzles is disrupted, causing ink to be replaced unnecessarily.

Innovation Solution

A liquid discharge apparatus with a circulation path that includes a bypass, a pressure generator, a deaerator, and a switchable path configuration, where a detector controls the switch to route the liquid through a path with a bypass when bubbles are detected, enhancing bubble removal without altering pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a circulation path is used to supply liquid to the liquid discharger, then the liquid can be continuously supplied and reused, but bubbles in the liquid cause poor discharge, discharge failure, and curved discharge

Engineering Contradiction:

Improveliquid supply continuityVSAvoiddischarge quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention extracts and removes bubbles from the liquid circulation path using a deaerator. The deaerator separates gas bubbles from the liquid phase, allowing the liquid to circulate continuously while maintaining discharge quality by eliminating the harmful bubble component.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a deaerator as an intermediary device in the circulation path. This mediator component handles the bubble removal function, allowing the main liquid supply system to operate continuously without direct interference from bubbles, thus resolving the contradiction between continuity and quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of substance

If ink injection pressure is controlled to move ink inward from the periphery of the discharge side outlet, then the staying ink is replaced with new ink, but the meniscus formed by ink staying in the nozzle is destroyed, causing poor discharge

Engineering Contradiction:

Improvestaying ink replacementVSAvoiddischarge quality

Core Design Contradiction:

Loss of substanceVSReliability

Solution Approach 1:

The invention converts the harmful effect of pressure control (meniscus destruction) into a beneficial process by using the deaerator to remove bubbles that would otherwise cause discharge failures. The pressure control is optimized to replace staying ink while the deaerator ensures bubbles are removed, transforming a potentially harmful process into a beneficial one.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The deaerator performs preliminary bubble removal action before the liquid reaches the nozzles. This preliminary action prevents bubbles from interfering with the ink replacement process, allowing pressure control to effectively replace staying ink without causing meniscus destruction and poor discharge.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If a bypass is added to the circulation path to improve bubble removal, then bubble detection and path switching can be implemented, but the device complexity increases

Engineering Contradiction:

Improvebubble removal efficiencyVSAvoidcirculation path configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention makes the circulation path dynamic by implementing a switchable configuration with bypass. The system can dynamically route liquid through different paths based on bubble detection, allowing flexible adaptation to operating conditions while maintaining relatively simple hardware through controlled complexity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention implements feedback control by detecting bubbles and switching the circulation path accordingly. The detector monitors the liquid phase, and when bubbles are detected, the system automatically switches to the bypass path for enhanced deaeration, creating a closed-loop control system that manages complexity through intelligent automation.

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

This configuration efficiently removes bubbles, stabilizes ink discharge, and reduces variations in discharge characteristics between nozzles, ensuring consistent and efficient ink supply.

Implementation Method 1

a deaerator configured to remove gas in the liquid circulating the circulation path

Methodology Applied

Scientific EffectGas removal:

Implementation Method 2

a pressure generator configured to generate and apply a circulation pressure to the liquid circulating through the circulation path

Methodology Applied

Scientific EffectPressure application: Pressure Increase

Data Source

PatentUS11760104B2Liquid discharge apparatus, and liquid discharge method

Publication Date: 2023.09.19 RICOH CO LTD

AI summary

A liquid discharge apparatus includes a head including a supply path and a discharge path circulating a liquid in a liquid circulation direction, the head configured to discharge the liquid, a circulation path coupled to the head, the liquid circulates through the head in the circulation path, a bypass coupled to a downstream end of the supply path of the head and an upstream end of the discharge path of the head in the liquid circulation direction, a pressure generator configured to generate and apply a circulation pressure to the liquid circulating through the circulation path, and a deaerator configured to remove gas in the liquid circulating the circulation path.