Liquid Discharge Head Pump Outflow Hole Orientation

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Solution Overview

Problem

Existing liquid discharge heads, such as those in inkjet printing apparatuses, face challenges with air bubbles getting trapped in the pump, leading to pressure loss and reduced liquid circulation due to the horizontal orientation of the pump outflow hole.

Innovation Solution

The liquid discharge head is designed with a pump outflow hole that faces upward in a substantially vertical direction, facilitating the discharge of air bubbles by leveraging the buoyant force, thus preventing air bubbles from being trapped and maintaining efficient liquid circulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pump outflow hole is oriented horizontally, then the pump structure is simple and easy to manufacture, but air bubbles are trapped in the pump causing pressure loss and reduced liquid circulation

Engineering Contradiction:

Improveliquid circulation efficiencyVSAvoidpump structure complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The pump outflow hole is reoriented from a horizontal direction to a vertical upward direction. This dimensional change in orientation allows air bubbles to escape naturally through buoyancy forces, resolving the contradiction by improving liquid circulation efficiency without adding structural complexity to the pump design.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The upward orientation of the pump outflow hole counteracts the gravitational force acting on air bubbles. By positioning the outflow hole to face upward, the design leverages buoyancy forces to oppose the weight of trapped air bubbles, enabling their natural escape and preventing pressure loss in the liquid circulation system.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

2Quantity of substance

If air bubbles are trapped in the pump, then the pump structure remains unchanged, but pressure is lost and liquid circulation is reduced

Engineering Contradiction:

Improveliquid flow rateVSAvoidpressure loss

Core Design Contradiction:

Quantity of substanceVSLoss of energy

Solution Approach 1:

Changing the orientation of the pump outflow hole from horizontal to vertical upward enables air bubbles to escape along a different path. This dimensional change in flow direction prevents air bubble accumulation, thereby maintaining liquid flow rate and reducing pressure loss in the circulation system.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The design converts the harmful effect of air bubble trapping into a beneficial outcome by orienting the outflow hole upward. This allows air bubbles, which would normally cause pressure loss, to be naturally expelled through buoyancy, transforming a potential problem into a self-cleaning mechanism that maintains liquid circulation efficiency.

Inventive Principle:

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

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 effectively reduces pressure loss and ensures continuous, efficient liquid circulation by ensuring air bubbles are discharged from the pump, thereby maintaining the integrity of the ink flow and preventing thickening or settling of ink components.

Implementation Method 1

The pump circulates a liquid using a change in pressure within the pump

Methodology Applied

Scientific EffectPressure change: Pressure Gradient

Implementation Method 2

since a buoyant force acts on air bubbles in ink in a vertical direction

Methodology Applied

Scientific EffectBuoyant force: Archimedes' Principle (Buoyancy)

Data Source

PatentUS20250115053A1Liquid discharge head and liquid discharge apparatus

Publication Date: 2025.04.10 CANON KK

AI summary

A liquid discharge head includes a discharge element substrate configured to discharge a liquid, an upstream-side flow path connected to the discharge element substrate and configured to supply a liquid to the discharge element substrate, a downstream-side flow path connected to the discharge element substrate and configured to collect a liquid from the discharge element substrate, and a pump connected to each of the upstream-side flow path and the downstream-side flow path and configured to cause a liquid within the downstream-side flow path to flow out to the upstream-side flow path, wherein the pump includes a pump outflow hole for causing the liquid within the downstream-side flow path to flow out to the upstream-side flow path, and wherein, in a use state of the liquid discharge head, an opening of the pump outflow hole faces upward in a substantially vertical direction.