Liquid Discharge Head With Opposing Thermal Expansion

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Solution Overview

Problem

Existing liquid discharge heads experience displacement due to heat generation, leading to inconsistent droplet discharge as a result of thermal deformation of components.

Innovation Solution

The liquid discharge head is designed with a driver having a reversed linear expansion coefficient compared to the valve and fixing member, connected via a heat transfer layer, and the housing is divided into sub-housings with heat shielding properties to minimize thermal displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the driver operates continuously to maintain droplet discharge, then the discharge function is sustained, but heat generation causes thermal deformation and displacement of the driver

Engineering Contradiction:

Improvedischarge function sustainabilityVSAvoiddriver temperature

Core Design Contradiction:

Duration of action of moving objectVSTemperature

Solution Approach 1:

The patent applies thermal expansion principle by selecting materials with different linear expansion coefficients for the driver and surrounding components. The driver uses a material with a first linear expansion coefficient, while the valve and fixing member use materials with a second linear expansion coefficient that is reversed in positivity and negativity. This causes the components to expand or contract in opposite directions when temperature changes, compensating for thermal displacement and maintaining the driver's positional accuracy during continuous operation.

Inventive Principle:

Principle #37Thermal expansion

2Loss of energy

If the driver is made of material with high thermal conductivity to dissipate heat, then heat dissipation is improved, but thermal deformation of surrounding components increases

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidcomponent positional accuracy

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The patent uses thermal expansion compensation by designing the driver and surrounding components with materials having opposite linear expansion coefficients. When heat is generated during operation, the driver and surrounding components expand or contract in opposite directions, which compensates for relative displacement and maintains the precise positional relationship between the driver, valve, and fixing member, thereby maintaining manufacturing precision despite heat dissipation.

Inventive Principle:

Principle #37Thermal expansion

3Strength

If the driver and fixing member are rigidly connected to maintain structural stability, then structural strength is improved, but thermal displacement cannot be compensated

Engineering Contradiction:

Improvestructural stabilityVSAvoiddriver positional accuracy

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent implements thermal expansion compensation by selecting materials with opposite linear expansion coefficients for the driver and surrounding components. The driver is rigidly connected to the valve and fixing member through coupling mechanisms, but the differential thermal expansion between materials creates compensatory movements that offset thermal displacement, maintaining both structural stability and positional accuracy under temperature variations.

Inventive Principle:

Principle #37Thermal expansion

4Stability of the object's composition

If the linear expansion coefficients of driver and surrounding components are made similar, then thermal expansion uniformity is improved, but thermal displacement compensation is lost

Engineering Contradiction:

Improvethermal expansion uniformityVSAvoiddischarge state consistency

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent deliberately uses materials with different linear expansion coefficients (first coefficient for driver, second coefficient for valve and fixing member, with reversed positivity and negativity) to create differential thermal expansion. This differential expansion provides compensatory movement that offsets thermal displacement, maintaining consistent discharge state despite temperature changes during continuous operation.

Inventive Principle:

Principle #37Thermal expansion

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 suppresses thermal displacement, maintaining a consistent discharge state by offsetting thermal expansion and contraction, thereby stabilizing droplet discharge.

Implementation Method 1

the driver is coupled to each of the valve and the fixing member via a heat transfer layer

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The driver has a first linear expansion coefficient, each of the valve and the fixing member has a second linear expansion coefficient, the first linear expansion coefficient and the second linear expansion coefficient are reversed in positivity and negativity

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS12427771B2Liquid discharge head, head module, and liquid discharge apparatus

Publication Date: 2025.09.30 RICOH CO LTD

AI summary

A liquid discharge head includes: a housing; a nozzle plate attached to the housing, the nozzle plate having a nozzle from which a liquid is to be discharged; a valve in the housing, the valve configured to move in an opening and closing direction and openably close the nozzle; a driver having one end coupled to the valve in the opening and closing direction, the driver configured to drive the valve; and a fixing member fixed to the housing and coupled to another end of the driver in the opening and closing direction. The driver has a first linear expansion coefficient, each of the valve and the fixing member has a second linear expansion coefficient, and the first linear expansion coefficient and the second linear expansion coefficient are reversed in positivity and negativity.