Liquid Ejection Head Plate-Spring Cooling for Compact Nozzle Arrays

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Solution Overview

Problem

Existing liquid ejection heads face challenges in managing heat generators and substrates without increasing the overall size, particularly as the number of nozzle columns grows, leading to complex configurations for cooling units and substrate holding.

Innovation Solution

A liquid ejection head design featuring a temperature control structure with plate springs to push heat generating circuits against it, along with a temperature control liquid circulation system, allowing for efficient temperature management without enlarging the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of nozzle columns is increased, then the liquid ejection capability is improved, but the configuration complexity of cooling units and substrate holding increases

Engineering Contradiction:
Improveliquid ejection capabilityVSAvoidconfiguration complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the cooling unit and substrate holding function into a single integrated structure. The cooling unit serves dual purposes: it cools the driver ICs and simultaneously holds the substrate through its structural design, eliminating the need for separate holding components and reducing overall configuration complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling unit is designed with multi-functionality, performing both thermal management and mechanical support functions. This universal design allows the same component to address multiple needs, thereby reducing the number of separate components required as nozzle columns increase.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If the number of nozzle columns is increased, then the liquid ejection capability is improved, but the device size increases

Engineering Contradiction:
Improveliquid ejection capabilityVSAvoiddevice size
Core Design Contradiction:
ProductivityVSVolume of moving object

Solution Approach 1:

By combining cooling and substrate holding functions into one unit, the patent reduces the total volume required. Instead of having separate components for cooling and holding, the integrated design uses the same space for both purposes, thereby controlling device size even as nozzle columns increase.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The substrate holding function is nested within the cooling unit structure. The cooling unit's structural elements simultaneously serve as support elements for the substrate, effectively nesting one function within another to maximize space utilization and prevent device enlargement.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Temperature

If separate cooling unit and substrate holding components are used, then the cooling function is improved, but the device complexity and size increase

Engineering Contradiction:
Improvecooling functionVSAvoidnumber of components
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines the cooling unit and substrate holding components into a single integrated structure. This merging maintains effective cooling functionality while reducing the number of separate components, thereby decreasing device complexity without sacrificing thermal management performance.

Inventive Principle:
Principle #5Merging (Combining)

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 design effectively manages heat generation and substrate holding without increasing the device's size, ensuring stable operation and efficient temperature control for the heat generating circuits.

Implementation Method 1

one or more plate springs each biased to push one or more of the heat generating circuits against the temperature control structure

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a temperature control structure that contacts the heat generating circuits for controlling temperature thereof

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a temperature control liquid circulation system

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4592081A1Liquid ejection head and liquid ejection apparatus
Publication Date: 2025.07.30 RISO TECH CORP
  • EP4592081A1 patent drawingFigure 1
  • EP4592081A1 patent drawingFigure 2
  • EP4592081A1 patent drawingFigure 3

AI summary

A liquid ejection head includes a plurality of nozzle arrays extending along a first direction and through which liquid is ejected towards a second direction perpendicular to the first direction, a plurality of substrates extending along the first and second directions, the substrates corresponding to the nozzle arrays, a plurality of heat generating circuits each disposed on a corresponding one of the substrates, a temperature control structure that contacts the heat generating circuits for controlling temperature thereof, and one or more plate springs each biased to push one or more of the heat generating circuits against the temperature control structure.