Liquid Ejecting Head Heat Release Member for Drive Circuit Cooling

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Solution Overview

Problem

The existing liquid ejecting heads face challenges in effectively releasing heat from the drive circuit, leading to potential damage due to insufficient heat dissipation, which limits the performance and efficiency of the liquid ejecting apparatus.

Innovation Solution

Incorporating a heat release member in contact with the flexible substrate of the drive circuit, which conducts heat to the diaphragm and subsequently transfers it to the ink, allowing for efficient heat dissipation through ink ejection, thereby preventing temperature rises in the drive circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If heat is released only by air or metal wiring in the drive circuit space, then the structure remains simple, but the heat release efficiency is insufficient causing drive circuit temperature to rise

Engineering Contradiction:

Improvedrive circuit temperatureVSAvoidheat release efficiency

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

A heat release member is introduced as an intermediary component between the drive circuit and the diaphragm/ink system. This heat release member includes a heat release portion that contacts the flexible substrate carrying the drive circuit, and a heat conduction portion that extends toward the ink ejection surface, enabling efficient heat transfer from the drive circuit to the ink without requiring direct contact between the drive circuit and ink reservoir

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the ink fluid itself as a heat sink medium. The ink circulating through the ink ejection surface and ink reservoir serves as a cooling medium that absorbs heat from the drive circuit via the heat release member, converting the thermal management problem into a fluid-based heat transfer solution

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If drive circuit performance is limited to prevent damage from high temperature, then reliability is maintained, but the full performance of the liquid ejecting head cannot be achieved

Engineering Contradiction:

Improvedrive circuit reliabilityVSAvoidliquid ejecting head performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent converts the harmful heat generated by the drive circuit into a beneficial cooling mechanism. By strategically placing the heat release member to conduct heat toward the ink ejection surface, the previously problematic heat generation is transformed into an effective thermal management solution that enables high-performance operation without compromising reliability

Inventive Principle:

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

Solution Approach 2:

The heat release member serves multiple functions simultaneously: it provides structural support in the drive circuit space, acts as a thermal conduction path from the flexible substrate, and directs heat toward the ink ejection surface for dissipation. This multi-functionality allows the component to contribute to both structural integrity and thermal management

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution enables efficient heat release from the drive circuit, preventing damage and maintaining performance, allowing for higher nozzle density and increased ink ejection speed without performance limitations.

Implementation Method 1

a heat release member that is either in contact with an opposite surface of the flexible substrate, the opposite surface being opposite of a surface on which the drive circuit is provided, or in contact with the drive circuit, and conducts heat of the drive circuit to the diaphragm

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

transfers it to the ink, allowing for efficient heat dissipation through ink ejection

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11845278B2Liquid ejecting head and liquid ejecting apparatus

Publication Date: 2023.12.19 SEIKO EPSON CORP

AI summary

A liquid ejecting head includes piezoelectric elements for ejecting liquid from nozzles, pressure chambers in communication with the nozzles, individual supply flow passages for supplying the liquid to the nozzles, individual collection flow passages for collecting the liquid not ejected from the nozzles, a diaphragm that defines a wall surface of the pressure chambers and deforms by driving the piezoelectric element, a flexible substrate having a drive circuit electrically coupled to the piezoelectric elements, and a heat release member that is either in contact with an surface of the flexible substrate that faces away from the drive circuit, or in contact with the drive circuit, and conducts heat of the drive circuit to the diaphragm. The heat release member is disposed closer to the individual supply flow passage than to the individual collection flow passage.