Metal-Base Drive Circuit Substrate for Inkjet Head Heat Dissipation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The increasing number of nozzles in ink jet printers leads to higher current output from drive circuits, resulting in increased heat generation, which can cause characteristic deterioration and malfunction due to inefficient heat release.

Innovation Solution

The use of a drive circuit substrate with a metal base material having excellent thermal conductivity, such as copper, to efficiently disperse and release heat generated by the amplified modulation signal and drive signal, reducing the risk of component deterioration and malfunction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of nozzles is increased to improve print quality and printing speed, then productivity is improved, but heat generation increases causing reliability deterioration

Engineering Contradiction:
Improveprinting speedVSAvoiddrive circuit reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent converts the harmful heat generated by the drive circuit into a beneficial effect by using it to drive a fan for active cooling. The fan is positioned to blow air across the drive circuit substrate, creating forced convection that efficiently removes heat from the high-power amplifier components, thereby preventing reliability deterioration while maintaining high productivity

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

Solution Approach 2:

The patent utilizes phase transition of air from still state to moving state through fan-driven forced convection. The moving air flow transitions from natural convection to forced convection regime, significantly enhancing heat transfer coefficients and improving the drive circuit's thermal management capability

Inventive Principle:
Principle #36Phase transitions

2Use of energy by moving object

If a class D amplifier circuit is used to reduce power consumption, then energy efficiency is improved, but heat generation increases causing characteristic deterioration

Engineering Contradiction:
Improvepower consumptionVSAvoiddrive circuit stability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces air as an intermediary cooling medium between the heat-generating drive circuit and the surrounding environment. The fan-driven air flow acts as a thermal intermediary that absorbs heat from the amplifier components through forced convection, preventing temperature rise that would cause characteristic deterioration while maintaining the energy-efficient class D amplifier operation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces passive thermal management (reliance on natural convection and radiation) with an active mechanical cooling system using a fan. This mechanical intervention enables controlled forced convection, providing reliable heat removal from the drive circuit even when high current is supplied to multiple nozzles

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 the likelihood of characteristic deterioration and malfunction in the drive circuit by efficiently releasing heat, thereby improving the reliability and performance of the ink jet printer.

Implementation Method 1

a drive circuit substrate with a metal base material having excellent thermal conductivity, such as copper, to efficiently disperse and release heat generated by the amplified modulation signal and drive signal

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3842232B1Liquid ejecting apparatus
Publication Date: 2022.11.23 SEIKO EPSON CORP
  • EP3842232B1 patent drawingFigure 1
  • EP3842232B1 patent drawingFigure 2
  • EP3842232B1 patent drawingFigure 3

AI summary

A liquid ejecting apparatus includes a liquid ejection head including a drive element, where the liquid ejection head ejects a liquid by a supply of a drive signal to the drive element, and a drive circuit that outputs the drive signal, wherein the drive circuit includes a modulation circuit, an amplifier circuit, a demodulation circuit, and a substrate on which the modulation circuit, the amplifier circuit, and the demodulation circuit are provided, wherein the substrate includes a base material and a first layer laminated on a first face of the base material, wherein the base material includes a metal, wherein the first layer includes a first propagation wire through which at least one of the amplified modulation signal and the drive signal propagates, and wherein the base material has a thickness greater than a thickness of the first layer.