Liquid Discharge Head Cooling Layout for Multiple Drive Boards

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Solution Overview

Problem

Existing liquid discharge heads face challenges in efficiently cooling multiple driving elements with uneven heat generation, leading to layout difficulties and increased parts count due to the need for individual heat sinks and coolant paths, especially when high-speed recording is required.

Innovation Solution

A liquid discharge head design that utilizes a common cooling member to distribute heat evenly across multiple driving elements, reducing the number of parts and simplifying coolant path layout by using a staggered pattern, with a cooling unit that includes coolant flow paths and heat conduction members to manage varying heat loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of discharge elements is increased to achieve high-speed recording, then productivity is improved, but the number of driving elements and drive circuit boards increases, leading to increased device complexity and heat generation

Engineering Contradiction:
Improverecording speedVSAvoidnumber of drive circuit boards
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Multiple drive circuit boards are merged onto a single support board, reducing the number of separate components and simplifying the overall structure. The cooling member is designed to cool multiple driving elements simultaneously through a shared coolant flow path, combining multiple cooling functions into one integrated component.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support board serves multiple functions: it mechanically supports the discharge element boards and also carries the drive circuit boards, acting as both a structural and electrical platform. The cooling member functions both as a thermal management component and as a structural element that facilitates coolant distribution across multiple heat sources.

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

2Temperature

If independent heat sinks are provided for each drive circuit board, then cooling effectiveness is improved, but the number of parts increases and layout flexibility is reduced

Engineering Contradiction:
Improvecooling effectivenessVSAvoidnumber of heat sinks
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

Multiple independent heat sinks are merged into a single integrated cooling member that serves multiple drive circuit boards simultaneously. The cooling member includes multiple cooling portions that can be positioned adjacent to different driving elements, providing targeted cooling without requiring separate heat sink components for each board.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling member is segmented into multiple cooling portions, each capable of cooling a specific driving element. The coolant flow path is divided into multiple flow paths that can be independently directed to different cooling portions, allowing selective cooling of different regions while using a single integrated component.

Inventive Principle:
Principle #1Segmentation

3Area of stationary object

If drive circuit boards are arranged in a staggered pattern, then space utilization is improved, but coolant path layout becomes more difficult with independent heat sinks

Engineering Contradiction:
Improvespace utilizationVSAvoidcoolant path layout
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The cooling member is designed as a universal cooling component that can adapt to staggered arrangements of drive circuit boards. The multiple cooling portions can be positioned to match the staggered layout, and the coolant flow paths can be routed to reach each cooling portion regardless of the underlying staggered arrangement of the circuit boards.

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

Solution Approach 2:

The cooling member extends in multiple dimensions to accommodate the staggered arrangement of drive circuit boards. Rather than requiring each heat sink to be independently positioned, the cooling member uses its three-dimensional structure to reach multiple heat sources distributed in a staggered pattern, simplifying the coolant path routing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Device complexity

If multiple drive circuit boards are mounted on one support board, then device complexity is reduced, but heat generation and cooling requirements increase

Engineering Contradiction:
Improvenumber of support structuresVSAvoidheat generation
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The cooling member is segmented into multiple cooling portions, each responsible for cooling a specific drive circuit board or region. This segmentation allows the cooling function to scale with the number of mounted boards, distributing the thermal management load across multiple specialized cooling zones within a single integrated component.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling member serves as a universal thermal management solution for multiple drive circuit boards mounted on the support board. It provides both mechanical support functionality and thermal management functionality, acting as a multi-functional component that addresses both structural and thermal requirements of the concentrated board arrangement.

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

The design efficiently cools driving elements, maintaining optimal temperatures while reducing part count and facilitating complex layouts, such as staggered patterns, by dispersing cooling loads and using a shared cooling member.

Implementation Method 1

a cooling unit provided with a plurality of coolant flow paths and heat conduction members

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP4656401A1Liquid discharge head and liquid discharge apparatus
Publication Date: 2025.12.03 CANON KK
  • EP4656401A1 patent drawingFigure 1
  • EP4656401A1 patent drawingFigure 2
  • EP4656401A1 patent drawingFigure 3

AI summary

A liquid discharge head includes a first discharge element board and a second discharge element board each having a discharge element for discharging a liquid from a discharge port, first and second drive circuit boards provided with first and second driving elements for driving the discharge element on the first and second discharge element boards, and a cooling member configured to come into contact with the first and the second drive circuit boards, wherein the cooling member includes an inlet configured to introduce a coolant from outside, an outlet configured to guide the coolant to the outside, first and second coolant flow paths disposed to sandwich the inlet and configured to connect the inlet and the outlet and cool the first and second drive circuit boards respectively.