Liquid Discharge Head Channel Geometry for Flow Resistance

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Solution Overview

Problem

The existing liquid discharge systems face a decrease in efficiency when dealing with the flow of two liquids, as the length of the channel increases, leading to higher flow resistance and reduced liquid supply efficiency.

Innovation Solution

A liquid discharge head is designed with a configuration that includes a plurality of liquid discharge modules, each with a pressure generating element and a flexible printed circuit board, allowing for easy attachment and detachment, and a specific channel and pressure chamber structure that adjusts the flow rates and viscosities of two liquids to maintain a stable laminar flow, reducing channel length and flow resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two-type liquids are supplied to channels on a substrate, then the discharge medium and bubbling medium can be brought into contact to form bubbles, but the channel length increases leading to higher flow resistance and decreased liquid supply efficiency

Engineering Contradiction:
Improvedischarge performanceVSAvoidliquid supply efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The liquid discharge head is divided into multiple independent liquid discharge modules, each handling the supply and discharge of two-type liquids separately. This segmentation allows optimization of the channel structure within each module to reduce flow resistance while maintaining the bubble formation function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical dimension by stacking multiple liquid discharge modules in the depth direction. This allows the system to maintain adequate channel lengths for proper liquid mixing and bubble formation while reducing the horizontal channel length, thereby decreasing flow resistance and improving liquid supply efficiency.

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

2Ease of operation

If the channel length increases to supply two-type liquids, then the discharge medium and bubbling medium can be properly supplied, but the flow resistance increases reducing liquid supply efficiency

Engineering Contradiction:
Improveliquid supply stabilityVSAvoidflow resistance
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

By segmenting the liquid supply system into multiple modules with separate supply channels for each liquid type, the patent optimizes the channel geometry within each segment to minimize flow resistance while ensuring stable supply of both discharge medium and bubbling medium.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs hydraulic principles by designing the channel structure and flow paths to optimize liquid flow dynamics, reducing turbulence and pressure losses, thereby decreasing energy loss due to flow resistance while maintaining stable liquid supply.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Ease of manufacture

If multiple liquid discharge modules are provided, then faulty modules can be easily replaced improving manufacturing yields, but the device complexity increases

Engineering Contradiction:
Improvemanufacturing yieldsVSAvoidmodule configuration
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The liquid discharge head is segmented into multiple identical, independent modules that can be manufactured separately and assembled. This modular architecture simplifies manufacturing by allowing standardized production of individual modules, easy replacement of faulty units, and improved manufacturing yields despite the overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each liquid discharge module is designed as a universal, interchangeable unit with standardized interfaces and functions. This universality allows any module to replace any other, simplifying manufacturing processes and inventory management, and improving manufacturing yields through standardized production methods.

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 configuration effectively suppresses the decrease in liquid supply efficiency while maintaining a stable interface between the two liquids, ensuring efficient discharge performance and improved manufacturing yields by allowing for easy replacement of faulty modules.

Implementation Method 1

pressure chambers are formed for each recording element and liquid is discharged from discharge orifices

Methodology Applied
Scientific EffectPressure generation: Pressure Increase

Implementation Method 2

a flow from the liquid supply channel through the pressure chambers to the liquid recovery channel is generated

Methodology Applied
Scientific EffectFluid flow: Pressure Gradient

Data Source

PatentEP3854594B1Liquid discharge head and liquid discharge module
Publication Date: 2023.09.13 CANON KK
  • EP3854594B1 patent drawingFigure 1
  • EP3854594B1 patent drawingFigure 2
  • EP3854594B1 patent drawingFigure 3

AI summary

A liquid discharge head (1) includes a substrate (15), pressure chambers (18), a pressure generating element (12), a discharge port (11), and a liquid channel (13). First and second communication supply channels (20, 21) and first and second communication collecting channels (25, 26) are formed in the substrate. A central axis of a first communication supply opening (50) is located closer to the corresponding pressure chamber than a central axis of a first common supply opening (54), or a central axis (60) of a second communication supply opening (51) is located closer to the corresponding pressure chamber than a central axis (60) of a second common supply opening (55), or a central axis of a first communication collecting opening (52) is located closer to the corresponding pressure chamber than a central axis of a first common collecting opening (56), or a central axis (60) of a second communication collecting opening (53) is located closer to the corresponding pressure chamber than a central axis (60) of a second common collecting opening (57).