Liquid Discharge Head Non-Uniform Flowability

Solution Overview

Problem

In liquid discharge apparatuses, the flowability of liquid from supply channels to discharge channels is non-uniform due to consistent cross-sectional areas of supply and discharge connection openings, leading to variations in channel resistance and ink circulation.

Innovation Solution

The liquid discharge head is designed with supply and discharge connection openings having different cross-sectional areas orthogonal to a specific direction, ensuring varying channel resistances that facilitate uniform flowability across the channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If consistent cross-sectional areas are used for all supply and discharge connection openings, then the device structure is simple and easy to manufacture, but the flowability of liquid through the channels becomes non-uniform

Engineering Contradiction:

Improveease of manufactureVSAvoidflowability uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by making each supply connection opening and discharge connection opening have different cross-sectional areas according to their specific positions in the channel system. The cross-sectional area of each opening is designed based on the distance from the liquid supply source and the cumulative resistance of the channel path, ensuring that each local position has the appropriate opening size to achieve uniform flow distribution across all individual channels.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If different cross-sectional areas are used for supply and discharge connection openings, then uniform flowability through channels is achieved, but the device complexity increases

Engineering Contradiction:

Improveflowability uniformityVSAvoiddevice complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by systematically varying the cross-sectional area parameter of connection openings based on their position in the channel network. The cross-sectional area is calculated and assigned according to the cumulative resistance of the liquid path from the supply source, creating a gradient distribution of opening sizes that compensates for the increasing channel resistance with distance from the supply opening.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If uniform cross-sectional areas are used for connection openings, then the device is easier to manufacture, but variations in channel resistance cause non-uniform ink circulation

Engineering Contradiction:

Improveease of manufactureVSAvoidink circulation consistency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by making each supply connection opening and discharge connection opening have different cross-sectional areas according to their specific positions in the channel system. The cross-sectional area of each opening is designed based on the distance from the liquid supply source and the cumulative resistance of the channel path, ensuring that each local position has the appropriate opening size to achieve uniform flow distribution across all individual channels.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies copying by creating a correspondence between the cross-sectional areas of supply connection openings and discharge connection openings at each position. The supply connection opening and discharge connection opening at each channel position are designed with matched cross-sectional areas that together compensate for the position-dependent resistance, ensuring consistent ink circulation throughout the system.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS10960668B2Liquid discharge head and liquid discharge apparatus

Publication Date: 2021.03.30 BROTHER KOGYO KK

AI summary

A liquid discharge head includes: individual channels including nozzles respectively; first supply channels through which liquid is supplied to the individual channels; first discharge channels through which the liquid is discharged from the individual channels; a second supply channel through which the liquid is supplied to the first supply channels; a second discharge channel to which the liquid is discharged from the first discharge channels; supply connection openings positioned between the first supply channels and the second supply channel and connecting the first supply channels and the second supply channel; discharge connection openings positioned between the first discharge channels and the second discharge channel and connecting the first discharge channels and the second discharge channel; a supply opening through which the liquid is supplied to the second supply channel; and a discharge opening to which the liquid is discharged from the second discharge channel.