Inkjet Print Head Array Dual Ink Supply Channels

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Solution Overview

Problem

Inkjet print head arrays face challenges in ensuring even ink supply to multiple print head modules, particularly when the number exceeds 24, leading to diminishing ink amounts for modules further from the ink inlet, and issues with air bubble evacuation in the ink supply system.

Innovation Solution

The implementation of a two-dimensional array configuration with dual ink supply channels for each group of 24 print head modules, where each module receives ink from both channels, and a circulating ink flow mechanism to remove trapped air bubbles by changing the direction of ink flow and utilizing O-rings to hermetically seal the ink path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single ink supply channel is used for the array, then the device complexity is reduced, but the ink supply uniformity deteriorates as the number of print head modules exceeds 24

Engineering Contradiction:

Improveink supply channel configurationVSAvoidink supply uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The ink supply system is segmented into multiple independent ink supply channels, with each channel serving a specific group of print head modules. This segmentation ensures that each module receives adequate ink supply without the diminishing flow rate problem that occurs in long single-channel configurations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each ink supply channel is configured with specific local characteristics optimized for its served group of print head modules. The channels are positioned and dimensioned to provide uniform ink distribution to their respective modules, ensuring local supply quality matches the specific requirements of each module group.

Inventive Principle:

Principle #3Local quality

2Area of stationary object

If print head modules are positioned further from the ink inlet port to increase array coverage, then the array area is expanded, but the ink flow rate to those modules diminishes

Engineering Contradiction:

Improvearray coverage areaVSAvoidink flow rate

Core Design Contradiction:

Area of stationary objectVSQuantity of substance

Solution Approach 1:

The array is divided into multiple groups, with each group served by a dedicated ink supply channel. This allows modules at various positions within the array (including those far from any single inlet) to receive adequate ink flow through their nearest dedicated channel, maintaining uniform supply across the entire expanded array area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The ink supply channels are arranged in a two-dimensional configuration rather than a single linear path. Multiple channels are distributed across the array plane, allowing modules to access ink from the nearest channel in any direction, effectively eliminating the distance-related flow rate diminishment problem.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If arcaded tubing is used for ink delivery, then the ink path is established, but air bubbles are trapped at the highest point of the arc changing the cross section available for ink conduction

Engineering Contradiction:

Improveink path configurationVSAvoidink conduction

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The harmful air bubbles are extracted from the ink supply system through dedicated air evacuation channels. These channels provide a separate path that allows trapped air to be removed from the ink delivery system, preventing bubble accumulation that would otherwise block ink conduction.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Air evacuation channels act as an intermediary mechanism between the ink supply channels and the external environment. These channels facilitate the removal of air bubbles without disrupting the primary ink delivery function, serving as a mediator that resolves the conflict between maintaining sealed ink paths and eliminating air pockets.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 ensures equal and consistent ink supply to each print head module, regardless of its distance from the ink inlet, and effectively evacuates air bubbles, enhancing print throughput and resolution by maintaining equal pressure drop and flow rate across the array.

Implementation Method 1

a circulating ink flow mechanism to remove trapped air bubbles by changing the direction of ink flow

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 2

utilizing O-rings to hermetically seal the ink path

Methodology Applied

Scientific EffectHermetic sealing:

Data Source

PatentUS8172376B2Method of ink supply to inkjet print head array

Publication Date: 2012.05.08 HEWLETT PACKARD IND

AI summary

Disclosed is an inkjet print head array with improved ink supply system. The system includes an ink manifold having at least two ink supply channels, a plurality of print head modules disposed along ink supply channels and forming the array, with each of the print head modules having at least two ink inlet ports. The ports are in fluid communication with the ink supply channels. Each of the ink supply channels supplies ink to each of the ports at a different flow rate, although the resulting ink supply flow rate is equal for each print head module.