Multi-plane filter laminate for piezoelectric printhead contamination control

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Solution Overview

Problem

Piezoelectric printheads face contamination issues due to thin film rock screens with larger holes required for lower fluidic resistance, leading to print quality defects like intermittent and missing jets, as smaller holes are limited by allocated area and pressure drop requirements.

Innovation Solution

A multi-plane laminated filter structure with rock screen subassemblies, including upstream and downstream pocket layers and rock screen plates with through holes, increases the effective filtering area by allowing smaller rock screen holes and reducing fluidic resistance, preventing contamination from reaching the actuator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If smaller rock screen holes are used to protect the jetstack from contamination, then filtration effectiveness is improved, but fluidic resistance increases

Engineering Contradiction:

Improvefiltration effectivenessVSAvoidfluidic resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The single rock screen plane is segmented into multiple rock screen planes (first rock screen plane, second rock screen plane, etc.) stacked in series. Each plane provides additional filtration surface area, allowing the use of smaller holes for better contamination protection while distributing the pressure drop across multiple planes rather than concentrating it in a single plane with larger holes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from a two-dimensional single-plane rock screen to a three-dimensional multi-plane stacked structure. By adding the vertical dimension (stacking multiple planes), the total filtration surface area increases without increasing the lateral footprint, enabling smaller hole sizes while maintaining acceptable fluidic resistance through the distributed filtration approach.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of energy

If larger rock screen holes are used to reduce fluidic resistance, then pressure drop is reduced, but contamination protection deteriorates

Engineering Contradiction:

Improvepressure dropVSAvoidcontamination

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The filtration function is segmented across multiple rock screen planes, each contributing to the overall filtration effectiveness. This segmentation allows the system to achieve both contamination protection and acceptable pressure drop by distributing the filtration task across several planes with smaller holes rather than relying on a single plane with larger holes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The multi-plane rock screen structure functions as a composite filtration system, where multiple filtration layers (rock screen planes) are combined in series. This composite structure provides enhanced filtration capability compared to a single layer, enabling the use of smaller holes while maintaining overall system performance.

Inventive Principle:

Principle #40Composite materials

3Device complexity

If a single rock screen plane is used with limited area, then device complexity is low, but the allocated area per jet is insufficient

Engineering Contradiction:

Improvefilter structure complexityVSAvoidallocated area per jet

Core Design Contradiction:

Device complexityVSArea of stationary object

Solution Approach 1:

By stacking multiple rock screen planes in the vertical dimension, the total filtration area available per jet increases without significantly increasing the lateral footprint or overall device complexity. The multi-plane structure efficiently utilizes the vertical space to provide additional filtration surface area for each jet allocation.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The multiple rock screen planes are nested in a compact stacked arrangement, with each plane containing pocket layers and rock screen plates integrated within the same vertical envelope. This nesting approach maximizes the filtration area within a compact structure, providing increased area per jet without proportionally increasing device complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 multi-plane filter laminate structure enhances print quality by reducing fluidic resistance and preventing contamination, allowing for smaller rock screen holes that effectively filter ink and maintain jet performance, thereby reducing the likelihood of print defects.

Implementation Method 1

a rock screen plate configured with through holes over an entire exposed surface area thereof

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentUS8567934B2Multi-plane filter laminate to increase filtration surface area

Publication Date: 2013.10.29 XEROX CORP

AI summary

A printhead including a jetstack configured to include a multi-plane filter laminate. The multi-plane filter laminate includes a first rock screen subassembly and a second rock screen subassembly. Each subassembly is configured to include an upstream pocket layer, a downstream pocket layer aligned with the upstream pocket layer, and a rock screen plate sandwiched between the upstream and downstream pocket layers, the rock screen plate configured with through holes over an entire exposed surface area thereof. A portion of the rock screen plate of the first subassembly is configured to overlay the rock screen plate of the second subassembly.