Wide-array Inkjet Printhead Shroud Profile Control

Solution Overview

Problem

Wide-array inkjet printheads face challenges due to increased size, which leads to higher component counts, increased costs, and stringent manufacturing tolerances, while also requiring precise capping surfaces and efficient electrical connection routing to maintain print quality and prevent ink evaporation.

Innovation Solution

A flexible stainless steel shroud is used to provide a capping surface that meets stringent profile specifications, supported by precision components to withstand wiping forces, and flexible sheet metal fabrication techniques are employed to minimize costs, with flex cables routed through rail indentations to reduce connection length and interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a wide-array inkjet printhead is designed to be substantially as wide as the substrate, then translation of the printhead is eliminated, but the number of components increases and manufacturing cost increases

Engineering Contradiction:

Improveprinthead translation capabilityVSAvoidnumber of components

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The printhead is divided into multiple modules, each containing a subset of nozzles and associated electronics. This segmentation allows the wide-array printhead to be constructed from manageable units, reducing the complexity of assembling and managing a large number of components while maintaining the overall wide coverage capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Electrical connections and control circuitry are integrated directly into the printhead structure, with electronics embedded within or alongside the nozzle arrays. This nesting of functional elements within the printhead body eliminates the need for separate external connection assemblies, thereby reducing the total component count while preserving the wide-array functionality.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of operation

If a wide-array inkjet printhead is designed to be substantially as wide as the substrate, then translation of the printhead is eliminated, but manufacturing cost increases

Engineering Contradiction:

Improveprinthead translation capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The printhead is divided into multiple modules, each containing a subset of nozzles and associated electronics. This segmentation allows the wide-array printhead to be constructed from manageable units, reducing the complexity of assembling and managing a large number of components while maintaining the overall wide coverage capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Electrical connections and control circuitry are integrated directly into the printhead structure, with electronics embedded within or alongside the nozzle arrays. This nesting of functional elements within the printhead body eliminates the need for separate external connection assemblies, thereby reducing the total component count while preserving the wide-array functionality.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If a capping surface is designed to meet stringent profile specifications, then effective sealing is achieved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvesealing effectivenessVSAvoidcapping surface profile tolerance

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The capping surface is constructed using flexible materials such as elastomeric seals or thin metallic foils that can elastically deform to conform to the underlying substrate surface. This flexibility allows the cap to achieve effective sealing even when the underlying surface has moderate variations, thereby reducing the stringent profile specification requirements while maintaining sealing reliability.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing mechanism transitions from relying on rigid geometric precision to utilizing material property variations. By changing from a rigid, precision-machined seal to a compliant, elastically deformable seal, the system achieves effective sealing through material deformation rather than geometric precision, thereby relaxing manufacturing tolerance requirements.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8702200B2Wide-array inkjet printhead with a shroud

Publication Date: 2014.04.22 HEWLETT PACKARD DEVELOPMENT COMPANY LP

AI summary

A wide-array inkjet printhead assembly with a shroud includes a backbone, an array of die in which the die are mounted on die carriers. The die carriers are attached to the backbone and include support features. The shroud includes a capping surface, with a surface profile that deviates from a reference plane by more than a target deviation. The support features interface with and support an undersurface of shroud such that the capping surface of the shroud, when biased against the support features, deviates from the reference plane by no more than the target deviation.