Liquid Ejecting Head Reservoir Compliance Segmentation

Solution Overview

Problem

Ink jet recording heads face issues with pressure wave propagation causing variations in droplet ejection rates due to inadequate compliance in reservoirs, leading to potential air bubble entrapment and vibration control deficiencies.

Innovation Solution

A liquid ejecting head design featuring a reservoir with a first compliance section and a second compliance section, where the second compliance section compensates for deficient compliance in narrowed areas, effectively controlling vibrations and maintaining consistent ink jet characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the reservoir width is reduced at end areas to prevent air bubble entrapment, then air bubble entrapment is reduced, but compliance in the narrowed areas becomes deficient

Engineering Contradiction:

Improveair bubble entrapment preventionVSAvoidcompliance

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The compliance section is divided into multiple segments (first compliance section and second compliance section) positioned at different locations within the reservoir. This segmentation allows each segment to contribute to overall compliance while accommodating the narrowed reservoir geometry, thereby maintaining sufficient compliance without requiring the reservoir to be wide throughout its entire length.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The compliance section is strategically positioned to be located within the narrowed end areas of the reservoir rather than uniformly distributed. This local concentration of compliance in specific regions compensates for the reduced width, ensuring that adequate compliance is achieved in the narrowed areas without requiring the entire reservoir to maintain a large width.

Inventive Principle:

Principle #3Local quality

2Device complexity

If a single compliance section is used in the reservoir, then the structure is simple, but vibration control is insufficient in narrowed areas

Engineering Contradiction:

Improvecompliance section structureVSAvoidvibration control

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The compliance section is divided into multiple segments (first compliance section and second compliance section) positioned at different locations within the reservoir. This segmentation allows each segment to contribute to overall compliance while accommodating the narrowed reservoir geometry, thereby maintaining sufficient compliance without requiring the reservoir to be wide throughout its entire length.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple compliance sections are combined within the reservoir structure to achieve cumulative compliance effect. The first compliance section and second compliance section work together to provide sufficient vibration control in the narrowed areas, achieving better performance than a single compliance section would provide while still maintaining structural integration.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If the reservoir maintains constant width, then manufacturing is simple, but pressure wave propagation causes variation in droplet ejection rate

Engineering Contradiction:

Improvereservoir geometryVSAvoiddroplet ejection rate consistency

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The compliance section is strategically positioned to be located within the narrowed end areas of the reservoir rather than uniformly distributed. This local concentration of compliance in specific regions compensates for the reduced width, ensuring that adequate compliance is achieved in the narrowed areas without requiring the entire reservoir to maintain a large width.

Inventive Principle:

Principle #3Local quality

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 design effectively controls vibrations and maintains consistent ink jet characteristics by compensating for deficient compliance, resulting in improved and uniform ink jet characteristics and print quality.

Implementation Method 1

The compliance member has a compliance value of 0.03 mL/kPa to 0.3 mL/kPa, and the reservoir has a volume of 0.03 mL to 0.3 mL. The compliance section is formed as a thinned portion at an area corresponding to the reservoir, and the thinned portion has a thickness of 1/10 to 10 times the thickness of the reservoir-forming substrate.

Methodology Applied

Scientific EffectCompliance: Elasticity

Data Source

PatentUS8157366B2Liquid ejecting head and liquid ejecting apparatus incorporating the same

Publication Date: 2012.04.17 SEIKO EPSON CORP

AI summary

A liquid ejecting head includes: a reservoir provided along a direction, the reservoir including a first area and a second area of a width smaller than that of the first area in a direction perpendicular to the direction in which the pressure generating chambers are parallelly-arranged; and compliance member provided in an area corresponding to the reservoir. The compliance member includes a first compliance section formed at one of the upper and lower surface sides of the reservoir and a second compliance section formed at the other of the upper and lower surface sides of the reservoir. The first compliance section is formed at an area corresponding to both the first area and the second area of the reservoir, and the second compliance section is not formed in at least an area corresponding to a part of the first area.