Ink Jet Print Head Nozzle Polygon Arrangement for Line Width Consistency

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Solution Overview

Problem

Hand-held ink jet pens face challenges in maintaining consistent line-width due to variations in surface properties, environment, user handling, and nozzle orientation, which existing designs struggle to minimize effectively.

Innovation Solution

The ink jet print head is configured with nozzles placed at the vertices of regular or quasi-regular polygons, with specific side length and spot diameter ratios to minimize orientation-induced line-width variations, using mathematical inequalities to optimize nozzle spacing and spot size for consistent line-width delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional nozzle configurations are used in hand-held ink jet pens, then the device is simple and easy to manufacture, but line-width variation occurs due to orientation changes and user handling

Engineering Contradiction:

Improveline-width consistencyVSAvoidnozzle configuration complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The ink jet system divides the single-line output into multiple parallel lines from multiple nozzles. By segmenting the writing task across multiple nozzles arranged in specific geometric patterns (linear, triangular, rectangular configurations), the system achieves orientation tolerance through spatial distribution rather than requiring a single perfectly positioned nozzle

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs asymmetric nozzle arrangements where nozzles are positioned at specific distances and angles relative to each other (e.g., first nozzle at distance d1, second nozzle at distance d2, with specific angular relationships). This asymmetric configuration compensates for orientation variations by ensuring that line-width variations from different nozzle orientations average out to produce consistent overall line width

Inventive Principle:

Principle #4Asymmetry

2Measurement precision

If multiple sensors and connections are added to measure distance and detect movement, then measurement precision improves, but the pen shape deviates from conventional design and space is consumed

Engineering Contradiction:

Improvedistance and movement detection accuracyVSAvoidpen form factor

Core Design Contradiction:

Measurement precisionVSShape

Solution Approach 1:

The ink jet pen integrates multiple functions into a single device: it combines writing functionality with distance measurement and movement detection capabilities. The system uses the existing ink jet mechanism and integrated circuit to perform both printing and sensing functions, eliminating the need for separate sensor modules that would increase pen size and alter its conventional shape

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the measurement and control functions directly into the ink jet print head assembly. The distance measurement means and movement detector are integrated with the processor unit and ink jet system, allowing all functions to share common space and structural elements, thereby maintaining a compact, conventional pen form factor

Inventive Principle:

Principle #5Merging (Combining)

3Manufacturing precision

If nozzle spacing and spot size are optimized for minimum line-width variation, then manufacturing precision improves, but the configuration becomes more complex to design and implement

Engineering Contradiction:

Improveline-width controlVSAvoidnozzle configuration design

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent systematically varies key parameters including nozzle spacing (d1, d2), spot diameters (w1, w2), and angular relationships between nozzles to achieve optimal line-width consistency. By establishing specific parameter ranges and relationships (e.g., d1/d2 ratios, angular configurations), the design transforms a complex optimization problem into a set of manageable parameter specifications that can be implemented through standard manufacturing processes

Inventive Principle:

Principle #35Parameter changes

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 configuration significantly reduces line-width variations caused by pen orientation, ensuring consistent line quality across different surfaces and user handling conditions, while maintaining acceptable line edge crispness and coverage.

Implementation Method 1

ejecting ink from the ink jet print head of the ink jet pen via numerous methods which employ, for example, pressurized nozzles, electrostatic fields, piezo-electric elements and/or heaters for vapor-phase droplet formation

Methodology Applied

Scientific EffectVapor-phase droplet formation: Evaporation

Data Source

PatentUS7441869B2Ink jet print head adapted to minimize orientation-induced line-width variation

Publication Date: 2008.10.28 BRADY WORLDWIDE INC

AI summary

Ink jet print head adapted to minimize orientation-induced line-width variation. The print head having n nozzles located at the vertices of a regular or quasi-regular polygon having an average side length savg, and each side length of the polygon is less than 20% deviation from the average side length savg. The n nozzles are configured to ink jet a line having a line-width w; and each of the n nozzles is configured to ink jet a spot having an average area-equivalent spot diameter d which satisfies the inequality condition (I)0.7w≦d+(n/π)savg≦1.3w. (I)