Electrostatic Ink Phosphorescent Pigment Visibility

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Solution Overview

Problem

Electrophotographic printing processes face challenges in creating multi-colored images that are visible under non-visible radiation, as existing technologies lack effective phosphorescent pigments that emit light for extended periods, affecting the visibility and quality of printed images.

Innovation Solution

An electrostatic ink composition comprising a phosphorescent pigment, such as strontium aluminate or zinc sulfide, dispersed in a liquid carrier with a resin, which is used to create images that can be transferred to a print substrate, ensuring the pigment emits light for an extended period, enhancing visibility under non-visible radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If existing electrostatic ink compositions are used, then the printing process can be completed, but the images are not visible under non-visible radiation

Engineering Contradiction:
Improvevisibility under non-visible radiationVSAvoideffectiveness of phosphorescent pigment
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes the optical parameters of the ink composition by incorporating phosphorescent pigments that emit light in the visible spectrum when exposed to non-visible radiation. This modifies the emission characteristics of the electrostatic ink to enable visibility under non-visible radiation sources.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite electrostatic ink composition by combining conventional ink components with phosphorescent pigments. This composite material exhibits both the electrostatic properties needed for printing and the phosphorescent emission properties for visibility under non-visible radiation.

Inventive Principle:
Principle #40Composite materials

2Duration of action of moving object

If phosphorescent pigments are added to enhance visibility, then the emission duration is extended, but the ink composition complexity increases

Engineering Contradiction:
Improveemission durationVSAvoidink composition complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The patent adjusts the concentration and type of phosphorescent pigments in the ink composition to achieve extended emission duration while controlling the overall complexity. By optimizing the phosphorescent material parameters, the patent extends the duration of action without proportionally increasing composition complexity.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If phosphorescent pigments are used to improve image quality, then the visibility is enhanced, but the manufacturing process becomes more difficult

Engineering Contradiction:
Improveimage qualityVSAvoidmanufacturing process difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent optimizes the particle size, concentration, and type of phosphorescent pigments to achieve high image quality while maintaining ease of manufacture. By carefully controlling these parameters, the patent enhances visibility without creating insurmountable manufacturing difficulties.

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

The use of phosphorescent pigments in the electrostatic ink composition allows for the creation of images that are visible under non-visible radiation, improving the visibility and quality of printed images by emitting light for an extended duration, addressing the limitations of existing technologies.

Implementation Method 1

The photoconductive surface is selectively charged with a latent electrostatic image having image and background areas with different potentials. The charged toner particles adhere to the image areas of the latent image

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentEP3325562B1Electrostatic ink compositions
Publication Date: 2020.06.03 HP INDIGO BV
  • EP3325562B1 patent drawingFigure 1

AI summary

Herein is disclosed an electrostatic ink composition. In some examples, the electrostatic ink compositions comprise: a carrier liquid; a resin; and a phosphorescent pigment.