Ink Set Hue Angle Control for Ozone Resistance
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Solution Overview
Problem
Existing ink-jet recording systems face challenges in maintaining long-term storage stability of images due to ozone exposure, as current evaluation methods using color difference (ΔE) and optical density difference (ΔOD) do not accurately reflect human perception of hue changes, particularly in yellow, magenta, and cyan colors.
Innovation Solution
An ink set for ink-jet recording is developed, comprising yellow, magenta, and cyan inks with specific dye compositions and concentrations, where the hue angle change (Δh) between before and after ozone resistance tests is controlled to minimize color degradation, ensuring improved ozone resistance and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If color difference (ΔE) or optical density difference (ΔOD) is used to evaluate long-term storage stability, then measurement can be performed objectively, but the evaluation does not correspond to human eye perception of hue changes
Solution Approach 1:
The patent changes the evaluation parameter from color difference (ΔE) or optical density difference (ΔOD) to hue angle change (Δh). This parameter transformation enables the measurement to directly reflect human eye perception of hue changes while maintaining objective measurement capability, thereby resolving the contradiction between objectivity and perceptual correspondence.
2Ease of manufacture
If conventional ink compositions are used, then manufacturing is straightforward, but ozone resistance and long-term storage stability are insufficient
Solution Approach 1:
The patent specifies precise parameter ranges for dye types, concentrations, and auxiliary components in the ink formulation. By defining these parameters within specific ranges, the patent maintains ease of manufacture while achieving superior ozone resistance and long-term storage stability, resolving the contradiction between manufacturing simplicity and reliability.
3Measurement precision
If optical density (OD value) of primary colors is measured to evaluate medium color density, then measurement is straightforward, but the value does not faithfully reflect the color density of the medium color itself
Solution Approach 1:
The patent changes the measurement approach from measuring optical density (OD value) of decomposed primary colors to measuring hue angle change (Δh) of the actual medium color. This parameter transformation enables the measurement to faithfully reflect the color density and characteristics of the medium color itself while remaining straightforward to perform, resolving the contradiction between measurement ease and accuracy.
Data Source
AI summary
An ink set for ink-jet recording is provided defined by an evaluation indicator approximately corresponding to an evaluation sensed by human eyes without relying on a color difference (ΔE) or an optical density difference (ΔOD) at the time of evaluating long-term storage properties of the ink set for ink-jet recording. In the ink set for ink-jet recording which contains a yellow ink, a magenta ink and a cyan ink, values of hue angle change (Δh), between before and after ozone resistance tests, of print regions corresponding to respective inks formed on glossy paper by using the yellow ink, the magenta ink and the cyan ink are not more than about 3° for the yellow ink, not more than about 2° for the magenta ink, and not more than about 6° for the cyan ink.