Clear Ink Bronzing Control in Inkjet Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for suppressing bronzing in printed images, particularly in monochrome printing, are inadequate as they fail to effectively reduce the perception of bronzing across various images and printing modes, and simply applying clear ink after printing does not sufficiently address the issue.
Innovation Solution
An image processing apparatus and method that utilize a print head to eject both coloring ink and clear ink, with specific settings for the use amounts of clear ink before and after applying coloring ink, based on image data, to control bronzing by varying the light interference and hue in different printing modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If clear ink is applied after printing to suppress bronzing, then the hue of bronzing can be controlled, but the perception of bronzing itself is not reduced
Solution Approach 1:
The patent applies clear ink during the printing process itself (in-line application) rather than as a post-processing step. The clear ink is applied in the same printing pass as the color inks, allowing the light interference effect to occur during image formation rather than as a subsequent treatment. This preliminary action directly addresses bronzing perception during the printing operation.
Solution Approach 2:
The clear ink acts as an intermediary layer that modifies the optical properties of the printed image. By applying clear ink that contains no color material but creates light interference through its thickness and coverage, the patent mediates between the color inks and the final observed image, controlling both hue and perception of bronzing simultaneously.
2Object-affected harmful factors
If clear ink is applied to monochrome images, then bronzing can be suppressed, but color may be introduced where none should exist
Solution Approach 1:
The patent utilizes the optical phenomenon of light interference to create apparent color changes without adding color material. The clear ink's thickness and coverage control the interference pattern, which can shift the perceived hue of reflected light. In monochrome printing, this allows bronzing suppression while maintaining the grayscale integrity by carefully controlling the interference effects to not introduce unwanted coloration.
Solution Approach 2:
The patent controls multiple parameters of the clear ink application including thickness, coverage amount, and application timing to achieve bronzing suppression. By precisely adjusting these parameters, the system can suppress bronzing in monochrome images while preventing color introduction, as the clear ink's optical effects are controlled to maintain the original grayscale appearance.
3Object-affected harmful factors
If different clear ink amounts are used, then light interference state can be varied to control bronzing hues, but the printing process complexity increases
Solution Approach 1:
The patent combines the application of color inks and clear ink into a single integrated printing process. The print head applies both types of ink in the same printing pass, merging two operations (color printing and clear ink application) into one unified process. This reduces overall process complexity compared to separate printing and post-processing steps while still enabling bronzing hue control through varied clear ink amounts.
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 approach effectively suppresses bronzing across various images and printing modes, including monochrome printing, by controlling the use amounts of clear ink to reduce the perception of bronzing and maintain image clarity.
Implementation Method 1
The light path length of the light 1004 is longer than the light 1003 by a distance equivalent to passing through the clear ink layer 1001. The shift in optical phase based on the light path difference strengthens or weakens the intensity at a specific wavelength to produce light interference, and the tints of bronzing become different.
Data Source
AI summary
In a color mode, among clear ink data CL1 and CL2, only the data CL2 is set to a uniform use amount of 20%, while the use amount for the data CL1 is set to zero. Meanwhile, in a monochrome photo mode, the data CL1 indicates a usage of 10% to 40% near a white point, but starting at the intermediate gradations the data CL1 use amount decreases while the data CL2 use amount increases, with a data CL2 use amount of 20% near a black point. In so doing, it is possible to sufficiently suppress bronzing in the color mode where coloring ink data exists, without imparting a particularly strong unnatural look except for specific colors. Meanwhile, in the monochrome photo mode where coloring ink data does not exist, high-level suppression of bronzing is possible, at the cost of a slight reduction in the glossiness of the printed material.