Ink Discharge Limiting for Uniform Gloss in UV Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Photocurable inkjet printing apparatuses face challenges in achieving uniform glossy finishes due to ink curing failures, which are not adequately addressed by existing methods that set total area coverage limits without considering the specific characteristics of each ink color, leading to mixed glossy and matte looks in printed matter.
Innovation Solution
A method that sets limit values for ink discharge specifically for secondary, tertiary, and colors including the K color component, with smaller values for K color components to prevent curing failures, and uses a gloss determination device with tables to evaluate gloss quality before printing, ensuring uniform glossy finishes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the total area coverage (TAC value) is set to limit the maximum amount of ink, then ink curing failure is prevented, but depending on the allocation of four color inks, ink curing failure may still occur and the finish includes both glossy-look portion and matte-look portion
Solution Approach 1:
The patent divides the ink discharge limitation into separate constraints for different color combinations. Instead of using a single TAC value for all colors, it sets different limit values for secondary colors (CMY combinations), tertiary colors (CMYK combinations), and colors including K component. This segmentation allows each color combination to be optimized independently, preventing curing failures while maintaining uniform glossy finish.
Solution Approach 2:
The patent applies different ink discharge limit values to different local color combinations in the print data. By analyzing the specific color composition at each pixel or region and applying appropriate limit values based on whether it contains K component or forms gray components, the system ensures optimal curing conditions for each local area, eliminating mixed glossy and matte looks.
2Reliability
If the TAC value is set to limit the total amount of ink per pixel, then ink curing failure is prevented, but colors that cause ink curing failure may still be included and entirely uniform printed matter cannot be obtained
Solution Approach 1:
The patent dynamically adjusts ink discharge limits based on the specific color combination detected in the print data. Rather than using a static TAC value, the system calculates appropriate limit values for each pixel or region based on its color composition (secondary, tertiary, or K-containing colors), enabling adaptive control that maintains both curing reliability and gloss uniformity.
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 inhibits ink curing failures and ensures entirely glossy, uniform printed matter by accurately limiting ink discharge and evaluating gloss quality, maintaining print quality and reducing operational inefficiencies.
Implementation Method 1
a photocurable (ultraviolet-curable) inkjet printing apparatus using using ultraviolet-curable ink (UV ink)... performs printing by irradiating UV ink discharged onto a base material with ultraviolet light (UV light)
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method for limiting the amount of ink discharged in a photocurable inkjet printing apparatus includes a conversion step of converting, an input grayscale value to the amount of ink; and a limit value setting step of setting, a limit value of the amount of ink discharged, for each of a secondary color not including a K color component, a tertiary color not including a K color component, and a color including a K color component. In the limit value setting step, the limit value for the tertiary color not including a K color component is set to a smaller value than the limit value for the secondary color not including a K color component, and the limit value for the color including a K color component is set to a smaller value than the limit value for the secondary color not including a K color component.