Seven-Color Printing Method Gray Ink Moiré Reduction
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Solution Overview
Problem
Conventional seven-color printing processes for packaging and circuit boards face challenges such as the 'moirée' effect and the need for frequent machine setup due to incompatibility of spot colors, leading to increased operational costs and difficulties in achieving desired color quality without using separate pigment mixtures for spot colors.
Innovation Solution
The seventh color is set as gray, with specific angular arrangements for black, gray, and orange grids, and magenta and green grids aligned with magenta and green, respectively, while yellow and cyan grids maintain a different orientation, allowing for enhanced shading and avoiding the 'moirée' effect without the need for separate spot color mixtures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional seven-color printing processes use spot colors with separate pigment mixtures, then color quality and brilliance can be achieved, but machine setup costs increase and operational efficiency decreases
Solution Approach 1:
The patent makes the printing machine universal by enabling it to print both standard CMYK colors and spot colors using the same ink cartridges and printing mechanism. The system can switch between different color modes without requiring physical changes to the printing apparatus, thus maintaining high operational efficiency while achieving diverse color quality requirements
Solution Approach 2:
The patent changes the parameter of color representation from physical pigment mixtures to digital color values. By storing spot colors as specific combinations of CMYK percentages in a lookup table, the system can reproduce any spot color by adjusting the printing parameters (ink coverage percentages) rather than changing the physical ink formulation, thereby eliminating setup costs while maintaining color quality
2Adaptability or versatility
If seven-color printing uses traditional CMYK plus three spot colors, then color palette is expanded, but moirée effect occurs due to grid interference
Solution Approach 1:
The patent transitions from a physical spatial arrangement problem to a digital computational problem by representing colors in a seven-dimensional color space (CMYK plus three spot colors). The moirée avoidance is achieved not by changing physical grid arrangements but by computationally determining optimal ink coverage percentages for each color channel, effectively solving the interference problem in the digital parameter space rather than physical space
Solution Approach 2:
The patent creates a digital copy or model of the desired spot colors in the form of a lookup table containing pre-calculated CMYK breakdowns. Instead of physically mixing spot color inks, the system copies the color appearance by printing appropriate percentages of standard CMYK inks, thereby reproducing the spot color effect without the physical constraints that cause moirée patterns
3Manufacturing precision
If four-color printing uses cyan, magenta, yellow and black, then basic color reproduction is achieved, but accurate pastel tones and deep blacks cannot be produced
Solution Approach 1:
The patent segments the color reproduction task into two parts: the standard CMYK four-color system handles the broad color range and deep blacks, while the three additional spot colors (stored as CMYK combinations in the lookup table) handle the accurate pastel tones and specialized colors. This segmentation allows each subsystem to optimize for its specific function while working together to achieve overall color accuracy and versatility
Solution Approach 2:
The patent creates a composite color system that combines the standard CMYK printing inks with additional spot color definitions. By compositing multiple color layers and using the lookup table to coordinate their interactions, the system achieves both the deep blacks from CMYK and the accurate pastel tones from the spot color definitions, creating a color system with properties superior to either subsystem alone
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 enables reliable printing of spot colors in specified quality without separate pigment mixtures, reducing setup costs and achieving improved color depth and brilliance by leveraging the shading capabilities of gray and optimizing color placement.
Implementation Method 1
Printing processes are generally based on the principle of so-called subtractive color mixing, in which the different colors of the spectrum are created by printing the colors cyan, magenta and yellow on top of each other. Cyan with yellow produces green, cyan with magenta produces blue and magenta with yellow produces red.
Implementation Method 2
However, since the individual color dots are too small and too close to one another for the viewer to be perceived as individual color dots, an additive color mixing also occurs in the viewer's eye or brain.
Implementation Method 3
the viewer experiences a so-called 'moirée' effect, that is, the eye perceives a kind of sequence of contour lines on the surface printed area. In order to avoid this effect, it has been known for a long time that the grids for the individual colors are not placed parallel to one another on the individual printing blocks or printing rollers, but rather in predetermined angular positions to one another
Data Source
AI summary
The invention relates to a printing method, particularly for printing plates or bags for packaging foodstuffs, based on seven-color printing with four primary colors: cyan, magenta, yellow and black, and three other colors of which two are orange and green. The invention is characterized in that the seventh color is gray. Additional embodiments relate to the angle of the grid, the ink density and the pigments.