Inkjet Print Resolution Adaptation for High-Speed Offset Printing
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Solution Overview
Problem
Inkjet printing devices struggle to achieve high printing speeds inline with offset printing processes due to limitations in print resolution, resulting in distorted images when trying to operate at speeds above the maximum inkjet printing speed, especially in newspaper printing presses where offset web-fed rotary printing speeds reach up to 15 m/s.
Innovation Solution
The print resolution of the inkjet printing process is determined as a function of the printing speed of the offset printing process, allowing for higher inkjet printing speeds without image distortion by adjusting the resolution in the transport direction while maintaining independence transversely, using a formula to set the inkjet print resolution inversely proportional to the offset printing speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the printing speed of the inkjet printing process is increased to match the offset printing speed, then the productivity is improved, but the print resolution deteriorates causing image distortion
Solution Approach 1:
The patent applies dynamics by making the inkjet printing system's resolution adaptive to the printing speed. The control unit dynamically adjusts the print resolution of the inkjet printing process based on the actual printing speed to maintain image quality. This is achieved by calculating a speed-dependent resolution value that compensates for the motion blur effect at higher speeds, allowing the system to operate at speeds up to 15 m/s without permanent image distortion.
Solution Approach 2:
The patent changes the print resolution parameter of the inkjet printing process as a function of printing speed. The control unit calculates the appropriate resolution based on the relationship between printing speed and maximum achievable resolution, then applies this adjusted resolution setting to the inkjet printing system. This parameter adaptation allows the system to maintain acceptable print quality across a wide range of printing speeds from 0.5 m/s to 15 m/s.
2Manufacturing precision
If the print resolution of the inkjet printing process is maintained at maximum quality, then the manufacturing precision is improved, but the printing speed must be reduced below the offset printing speed
Solution Approach 1:
The system dynamically adjusts the print resolution based on the printing speed rather than maintaining a fixed maximum resolution. At lower printing speeds, the system uses higher resolution settings to maintain image quality, while at higher speeds, it calculates and applies an optimized resolution that prevents distortion. This dynamic adaptation resolves the contradiction by allowing the system to achieve both high speed and acceptable quality through speed-dependent resolution control.
Solution Approach 2:
The patent implements parameter changes by making the print resolution a variable parameter that changes with printing speed. The control unit calculates the optimal resolution parameter based on the current printing speed and applies it to the inkjet printing process. This allows the system to operate at high speeds (up to 15 m/s) with appropriately adjusted resolution settings, rather than being constrained to low speeds to maintain maximum resolution.
3Productivity
If multiple inkjet printheads are arranged in a matrix to increase printing speed, then the productivity is improved, but the device complexity increases
Solution Approach 1:
The patent inverts the conventional approach by not increasing the number of printheads to achieve high speed, but rather by improving the speed capability of a single printhead through resolution adaptation. Instead of adding more printing elements (which would increase complexity), the system achieves high-speed printing by dynamically adjusting the resolution parameter, allowing a single printhead to effectively deliver high-speed output without distortion.
Solution Approach 2:
The patent uses parameter changes to achieve high printing speeds without increasing device complexity. Rather than adding multiple printheads in a matrix arrangement, the system changes the resolution parameter of a single printhead based on printing speed. This parameter-based solution achieves the same productivity improvement as a multi-printhead system but with significantly lower complexity, as it requires only control unit calculations and single-printhead operation.
Data Source
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AI summary
A method for printing on a substrate, wherein the substrate is printed upon with a plate-based printing process, i.e., an offset printing process, and with a plateless printing process, i.e., an inkjet printing process, inline with the plate-based printing process. In accordance with the invention, the printing resolution of the plateless printing process is determined depending on a printing speed of the plate-based printing process.