Keyless Inker Temperature Control via Pixel Counting
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Solution Overview
Problem
In variable data lithographic printing, the existing ink supply systems lack an automated mechanism to adjust ink temperature dynamically in response to varying ink loads across different image content areas, leading to potential defects like starvation or over-inking, which affect image quality.
Innovation Solution
A system using feedforward and feedback control loops to adjust the temperature of keyless inkers based on pixel counting, allowing for dynamic ink supply adjustments across the imaging drum, with heaters controlling individual zones and a dynamic model updated by ink density feedback to ensure precise ink delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manual ink supply adjustment is used in traditional lithographic offset printing, then the ink supply can be tuned for static documents, but the system cannot adapt to varying ink loads in variable data printing
Solution Approach 1:
The patent implements a feedback control system where ink density is measured on the imaging drum and used to adjust ink supply parameters. The system continuously monitors ink density and automatically modifies ink flow rates to maintain optimal ink-to-fountain-solution ratio despite varying image content, eliminating the need for manual intervention in variable data printing
Solution Approach 2:
The patent transitions from static manual adjustment to dynamic automated control. The ink supply system continuously adapts its parameters based on real-time ink density measurements and pixel counting, allowing the system to respond dynamically to varying ink loads across different zones and time periods in variable data printing operations
2Reliability
If ink supply is increased to prevent starvation defects, then sufficient ink is available for high ink load areas, but fine detail is washed out in low ink load areas
Solution Approach 1:
The patent applies different ink supply parameters to different cross-process zones based on their specific ink load requirements. By dividing the imaging drum into zones and measuring ink density locally, the system adjusts ink flow rates individually for each zone, providing sufficient ink to high-density areas while preventing over-inking in low-density areas, thus maintaining fine detail quality
Solution Approach 2:
The patent dynamically changes ink supply parameters including flow rate, temperature, and viscosity based on measured ink density and pixel counting data. This allows the system to optimize ink delivery for each specific printing condition, preventing both starvation defects and over-inking by adjusting parameters in real-time according to actual ink load requirements
3Manufacturing precision
If manual tuning of ink supply is performed, then the process can be optimized for each cross-process location, but the process requires operator intervention and is not suitable for variable data printing
Solution Approach 1:
The patent implements a self-regulating ink supply system that automatically measures ink density, calculates optimal ink flow rates, and adjusts supply parameters without operator intervention. The system uses embedded sensors, pixel counting algorithms, and feedback control to autonomously optimize ink supply for each zone and time period, making the process suitable for variable data printing where manual tuning would be impractical
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 automatic and precise control of ink supply, maintaining image quality by matching ink load with varying image content, reducing defects and ensuring consistent ink distribution across the print media.
Implementation Method 1
at least one heater element to control the temperature of the at least one ink bath in response to the feedforward controller
Data Source
AI summary
A method and systems to control the temperature of a Keyless inker for variable data lithography printing. Inker heating elements are adjustable to control ink feed to individual zones located across the width of an ink roller. Feedforward and feedback control loops adjust the ink supply dynamically based on a pixel count of the image content. The pixel count looks ahead in the video stream to allow time for the adjustment at the inker heating elements to propagate through the inker unit to affect ink output onto the imaging drum surface. Feedback of the achieved ink density on control patches on the imaging drum is also used to command the inker heating elements. Feedback is also used to update the inker propagation delay and dynamic model used to determine how much the inker keys need to be adjusted based on the pixel count stream.