Intermediate Transfer Member Velocity Control for Digital Printing
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Solution Overview
Problem
Digital printing systems face challenges with inkjet printing on porous paper due to substrate wetting issues, leading to poor image quality and difficulty in duplex printing, as the ink's physical properties affect the printing process, and indirect printing techniques are needed to maintain image quality but require precise control of the intermediate transfer member's velocity and length to prevent alignment issues and ensure synchronization.
Innovation Solution
A control method and apparatus for a digital printing system that involves a moving intermediate transfer member, where the surface velocity is controlled to maintain consistency at the image formation station and locally accelerated or decelerated to prevent alignment issues during engagement with the impression cylinder, using powered dancers and torque to regulate the belt's tension and length, and monitoring phase differences and non-uniform stretching to adjust ink deposition timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inkjet printing is performed directly onto porous paper substrate, then the printing process is simple, but the image quality deteriorates due to substrate wetting and ink penetration
Solution Approach 1:
An intermediate transfer member (ITM) is introduced as a mediator between the inkjet print head and the substrate. The ITM receives the inkjet image and transfers it to the substrate, preventing direct ink-substrate interaction that causes wetting and quality issues. This intermediary approach maintains process simplicity while dramatically improving image quality.
2Device complexity
If the intermediate transfer member velocity is maintained constant throughout, then the printing process is simple, but alignment issues occur during engagement with the impression cylinder
Solution Approach 1:
The ITM velocity is made dynamic rather than constant. The system accelerates or decelerates the ITM locally at specific zones (such as the engagement zone with the impression cylinder) to maintain proper synchronization and alignment. This dynamic velocity control prevents alignment issues while maintaining overall process simplicity.
3Adaptability or versatility
If the intermediate transfer member is made flexible to accommodate substrate variations, then adaptability improves, but synchronization control becomes more difficult
Solution Approach 1:
A feedback control system monitors the position and velocity of the flexible ITM and adjusts the drive mechanism accordingly. Sensors detect deviations in ITM position or speed, and the control system compensates by adjusting motor speed or tension, maintaining precise synchronization despite the flexibility that enables substrate adaptation.
4Manufacturing precision
If local acceleration and deceleration of the intermediate transfer member is implemented, then alignment precision improves, but energy consumption increases
Solution Approach 1:
Instead of continuously accelerating and decelerating the entire ITM, the system applies partial action by only locally adjusting velocity in specific zones where alignment is critical (such as the engagement zone with the impression cylinder). This minimizes energy consumption while maintaining alignment precision where it matters most.
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 enhances image quality by maintaining consistent surface velocity and preventing alignment issues, improving synchronization and reducing image distortion, allowing for efficient duplex printing and maintaining image quality across varying substrate properties.
Implementation Method 1
The intermediate transfer member is engaged to and disengaged from a rotating impression cylinder... to transfer the ink images
Implementation Method 2
using powered dancers and torque to regulate the belt's tension and length
Implementation Method 3
monitoring phase differences and non-uniform stretching to adjust ink deposition timing
Data Source
AI summary
Embodiments of the present invention relate to control apparatus and methods of a printing system, for example, comprising an intermediate transfer member (ITM) and to user-related features of a printing system. Some embodiments relate to regulation of a velocity and/or tension and/or length of the ITM. Some embodiments relate to regulation of deposition of ink on the moving ITM. Some embodiments regulate to apparatus configured to alert a user of one or more events related to operation of the ITM. Some embodiments relate to a time-line GUI for visualizing and/or manipulating queued print jobs which may be employed. Some embodiments relate to a reversed augmented reality GUI for visualization and/or control of the printing system. In some embodiments, a display screen is mounted to a printer housing and/or able to control access to moving parts of a printing system.