Ink Jet Printer Warping Mechanism for Print Sheet Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed ink jet printing systems face issues with print sheet misalignment due to oblique transfer, leading to excessive tension and potential wrinkles or fractures, which degrade printing quality and require larger designs to avoid misalignment.
Innovation Solution
The system warps the print sheet to correct its transfer direction and tension, with the first ink jet head positioned between the feed unit and the second ink jet head, where the elastic force of warping exceeds adherence, ensuring the print sheet aligns correctly at the second ink jet head, which ejects darker ink, minimizing quality degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the print sheet is warped to correct transfer direction and absorb excessive tension, then print sheet damage is prevented and transfer alignment is improved, but the device size increases due to additional warping mechanisms
Solution Approach 1:
The feed unit performs preliminary warping action on the print sheet before it reaches the ink jet heads. By pre-correcting the transfer direction and absorbing excessive tension in advance, the system prevents misalignment and print sheet damage without requiring complex real-time correction mechanisms at the printing zone.
Solution Approach 2:
The warping function is extracted as a separate feed unit operation, distinct from the ink jet printing process. This allows the warping mechanism to be optimized independently and positioned upstream, reducing its impact on the overall printing system complexity and allowing compact integration of the printing zone.
2Device complexity
If the first ink jet head is positioned where the print sheet is misaligned, then device size is minimized, but printing quality degrades due to misalignment at the ink ejection point
Solution Approach 1:
The system applies different quality requirements to different ink jet heads based on their position. The first ink jet head (ejecting light-colored ink) is positioned in the misalignment zone where compact spacing is critical, while the second ink jet head (ejecting dark-colored ink) is positioned downstream where the print sheet has aligned with the conveyor belt, ensuring high printing quality for the most visible ink.
Solution Approach 2:
The system changes the parameter of ink color darkness to compensate for misalignment. By using light-colored ink at the first head where misalignment occurs and dark-colored ink at the second head where alignment is achieved, the system maintains overall printing quality while minimizing device size.
3Manufacturing precision
If dark-colored ink is ejected at the first ink jet head position, then printing quality is maintained, but the elastic force of warping causes misalignment that affects ink placement
Solution Approach 1:
The feed unit performs preliminary warping correction before the print sheet reaches either ink jet head. By absorbing excessive tension and correcting transfer direction in advance, the system reduces the elastic force of warping that would otherwise cause misalignment during ink ejection, ensuring accurate ink placement.
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 prevents print sheet damage, maintains high-speed printing quality, and miniaturizes the device by correcting transfer direction and tension, while ensuring only light-colored ink is affected by misalignment, thus preserving printing quality.
Implementation Method 1
give an extra length to the print sheet by warping the print sheet when feeding the print sheet to the transfer path from the paper feed unit, regulate the arriving direction by the elastic force of the warping
Implementation Method 2
the elastic force of the warping of the print sheet is greater than the adherence between the print sheet and the conveyor belt
Data Source
Figure 1(a)~1(c)
Figure 2
Figure 3
AI summary
An ink jet printer comprising a conveyor belt unit 106 for transferring a print sheet 2 on a rotating conveyor belt 106a, a resist roller pair 111 and a BU roller 112 for feeding the print sheet 2 while flexing it in the transferring direction, and first and second ink jet head 104a, 104b for ejecting ink toward the print sheet, wherein the ink jet head 104b ejects ink darker in color than ink ejected from the ink jet head 104a. The ink jet head 104b serves to eject ink, that is darker in color than that of the ink jet head 104a, and is located at a position farther than the arriving position of the print sheet 2 when the print sheet 2 is displaced from the conveyor belt 106a in the transferring direction as the elasticity of the print sheet 2 due to flexure exceeds adhesion between the print sheet 2 and the conveyor belt 106a, while the ink jet head 104a is arranged between the ink jet head 104b and the BU roller 112. By this configuration, print quality can be sustained with high speed printing by using an ink jet head and reduction in printer size achieved.