Contoured Media Guide Roller for Inkjet Printers
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Solution Overview
Problem
Inkjet printing systems face challenges with receiver media expansion due to moisture absorption, leading to dimensional changes and image quality issues, such as buckling and smearing of ink, as the media expands and contacts support structures.
Innovation Solution
A contoured media guide surface is introduced, which is closer to the inkjet printhead during inkjet nozzle array regions and farther away during non-printing regions, reducing contact between the media and printhead, allowing for greater media expansion and improved airflow to reduce moisture condensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the receiver media is supported by a flat media guide surface, then the media is constrained from vibrating and moving, but the media expansion causes flutes to form and contact the support structure resulting in ink smearing
Solution Approach 1:
The media guide surface is contoured with different heights at different locations: lower in the printing region to allow media expansion and higher in non-printing regions to maintain media support. This local variation in surface height resolves the contradiction by providing appropriate support characteristics for different functional zones.
Solution Approach 2:
The solution moves from a flat two-dimensional media guide surface to a three-dimensional contoured surface with varying heights. This dimensional change allows the surface to accommodate media expansion in the cross-track direction while maintaining media support, eliminating flute contact with the support structure.
2Reliability
If the media guide surface is kept close to the printhead, then media support is improved, but moisture condensation on the support structure transfers to the media degrading print quality
Solution Approach 1:
The media guide surface is contoured with different heights at different locations: lower in the printing region to allow media expansion and higher in non-printing regions to maintain media support. This local variation in surface height resolves the contradiction by providing appropriate support characteristics for different functional zones.
Solution Approach 2:
The contoured media guide surface acts as an intermediary that separates the media from the printhead support structure in non-printing regions, preventing moisture condensation transfer while maintaining media support in printing regions through the contoured surface geometry.
3Adaptability or versatility
If the media guide surface is contoured to be closer to the printhead in printing regions, then media expansion is allowed, but the surface area for media support is reduced
Solution Approach 1:
The media guide surface is contoured with different heights at different locations: lower in the printing region to allow media expansion and higher in non-printing regions to maintain media support. This local variation in surface height resolves the contradiction by providing appropriate support characteristics for different functional zones.
Solution Approach 2:
The media guide surface is segmented into different functional zones with different heights: a printing region with lower surface height to accommodate media expansion and non-printing regions with higher surface height to maintain media support. This segmentation allows each zone to optimize for its specific function.
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 solution minimizes the formation of flutes on the receiver media, reduces the likelihood of ink smearing, and enhances print quality by allowing unconstrained media expansion and effective moisture removal.
Implementation Method 1
liquid (e.g., ink), is applied to the receiver media by one or more printheads through a process commonly referred to as jetting of the liquid. The jetting of liquid onto the receiver media introduces significant moisture content to the receiver media, particularly when the system is used to print multiple colors on a receiver media. Due to the added moisture content, an absorbent receiver media expands and contracts in a non-isotropic manner
Implementation Method 2
The larger spacing between receiver media and contoured media guide surface in the non-printing regions allows for greater airflow between the inkjet printhead and the receiver media, thereby removing moisture more effectively
Data Source
AI summary
A printing system including a staggered inkjet printhead including at least two inkjet nozzle arrays arranged along first and second print lines in an alternating pattern, wherein the inkjet nozzle arrays along a particular print line alternate with non-printing regions. A media guide including first and second rollers is used for guiding receiver media along a media path past the first and second print lines of the inkjet printhead. A center roller having a contoured media guide surface is positioned between the first and second rollers for guiding the recording media along the media path between the first and second print lines, wherein the diameter of the center roller is smaller for portions of its length corresponding to the inkjet nozzle arrays of the first print line than it is for at least some portion of its length corresponding to the non-printing regions of the first print line.