Print Bar Shroud Bumps Guide Media Away From Printheads
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Solution Overview
Problem
Inkjet printers with stationary media wide printhead assemblies are prone to media jams and print quality defects due to the print media contacting the printheads during printing.
Innovation Solution
A new media guide system featuring a series of bumps on the print bar shroud or suspended plates that guide the leading edge of the print media away from the printheads, with the bumps acting as spacers to maintain the plates' position and prevent contact, thereby reducing jams and improving print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a stationary media wide printhead assembly is used, then printing width and productivity are improved, but media jams and print quality defects increase due to media contacting the printheads
Solution Approach 1:
A media guide structure is introduced as an intermediary component between the print media and the printhead assembly. This guide structure physically separates the media path from the printhead, preventing direct contact while allowing the media to pass through. The guide structure acts as a mediator that protects the printhead from media contact without interfering with the printing function, thus resolving the contradiction between maintaining wide printing capability and preventing media jams.
2Reliability
If media guides are added to protect the printhead, then media jam prevention is improved, but device complexity increases
Solution Approach 1:
The media guide structure is segmented into multiple components including guide plates, support structures, and positioning elements. This segmentation allows each component to perform a specific function while maintaining overall simplicity. The guide plates are divided into individual units that can be independently positioned and adjusted, reducing the complexity of the entire assembly while maintaining effective protection against media contact.
Solution Approach 2:
The media guide structure incorporates self-aligning and self-adjusting features that automatically position the guide plates correctly without requiring complex external control mechanisms. The structure uses gravity, elastic forces, or mechanical interlocks to maintain proper positioning, thereby reducing device complexity while ensuring reliable media path guidance and printhead protection.
Data Source
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AI summary
In one example, a shroud to protect a printhead in a print bar includes: an elongated body having an opening therein through which a printhead may dispense liquid past the shroud when the shroud is affixed to the print bar; and a bump on an exterior surface of the body next to the opening. The bump is configured to guide a leading edge of print media away from the printhead during printing when the shroud is affixed to the print bar and the print bar is installed in a printer.