Loop-the-loop Printer Media Guide for Duplex Speed
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Solution Overview
Problem
Conventional duplex inkjet printers operate at slower speeds and are prone to paper jams and noise due to complex media feed paths and the need for two printheads or complex feed mechanisms.
Innovation Solution
A printer design featuring a stationary inkjet printhead with a 'loop-the-loop' media feed path that allows print media to be fed unidirectionally at a constant speed, using a single printhead and minimizing the footprint by positioning the output tray above the input tray, with a guide system that includes idler rollers and a jink to reduce radial loads and prevent paper jams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional duplexing methods are used with complex media feed paths, then duplex printing functionality is achieved, but printing speed is reduced to about half of simplex printing speed
Solution Approach 1:
The media feed path is divided into distinct sections: a first section for feeding media past the printhead in a first direction, a second section for guiding media around a loop at the opposite side of the printhead, and a third section for feeding media past the printhead in an opposite second direction. This segmentation allows the media to follow a controlled loop-the-loop path that enables duplex printing while maintaining consistent feed speed throughout the process.
2Productivity
If conventional duplexers with reverse-feeding mechanisms are used, then duplex printing is enabled, but the device becomes noisy and requires drive rollers operating in two directions
Solution Approach 1:
Instead of reversing the feed direction to achieve duplex printing, the invention inverts the approach by maintaining unidirectional feeding throughout. The media is fed unidirectionally through the entire loop-the-loop path, with the direction change occurring naturally as the media travels around the loop and passes the printhead from the opposite side, eliminating the need for reversing mechanisms and reducing noise.
3Productivity
If two printheads are used for duplex printing as described in WO00/65679, then duplex printing speed is improved, but the cost and maintenance complexity increase
Solution Approach 1:
A single printhead is designed to perform both simplex and duplex printing functions. The printhead remains stationary while the media is fed past it in two different directions through the loop-the-loop feed path, allowing the same printhead to print on both sides of the media without requiring dual printheads or complex switching mechanisms.
4Productivity
If serpentine media feed path with two printheads is used as in WO2011/020152, then duplex printing is achieved, but the printer footprint becomes relatively large
Solution Approach 1:
The media feed path is configured as a compact loop-the-loop arrangement where the second section guides media around a loop positioned at the second side of the printhead opposite the first side. This nested loop configuration allows the media to return past the printhead in a space-efficient manner, enabling duplex printing within a smaller footprint compared to extended serpentine paths.
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
Enables high-speed duplex printing without speed reduction, reduces the risk of paper jams, and maintains a minimal printer footprint while using lower power motors and simpler maintenance, achieving smooth and quiet operation.
Implementation Method 1
the guide is configured to provide a curvature in the print media path... Any resultant drag is typically small
Data Source
AI summary
A printer having a beltless guide for guiding print media around a curved media feed path. The guide includes: first and second opposed guide surfaces for guiding print media therebetween; and a chicane corresponding to a point of inflection in the curved media feed path. The media path does not follow a curvature of the chicane and the chicane is configured to transfer print media from contact with the second surface to contact with the first surface or vice versa.