Inkjet Printer Pump Isolation via Selective Valve
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Solution Overview
Problem
Inkjet printers face issues with nozzle clogging, de-priming, color mixing, and ink contamination due to the wear and friction of active fluidic system components, particularly pumps, which generate particles that can be detrimental to print quality, and the need for large filters to maintain high-speed ink flow rates.
Innovation Solution
A fluidic system architecture that isolates the pump from the direct ink flow between the reservoir and printhead, using a valve arrangement to connect the pump to the reservoir or printhead only when necessary, allowing for separate purging and priming processes and incorporating a filter to remove contaminants without constraining ink flow during printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a pump is used to draw ink from the reservoir and pump it into the printhead, then ink flow control is improved, but pump wear and friction generate particles that contaminate the ink and clog nozzles
Solution Approach 1:
The pump is extracted from the direct ink flow path between the reservoir and printhead. A valve arrangement selectively opens fluid communication between the pump and printhead only when necessary, isolating the pump from continuous ink exposure and preventing particle generation during normal printing operations
Solution Approach 2:
The fluidic system is segmented into separate pathways: a first pathway for purging/priming operations connecting the pump to the printhead, and a second pathway for normal printing connecting the reservoir directly to the printhead. This segmentation allows the pump to be isolated from the main ink flow while maintaining functional connectivity when needed
2Object-generated harmful factors
If a filter is used to remove ink borne contaminants, then ink purity is improved, but the filter surface area must be impractically large to maintain high-speed ink flow rates
Solution Approach 1:
The pump is removed from the direct ink flow path, eliminating the primary source of contamination at the source rather than requiring extensive filtration. This extraction approach reduces the burden on any filter system and allows for more compact filter design that can maintain high flow rates
Solution Approach 2:
The system performs purging and priming operations separately before normal printing begins. By conducting contamination removal activities in advance through isolated pump operations, the main printing process can proceed at high speed without continuous filtration requirements
3Productivity
If peristaltic pumps are used to compress tubing to form a seal, then pumping function is achieved, but the pump requires high torque and has a large form factor
Solution Approach 1:
The peristaltic pump is extracted from the ink delivery system entirely. The patent uses alternative pumping mechanisms or passive flow control that do not require high-torque peristaltic compression, thereby reducing pump size and torque requirements while maintaining the ability to deliver ink to the printhead
Data Source
AI summary
An inkjet printer that has a printhead for printing onto a media substrate, a reservoir for supplying ink to the printhead, a pump for drawing ink from the reservoir and pumping ink into the printhead and, a valve arrangement for selectively opening fluid communication between the pump and the printhead, and closing fluid communication between the pump and the printhead while opening fluid communication between the reservoir and the printhead.