Dual Pump Ink Delivery for Printhead Priming
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Solution Overview
Problem
Existing ink delivery systems for Memjet printers, particularly those with pagewidth printheads, face inefficiencies in pressure priming due to non-uniform pressure distribution along the printhead length, leading to inadequate priming of nozzles and excessive ink consumption.
Innovation Solution
A dual pump arrangement is introduced, with a peristaltic pump in the second ink conduit and a second pump in the first conduit, allowing simultaneous pumping towards both ends of the printhead to achieve uniform pressure priming, reducing ink consumption, and enabling lower-powered pumps to be used.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pump is used in the ink delivery system, then the device complexity is reduced, but the pressure uniformity across the printhead deteriorates
Solution Approach 1:
The single pump function is segmented into two separate pumps positioned at different locations in the ink delivery system. The first pump is positioned near the ink container and the second pump is positioned near the printhead, allowing independent control of pressure in different sections of the system to achieve uniform pressure distribution across the entire printhead width.
Solution Approach 2:
Different pressure conditions are applied to different regions of the ink delivery system. The dual pump arrangement enables localized pressure optimization, with each pump adjusting pressure in its respective zone to ensure uniform pressure delivery across all nozzles of the pagewidth printhead.
2Reliability
If higher powered pumps are used to achieve adequate priming pressure, then the priming effectiveness is improved, but the energy consumption increases
Solution Approach 1:
The pumping function is divided between two lower-powered pumps positioned strategically in the ink delivery path. This segmentation allows each pump to operate at lower power levels while collectively achieving the required priming pressure, reducing overall energy consumption compared to using a single high-powered pump.
Solution Approach 2:
The dual pump arrangement enables continuous and efficient ink delivery to the printhead by maintaining optimal pressure throughout the ink path. This continuous pressure management improves priming effectiveness while reducing energy waste associated with pressure fluctuations and ink waste.
3Device complexity
If pressure priming is performed with non-uniform pressure distribution, then the priming process is simplified, but the ink consumption increases
Solution Approach 1:
The dual pump system applies locally optimized pressure to different sections of the printhead, ensuring uniform pressure distribution across all nozzles. This prevents over-pressurization in certain regions that would cause excessive ink consumption, while maintaining simplified priming operations through automated pressure control.
Solution Approach 2:
The ink delivery system incorporates feedback mechanisms that monitor pressure and ink flow, allowing the dual pump arrangement to adjust pressure distribution in real-time. This feedback control ensures uniform priming across the printhead while minimizing ink consumption by preventing pressure-related waste.
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 provides more uniform pressure across the printhead during priming operations, improving efficiency, reducing ink usage, and allowing for effective recovery of blocked nozzles and full priming of new printheads, especially beneficial for pagewidth printheads over 200 mm long.
Implementation Method 1
a peristaltic pump in the second ink conduit
Data Source
AI summary
An inkjet printer includes a printhead having first and second ports; an ink container for supplying ink to the printhead, the ink container having a supply port and a return port; a first ink conduit interconnecting the supply port and the first port; a second ink conduit interconnecting the return port and the second port; an ink valve positioned in the first ink conduit; a first pump positioned in the second conduit; and a second pump positioned in a valve bypass conduit. The first and second pumps are employed during pressurized priming of the printhead so as to optimize a pressure gradient along a length of the printhead.