Ink-jet off axis ink delivery system
AssigneeHewlett-Packard Company
InventorsEric J. Johnson, Brian D. Gragg
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Abstract
An off-axis ink delivery system for an ink-jet hard copy apparatus includes a multifunctional ink pump and flow switch device. A semipermanent, negative pressure, pen and printhead has a fluidic coupling to a static, refillable or replaceable, off-axis, ink reservoir via the ink pump and flow switch device.. The pen's mechanism for creating the negative pressure operational condition is used to pull ink from the reservoir when the ink pump and flow switch device is in an "open" position. Negative pressure reset, nozzle priming, pen air purging functions are also provided by the same ink pump and flow switch device. A system for each color ink is employed in the hard copy apparatus.
Claims13
An ink delivery system for a hard copy apparatus, comprising:
- ink-jetting means, mounted within said hard copy apparatus and including a printhead and an ink accumulator coupled to said printhead providing printhead back-pressure regulation, for jetting ink onto print media adjacent thereto;
- off-axis ink storage means for containing a supply of ink for said ink-jetting means;
- and
- ink pumping and flow switching means, fluidically coupling said ink-jetting means and said off-axis ink storage means, for selectively controlling refilling of said ink accumulator and for selectively resetting said ink accumulator to a predetermined back-pressure set point following refilling of said ink accumulator, wherein said ink pumping and flow switching means includes selectively positionable piston means for controlling the flow of ink from said ink storage means and for controlling the direction of flow of ink to and from said ink-jetting means, said piston means having a piston head, including a first sealing member and a second sealing member, said second sealing member having an ink flow channel therethrough, wherein said piston means is mounted on a piston shaft with a gap between said first sealing member and said second sealing member such that a predetermined volumetric region is defined by said gap and predetermined shape and dimensions of said first sealing member and said second sealing member, and said ink pumping and flow switching means further having housing means having a central chamber for retaining said piston means therein, an ink inlet port coupled to said ink storage means positioned such that said first sealing member and said second sealing member are selectively positionable to open and close said ink inlet port on demand, and an ink pumping port coupled to said ink accumulator such that ink flow is permitted from said ink storage means into said gap, through said ink channel, and through a region of said central chamber adjacent said ink pumping port to said pumping port, such that ink is transferred from said ink storage means to said accumulator when said piston means is at a first predetermined position with said gap open to said ink inlet port.
Dependencies are inferred from the claim text.