Ink supply system for an ink jet apparatus
AssigneeDataproducts Corporation
InventorsJohn A. McCormick, Lisa M. Schmidle
Life of this patent
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Abstract
A method and apparatus for supplying ink to an array of ink jets is provided by two fluidically independent reservoirs, each reservoir supplying ink to a respective end of a manifold which communicates with the array of ink jets via their inlet restrictors. During normal operations involving an acceleration of the array along a scanning path, the ink levels in the two reservoirs will remain the same since any difference in their levels will create a pressure differential that drives a flow of ink through the manifold from the higher level reservoir until such time that their levels equalize.
Claims20
Ink jet apparatus, comprising:
- a scanning print head having a plurality of ink jet chambers, each of said chambers including an ink droplet ejection orifice and an inlet;
- means for holding a supply of ink under pressure, said holding means including a pair of fluidically independent reservoirs mounted upon said scanning print head;
- and
- means for feeding ink from said holding means to said chambers, said feeding means including a manifold in communication with each said chamber inlet and a pair of feed tubes each said feed tube connecting a respective one of said reservoirs with said manifold, said feed tubes coupling to said manifold substantially at right angles thereto.
Ink jet apparatus comprising an ink jet head adapted to be accelerated along a scanning path, the ink jet head having means for holding a supply of ink and at least one ink jet orifice, the improvement comprising in combination therewith:
- means for dividing the holding means into a pair of fluidically independent reservoirs, each said reservoir being adapted to store the supply of ink upon the scanning ink jet head under atmospheric pressure;
- a manifold, of a first predetermined flow resistance R.sub.M, arranged within the ink jet head substantially parallel to the scanning path, said manifold connected to supply ink from each of said pair of fluidically independent reservoirs to said at least one ink jet orifice;
- first feed means, of a second predetermined flow resistance R.sub.L, for connecting one of said pair of fluidically independent reservoirs and said manifold, said first feed means coupling to said manifold substantially at right angles thereto;
- and
- second feed means, of a third predetermined flow resistance R.sub.R, for connecting the other of said pair of fluidically independent reservoirs and said manifold, said second feed means coupling to said manifold substantially at right angles thereto;
- whereby a ratio of the sum of said second and third predetermined flow resistances R.sub.L and R.sub.R to the total sum of said first, second and third flow resistances R.sub.T is substantially less than unity such that an acceleration head developed in said manifold during acceleration of the ink jet head along the scanning path is substantially greater than a total pressure drop thereover.
A method of supplying hot melt ink to an ink jet apparatus having a print head adapted to be accelerated along a substantially horizontal scanning path, the print head including an array of ink jets connected to a manifold arranged within said print head substantially parallel to the scanning path, said method comprising the steps of:
- forming a pair of fluidically independent reservoirs each of which is adapted to store ink under pressure within the scanning print head;
- separately connecting each said reservoir to the manifold through respective inlet tubes mounted parallel to the manifold;
- and
- forming a pair of vents, each said vent separately venting a respective reservoir.
Dependencies are inferred from the claim text.