PRINTING SYSTEM WITH INK ACCUMULATORS FOR HYDROSTATIC PRESSURE REGULATION
A printing system with a printhead assembly with nozzles for ejecting ink, a plurality of ink containers, a accumulator reservoirs each having an inlet for connection to one of the ink containers, an outlet for connection to the printhead assembly and a fluid level regulator for maintaining fluid levels in the reservoir within a controlled fluid level range. The ink accumulator reservoirs are mounted at a fixed elevation relative to the nozzles such that hydrostatic fluid pressure at the nozzles is maintained within a predetermined range.
1 . A printing system comprising:
a printhead assembly with nozzles for ejecting ink;
a plurality of ink containers;
a plurality accumulator reservoirs, each having an inlet for connection to one of the ink containers, an outlet for connection to the printhead assembly and a fluid level regulator for maintaining fluid levels in the reservoir within a controlled fluid level range; wherein during use,
the plurality of ink accumulator reservoirs are mounted at a fixed elevation relative to the nozzles such that hydrostatic fluid pressure at the nozzles is maintained within a predetermined range.
2 . The printing system according to claim 1 wherein the fluid level regulator has an inlet valve at the inlet to the respective accumulator reservoir, the inlet valve configured to open fluid communication with the corresponding ink container when the fluid level approaches a lower limit of the controlled fluid level range.
3 . The printing system according to claim 2 wherein the printhead assembly has a staggered arrangement of individual printheads collectively spanning a media path.
4 . The printing system according to claim 3 wherein each of the printheads has a plurality of parallel rows of nozzles, each of the rows corresponding to one of the ink containers and one of the accumulator reservoirs.
5 . The printing system according to claim 4 wherein the inlet valve has a float mechanism for opening and closing fluid communication with the corresponding ink container in response to fluid level changes.
6 . The printing system according to claim 5 wherein each of the parallel rows of nozzles has a first end and a second end and is coupled to the outlet valve of the corresponding accumulator reservoir at both the first end and the second end.
7 . The printing system according to claim 6 further comprising a pumping system configured to prime the printheads.
8 . The printing system according to claim 7 wherein the pumping system is configured to prime the printheads sequentially.
9 . The printing system according to claim 8 wherein the pumping system has a peristaltic pump.
10 . The printing system according to claim 1 further comprising:
a drive roller for feeding different sizes of media along a media path; and,
an ink aerosol collection system for removing ink aerosol from areas adjacent the media path; wherein,
the ink aerosol collection system is configured to remove aerosol at a greater rate in response to an increase in the media size.
11 . The printing system according to claim 10 wherein the printhead assembly is positioned on a first side of the media path and the aerosol collection system has a first aerosol collection opening positioned on the first side of the media path and a second aerosol collection opening positioned on a second side of the media path.
12 . The printing system according to claim 11 wherein the media path has a width corresponding to a maximum width of media that can be printed by the printing system and the aerosol collection system is configured to collect ink aerosol from the first and second aerosol collection openings when the media being printed is less than the maximum width.
13 . The printing system according to claim 12 further comprising:
a platen for supporting the media during printing; wherein,
the platen has a spittoon system for collecting non-printing drops of ink ejected from the inkjet printhead assembly.
14 . The printing system according to claim 13 further comprising a plurality of service modules, wherein the printhead assembly has a plurality of separate printheads fixed relative to the media path and one of the service modules corresponding to each of the printhead respectively, the service modules being configured to operate in a spittoon mode to provide the spittoon system.
15 . The printing system according to claim 14 wherein any of the printheads not fully required to print media that is less than the maximum width, have the corresponding service module operating in the spittoon mode.
16 . The printing system according to claim 14 wherein the service modules are configured to operate in a platen mode when all the corresponding printhead is printing the media.
17 . The printing system according to claim 16 wherein the service modules are configured to operate in a capped mode when the corresponding printhead is not required for printing the media.
19 . The printing system according to claim 16 wherein the service modules are independently operable.
20 . The printing system according to claim 16 further comprising a vacuum platen opposite the printhead assembly, the vacuum platen having a plurality of apertures in which the services modules are positioned.