PRINTING SYSTEM WITH MULTIPLE INK ACCUMULATORS
A printing system that has an ink supply, an accumulator reservoir, a valve coupling the accumulator reservoir to the ink supply, the valve being configured to open when the ink level in the accumulator reservoir reaches a lower limit of a predetermined ink level range, and close when the ink level in the accumulator reservoir reaches an upper limit of the ink level range, and a plurality of printheads in fluid communication with the accumulator reservoir. Each of the printheads has nozzles for ejecting ink onto media. During printing, the accumulator reservoir is fixed relative to the printheads such that hydrostatic ink pressure at the nozzles is generated by the elevation of the ink level in the accumulator reservoir relative to the elevation of the of the nozzles.
1 . A printing system comprising:
an ink supply;
an accumulator reservoir;
a valve coupling the accumulator reservoir to the ink supply, the valve being configured to open when the ink level in the accumulator reservoir reaches a lower limit of a predetermined ink level range, and close when the ink level in the accumulator reservoir reaches an upper limit of the ink level range; and,
a plurality of printheads in fluid communication with the accumulator reservoir, each of the printheads having nozzles for ejecting ink onto media; wherein during printing,
the accumulator reservoir is fixed relative to the printheads such that hydrostatic ink pressure at the nozzles is generated by the elevation of the ink level in the accumulator reservoir relative to the elevation of the of the nozzles.
2 . The printing system according to claim 1 wherein the valve is a float valve with a float that is buoyant on the ink in the accumulator reservoir to open the valve when the ink level reaches the lower limit and close the valve as the ink level approaches the upper limit.
3 . The printing system according to claim 1 further comprising a feed line coupled to the accumulator reservoir and a return line coupled to the accumulator reservoir, each of the printheads being connected to both the feed line and the return line via separate couplings.
4 . The printing system according to claim 3 further comprising a bypass line coupling the feed line to the return line.
5 . The printing system according to claim 4 wherein the return line is configured to receive ink from the ink supply through the bypass line during a printing operation.
6 . The printing system according to claim 5 further comprising a bypass valve in the bypass line for selectively opening or closing fluid communication between the feed and return lines.
7 . The printing system according to claim 1 wherein each of the accumulator reservoirs has an inlet for connection to one of the ink containers, an outlet for connection to the printheads 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.
8 . The printing system according to claim 1 wherein the valve is 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.
9 . The printing system according to claim 1 further comprising a pumping system configured to prime the printheads sequentially.
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 printheads are 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 printheads.
14 . The printing system according to claim 13 further comprising a plurality of service modules, one of the service modules corresponding to each of the printheads 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.