PRINTHEAD SYSTEM WITH NOZZLE REJUVENATION SYSTEM

1 . A marking system comprising:

a printhead comprising a plurality of nozzles configured to eject ink;

a fluid supply system configured to supply ink to printhead, the fluid supply system comprising:

an ink reservoir fluidly positioned to hold the ink for delivery to the printhead,

a degasser fluidly coupled to a conduit that is positioned to supply the ink from the degasser to the ink reservoir, the degasser configured to degas the ink as ink passes therethrough, and

a pump fluidly configured to provide pressure to one or more components of the fluid supply system; and

a control system configured to:

control the ejection of ink from the plurality of nozzles, and

in response to detection of a missing nozzle condition in the printhead, activate a protocol that comprises initiating one or more cycles that comprise operating the pump at a pressure that is lower than a normal operating pressure of the pump to eject the degassed ink through the plurality of nozzles until the missing nozzle condition ends, a threshold number of cycles have completed, or a threshold period of time is reached.

2 . The marking system of claim 1 , wherein the pump is a purge pump that is:

fluidly coupled to the ink reservoir, and

configured to apply pressure thereto, thus causing the ink to move from the ink reservoir to the printhead and thereby providing ink to the plurality of nozzles.

3 . The marking system of claim 1 , further comprising:

a purge valve coupled to the ink reservoir and configured to bleed to atmospheric pressure allowing for the ink reservoir to maintain atmospheric pressure during normal operation; and

the protocol further comprises closing the purge valve.

4 . The marking system of claim 1 , further comprising a peristaltic pump fluidly connected to the conduit and configured to:

during operation, draw the ink therethrough via vacuum pressure and transport the ink from the degasser to the ink reservoir via the conduit, and

act as a stop when not in operation.

5 . The marking system of claim 1 , wherein the missing nozzle condition comprises the control system detecting that at least a threshold amount of the plurality of nozzles are not operating.

6 . The marking system of claim 1 , wherein the missing nozzle condition comprises an image quality of a document printed by the marking system not meeting a threshold image quality measure.

7 . The marking system of claim 1 , wherein the pressure at which the pump is operated during the protocol is a pressure from about 1% to about 10% of the standard operating pressure of the pump during typical printing operations of the marking system.

8 . The marking system of claim 7 , wherein the pressure during the protocol is in a range of 0.25 PSI to 0.5 PSI.

9 . The marking system of claim 1 :

wherein the pump is a purge pump that is:

fluidly coupled to the ink reservoir, and

configured to apply pressure thereto, thus controlling the pressure applied to the ink as the ink moves from the ink reservoir to the printhead and through the plurality of nozzles; and

the system further comprises an ink supply pump that is a peristaltic pump fluidly connected to the conduit and configured to:

during operation, draw the ink therethrough via vacuum pressure and transport the ink from the degasser to the ink reservoir via the conduit, and

act as a stop when not in operation.

10 . The marking system of claim 1 ,

wherein the protocol comprises a drool protocol; and

the control system, before initiating the drool protocol initiates a purge protocol in which the pump increases pressure applied to the one or more components of the fluid supply system, and

initiates the drool protocol after the purge protocol,

wherein during the drool protocol, the pump reduces the pressure applied to the one or more components of the fluid supply system.

11 . A method of removing gas from a marking system, the method comprising:

providing a marking system comprising:

a printhead including a plurality of nozzles,

a control system, and

an ink supply system comprising:

an ink reservoir fluidly positioned to hold the ink for delivery to the printhead,

a degasser fluidly coupled to a conduit that is positioned to supply the ink from the degasser to the ink reservoir, the degasser configured to degas the ink as ink passes therethrough, and

a pump fluidly configured to provide pressure to one or more components of the fluid supply system; and

by the control system, in response to detecting a missing nozzle condition in the printhead, activating a protocol that comprises operating the pump at a pressure that is lower than a normal operating pressure of the pump to create an ink flow through the plurality of nozzles until the missing nozzle condition ends, a threshold number of cycles have completed, or a threshold period of time is reached.

12 . The method of claim 11 , wherein:

the pump is a purge pump that is fluidly coupled to the ink reservoir; and

activating the protocol causes purge pump to reduce the pressure applied to the ink as the ink moves from the ink reservoir to the printhead.

13 . The method of claim 11 , wherein:

the ink supply system further comprises a purge valve coupled to the ink reservoir and configured to bleed to atmospheric pressure allowing for the ink reservoir to maintain atmospheric pressure during normal operation; and

the protocol further comprises closing the purge valve.

14 . The method of claim 11 , wherein the ink supply system further comprises a peristaltic pump fluidly connected to the conduit and configured to:

during operation, draw the ink therethrough via vacuum pressure and transport the ink from the degasser to the ink reservoir via the conduit; and

act as a stop when not in operation.

15 . The method of claim 11 , wherein detecting the missing nozzle condition comprises detecting that at least a threshold amount of the plurality of nozzles are not operating.

16 . The method of claim 11 , wherein detecting the missing nozzle condition comprises detecting that an image quality of a document printed by the marking system not meeting a threshold image quality measure

17 . The method of claim 11 , wherein the pressure at which the pump is operated during the protocol is a pressure from about 1% to about 10% of the normal operating pressure of the pump.

18 . The method of claim 17 , wherein the pressure during the protocol is in a range of 0.25 psi to 0.5 psi.

19 . The method of claim 11 ,

wherein the pump is a purge pump that is:

fluidly coupled to the ink reservoir, and

configured to control pressure applied to the ink as the ink moves from the ink reservoir to the printhead; and

the system further comprises an ink supply pump that is a peristaltic pump fluidly connected to the conduit and configured to:

during operation, draw the ink therethrough via vacuum pressure and transport the ink from the degasser to the ink reservoir via the conduit, and

act as a stop when not in operation.

20 . The method of claim 11 , wherein:

the protocol comprises a drool protocol; and

the method further comprises:

before initiating the drool protocol, initiating a purge protocol in which the pump increases pressure applied to the one or more components of the fluid supply system, and

initiating the drool protocol after initiating the purge protocol,

wherein during the drool protocol, the pump reduces the pressure applied to the one or more components of the fluid supply system.