Monitoring of fluid supply
A method of monitoring a fluid supply is provided, the fluid supply including a supply tank, an intermediate tank and a fluid pump operatively coupled to the supply tank and the intermediate tank; the method comprising with the intermediate tank having a defined first fluid level, starting to feed fluid from the intermediate tank; when a defined amount of fluid has been fed from the intermediate tank, with the feeding of fluid from the intermediate tank proceeding, activating the fluid pump to supply fluid from the supply tank to the intermediate tank; monitoring the fluid level of the intermediate tank while the fluid pump remains activated; and diagnosing operation of the fluid pump as a function of the fluid level of the intermediate tank.
1 . A method of monitoring a printing fluid supply, the printing fluid supply including a supply tank, an intermediate tank and a fluid pump operatively coupled to the supply tank and the intermediate tank; the method comprising
with the intermediate tank having a defined first printing fluid level, starting to feed printing fluid from the intermediate tank;
when a defined amount of printing fluid has been fed from the intermediate tank to a printhead, with the feeding of printing fluid from the intermediate tank proceeding, activating the fluid pump to supply printing fluid from the supply tank to the intermediate tank;
monitoring the printing fluid level of the intermediate tank while the fluid pump remains activated; and
diagnosing operation of the fluid pump as a function of the printing fluid level of the intermediate tank.
2 . The method of claim 1 wherein diagnosing operation of the fluid pump comprises:
monitoring a time period from activation of the fluid pump until a defined second printing fluid level of the intermediate tank is detected; and
if the time period is below a threshold value, diagnosing operation of the fluid pump as correct.
3 . The method of claim 2 , further comprising:
if the time period is above the threshold value, diagnosing operation of the fluid pump as degraded.
4 . The method of claim 2 , wherein the defined first printing fluid level and the defined second printing fluid level are the same.
5 . The method of claim 2 , wherein at least one of the defined first printing fluid level and the defined second printing fluid level corresponds to the intermediate tank detected as full.
6 . The method of claim 1 , further comprising, before starting to feed printing fluid from the intermediate tank:
providing the supply tank with at least a minimum amount of printing fluid therein;
activating the fluid pump to supply printing fluid from the supply tank to the intermediate tank until the defined first printing fluid level is reached in the intermediate tank; and
stopping the fluid pump.
7 . The method of claim 1 , wherein the intermediate tank is in fluid communication with a printhead,
wherein feeding printing fluid from the intermediate tank comprises:
feeding the printing fluid from the intermediate tank to the printhead to print a diagnostic image, and
wherein determining that the defined amount of printing fluid has been fed from the intermediate tank comprises:
monitoring a time period of printing the diagnostic image, the time period corresponding to an amount of printing fluid fed from the intermediate tank to the printhead.
8 . The method of claim 7 , wherein
the fluid pump is activated to supply printing fluid from the supply tank to the intermediate tank at a defined time after printing of the diagnostic image has started; and
printing of the diagnostic image continues while the fluid pump is activated to supply printing fluid from the supply tank to the intermediate tank.
9 . The method of claim 1 , wherein the monitoring the printing fluid level of the intermediate tank while the fluid pump remains activated is performed while the fluid pump remains activated via a differential pressure sensor.
10 . The method of claim 9 , wherein the differential pressure sensor operates based on a pressure difference between air pressure supplied to the intermediate tank and fluid pressure inside the intermediate tank.
11 . A printer comprising a supply tank, an intermediate tank, a printhead, a printing fluid pump in fluid communication with the supply tank and the intermediate tank, a printing fluid connection between the intermediate tank and the printhead, a printing fluid level sensor at the intermediate tank, and a controller programmed to:
activate the printing fluid pump to fill the intermediate tank with printing fluid from the supply tank;
deactivate the printing fluid pump when the printing fluid level sensor detects that a defined first printing fluid level in the intermediate tank has been reached;
control the printhead to print a diagnostic image;
reactivate the printing fluid pump to refill the intermediate tank with printing fluid from the supply tank after a defined portion of the diagnostic image has been printed;
monitor the printing fluid level of the intermediate tank while the printing fluid pump is activated; and
diagnose operation of the printing fluid pump as a function of the printing fluid level of the intermediate tank.
12 . The printer of claim 11 , wherein the controller is further programmed to
diagnose operation of the printing fluid pump as a function of a time needed to reach a defined second printing fluid level in the intermediate tank after re-activation of the printing fluid pump while printing of the diagnostic image.
13 . The printer of claim 11 , comprising a number of pairs of a supply tank and an intermediate tank respectively in fluid communication via an associated printing fluid pump, each pair and associated printing fluid pump associated with a dedicated printing fluid color, wherein the controller is further programmed to
independently control the printing fluid pumps associated with different printing fluid colors.
14 . The printer of claim 11 , further comprising:
a user interface to prompt a user to control or trigger at least part of a diagnostic process.
15 . The printer of claim 11 , wherein the printing fluid level sensor comprises a differential pressure sensor.
16 . The printer of claim 15 , wherein the differential pressure sensor operates based on a pressure difference between air pressure supplied to the intermediate tank and fluid pressure inside the intermediate tank.
17 . A user interface of a printer, comprising:
a first entity to allow a user to trigger printing of a diagnostic plot;
a second entity to prompt a user to provide a printing fluid supply with a minimum amount of printing fluid stored therein;
a third entity to inform the user about progress of a diagnostic operation including information about at least one of a printing fluid refill progress and information about a printing progress; and
a fourth entity to inform the user about a diagnostic result as a function of the printing fluid refill progress and the printing progress, wherein the diagnostic result includes a diagnosis of an operation of a printing fluid pump as incorrect if a time period of printing fluid refilling progress is above a threshold value.
18 . The user interface of claim 17 , wherein
the printing fluid refill progress relates to refilling an intermediate tank from a printing fluid supply during the printing of the diagnostic plot, the intermediate tank supplying printing fluid to a printhead for printing the diagnostic plot.
19 . The user interface of claim 18 , further comprising at least one of:
a fifth entity to inform the user if the printing fluid supply holds insufficient printing fluid;
a sixth entity to inform the user if the printing fluid refill progress exhibits an error; and
the fourth entity to inform the user that a diagnostic process has been completed.
20 . The user interface of claim 17 , wherein the third entity comprises a differential pressure sensor that operates based on a pressure difference between air pressure supplied to an intermediate tank and fluid pressure inside the intermediate tank.