Do Canon's fire the nozzles during cleaning cycles?

[turbguy]

Anybody know? Seems that would be really heavy duty on them during cleaning if they did.

Wayne

 

[ghwellsjr]

Yes, they do.

It's very difficult to tell until you get a clogged purge system which no longer "sucks" on the bottom of the print head during a head cleaning and even then it's hard to tell because the pads are saturated black with ink but if you remove them and clean them and put them back in and do a cleaning cycle, you can see the ink patterns coming from the bottom of the print head. You have to do this test with a print head that was primed on another printer.

Of course, this doesn't mean that they are firing during the entire cleaning cycle but we do know that at least some time during the cycle the nozzles are fired.

 

[turbguy]

It's very difficult to tell until you get a clogged purge system which no longer "sucks" on the bottom of the print head during a head cleaning and even then it's hard to tell because the pads are saturated black with ink but if you remove them and clean them and put them back in and do a cleaning cycle, you can see the ink patterns coming from the bottom of the print head. You have to do this test with a print head that was primed on another printer.

Of course, this doesn't mean that they are firing during the entire cleaning cycle but we do know that at least some time during the cycle the nozzles are fired.

The ink pattern observed on a cleaned "parking plate" really isn't evidence that they fire, is it? After all, you get the same pattern by touching a primed printhead to a clean tissue, no? Unless you meant the pattern appears with a known non-functional purge system....then maybe that's evidence.

If someone actually detected current flow through the ribbon (should produce enough RF to detect), that would confirm it for me.

 

[ghwellsjr]

It's very difficult to tell until you get a clogged purge system which no longer "sucks" on the bottom of the print head during a head cleaning and even then it's hard to tell because the pads are saturated black with ink but if you remove them and clean them and put them back in and do a cleaning cycle, you can see the ink patterns coming from the bottom of the print head. You have to do this test with a print head that was primed on another printer.

Of course, this doesn't mean that they are firing during the entire cleaning cycle but we do know that at least some time during the cycle the nozzles are fired.

The ink pattern observed on a cleaned "parking plate" really isn't evidence that they fire, is it? After all, you get the same pattern by touching a primed printhead to a clean tissue, no? Unless you meant the pattern appears with a known non-functional purge system....then maybe that's evidence.

If someone actually detected current flow through the ribbon (should produce enough RF to detect), that would confirm it for me.

I said it was done with a clogged purge system.

I didn't think the pads actually touch the bottom of the print head, otherwise, it would wick all the ink out of the cartridge, wouldn't it?

 

[lin]

Hi turbguy, few years ago after I had disassembing the printer and cleaning it, and powering it on without the printertop casing, from the side view with flash light, I had seen with my own eyes (those older printer series that uses those tri-cartridges (not the individual cartridges like CLI/BCI series)), they do the spray out (fire the nozzles) during cleaning cycles.

It's not easy to tell, if there is a nozzle not firing, because the spray is very fine and the timing of the cycling cycle where they firing the nozzles is rather short. And there is 2 groups of nozzles each for each color channel for the tri-cartridges (can't tell if there is more group since the spray is like a mist) firing altogether. So if there is clog, it's hard to identify when there would be several groups nozzles all firing altogether. It's like raining accept there is a a pattern (straight nozzles spraying). Just like a rainfall, can you easily pickout each individual raindrop during a rainfall? No right.

For the individual cartridges printer series like those printer that uses CLI/BCI, I didn't go about observing so I can't answer what I didn't see.

 

[turbguy]

ghwellsjr, thanx for the clarification!

Seems that installing a dry printhead into a printer might be a bad idea, particularly if the chambers behind the nozzles aren't primed with SOMETHING to cool the firing resistors. Perhap thats why new printheads ship with a fluid installed?

Wayne

 

[ghwellsjr]

Maybe that fluid is used during manufacture to test that the nozzles are all working.

Since the printers are designed to tolerate some very small amount of nozzle firings during a nozzle check and head cleaning, I wouldn't worry about it. What you don't want to do is ordinary pages of printouts while you have clogged nozzles.

 

[The Hat]

When you install a new print head followed by the cartridges the first thing that the printer does is to park the print head.
If you listen carefully you will observe the purge unit in action sucking ink down from the cartridges and through the print head.

The print head will then move to the centre of the carriageway and check that all of the cartridges are correct by using the red led sensor
and then return to the park position to suck and fire off some ink several times.

From what I can tell is that a print head once its had ink go through it can then cope very well with blocked nozzles
or ink starvation for a limited time without causing any permanent damage to it.

The reason I have come to that conclusion is when using only colour or pigment black in a print run
the print head will work very efficiently despite not using all of its nozzles.

But will return to the park position every now and then to fire off some ink
from the unused nozzles just to keep them from clogging and possible damage.

This of course is just my observation and opinion and not necessarily totally correct so please step in guys
with your opinions and or corrections as it can only help us understand more on the subject..

 

[ThrillaMozilla]

You guys have seen it and I haven't, but:

1. I wonder if the purge unit may have been working partly. That would be sufficient to make the purge pads look as if nozzles had been fired.

2. I wonder if a vacuum from the purge unit would create a spray just as if the nozzles had been fired.

In other words, are you guys certain that you can tell the difference between nozzles firing and the action of the purge unit?

 

[lin]

@ThrillaMozilla, during cleaning cycle (where you execute the cleaning) when the printhead nozzles firing above the purge unit, the purge unit does not cap onto the bottom of the printhead. The way they fire is much like the way it dispensing/firing ink during printing. During printing, the printhead do not touch directly on top of the paper. There is some height clearance between the bottom of the printhead and the paper media during printing. So during the cleaning cycle (executing the cleaning), the printhead fire on top of the purge unit pad without being cap onto it. That is the reason why I was able to watch the tri-cartridges being fired/spraying out ink during the cleaning cycle. If the purge unit had cap onto the bottom printhead all the time during cleaning, I won't be able to see the spraying ink.

And they do not fire throughout the entire process of the cleaning cycles, it's only at some point of the stage where firing/spraying is involved.