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  • Welcome to the new site. Here's a thread about the update where you can post your feedback, ask questions or spot those nasty bugs!

Canon Pixma G3270—an inexpensive tank-type 4-color inkjet printer

Doug Kerr

Well-known member
Prior

About 15 years ago we bought an Epson Stylus Photo R1900 inkjet printer. It will print on paper at least 11" wide, and will nicely print on (printable) CD and DVD disks. It uses ink cartridges, with two kinds of black ink (which one is used depends on the paper type), plus yellow, cyan, magenta, red, and orange, plus a "gloss optimizer", a sort of lacquer used when printing on glossy paper.

But our use of this printer has been very infrequent, and over the years I have neglected to print a nozzle test pattern every couple of weeks, and so we often had severe nozzle clogging problems. The machine has a very clever nozzle unclogging system, but it uses a lot of ink, which all goes into the waste ink collection system.

In that machine the ultimate destination for waste ink is a field of absorbent pads located at the very bottom of the machine. When the machine reckons they are almost "full", it gives a repeated error message. When it reckons that they are "full", it gives an error light display and will not operate.

There is no authorized Epson repair facility within reach, and the local printer repair technician (quite knowledgeable) was not optimistic about replacing the pad field.

For this and other reasons, we decided to retire the R1900.

A new printer—choosing

Over the years our need for a color printer have changed. We never any more print photos in the sense of making a print that would be exhibited. The need to print on CD or DVD disks has vanished with changes in how data is distributed. And on the occasions when we really need a large format print, the local office supply store can do that conveniently and at small cost.

So the most sensible thing would be to not get any kind of replacement color printer. But it just didn't seem tight not to be able to print in color at all. So what kind of printer should we get? We pondered this for a couple of weeks.

One attractive choice would have been a so-called color "laser" printer (the modern ones don't actually use a laser but rather a line of tiny LEDs to expose the photosensitive drum). An advantage is that under infrequent use one does not need to have the printer "blow its noses" periodically to avoid nozzle clogs.

But, interpolating among many reviews and opinions, it seemed that this style of printer would not do as well at photo printing as an inkjet printer, even the "4-color" kind.

The new printer

The ultimate result of this pondering was that we bought a Canon Pixma G3270 four-color inkjet printer, essentially an entry-level machine, and quite inexpensive ($149.99 almost everywhere). We bought the white version. Here we see it in place:

R06798-01-s800.jpg

This machine uses a continuous ink supply system (CISS): rather than having cartridges with a small quantity of ink, this has stationary tanks with a substantial capacity, which are refilled from bottles. The standard bottle for each color contains enough ink to refill the corresponding tank when it is at the "replace ink soon" level. (There is a sight glass for each tank so the actual ink level can be seen.) The machine is shipped with a full set of bottles, of the normal capacity (not "starter" bottles with a wee amount of ink).

In addition to direct connection via a USB port, this machine has a variety of "wireless" modes, including using it as a network printer on a wireless LAN or allowing it to be directly driven from a smartphone or tablet. I don't expect us to exploit any of that. But who knows!

The machine has in its lid a flatbed scanner that will accept up to a letter-size or A4 page. We didn't really need this, but that ls the way most inkjet printers come these days. It has a "copier" mode that seems to work very well.

For making settings without going to the driver control panel, the machine has an easy-to-use control panel, but with a really tiny LCD screen. (There is a "higher" model that has a larger, touch-screen display and more control keys, such as a 10-key pad for entering numeric values. We decided not to spring for that.)

First tests of printing photos on glossy inkjet paper were very encouraging. But those were "quick 'n' dirty". I'll have some further observations later.

Best regards,

Doug
 
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Asher Kelman

OPF Owner/Editor-in-Chief
Doug,

One valid criticism of digital photography is absence of receiving pictures to hold and admire like the old days of film.

“The ultimate result of this pondering was that we bought a Canon Pixma G3270 four-color inkjet printer, essentially an entry-level machine, and quite inexpensive ($149.99 almost everywhere).”

Here you have given the answer! I love your picture of years back of “longhorns”!

The ability to print for a low price means we are now likely to finally get the prints we longed for!

Asher
 

Doug Kerr

Well-known member
As I mentioned earlier, nozzle clogging, when an inkjet printer is used only infrequently, is a recurrent problem.

It seems that the Canon Pixma G3270 printer, if idle for some period (not known here), at some interval (not known here) makes some small, quick maneuver of the print head (the specifics of which are not known here) to keep the nozzles clear. I speak of this colloquially as "wiping its nose".

It also seems that if the printer is off, but the "automatic on" feature is enabled (this makes the printer, if off, turn on when a print job is to be sent to it), it turns on for a few seconds to do the above.

Definitive information on all this is hard to come by.

Best regards,

Doug
 
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Doug Kerr

Well-known member
A fellow at Canon Customer Support, asked about this phenomenon, at first gave an answer that was not credible, but after consulting with a colleague told me that yes, this is a "mini clean" the printer performs on some schedule if it can (meaning either that it is ON, or if OFF, the "automatic ON" feature is in effect). He had no idea exactly what that process entails.

I then asked, given that this happens, does this remove the need for me to be sure to print something (even a nozzle test page) every couple of weeks to keep the nozzles from clogging?

He said that I should be sure to print something at least every couple of weeks.

Ah, the Mind of Canon.

Best regards,

Doug
 

Robert Watcher

Well-known member
I started running the nozzle test page every week or two out of habit, after I came to the realization that every nozzle will be “exercised” with that procedure. I have Epson printers, so it may be more useful with their style of print heads.

One thing that I stopped doing as well, is the turning the printer off. I’ve never shut my mac computer and external hard drives off in years, except when the power goes out or software updates for the most part. So keeping my printer on, follows that pattern.

Copilot response to my query about not turning off my printer is: “Leaving an Epson printer on all the time can help prevent the print head nozzles from clogging, as it keeps the ink flowing and reduces the chances of the ink drying out. However, it's not a guaranteed solution and may not address all causes of clogging, such as debris or air bubbles.” That query supports what I heard from a couple of specialists in the field of injet printing.


We’ll see how it works out in the long run.
 
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Doug Kerr

Well-known member
Hi, Rob,

Thanks for all that.

You say that it was said:

Leaving an Epson printer on all the time can help prevent the print head nozzles from clogging, as it keeps the ink flowing and reduces the chances of the ink drying out.

It would be interesting to know exactly why that is. The intimation is that if it is on, it periodically "blows its noses" or such.

Again, I suspect what my Canon G3270 does periodically is something like that. (The way I have the options set, if it is off, it turns on to do that and then turns off.) But I have so far gotten no clue as to exactly what it does.

But no doubt there will eventually be a YouTube video about that!

Best regards,

Doug
 

Robert Watcher

Well-known member
My search specific to your printer “Is there a benefit to never turning off the Canon PIXMA G3270 inkjet printer?” provided this response that you may find value in:

“There are a couple of benefits to never turning off the Canon PIXMA G3270 inkjet printer.

By keeping your printer on instead of turning it off when not in use, you can reduce the number of printhead cleaning cycles. This is because each time you turn the printer off and back on, the printhead nozzles are cleaned during initialization. Keeping the printer on minimizes these cleaning cycles, which can save ink.

Additionally, when the printer is already on, it can respond more quickly to print requests. This can be convenient if you need to print something urgently.

However, it's important to note that keeping the printer on will use more electricity. If you're concerned about energy consumption, you might want to use the printer's power-saving mode instead of completely turning it off.”

For my purposes, I just leave the printer on for the small about of electricity it may consume —- that along with weekly/biweekly running a nozzle check, while uses all nozzles with little ink use. That is the case with my computers and attached hard drives as well, a practice I have done with them for decades.
 

Robert Watcher

Well-known member
When I queried coPilot (AI search) with the more specific question of why leaving a printer on all the time reduces clogging? This is response - which appears pretty logical to me:

Leaving a printer on all the time can reduce clogging of ink nozzles for a few reasons:

1. **Continuous Flow**: When the printer is left on, there is a continuous flow of ink through the nozzles, even if it’s minimal. This helps keep the ink from drying up and clogging the nozzles.
2. **Temperature Stability**: Printers that remain powered on can maintain a more consistent internal temperature. Frequent power cycling can lead to temperature fluctuations, which can cause the ink to dry out and lead to clogging.
3. **Reduced Startup Cycles**: Each time you turn the printer off and on, it goes through a cleaning cycle. While this helps keep the nozzles clean, it also uses a bit of ink each time. If the printer remains on, fewer cleaning cycles are initiated, reducing the risk of clogs from dried ink.

These factors together contribute to a more consistent and reliable ink flow, helping to prevent clogs in the nozzles.
 

Doug Kerr

Well-known member
Hi, Rob,

The thing about AI-based responses is often that they are usually essays of impeccable grammatical structure and use a lot of words and terms somehow known to the AI engine and relatable to the topic asked about. But they often end up with ambiguous notions.

So as to this passage:

When the printer is left on, there is a continuous flow of ink through the nozzles, even if it’s minimal.

I'm not sure exactly how that can be so (and of course it sounds as if it is typical of "typical" inkjet printers).

It could in fact mean that "continuously", each of the nozzles of the head, while it is parked on its "parking pad", actually squirt a tiny drop every so often (maybe once a second, or once a minute, or once and hour, or once a day, or once a week. If so, I hadn't known that. And maybe I still don't.

In any case, it is not at all surprising that, especially in printers that do not have an "automatic turn on" feature (as my Canon G3270 does), it is attractive to keep them turned on so what ever they do "continuously" can happen.

In any case, few of us will ever know exactly what a given printer does and when!

Maybe.

Best regards,

Doug
 

Doug Kerr

Well-known member
Hi, Rob,

In the case of the Canon Pixma G3270 printer, Canon suggests leaving it on all the time so the periodic "mini clean" can take place (whenever that is). (The User Guide does not recommend this, but Canon Customer Service tells one that. The User Guide only recommends that something be printed at least once a month.)

But I asked their customer service representative if I normally leave the printer turned off, but have the "automatic turn on" feature enabled, would that be just as good. He said, "Oh yes".

Best regards,

Doug
 

Jerome Marot

Well-known member
The thing about AI-based responses is often that they are usually essays of impeccable grammatical structure and use a lot of words and terms somehow known to the AI engine and relatable to the topic asked about.

Well said. But AI systems are simply language models. They don't know anything about the real world. Asking them for advice is like asking a monk who read all sacred books but never went out of his cell.


In any case, few of us will ever know exactly what a given printer does and when!

I am confident that, for example, a retired telephone engineer could devise a device to monitor power use or record noises, that kind of things.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Hi, Rob,

In the case of the Canon Pixma G3270 printer, Canon suggests leaving it on all the time so the periodic "mini clean" can take place (whenever that is). (The User Guide does not recommend this, but Canon Customer Service tells one that. The User Guide only recommends that something be printed at least once a month.)

But I asked their customer service representative if I normally leave the printer turned off, but have the "automatic turn on" feature enabled, would that be just as good. He said, "Oh yes".

Best regards,

Doug
Doug,

There are different AI models. Some can decide to tackle problems using advanced scientific calculations and optimizations, such as improving design of large concrete cable-tension bridges with few cantilever supports in a river below or optimization of multiple shaped radiation beams in a radiation treatment plan for cancer and determine in each, relative time and costs, risks and hazards compared to alternative approaches.

These are not simply based on language models, but rather sophisticated data descriptions of properties of all matter, subject to all known forces in a society with limited resources, the latter each having variable costs and different availability and practicality of application to the problem at hand at the time needed and in the location defined by the problem at hand!

Asher
 

Doug Kerr

Well-known member
Work to date with the Canon Pixma G3270 printer has made an excellent impression overall. The machine behaves well, and we are beginning to get further insight into its handling of color matching and its practices for keeping its nozzles unclogged.

As to photos, we have so far printed a photo of Carla from the same JPEG file using various papers. As to Canon brand paper, we have printed on the Photo Paper Plus Glossy II (about $0.48/sheet) and the Matte Photo Paper (about $0.12/sheet). We will hopefully later today print that photo on the Photo Paper Pro Luster (about $0.42/sheet).

We have also printed that photo on several types of Epson brand paper, of which we have a fair inventory.

All these prints have been very nice. I am in no position to make a sophisticated critique of their properties, but I would certainly not be at all reticent to send any of them to a friend or relative for display.

There is an initiative now in its early stages to use a test image that is more "challenging" of a printer's capability and to include comparison prints done on a high-end 11-color ink Canon inkjet printer. I will report the findings of that test program when possible.

Best regards,

Doug
 

Doug Kerr

Well-known member
Color matching for the Canon Pixma G3270 printer

The overall topic of "color matching", and of the roles of ICC profiles in that art, is hard to get straight. The literature opften seems to give the facts, but in reality almost always tells only part of the story, often leading to misconceptions or at least uncertainty. And there is great uncertinty and ambiguity in the teminology that is oftem used. (It is all-too-familiar case of, "If you alreaady understand it all, you can understand the explanations of any part of it".)

The situation as to the Canon Pixma G3270 printer is no different.

Because this is a "lower end" machine, Canon has tried (and I would say done well) to remove from the user any need to understand this mysterious art. They have done less well in describing just what they have done.

Mike Chaney, developer and publisher of the well-respected printing application Qimage and now Qimage Ultimate, who not surprisingly know a great deal about this area, and who, unlike many others, is able to give clear and concise explanations of many points, has been very helpful to me in this matter. Based on his inputs, as well as my own "triangulation" among conflicting information from various sources (including Canon), I can report with some confidence these key points as to the matter of color matching for the Canon Pixma G3270:

• Canon does not provide any ICC profiles for this printer as files for use by applications that can print to this printer.

• There are "built into" the Canon printer drivers for this printer color matching profiles for its use with five Canon-brand paper types (and plain paper as well). When one of these is used, the transformation from (1) the color space of the image as sent to the printer driver to (2) the color space of the printer proper is done by the printer driver. (There are not any such for, for example, "generic glossy paper".)

• The profile matching the chosen media type is put in place automatically (if the "mode" chosen is appropriate).

• The appropriate "mode" of the printer driver for having the printer driver do the color transformation, using a built in profile, is the one labeled "ICM".

• When the printer driver is set to ICM, the driver is receptive to the "image message" sent it by the printing application containing a profile (the "source profile") that describes the color space in which that image is cast. (I have a feeling that if the "message" does not include a "source profile", the printer driver will assume that the arriving image is cast in the sRGB color space, but i really have no idea.)

• The application can thus use, for transmission of images to a printer system, any color space its designer deems desirable, including one that is parochial to the application.

• In Qimage Ultimate, to operate in the fashion I have described above, the Printer Profile field should be set to "Let printer/driver manage color".

• If a user wishes to use a paper of other than the specific Canon brand papers that can be seelcted (and good resuolts can certainly be had with varioius non-Canon papers), the user has to try it with various paper setting choices to find the one that gives a result the user deems most suitable.

I think.

Best regards,

Doug
 

Doug Kerr

Well-known member
The mini nose blow

I discussed earlier in this thread the fact that my Canon Pixma G3270 printer, if ON, every so often makes a short grunting noise.

But I have my printer set up so that, if it is OFF, it will come ON when an application threatens to send it a print job.

And so if it is OFF, every so often it comes ON, makes this same short grunting noise, and then turns off (the latter taking about five seconds, the ON light blinking during that time, just as when one turns the printer OFF manually).

As I mentioned earlier, it has been very hard to find out exactly what this is.

But based on triangulation among many partial and questionable "facts", and reflecting on this with colleagues, I am now fairly certain that this is a "mini nose blow" to keep the nozzles from clogging when they have not been used for an actual print job for some while.

Likely what happens is this.

• The "parking pads", which keep the print nozzles "capped" when the printer is wholly idle, retract.

• Every nozzle shoots a tiny drop of ink (which falls onto the parking pad and is ultimately led away to the "ink sump").

• The "parking pads" rise to the position where they cap the nozzles.

I have the feeling that this alone is enough to keep the nozzles from clogging even if the printer does no actual printing for a long time (but is plugged in and either left ON or set so it will come on when that is needed, as for this process).

But the official advice from Canon Customer Support (from an agent who had no idea that this even happened until a colleague confirmed it) was, "Oh no, one should still print at least a nozzle test pattern (if no actual print job) at least once a month." And the manual, which certainly does not mention the "mini nose blow" at all, recommends essentially the same.

******

I have a feeling that the mini nose blow happens on a certain periodic schedule independent of when, if at all, an actual print job is done.

Maybe.

Best regards,

Doug
 
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admin

Administrator
Staff member
Doug sent me prints from this inexpensive Canon “bulk ink printer”. I was really surprised at the vivid colors and beautiful rendering of a picture of Carla, Doug’s unusually lovely wife!

The advantage here is that the colors are so rich and vivid yet suffer no bronzing or metamorisnm, (shift in hue), when viewed at angle, (metabolism), as can occur with more expensive and finely detailed pigment inks).

My opinion is that, (with UV blocking glass/plastic), these images should last for decades.

[Adding a strip of copper within the sealed framing to take up hydrogen sulfide, would be an idea for larger masterpieces for long term exhibition.]

So don’t be reticent in getting this or the equivalent bulk Epson printer. For sure anyone receiving the prints on a matte, semi glossy or glossy paper by either of these manufacturers, (or Kodak), will be delighted by the fabulous appearance of your favorite images.

Asher
 
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Jerome Marot

Well-known member
One attractive choice would have been a so-called color "laser" printer (the modern ones don't actually use a laser but rather a line of tiny LEDs to expose the photosensitive drum). An advantage is that under infrequent use one does not need to have the printer "blow its noses" periodically to avoid nozzle clogs.

But, interpolating among many reviews and opinions, it seemed that this style of printer would not do as well at photo printing as an inkjet printer, even the "4-color" kind.

I can confirm that. Back in 2010 or 2011 I bought a color Laser printer, an HP CP3525. I still have it. It can print photographs, but they have a particular "business print" look. I am not sure why, maybe this comes from the kind of paper used: the printer cannot really print on photo-quality paper.

The reason I bought that at the time was that inkjet was extraordinary costly (the printers ate cartridges for breakfast, silently running them empty in the course of a month even when unused) and the inkjet printers were extremely finicky, jamming the paper every so many pages. Business lasers were designed for small offices needing lots of prints and not willing to put up with a finicky printer. I also wanted a printer sitting on the network and working without fancy drivers, which would only be available for Windows and for a few years and I needed duplex printing. I bought that particular model second hand for a fifth of the price new. Apparently, small businesses replace their printers regularly, so there is a lively second hand market.

I use it irregularly for medium volume printing, e.g. mailing for my beekeeping club (about 300 pages). It will simply run this kind of job without trouble.

Until it didn't, but why it stopped and how I repaired it is another story...
 
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Doug Kerr

Well-known member
I have this further observation regarding the use of various types of paper on my Canon Pixma G3270 printer.

I recently printed a test image having a number of smaller images of various natures on three types of Canon paper (for which the printer in question has specific "built-in" color profiles), Photo Paper Plus Glossy II, Photo Paper Pro Luster, and Matte Photo Paper. (There is also Canon Photo Paper Plus Semi-gloss, but I don't have any of that.)

There is of course the issue of whether the viewer prefers the reflective properties of one or the other, which is perhaps largely a separate matter of taste, possibly in light (!) of the environment in which the photo is expected to be regarded. I will just set that consideration aside for now.

That having been said, except for the issue of portions of the image that are black or have "shadow detail" (I'll come to that in a moment), I find that the photos on all three kinds of paper to overall be equally "nice".

But I find that the "depth" of blacks is much greater (and the rendering of "shadow detail" better) with the Glossy paper than with the Matte paper. And in fact on those issues, it seems that the result with the Photo Paper Pro Luster is essentially the same as with the Glossy paper.

Best regards,

Doug
 
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admin

Administrator
Staff member
Doug,

The important breakthrough you are making, at least for this first printer you have tested so carefully, is that you can readily find the best paper for the impression you wish to give for a particular program.

The next step is to use standardized universally available pictures which could be tested on ones printer once, so in future one could likely predict accurately in advance the paper and profile combination most likely to give the hoped for appearance of detail, hues and grey scale distribution.

I do hope you will get to this stage which will be advantageous for us to learn more about!

Asher
 

admin

Administrator
Staff member
A reliable subjective observer measures system has been devised for combinations of printer, paper and inks, called SQF!

It’s worth read this abstract here!

Asher
 

Asher Kelman

OPF Owner/Editor-in-Chief
I am looking forward to your results on testing various competitive papers and Platinum Pro by Canon on your Canon Pixma printer using standardized reference images that anyone here can use on their own printers.

I will try they ASAP on my 12 ink Canon printer with their best paper and send them to you for your evaluation compared to your I preSion on prints with the sand paper on your printer! I have ordered the Platinum Pro paper and tomorrow whatever genuine Canon ink I need!

Asher
 

Doug Kerr

Well-known member
Hi, Asher,
I am looking forward to your results on testing various competitive papers and Platinum Pro by Canon on your Canon Pixma printer using standardized reference images that anyone here can use on their own printers.

Yes.

I will not be testing the Canon Photo Paper Pro Platinum on my Canon G3270 printer, as it does not have a built-in profile for same, and we do not have any of it.
I will try they ASAP on my 12 ink Canon printer with their best paper and send them to you for your evaluation compared to your I preSion on prints with the sand paper on your printer! I have ordered the Platinum Pro paper and tomorrow whatever genuine Canon ink I need!
I am looking forward to the results.

Best regards,

Doug
 

Asher Kelman

OPF Owner/Editor-in-Chief
Well, you can test the Platinum paper I will send you with the various profiles you have available!

… and like you tried out with Epson papers on your Canon printers, you will have a least reasonable and most likely fabulous success once more!

Asher
 

Doug Kerr

Well-known member
Hi, Asher,
Well, you can test the Platinum paper I will send you with the various profiles you have available!

… and like you tried out with Epson papers on your Canon printers, you will have a least reasonable and most likely fabulous success once more!
Well, that will be great. It will be very valuable to see if the Canon Photo Pro Platinum paper produces a "superior" result to that with the Canon Photo Paper Plus Glossy II (with the system operating with the profile for the latter paper).

Thanks.

Best regards,

Doug
 

Doug Kerr

Well-known member
I have been fascinated, as to my Canon Pixma G3270 "tank and bottle" printer, about some fundamental matters of ink management, initially these:

• When we first commission the printer, how is the initial ink load drawn through the supply tubes up to the head (which is high than the ink level in the tanks?

• In ongoing operation, how is the ink drawn to the head?

There were no clues in the available literature, so I resorted to consulting with the pertinent patents. Of course there are a zillion that maybe) apply to the system in the G3270. But after pondering a number of them, certain themes began to appear.

First I note that many of us are aware that in the typical inkjet printer, when the printer is not printing, the head is parked over an absorbent pad, surrounded by a flexible gasket wall. We thing of this are "capping" the head so the ink in the nozzles does not dry out and clog the nozzles And we realize that the absorbent pad is (at least in part) to collect the ink that is shot through the nozzles when we do a nozzle cleaning operation (and perhaps this is done a little bit by the printer automatically, perhaps just before a new print job, or just after one).

And while contemplating this general matter with regard to my Epson R1900, I learned that there is in fact a little pump that pumps this "wasted" ink from the absorbent "parking" pad into a collection facility (which in the R1900 is a field of absorbent pads in the bottom of the printer case, which is expected to be the final resting place for all the ink discharged into the absorbent pads for the life of the printer).

Now. as to the Canon printers, it seems that this pump is not only meant to convey the wasted ink to its sump (which in modern printers is a replaceable “drawer”), but also to “suck on the nozzles” from time to time.

So certainly, when the printer is first commissioned, this capability is used to suck on the “then empty” nozzles to draw enough ink from the tanks to fill the tubes leading to the heads and in fact to fill what I will call the ink reservoir(s) in the heads.

But the patents suggest a further use of this sucking operation. Seemingly, it is possible for air bubbles to collect in the “ink anteroom” that is just behind each set of nozzles. Exactly how that happens is not yet clear to me.

But in any case, at an appropriate time, the head is moved to the parking area and the pump used to suck on the nozzles so as to remove some ink that will carry with it any air bubbles in the respective “anterooms”.

Now back to the spontaneous “nose blowing” operation I spoke of earlier. Recent observations suggest that this happens some relatively fixed time (perhaps one hour) after the end of the last print job. So I suspect that its main objective is to purge the anterooms of air bubbles, perhaps after allowing enough time for them to gather together. But of course this itself is enough to “flush” the nozzles.

Now whether in fact this happens every few days, to “flush out” the nozzles, I don’t yet know. More observations will be needed to clarify this.

Best regards,

Doug
 

Doug Kerr

Well-known member
This is my current belief with regard to the "firing" of the nozzles in an inkjet printer of the class of the Canon G3270 and how the ink continues to be drawn from the tanks (those being lower that the heads) during ongoing operation. Not that this is conjecture, although supported by various descriptions, including from some Canon patents.

Each nozzle consists of a short passage, terminating in a very small diameter orifice.

The passage is fed ink from what I call the "ink anteroom", which is in turn kept filled from what I call the "ink reservoir" in the head. (How that is filled with ink I will get to shortly.)

Just behind the orifice in the passage wall there is a small resistive heater.

I note that, owing to the fact that the ink tanks are lower than the nozzles, the overall pressure (with respect to atmospheric pressure) in the system is negative.

This would tend to draw ink back from the discharge orifice, being followed by air. But the diameter of the orifice is very small, and the effect of surface tension is such that the pressure difference across the orifice is not enough to "break" the surface tension, and so ink does not drain back from the nozzle.

When a nozzle is to be "fired", a electrical pulse is sent to its heater, This raises the temperature of the ink adjacent to the heater such that the ink there vaporizes. The "bubble" of vaporized ink expands, creating a pressure wave in both directions along the nozzle channel from the site of the heater.

The wave toward the orifice "breaks" the surface tension of the ink there, forming a droplet of ink that is ejected toward the paper. The wave in the opposite direction causes a tiny bit of ink to flow back into the ink "anteroom" and from there back into the ink reservoir of the head.

But as soon as the heating pulse ends, the bubble of vaporized ink condenses. That requires the volume formerly occupied by ink vapor to be refilled with liquid ink. This causes a negative pressure wave to travel in both directions from the site of the vaporized ink bubble (seeking that ink). But this wave is more "gentle" than the positive pressure wave caused by the heater. Thus, when it reaches the orifice, the peak pressure difference across the orifice is not enough to "break" the surface tension, and so no air can flow in through the orifice.

The net result is that the entire (tiny) shortfall of ink in the nozzle (from the ejection of the droplet) is made up by ink drawn from the anteroom, and in turn from the ink reservoir, and in turn through the feed hose from the ink tank.

So, with the behavior of the surface tension at the orifice playing the role of a check valve, the nozzle serves as a kind of thermally-actuated pump that draws ink from the tank, even though that is at a lower level than the head.

I think.

Best regards,

Doug
 
Last edited:

Doug Kerr

Well-known member
It may in fact be that the "drawback" of the ink when the heater is stopped is needed to clearly separate the nascent droplet so that it can begin its flight toward the paper not in any way seriously tethered to the following body of ink.

Maybe.

Best regards,

Doug
 
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