Absorbent sponges in Canon printers

[Grandad35]

I took a few pictures of the absorbent sponges in my i9900 that might be of interest.

This shows the sponges in the "home" position. These sponges absorb the ink from the cleaning cycles, and explain how the wrong colors sometimes show up in a nozzle test or even on the first print after a period of inactivity. Since a single sponge covers as many as 5 colors, it is easy to see how the colors can migrate through the sponge to other nozzles. These sponges apparently raise into position when the head is parked to cover the discharge of the nozzles and prevent them from drying out. This also shows what appear to be "scrapers" that mechanically clean the bottom of the nozzles during a cleaning cycle by moving back and forth across the bottom surface of the nozzles.

This shows the sponge that runs across the full width of the printer at the 4 inch position. This printer has been used for some borderless prints, and the "end overspray" can be seen across the full length of the sponge. At the 4 inch position it can be seen that the opening over the sponge is enlarged to accept the "edge overspray" from the entire print head (about 15 mm), and the overspray from printing 4x6s can clearly be seen. At the far left edge of the previous photo, you can see the opening for the right edge of all paper sizes. These openings are why only certain paper sizes can be printed borderless even if you could hack the printer software - a full width slot must also be opened above the sponge in that position to avoid ink buildup that will transfer to the bottom of the following prints.

This shows the 13 inch, 11.7 inch (A3) and 11 inch cutouts. It also shows what happens when you mistakenly select a wide print with narrow paper - the ink just sprays onto surfaces where it will be picked up on the bottom of the next few sheets of wide paper. There were similar cutouts at the 5, 8.26 (A4) and 8.5 inch positions, but they are covered by the print head when it moves out when the cover is opened.

This is a similar photo at the far left - past the max paper width. The printer apparently sometimes elects to spray ink from all of the nozzles at this position. The reason that the left color band is wider is that there are 5 colors sprayed from the left set of nozzles (PM, Red, Black, Green and PC from left to right) while only 3 colors are sprayed from the right set of nozzles (Cyan, Magenta and Yellow).

Conclusions/Conjectures:
1. The overspray ink from borderless printing ends up in a sponge. This ink may or may not be fed to the waste ink tank. If it is, borderless printing will probably shorten the time until the "waste tank full" message appears.
2. Avoiding cleaning cycles will reduce the "ink tank full" problem, but not eliminate it, since ink is sprayed into the sponges even during normal printing. A heavily used printer can be expected to fill the waste tank more quickly than a lightly used printer, even if both have the same number of cleaning cycles.
3. It would not be surprising if the software assumes that there is some evaporation of the water in the waste ink over time, so a lightly used printer might theoretically never get the alarm.

Comments?

 

[Nifty]

gd, great post... again!

It is about time these companies started putting sponges down there (under the paper) instead of a metal bar or plastic. My HP and Lexmarks were such a pain because I'd often have (or create) situations where the ink would miss the paper and land on this surface, causing a big mess and a lot of smearing on the back of the next page.

The "wipers" have been around on the Canon's for a while. I remember watching my BJC-1000 do it's thing (it wouldn't stop printing or cleaning with the cover open) and watched these little squeegee men do their job.

Hopefully the next time someone has to go into their Canon to do a waste tank full cleaning they will take a TON of pictures of the WHOLE process.

 

[hseeng]

Just a note. I just took apart my HP 720 to clean it. I also uses wipers and a pickup sponge.
I found out after cleaning since it was apart that before and after every print the printer sprays out a little ink into the sponge. My HP printer is 6 years old and still going as a back to my i960.

I was amazed in how much black ink was built up. I looked into the corner where the head parks itself and realized there was a huge pile of dyed up old ink sitting there that acually was touching the botton of the print head as it went by. Thats why I cleaned it and reordered a sponge from HP for 95 cents.

The dried ink was just like black shoe polish. Hard but still kinda soft. The pile of ink from top to bottom was 3/4 inch high. A mini printer stalagmite.

Just watch out

 

[conrod]

I'm glad I found this forum - a mine of useful information!

I've just replied to another post regarding the yellow cartridge on an i950 turning black, which mine has suffered. Now having read this post, I think I can see the problem. I've just bought a Canon digital SLR, so for the first time have been doing a lot of borderless A4 photo printing on my i950. The leftmost pad is absolutely soaking with black ink - probably due to the borderless printing. So I'm guessing this has been picked up by the yellow printhead and has transferred itself through to the cartridge.

This raises a number of questions!

1) I haven't attempted to take the printer apart, so I don't know whether this is a single sponge or part of one long length. However, can it be removed and cleaned, and if so what's the best way to do this?

2) Does anyone know a source of replacement sponges in the UK?

3) Is this an occupational hazard with borderless printing? Should I avoid it? Is there any way to keep the border but reduce its width (to maximise the photo size after trimming)?

4) I've just supplemented the i950 with an i9100 for A3 borderless printing - am I going to have the same problem on the i9100?

5) Am I also running an increased risk of hitting the dreaded "ink tank full" problem with borderless printing?

Must go now and try to get the black ink off my test probes - aka fingers!

Conrod

 

[Grandad35]

Conrod,

Welcome to the forum.

Even though the leftmost pad is soaked with ink, I don't believe that the print head actually touches this pad. The pads shown on the far right in the first photo raise up into contact with the print head when the carriage is parked. When the printer runs a cleaning cycle, it pulls a vacuum on the heads, sucking ink from the nozzles into the sponges. I believe that it is these sponges that are the source of the dark ink and that need to be blotted (http://www.nifty-stuff.com/forum/viewtopic.php?id=47).

In answer to your questions:
1. I haven't done it yet myself.
2. Most people just wash the pad in soap and water, then dry it and reinstall it.
3. I don't think that your problem is related to borderless printing (the "parked position" sponges aren't involved in borderless printing), but I suspect that borderless printing will fill the pads/waste tank more quickly. There is an adjustment in the "Printing Preferences/Page Setup/Borderless Printing/Amount of Extension" that determines the size of the ink pattern. On my printer, the ink pattern is actually slightly smaller than the paper at the lowest setting.
4. I don't know.
5. I think so.

 

[conrod]

Thanks Grandad!

From the reply to the "Canon i950 Problem" post, it seems to be the parking pad on the RH side that was the problem. It looked dry, but was soaked with predominantly black ink.

Re borderless printing and overspray, I've found a good article by Mike Chaney (Qimage author) here:

http://steves-digicams.com/techcorner/March_2005.html

which confirms your answer no 3. The "Amount of Extension" control is indeed the way to minimise overspray and potential "ink tank full" issues. It would be useful if Canon explicitly mentioned the impact/consequences of overspray in the documentation for this control!

Many thanks for your reply.

 

[Craig Ross]

I,m not sure if the i950 is the same as my s9000 but I believe it is the overspray sponge drains
to a much larger pad that lays across the bottom of the printer as descibed on neil slades
website and it is this pad that requires cleaning after an ink waste full message. although
I've found blotting up excess ink from the overspay sponge certainly stops ink marking on the back of prints

 

[jofus54]

Where can i find pads for my ink tank on a Canon i860? Also looking for a manual

 

[fotofreek]

I am a bit confused about the "waste tank." I am using an I960. I do understand the vacuum system pulling ink into the pad at the far right when running a cleaning cycle and also that pad touching the print head in the park position. My question is - is there an actual receptical (tank) or is it merely the recess in which the pad sits and the "tank" is actually the absorbent pad? Also, since it is in plain sight and easily reached with something like a hemostat does it just lift out for replacement (or cleaning) or is some disassembly required? When doing the front panel buttons reset of the ink tank full counter can you simply blot the ink from the top of the pad or possibly do a few windex/blotting cycles to clean it enough while in the printer?

 

[Endmukbud]

According to what i know....the waste tank was a sponge... a wide enough sponge which could take a bout 75 or 100 ml of ink.....it usually located in the bottom area of your printer...covered by those complex mechanisme...and the vacuum pump...pull an ink from your nozzle then spray it to the " sponge " waste tank...
yes it's just a sponge and the pump was a centrifugal pump...you can not clean it just by put a windex on it....but i think the ink in the sponge will dry by it self....cause it tends to spread all over the sponge...and dry ( i have it mine like that ) i think it was 1 cm height and the wide is about to cover all your printer bottom side.....

Just like what Grandad said...

One thing that bother me also was, why i never got a waste tank full message...even if i print about 1500 page a month....???

oh..ya...one more...the pad bellow the paper which lie accross the printer....
which showed by the 2 and the 3 picture in grandad post...it was connected to the
waste tank...and it appears didn't always available on every type of printer

And how the could detect a waste tank full ??? by a ink sensor or dot counter ??