How is ink level determined?

[stratman]

And still pre-chip cartridges with just a prism to assist guidance of ink level monitoring was not the proximate or indirect cause of burned out print heads.

Residual ink was a non-issue for the refiller. Ten percent, twenty percent - so what. I'm refilling.

Without the dissatisfaction of some inkjet consumers, the evolution of chips may have been delayed by years and the whole rigamarole of defeating the chip when refilling averted for some time.

It is always the few who ruin it for the many. The law of unintended consequences. Put another way, the road to Hell is paved with good intentions. Thanks complainers.

On the bright side, this forum would have far fewer posts to enjoy were the chip delayed, and, Precision Colors would have fewer items for refillers to buy. Lord knows we like our gadgets.

 

[stratman]

If Canon were devious printer would detect a change from empty reservoir to not-empty and refuse to print since that means you refilled it.

How would that work with a reset EEPROM chip?

 

[The Hat]

These routines have also been revised throughout the generations and only Canon firmware engineers would know the details. All we can do is observe and surmise.

I have used CLl-8 carts in a CLl-521 printer for years and these larger carts have never caused a single issue or error to occur with the printers’ memory, the prism works when it should and the printer has never got it wrong yet.

It’s got to be remembered that the final countdown is only taken when the prism signals the reservoir is empty and the calculation of how much ink is held in the sponge at that point never varies, all this information is based on an untampered cart and not a refilled one.

But all of this means nothing to a user who’s refilling their OEM carts, because a refilled cart has more ink in it that a new cart has and we always advocate changing the cart when the reservoir is empty, so none of this applies to the refill club and our print heads should always stay safe, in theory...

 

[mikling]

Yeah, they don't have VW engineers.

Bosch was the cook. Now who served that meal? VW? We'll never know for sure.

 

[Tin Ho]

I once put my Pro-100 aside for a long while. The next time when I turned it on trying to use it I found almost all cartridges were completely empty. I don't remember they were so empty before I put the printer aside. I suspect the print head somehow sucked the ink out of the cartridges and the ink ended up in the waste tank.

I can't explain and have no proof of this. But I really can not believe all my carts were bone dry before I put the printer aside for something like 2 months. If the print head did suck out my ink it probably will mess up ink level tracking by the printer.

 

[The Hat]

The next time when I turned it on trying to use it I found almost all cartridges were completely empty

It's more likely that your purge unit was not in the best condition before you set the printer aside, and the residue on the pads reacted by capillary action to slowly empty each of the carts in turn, that’s known to happen.

Now that all the carts are empty you’ll need to either refill or get new ones, but before you do that you should spend a bit of time cleaning the purge unit and surrounding area so the same thing can’t happen again to you overnight...

 

[Tin Ho]

Does that happen to almost new Pro-100? My printer had not printed much after buying it new. The cartridges were OEM cartridges. I don't really think I had emptied almost all of them before I put the printer aside. I have since refilled the original cartridges. The printer did a long cleaning cycle by itself. The nozzle check turned out to be normal and the printer printed fine afterwards.

Since the printer is so new should I mess with the purge unit still? It seems to do the cleaning cycle fine. Do you mean I should empty the purge unit by running some cleaning cycles? How will this make a difference to the purge unit? If the purge unit is indeed emptied so that it stops the capillary action will the purge unit provide the same protection to the print head to keep it from drying out?

I do suspect that it is a capillary action of the purge unit. But it did not happen over night. It happened over a period of about 2 months. I never experienced this with my older printers before. It's weird. And it is dangerous for long term storage for the printer.

 

[Tin Ho]

I was once a frequent visitor of this forum years ago. My understanding of how ink level is determined is mostly learned from this forum. Here is what I learned:

The chips on the OEM carts have memory chips (EEPROM?) on them. The initial data in them are interpreted by the printer as ink level being full. Every time the printer prints the nozzle firing count is recorded into the chip. The printer reads the chip before printing a job and the data are translated into the ink level displayed on the ink level status window. When enough firing count is recorded the data will be translated into near empty eventually. The counting will continue and when it reaches empty the printer will stop printing.

The prism is an extra insurance provider. If ink leaks out of a cart for any reason the chip of the cart will not reach empty before the cart is emptied. The prism and the IR detector of the printer will work together to detect that the cart is empty. This detection is mechanical and is independent of the chip. If you refill the carts without resetting the chips the ink level status will no longer be accurate. The printer simply disables the ink level status when it detects that you are refilling the carts. At this point you are pretty blind in terms of ink level in the carts. Besides it was said that the IR detector is also disabled by the printer. The printer will not detect empty reservoir any more.

This is when you will consider replacing OEM carts with aftermarket refillables that come with ARC. Aftermarket carts with ARC have a different set of issues. I stick to refill my OEM carts now. I keep an eye on my carts and keep them topped off from time to time.

 

[apetitphoto]

Pretty close to how I would implement it, @Tin Ho . When you reset the chip it gets loaded with FULL. Each time you print with that cart you lower the volume. When the volume reaches EMPTY, you stop printing. The mirror mechanism is a fail safe that is used to indicate ALMOST_EMPTY at which point you set the volume to ALMOST_EMPTY and decrease it based on use until it hits EMPTY. Which is pretty much what you said. This is not a complex process.

 

[mikling]

The carts are open to the atmosphere and still subject to drying out from no use. Keep leaving printers with carts near empty and not using the printer and then you are looking for clogged heads when the carts dry out enough and the ink recedes back into the dried out cart.

All Canon carts will eventually dry out if left open to the air especially when they are near empty. Why? Much higher air volume to breathe and expand and contract due to pressure and temp fluctuations.

Think about it, the buffers in the serpentine help but do not eliminate this issue.