Inkjet ink level sensing?

D

DaveC

Guest
One source I found says that Canon uses light from an LED--bounced from a
prism at the bottom of the cartridge after ink is depleted--to trigger the
"Empty" signal. Epson apparently counts the spurts of ink and calculates the
arrival of "empty".

I couldn't find how HP do this. Anybody know?

Thanks.
 
In article <0001HW.D11FE2B10634B0ABB01029BF@news.eternal-september.org>,
invalid@invalid.net says...
One source I found says that Canon uses light from an LED--bounced from a
prism at the bottom of the cartridge after ink is depleted--to trigger the
"Empty" signal. Epson apparently counts the spurts of ink and calculates the
arrival of "empty".

I couldn't find how HP do this. Anybody know?
Click to expand...

I believe HP just estimates based on the cartridge type it detects, and
the amount of ink it uses.

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On Fri, 6 Mar 2015 23:03:13 -0800, DaveC <invalid@invalid.net> wrote as
underneath :

One source I found says that Canon uses light from an LED--bounced from a
prism at the bottom of the cartridge after ink is depleted--to trigger the
"Empty" signal. Epson apparently counts the spurts of ink and calculates the
arrival of "empty".

I couldn't find how HP do this. Anybody know?
Click to expand...
Any inkjet that uses chipped cartridges guestimates the emptiness. Old
Canon printers certainly used the reflective prism, IP4000 was about the
last that had unchipped carts. and thus had an accurate end level
warning. I think most printers now would guestimate on the safe side
judging by the complaints of half full carts being classed as empty. I
dont know if Canon still uses the prisms on their modern chipped carts
but I would think probably not as the guestimate method gets you to buy
more ink earlier! Someone with one of the more modern Canons will know
Im sure! ... HP have had chips since very early days so levels will be
guestimated by software. C+
 
On Fri, 6 Mar 2015 23:03:13 -0800, DaveC <invalid@invalid.net> wrote:

One source I found says that Canon uses light from an LED--bounced from a
prism at the bottom of the cartridge after ink is depleted--to trigger the
"Empty" signal. Epson apparently counts the spurts of ink and calculates the
arrival of "empty".

I couldn't find how HP do this. Anybody know?
Click to expand...

HP has two methods. One is to just guess based on usage:
<http://support.hp.com/us-en/document/c00216780>
The other adds an expiration date to the cartridge:
<http://support.hp.com/us-en/document/c01764161>
Both suck.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
On 08/03/2015 1:22 AM, Charlie+ wrote:
On Fri, 6 Mar 2015 23:03:13 -0800, DaveC <invalid@invalid.net> wrote as
underneath :

One source I found says that Canon uses light from an LED--bounced from a
prism at the bottom of the cartridge after ink is depleted--to trigger the
"Empty" signal. Epson apparently counts the spurts of ink and calculates the
arrival of "empty".

I couldn't find how HP do this. Anybody know?

Any inkjet that uses chipped cartridges guestimates the emptiness. Old
Canon printers certainly used the reflective prism, IP4000 was about the
last that had unchipped carts. and thus had an accurate end level
warning. I think most printers now would guestimate on the safe side
judging by the complaints of half full carts being classed as empty. I
dont know if Canon still uses the prisms on their modern chipped carts
but I would think probably not as the guestimate method gets you to buy
more ink earlier! Someone with one of the more modern Canons will know
Im sure! ... HP have had chips since very early days so levels will be
guestimated by software. C+
Click to expand...
My old(?) Canon MP 620 uses chipped cartridges as far as I know and when
I get an empty signal -the cartridge is fully emptied.



--
Don Kelly

remove the 'cross' to reply directly
 
On Wednesday, March 11, 2015 at 1:04:41 AM UTC, Don Kelly wrote:
On 08/03/2015 1:22 AM, Charlie+ wrote:
On Fri, 6 Mar 2015 23:03:13 -0800, DaveC <invalid@invalid.net> wrote as
underneath :

One source I found says that Canon uses light from an LED--bounced from a
prism at the bottom of the cartridge after ink is depleted--to trigger the
"Empty" signal. Epson apparently counts the spurts of ink and calculates the
arrival of "empty".

I couldn't find how HP do this. Anybody know?

Any inkjet that uses chipped cartridges guestimates the emptiness. Old
Canon printers certainly used the reflective prism, IP4000 was about the
last that had unchipped carts. and thus had an accurate end level
warning. I think most printers now would guestimate on the safe side
judging by the complaints of half full carts being classed as empty. I
dont know if Canon still uses the prisms on their modern chipped carts
but I would think probably not as the guestimate method gets you to buy
more ink earlier! Someone with one of the more modern Canons will know
Im sure! ... HP have had chips since very early days so levels will be
guestimated by software. C+
My old(?) Canon MP 620 uses chipped cartridges as far as I know and when
I get an empty signal -the cartridge is fully emptied.



--
Don Kelly

remove the 'cross' to reply directly
Click to expand...


On my old Canon ip4300 printer the ink level can be seen through the
clear plastic of the cartridge,unlike my Epson BX525WD multifunction
printer.


Doug.
 
On Wed, 11 Mar 2015 19:03:25 -0700 (PDT), doug.morsit@gmail.com wrote as
underneath :

snip
On my old Canon ip4300 printer the ink level can be seen through the
clear plastic of the cartridge,unlike my Epson BX525WD multifunction
printer.
Click to expand...
Yep, any (prism) level measurement in the visible spectrum would need
clear cartriges! Nearly all modern OEM carts. are black or an opaque
colour! C+
 
Yep, any (prism) level measurement in the visible spectrum would need clear
cartriges! Nearly all modern OEM carts. are black or an opaque colour! C+
Click to expand...

Or a vertical light path from the led chip on the bottom of the cartridge, up
through the (now) empty cartridge, reflecting off of a prism inside the top
of the cartridge back to a receiver on the same chip as the LED is mounted.
 
On Thu, 12 Mar 2015 07:01:31 +0000, Charlie+ <charlie@xxx.net> wrote:

On Wed, 11 Mar 2015 19:03:25 -0700 (PDT), doug.morsit@gmail.com wrote as
underneath :
On my old Canon ip4300 printer the ink level can be seen through the
clear plastic of the cartridge,unlike my Epson BX525WD multifunction
printer.

Yep, any (prism) level measurement in the visible spectrum would need
clear cartriges! Nearly all modern OEM carts. are black or an opaque
colour! C+
Click to expand...

Not exactly. There are more than a few problems.

Most older cartridges have open cell foam inside to prevent sloshing
in transit. Kinda difficult to design a liquid level sensor that
works in foam. Neither dye or pigment type inks are very conductive,
so that's not going to work.

Some carts don't have any foam and are often clear or at least
translucent. However, they are usually used with dye type inks, which
are optically transparent. So, that's not going to work.

Older HP color carts have 3 colors in one cartridge. 3 sets of
optical sensors in one cart isn't exactly economical or practical.

Optical sensing might work with pigment type inks, but I suspect the
optical transmission characteristics will vary with the color. Also
yellow is nearly transparent.

There is one place where optical sensing works... laser printers. The
toner is optically opaque. Brother printers have windows on each end
of the cartridge. Then the light can be seen through the cartridge,
it's considered out of toner. The problem is they located the windows
a bit too high on some printers. I forgot the model, but one of their
older color laser printers leaves about 25% in the cartridge when it
claims it's empty. The fix is to put some electrical tape over one of
the windows.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
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