How does borderless printing work?

[RCC]

This question is just for interest really, but generally I find the
better you understand how things work the better you can use them.

My (very) old printer was not designed for borderless printing. If you
set print area to maximum rather than standard, and printed photos, it
often made a mess of the paper edges and sometimes the feed rollers. To
be fair, the dialogue box does warn against doing that.

My new printer has a borderless setting. As it is impossible to
guarantee that the paper feeds exactly against the right hand guide, or
even exactly square (by exactly I mean to 1/32 inch perhaps) how does
the printer deal with borderless and how does it avoid getting ink in
the paper transport mechanism?. Do the print heads have some sort of
edge sensor, or is it a mixture of magic and luck?

 

[me]

This question is just for interest really, but generally I find the
better you understand how things work the better you can use them.

For the most part the image is over expanded to ensure the "printed page"
is filled.

 

[Bob AZ]

�Do the print heads have some sort of

edge sensor, or is it a mixture of magic and luck?

Richard

My Epson 4800 seems to have Borderless printing somewhat defined. I
see it measure the width and length of the paper on the fly. I have
set the parameters for a particular papers' width and length, and the
dimensions of the paper are not quite that, and the printer will
refuse to print. (Must be an easier way to say this) The printers
selectivity for dimension seems to be in the 1/100ths of an inch. I am
not sure of the Epson specs if there are any.

Bob AZ

 

[Arthur Entlich]

The process is pretty much unchanged from your earlier printer. The
main difference is the mess is better handles. There is usually an ink
pad below the paper on the print platen to absorb the overspray of ink.

Also, the drivers have been adapted to decrease the amount by which the
image is enlarged beyond the paper size, to lessen the amount of ink
that is not reaching the paper.

Lastly some changes were made in the paper handling and head design such
that the heads are less likely to get caught on the paper edges.

Art