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Most printers that print on wide paper (i.e. a meter wide or so) are inkjet printers. They work pretty much exactly the same as regular-
size inkjet printers, just scaled up in width. The same mechanism still works just fine, because regular-size inkjet printers already use a
small printhead that
slides on rails to be able to access the full width of the paper. All they have to do to make that capable of printing
on wider paper is increase the length of the rails, frame, and cables.
There are a few wide-format laser printers already [links]. They took the same approach of simply scaling up the existing mechanism in
width. That works, but not as well as it does for inkjet printers. In inkjet printers, the parts that need to be lengthened (steel rods, steel
stampings, flat flexible cables) are all cheap parts that are widely used in many industries, and are readily available in any reasonable
length. But in laser printers, the parts that need to be scaled up are mostly parts that are specific to laser printers (and usually specific
to each family of laser printers). These parts include the photoconductive imaging drum, the laser scanner (which also needs to be
enlarged in depth when being enlarged in width, due to geometric considerations), and the fuser.
A potentially advantageous alternative method for making a wide-format laser or LED printer would be to make it work more like an
inkjet printer: simply take the existing regular-width laser or LED printer mechanism, and mount it sideways in place of the inkjet
printhead on a rail-and-carriage system like that of a wide-format inkjet printer. (Actually, inkjet printers usually only have rails behind
the carriage, because the carriage isn't very deep. In this kind of printer, another rail supporting the front of the carriage is probably
The potential advantages over current wide-format laser printers that I've identified are:
- It should be less expensive, because the specialized parts are smaller.
- It should be less expensive, because the specialized parts can be shared with regular-width laser printers from the same manufacturer.
- It should be a lot easier to make one on a DIY basis, by using parts from a regular-width laser printer.
A disadvantage is that it will print more slowly than I assume existing wide-format laser printers do. However, it will print faster than
existing wide-format inkjet printers, because it prints a swath ~8.5" wide on each pass (or 11" with parts from existing 11"-wide laser
Xerox 6604/6605 wide-format laser printers
Mentioned in idea body. You can just barely tell from the maintenance section of the user manual that they use wide components. [notexactly, Dec 06 2019]
The Wide Format Company's wide-format laser printers
Mentioned in idea body. Lots of models. All seem to use wide components. [notexactly, Dec 06 2019]
||Hmm. You'll still have the issue of registration between the
swathes of print. And the thing you're moving will be quite
heavy. I'm not sure how the economics will work out: making
wider components versus adding a whole new mechanism to
move the narrower ones.
||I like this
If you print a 1-2 meter long 1 or 2 meter wide object does that mean you have to have a big 1-2 meter photodrum or is there a way around that with on the fly lasering of a narrower diameter drum, on the fly rewriting of the drum many times for a 2 meter sheet, spray on tonor and an amazingly effective squeegee to get the .1% of toner that would build up at repeated use?
||I do not know how they keep the drum clean now, if that can get just 4x cleaner then you could clean the platen on the fly
||Another possibility is a new kind of toner that does very specific bleaching, then you could squegee the mini-platen less and just use a cleaning squeegee to bleach the stray toner particles
||// You'll still have the issue of registration between the swathes of print. //
||Indeed. I assume inkjet printers have the same issue. In the ones I've taken apart (regular-
width ones only), I haven't seen any special mechanism for that. There's just a very finely
graduated optical encoder on the paper feed roller axle. They must rely on that being
perfectly parallel to the carriage rail, and the ink cartridges mounting perfectly
perpendicular to both of those.
||If it turns out to be a bigger issue, I have no doubt that printer companies are up to the
||I think maybe optical mouse sensors could be used, maybe one on each side of the paper
path, to track the motion of the paper and adjust for it (or maybe correct it, if the paper
path has a drive mechanism that can do that).
||// If you print a 1-2 meter long 1 or 2 meter wide object does that mean you have to
have a big 1-2 meter photodrum or is there a way around that with on the fly lasering of a
narrower diameter drum, on the fly rewriting of the drum many times for a 2 meter sheet,
spray on tonor and an amazingly effective squeegee to get the .1% of toner that would
build up at repeated use? //
||I don't know. I was thinking I'd find out once I built the machine, and then figure out a
solution at that time if it's a problem. Can existing regular-width laser printers print 12
m-long sheets of paper in one go? The ones I've disassembled generally have pretty narrow
drums, with a circumference much smaller than 11", so I expect they already do the
necessary stuff to reuse the drum within one page.
||Also, I was thinking of possibly using the mechanism out of a color laser printer (i.e. 4
drums, 4 laser scanners, 4 toner cartridges) on this kind of machine.
||//I assume inkjet printers have the same issue.// Yes and no.
One difference is that, if you use a sort of multi-pass laser
printer, the paper will expand and contract significantly with
each pass, due to heat, drying and ink deposition.
||Paper expands when wet with inkjet ink too. But as long as
the drive mechanism is pushing the paper toward the head,
and the paper is free on the output side, it shouldn't matter
because the paper between the drive roller and the head
will be dry and cool.
||// And the thing you're moving will be quite heavy. //
||Not that heavy - only a few hundred grams. But there is an issue of keeping a wider strip of paper perfectly flat under the platen. Using composites (which are very stiff) rather than metal would keep the mass and therefore inertia down.
||<Ruefully contemplates disassembled components of [MB]'s new laser printer/>
||You, er, weren't wanting to use that any time soon, were you ?