Manufacturers
of ink jet printers have traditionally focused on the small office/home
office market. In the past few years, however, a new class of
up-scale ink jet printers have come to market. This type of printer
is used primarily for creating wide format posters and signs,
bar coding, name tags, and photo quality prints. There are very
few serious players in this market, with HP, Epson, and Lexmark
leading the pack. For use in a business environment, these machines
should include Ethernet compatibility and a high duty cycle of
5,000 pages or more.
Drop-on-demand ink jet printers
Inkjet printers in this segment of the market use a technology
called drop-on-demand. There are two kinds of drop-on-demand technology:
thermal (HP, Lexmark, Canon) and piezoelectric (used only by Epson).
Thermal printers use a tiny resistor to heat up the ink in each
nozzle located in the printhead. In each printhead there can be
anywhere from 300 to 600 nozzles that vaporize the ink and transfer
it to the paper. Piezoelectric technology produces the same result,
but uses small crystals to transmit the ink to paper. With improved
ink quality, both approaches work amazingly well.
Printheads
The printhead contains the nozzles used to spray ink onto the
paper. The spacing of the nozzles determines the resolution of
the printer. A printer with a resolution of 600 dpi (dots per
inch) has 600 nozzles per inch. One problem that can occur with
an ink jet printer is the printhead becoming clogged, especially
when not in use frequently. In this case the ink has dried on
the printhead, and the solution is to clean the head with an approved
cleaning solvent for this purpose. Notably, newer ink jet printers
have a self-cleaning function.
Ink cartridges
Older machines used three basic colors - cyan, yellow and magenta
to print color, which were combined to produce black. New inkjet
printers use separate cyan, yellow, magenta and black. Depending
on the machine you purchase, the three color inks can be combined
into a single cartridge or can be separated into independent cartridges.
Individual cartridges can be less expensive in the long run as
you just have to replace the single color, instead of the entire
3-color cartridge which may have remaining ink.
In certain cases the ink cartridge and the printhead are integrated together. This has the benefit of ensuring that there is a clean printhead every time the ink is replaced. However, it can also increase ink cartridge cost.
