English
User’s Guide 25
Each of the jets is constructed with a heater, a supply of ink in
the jet and an opening where the ink is expelled. When a
command is sent to the ink cartridge to place a drop of ink on
the media, the heater switches on and heats the ink until the ink
expands into a bubble. As the bubble expands, the ink is then
expelled out of the nozzle onto the media.
The heating and expulsion of the bubble of ink takes place in a
matter of a few nano-seconds.
Technical Data

Printing system

The OKIJET 2500 printer accepts 2 different print heads; a 128 jet
black only, and a 120 jet segmented four Colour Print Head. The
system uses a scanning carriage in conjunction with a precision
paper advance mechanism to position the paper prior to being
marked by the ink jet.

Ink jet technology

The ink jet technology used in the OKIJET 2500 is called a Thermal
(Bubble) Drop-On-Demand (DOD) Ink Jet. The principles of this
type of ink jet are as follows:
All data sent to the printer is converted to raster data. Raster data is
essentially a string of 1s and 0s that are translated into drops of ink
across a scan line. As the carriage travels across the media, the
black and colour ink cartridges place drops of ink on the media as
directed by the data sent to the printer.
There are 24 ink jets for each of the three colours (Cyan, Magenta
and Yellow) and 48 for Black, giving a total of 120 jets on the four
colour ink cartridge. The black cartridge contains 128 ink jets.
2500ugb.p65 02/06/98, 11:3325