Color Ink-Jet Print Head Operation - Olivetti JP 90 Service Manual

Listed below are some useful tips that will guarantee the optimum use of the print head:
- Remove the print head from its sealed container only when you are about to install it in the printer. The
print head has an 18-month warranty if stored in a sealed container, otherwise the warranty is reduced
to about six months (both warranty periods are cumulative).
- Never rest the print head on its nozzle or electric contact sides. Never rest the head on heat sources, air
conditioners, nor on dirty or dusty surfaces.
- If necessary (when the nozzles are clogged), run the nozzle cleaning function (turn to section 7.1).
This function forces ink through the nozzles to clear the passages, and will have to be run whenever one
or more nozzles clog.
- After a print job, tightly seal the nozzle bay so the nozzles are protected against dust and to avoid the inlk
from drying-out when exposed for a certain period of time. Since on the JP 90 this operation is carried out
automatically after a few minutes of printer inactivity, wait a few seconds before powering off the machine
after a print job.
If a blackout occurs while the printer is on, power off the printer and manually push the print head to its
farthest right-hand position.
Note: If after a print job the personal computer is powered off before the printer, the printer will reset itself.
If the printer is powered off during its reset phase, chances are that the print head may come to a
stop outside of its parking position.
It is therefore suggested to power off the printer before the personal computer.

1.8 COLOR INK-JET PRINT HEAD OPERATION

Color Ink-Jet Print Head
The color ink-jet print head is made up of an interchangeable sealed shell containing 51 print nozzles, three
liquid ink cartridges (one for each major color) and an electrical circuitry with 51 resistive heating elements
(see Fig. 1-7a).
The nozzles are divided among the three major colors as follows:
- Yellow: 18 nozzles
- Magenta: 17 nozzles
- Light blue: 16 nozzles
The nozzles are constructed in the same way as the ones on the monochrome ink-jet print head. They
are assembled on a nichel and gold compound referred to as electroformatted, and have a conical shape as
shown in figure 1-7b.
The ink is contained in three cartridges, one for each color.
A sponge inside each cartridge prevents the ink from being shaken during print head movements. This
avoids problems during carriage translations, avoids the ink from leaking out of the bleedholes and the forming
of froth.
The ink flows to the nozzles through small channels in the print head's resin layer. This layer is electrically
insulated from the heating elements.
Each heating element corresponds to a nozzle and is connected to the head's external electric contacts.
681640J JP 90 - Service Manual
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