
306
G I D 2 0 0 0
Model Name:
RJ–4100
G I D 2 0 0 0
Model Name:
RJ–4100
Principles of Operation
Principles of Operation
Principles of Operation
1. Ink ejection principle
The printing system of RJ-4100 Series heads is an on-demand piezoelectric operated system. The principle of this system is that, using the vibration of a piezo element,
ink enters the flow path and the path expands and contracts when the piezo element vibrates, ejecting the ink.
Therefore, when the head is to be used in a stable condition, it is vital that the ink enters and remains in the flow path in a stable condition. Also, at the leading edge of
the head (the ends of the nozzles) it is extremely important that the ink is kept in a condition (meniscus) such that it can be ejected at any time.
2. For stabilizing and ejecting ink
So long as the meniscus of the nozzle section is kept in a constant condition, the piezo head ought to be capable of stable ejection throughout its physical life. However,
the ink is not being ejected from the nozzle at constant intervals. In the periods when there is no ejection, the ink hardens in the nozzle and the meniscus may be
destroyed.
Therefore, restoring these conditions is a mandatory requirement for using the piezo head in a stable condition. Accordingly, a piezo type system is provided with a clean-
ing unit and it would be no exaggeration to say that the reliability of the cleaning system is more important than the ejection. (Causes of nozzle clogging include dust and
hardening of the ink that has been left too long.)
3. Printing sequence
The piezo head is most stable when ink is being ejected regularly. Therefore, ink is ejected from all nozzles at certain regular intervals during printing. Naturally, it would
be wrong if this were to be ejected onto the media so a place for this ejection is provided near the cleaning unit. (For flushing: the flushing box)
4. Initial filling operation
After the user has purchased a printer, this operation is required once only and it is intended to enable the head to print by filling the head with ink from the ink cartridges.
ink filling uses the cleaning unit pump motor to suck ink from the ink cartridges until it arrives at the head.
5. Cleaning and strong cleaning
This operation is to restore the head to normal condition by removing any foreign matter clinging to the head face or when the ink at the ends of the nozzles has hard-
ened.