Leibinger JET3, Руководство пользователя

Страница: 43 / 233

Group 6 Operation – Functional principle Page 43
Release R1.03e LEIBINGER JET3
6.2.3 Drop charging
In order to be able to charge the drops it is necessary for the ink to have electrical
conductivity. This is possible through the use of specific salts that dissociate in the
solvent used. The drop brake-off point of the modulated jet is automatically set in
such a manner that this happens inside the charging electrode.
The drops can now be charged up by creation of voltage between jet and charging
electrode, because they are given a negative charge through the charge shift
resulting in the charge electrode gap. A specific charge voltage is clearly allocated
for each drop charge.
6.2.4 Drop deflection
After the drops have left the charging electrode they fly through an electrical field.
Here, those droplets that were previously charged in the charging electrode are
deflected. The drops that have not been charged fly straight ahead into the gutter.
Here they are sucked up and fed back to the circular flow of ink. The charged drops
are only deflected in one direction, the other direction is performed by the product
to be inscribed.
6.2.5 Creation of a character
Each character is defined by a two-dimensional matrix, e.g. 7 x 5. An ink drop can
be assigned to every point of intersection. The character is formed by deflecting the
ink drops in a vertical direction and by moving the product which is to be imprinted
horizontally. The ink drops which are not to be positioned are not given electrostatic
charges in the charging electrode, and pass through the electrical field without
being deflected and on into the gutter tube. The controller (CPU) of the printer
calculates the values which are required for the generation of charging voltages of
the single characters.