Lote 5

The printer comprises four main assemblies:

• Cabinet

• Printhead

• Electronics system

• Ink system

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Cabinet

Figure 6-1. Printer Cabinet

The 43s cabinet is constructed of stainless steel. The following additional features are integrated into this structure:

• The ink and top up reservoir caps (1) are provided for easy filling of the internal reservoirs. They are constructed of a plastic

material.

• The electronics compartment door (2) is mounted on two hinges and its seal is water resistant when closed. A locking mechanism and compartment key prevent unauthorized access to the

potentially lethal voltages housed here. See “Control Electronics”

on page 6-14 for more information on the contents of this compartment.

• A vent (3) allows cooling air to enter the cabinet through a filter element.

• The control panel (4) provides the user interface to the printer. See

“Control Panel” on page 6-9 for more information.

• The ink system compartment door (5) is mounted on two hinges and its seal is water resistant when closed. See “Ink System” on

(1) Ink and top up filler ports

(2) Electronics compartment door (3) Vent (on right side) (4) Control panel

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page 6-42 for more information on the contents of this compartment.

• The umbilical that connects the printer cabinet to the printhead is attached to the cabinet via a threaded fitting, secured with

appropriate nuts and washers.

• The connector panel provides inputs for several types of external devices. See “Connector Panel” on page 6-11 for more

information.

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Printhead

Figure 6-2. Printhead

Construction

The printhead consists of a chassis on which are mounted the following components:

• The nozzle assembly (4) which forms the ink into a stream of droplets as described below:

The jet valve (17) delivers ink from the ink system to the nozzle assembly.

The bleed valve (18) mounted on the heater module block is normally closed, only opening during purging, flushing of the nozzle and start up and shutdown.

The bleed valve when energized removes air from the feed and return pipework and the nozzle when being purged.

A vacuum is also applied through the bleed valve to the nozzle during a nozzle flush.

The ceramic transducer (11) is fed with a modulation signal. The transducer causes the nozzle assembly to vibrate along its length

1 3

(1) Ground potential deflector electrode (2) Phase detector

(3) Charge electrode (4) Nozzle assembly (5) Cover switch (6) Knurled screw (7) Rear cover (13) LED

(8) Head manifold (14) High voltage deflector electrode (9) Umbilical (15) Gutter

(10) Gutter detect(16) Front cover (11) Ceramic transducer(17) Jet valve (12) Nozzle jet orifice(18) Bleed valve

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so that the ink stream from the nozzle jet orifice is formed into individual droplets.

The nozzle jet orifice (12) has a diameter of 60 microns.

• The Light Emitting Diode (LED) (13) is located behind the charge electrode (3). The LED is strobed at the modulation frequency so that the position of individual droplets can be observed with a magnifying glass (x10 minimum). The charge electrode applies an electrical charge to each individual ink droplet. The charge

applied to the droplet is variable and affects the position of the droplet on the substrate.

• The phase detector (2) senses the strength of the electrical charge applied to the ink droplets and adjusts the charge pulse timing accordingly.

• The ground potential deflector electrode (1) and the high voltage deflector electrode (14) are parallel rectangular plates. The

deflector electrodes generate a constant electrostatic field through which the electrically charged ink droplets pass. The charged ink droplets are deflected by the electrodes, the amount of deflection is dependent on the charge applied to the ink droplet.

• The gutter (15) is the return path for ink droplets which are not used for printing. The gutter delivers the ink back to the ink system.

• The front cover (16) is secured to the printhead by a knurled screw (6). The front cover protects the printhead components. Removal of the cover is sensed by the printer via the cover switch (5). When the cover is removed the voltage to the deflector electrodes is turned off.

• The rear cover (7) protects the printhead internal electrical wiring and ink system tubing.

• The umbilical (9) contains the electrical wiring and ink system tubing from the printer.

• The head heater (8) maintains the temperature of the ink; it consists of a heating element and a temperature sensor.

• The jet valve (17) is mounted on the heater module block. The valve is open whilst printing and closed during the flushing cycle.

• The gutter detect (10) senses when ink is present in the gutter. It’s ink feed tubes are metallic and a signal is fed to one of them. A signal return lead is connected to the other. When ink (which is conductive) is present, the signal passes through it to the return lead. The gutter detect signal is then fed, via the umbilical, to the I/O board in the electronics system.

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Wiring diagrams for the printhead electrical and ink systems are shown in Figure 6-3 and Figure 6-4.

Figure 6-3. Printhead Electrics and Ink System Wiring Diagram

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Figure 6-4. Wire routing under printhead manifold block

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