Davin J012, Руководство по обслуживанию

Страница: 300 / 365

This is done with pressure. At the prescribed time, an electric charge is applied to the PZT. This makes the
PZT expand. The expansion of the PZT puts pressure on the ink below. This makes the ink move in both
directions. The ink on the right is forced out the ejection port.
This device is unique. Other printers on the market use small heaters that form bubbles to eject ink from the
ports.
Ink Near End
The printer detects ink near-end in two ways:
• The printer software maintains a count of how much ink is consumed from each cartridge and signals
near-end when a cartridge is nearly empty.
• As a backup method, the ink level sensor monitors the positions of the ink level levers on the sides of
the ink tanks. This is described below.
Each print head in the ink tank unit [1] has a ink level lever This lever presses against a spring loaded
bellows in the center of the print head tank. The right side of each tank is constructed of flexible plastic:
• As ink enters the tank, the pressure of the ink pushes against the side of the tank and moves the lever
away from the side of the print head tank.
• As ink is consumed during printing, the vacuum created by the ink leaving the tank pulls the lever
toward the side of the print head tank.
The ink level sensor [2], mounted above the front guide rail, checks the left and right positions of the ink
level levers [3] and [4] every time the carriage passes.
When the ink level sensor detects that a lever is completely flat against the side of the tank, the printer sends
a prescribed amount of ink to the tank from the ink cartridge.
The sensor signals the ‘ink near-end’ if the ink level lever does not return to the full position (away from the
side of the tank) within the prescribed time after the printer requests a refill from the ink cartridge.
Print Heads
299
6