Tektronix PHASER 380, Service Manual

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Service Manual 5-17
Theory of Operation
5
Ink loader
The ink loader consists of four parallel channels with an ink melting element at
the end of each of the four channels. Ink sticks, one color loaded in each channel,
are pressed by constant force springs into the melting elements. The printer uses
pixel counting, melt rates, purge accounting and ink-level signals from the
printhead to determine ink levels in the printhead and when to activate the ink
melters.
As ink is required by the printhead, the printer positions the printhead under the
ink loader. Once the printhead is positioned, the appropriate color’s melting
element is activated for the appropriate amount of time to melt the end of the ink
stick to refill the color’s ink reservoir. The melted ink drips into the ink
reservoirs of the printhead underneath. Sensors in the ink loader alert the
customer to install more ink sticks before the current sticks are completely
consumed.
Figure 5-11 The ink loader
9661-133
Coil spring
Ink melt units
Ink stick
Ink out sensor
Printhead
Ink low sensor