Laser Exposure; Figure 5-5 Laser Exposure Of The Photoconductive Belt - Tektronix PHASER 560 Service Manual

5
Theory of Operation

Laser exposure

5-8 Phaser 560 Color Printer
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As the photoconductive belt rotates, the uniformly charged portion of the belt is
exposed by the modulated laser beam. As the vertically-moving belt passes in
front of the horizontally scanning laser beam, negative charges on the belt
surface are neutralized where exposed by the beam. This forms a latent image
on the belt. The laser beam is turned off for "non-written" portions of the image.
The power of the laser beam is varied from 0.4 mW to 0.5 mW depending on
whether the printer is printing in 1200 dots per inch (dpi) mode or 600 dpi mode.
Following laser exposure, the negative potential of the belt varies from -500 volts
or -540 volts (unexposed) to -10 or -20 volts (fully exposed).

Figure 5-5 Laser exposure of the photoconductive belt

manuals search engine
Laser scanner
The laser beam
selectively neutralizes
some of the negative
charges on the belt
surface.
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