Electrophotographic Process (Ep Process); Printhead; Step 1: Charge - Konica Minolta bizhub 4020 Service Manual

Rollers

12.6 Electrophotographic process (EP process)

12.6.1 Printhead

The printhead scans the photo conductor drum surface with a laser beam. It consists of the following
components:

Laser diode (LD) board assembly

Oscillator

Start of scan board assembly
When a laser beam is scanned across the photoconductor drum surface from one end to the other
while turning on and off the beam, one line of latent image is created. If the scanning by the laser beam
is repeated while rotating the drum, a two-dimensional image is created. The resolution in the scanning
direction (from right to left) is determined by the rotational speed of the printhead motor, depending on
how quickly the laser is adjusted. The resolution in the process direction (from top to bottom) is
determined by the rotational speed of the printhead motor. The higher the scanning speed becomes,
the sooner the scanning of the next row can be started.

12.6.2 Step 1: Charge

During the charge step, voltage is sent from the HVPS to the charge roll beside the photoconductor.
The charge roll applies a uniform negative charge over the entire surface of the photoconductor to
prepare it for the laser beam.
bizhub 4020/3320 Service Manual
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