HL-6050/6050D/6050DN SERVICE MANUAL
3-29
2.6 Print
Process
2.6.1 Charging
The drum is charged to approximately 870V by an ion charge which is generated by the
primary charger. The charge is generated by ionization of the corona wire, which has a DC
bias from the high-voltage power supply applied to it. The flow of the ion charge is controlled
by the grid to ensure it is distributed evenly on the drum surface. The aluminum drum sleeve
in the photosensitive drum is grounded.
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Fig. 3-35
The primary charge uses a corona wire, but since the drum is positively charged, only less
than 1/10 of the usual quantity of ozone is generated compared with the negatively charged
drum. The level of ozone expelled from the printer is therefore not harmful to the human body.
Applicable safety standards have been complied with.
2.6.2 Exposure
stage
After the drum is positively charged, it is exposed to the light emitted from the laser unit.
Fig. 3-36
<Laser exposure unit>
The HL-6050 series printer has a twin laser beam unit to get a resolution of 1200 dpi x 1200
dpi at full-speed printing (A4/LETTER: 24/25 ppm).
1. The two laser beams radiated from a laser diode inside the laser unit are concentrated
into a constant width by a slit in the CO lens cell and then reflected by a polygon mirror
rotating at high speed.
Drum
Lens
Laser beam
Polygon mirror
Paper
Laser detector
Laser diode
Motor
Laser beam
f
θ
lens
Aluminum drum sleeve
Organic photoconductor layer
Photosensitive
drum
Voltage
regulator
870V
Grid
HVPS
Corona wire
