Brother HL-4200CN, Service Manual

Page: 99 / 366

III-35
5.8 Xerographics
5.8.1 Major functions
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Scanner ASSY
Scanner ASSY (raster output scanner assembly) is an exposure unit to generate laser
beams to form electrostatic latent image on the drum surface.
In this manual, the scanner ASSY is referred to as scanner ASSY.
The scanner ASSY mainly consists of the following parts:
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LD ASSY
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Lens
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Scanner ASSY
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Mirror
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SOS PWB
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Window
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Print head cartridge ASSY
Print head cartridge ASSY carries out a series of operation in the print process such
as charging, developing and transfer.
Print head cartridge ASSY mainly consists of the following parts.
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Drum (Y)
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Developer (Y)
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Drum (M)
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Developer (M)
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Drum (C)
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Developer (C)
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Drum (K)
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Developer (K)
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RTC (Y)
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Refresher (Y)
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RTC (M)
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Refresher (M)
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RTC (C)
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Refresher (C)
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RTC (K)
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Refresher (K)
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IDT 1 (2)
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IDT 2
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IDT 1 cleaner (2)
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IDT 2 Cleaner
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Chute REGI (REGI clutch)
The chute REGI is composed of the REGI clutch, REGI roll and metal roll.
Drive from the drive ASSY main is transmitted to the REGI roll through the REGI
clutch. Feeds paper from the tray, MSI and duplex path in the print head cartridge
ASSY direction. When the paper tip reaches the chute REGI, the chute REGI has the
paper make a loop until the REGI roll starts rotating and correct the skew (feeding the
paper in inclined condition) of the tip of the paper.
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Sensor photo (REGI sensor)
Detects that the paper tip has reached the chute REGI.
(Paper present: Beam is received)
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OHP sensor
As plain paper scatters the radiated light, the OHP sensor can capture the reflected
light to detect the paper. The OHP paper scarcely scatters the radiated light, and
therefore the OHP sensor cannot capture the reflected light. Thus, whether the paper
fed from MSI is plain paper or OHP paper is judged.