Lsu (Laser Scanner Unit) - Xerox Phaser 3300 Servce Manual

Theory of Operation

LSU (Laser Scanner Unit)

Item
Resolution
Spot Size Main
Sub
Variation
Laser Property Wavelength
Power
Vignetting
θ
Magnification error
f Property
Partial Magnification error
2-16
Safety Features
To prevent overheating
1st protection device: H/W cuts off when detecting an overheating
2st protection device: S/W cuts off when detecting overheating
3st protection device: Thermostat cuts off power to the lamp
Safety device
Fuser power is cut-off when the front cover is open
LSU power is cut off when the front cover is open
The temperature of the fuser cover's surface is maintained at less
than 80ºC to protect the user and a caution label is attached where
the customer can see it easily when the rear cover assembly is
opened.
The LSU unit is controlled by the video controller. It scans the video data
received from video controller with laser beam by using the rotation principle
of the polygon mirror to create a latent image on the OPC drum. It is the core
part of LBP.
The OPC drum rotates as the same speed as the paper feeding speed. It
creates the /HSYNC signal and sends it to the engine when the laser beam of
the LSU reaches the end of the polygon mirror, and the engine detects the /
HSYNC signal to arrange the vertical line of the image on the paper. After
detecting the /HSYNC signal, the image data is sent to the LSU to arrange the
its margin on the paper.
Each facet of the polygon mirror scans a single line.
Specification
Real 600 dpi
75 + 20/-20
85 + 25/-25
μ
40
785 + 10/-15 nm
0.33 mW
Min 80%
Max 0.7%
max 1.5%
μ
m
μ
m
μ
m/50 m
±
0.02 mW
Item
main direction x sub direction
-beam diameter at the level
of 1/e2 of intensity
-at the spot location of 0,
±
100 mm of image height
main/sub, within image height of -
100 ~ +100 mm range
at 25 °C
at the center of image on
the focal plane, with stationary
condition, power supplied
at DC 5 volt
spot power variation within image
height of -100 ~ +100 mm
based on the printable area,
216 mm
based on the 2.54 mm width within
the printable area,
216 mm
Phaser 3300MFP Service Manual