Epson EPL-5800, Service Manual

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EPSON EPL-5800 Revision B
Operating Principles Operating Principles of Mechanism 50
2.1.4 Exposure Process
The laser beam from the print head creates an electrostatic latent image on the OPC drum
surface.
The following control is performed in order to find appropriate timing to print the image.
Figure 2-6. Exposure Mechanism
SUB SCANNING DIRECTION
(VERTICAL SCANNING DIRECTION)
!
When the printer receives the PRINT signal, the polygon motor (M3) and the main
motor (M1) rotate, and the main motor (M1) starts the paper feeding operation.
!
When the specified period of time passes after the end of fed paper turns the paper
feed sensor ON (TOD signal), the main control board sends the VIDEO signal to
the print head, and printing starts.
!
When moving on from the first line to the second line, the print starting position is
shifted down by delaying the VIDEO signal sending time.
MAIN SCANNING DIRECTION
(HORIZONTAL SCANNING DIRECTION)
!
To unify the laser exposure timing emitted every one line of main scanning, the
SOS sensor is mounted on the laser diode control board (PWB-D).
SOS (Start of Scan) Sensor
(PWB-D)
Laser Diode
OPC Drum
Print Head Unit
Polygon Motor (M3)
4121s028
4110s032