Epson EPL-5700, Service Manual

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EPL-5700 Chapter2 Operating Principles
Rev. A
2-6
2.1.5 Laser Exposure
An electrostatic latent image is created on the OPC drum by the laser beam
emitted from the print head. In order to count appropriate timing to print the
image, following control is performed.
PC Drum
SOS Sensor
Laser Diode
Polygon Motor
Print Head
Laser diode
Control Board
Figure 2-7. Exposure Mechanism
2.1.5.1 Sub Scanning Direction(Vertical scanning direction)
1. After the printer receives printing signal, the polygon motor(M2) and main
motor(M1) rotate, and paper feeding starts.
2. After the fed paper tip turns ON the paper feed sensor(/TOD signal),
main control circuit sends /VIDEO signal to the print head, and printing
starts.
3. When the print starting position moves from the first line to the second
line, it is moved down by delaying emitting time of the /VIDEO signal.