Main Scanning Direction(Horizontal Scanning Direction); Printable Area; Charging Process; Overview (Refer To Figure2-9 On The Next Page) - Epson EPL-5700 Service Manual

EPL-5700

2.1.5.2 Main Scanning Direction(Horizontal scanning direction)

In order to make the timing of laser emission, which is emitted every one line
is scanned, SOS sensor is mounted on the laser diode control board.

2.1.5.3 Printable Area

1. Controller sends /VIDEO signal, which suits the paper size, to the engine.
2. Controller determines print starting position by /TOD signal(sub scanning
direction) sent from engine and /HSYNC signal.
3. Print head starts laser exposure after receiving /VIDEO signal.
/HSYNC
/VIDEO
4 mm
4 mm
Figure 2-8. Printable Area
Rev. A
Printable Area

2.1.6 Charging Process

2.1.6.1 Overview (Refer to Figure2-9 on the next page)

It is charged by giving static electricity to OPC drum(Organic
Photoconductor) before laser exposure.
Surface of OPC drum is charged by rotation brush and pre-charging film.
Electric potential on the surface of OPC drum after charging is about 800 V.
Charging by rotation brush and pre-charging film has low rate of ozone
occurrence by corona discharge, and also has low voltage because of direct
charging to the OPC drum. Also, it is excellent in uniformity of charge
potential and stability. Rotation brush is rotated when the driving power is
transmitted from main motor(M1) to the gear of the rotation gear. The
surface of the brush is charged by pulse(40Hz) duration -1286 VDC and -
336 V.
Before charging by rotation brush, pre-charging film performs charging in
advance in order to improve efficiency of charging. -1280VDC is provided to
pre-charging film through the diode from pulse, which is charged to the
rotation brush. Paper powder cleaner removes paper dust attached at the
OPC drum. The surface abrasive removes obstacles on the OPC drum that
can not be removed by paper powder cleaner so that it does not give bad
influence on the printing quality.
Chapter2 Operating Principles
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