Canon    LBP3310, Service Manual

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Chapter 2
2-3
6) The two laser beams pass through the collimator lens and the cylindrical lens to strike the four-sided mirror, which is rotating at a constant speed.
7) The laser beam reflected by the four-sided mirror focuses on the photosensitive drum passing through the focus lens and the reflective mirror at the front of the
four-sided mirror.
8) When the four-sided mirror starts to rotate at prescribed speed, the laser beam on the photosensitive drum starts to scan the surface of the drum at its prescribed
speed.
9) When the photosensitive drum rotates and the laser beam scans on the drum at each prescribed speed, the latent image is formed on the photosensitive drum.
Twin beam method
The laser unit unifies with two laser diodes (LD1, LD2). In one scanning operation, the two diodes (LD1, LD2) emit light to write two lines simultaneously.
This enables a twofold printing with same printing speed.
F-2-3
2.3.1.2 Laser Control Circuit
0018-3094
LBP3370 / LBP3310
The laser control controls the laser driver to turn the two laser diodes (LD1, LD2) ON/OFF according to the LASER CONTROL signals sent from the engine con-
troller.
The circuit diagram of the laser control is illustrated below.
LD1 scanning line
LD2 scanning line
Feed direction
Image area
1st scanning line
2nd scanning line
3rd scanning line
4th scanning line