The laser beam generated by the laser unit based on the signals from the DC controller PCB moves through the collimator lens (inside the laser unit) and the cylin-

drical lens to reach a 4-face polygon mirror rotating at a constant speed.

When reflected by the 4-face polygon mirror, the laser beam moves through the imaging lens, and is bent by the reflecting mirror to reach the photosensitive drum.

At this time, the laser beam also is directed to the BD circuit of the laser driver/BD PCB.

As the 4-face polygon mirror rotates at a constant speed, the laser beam scans the surface of the photosensitive drum at a constant speed, thereby removing charges

and forming static images.

- copy image data

- print image data

(if equipped with printer functions)

- fax image data

(if equipped with fax functions)

5-2

Image processor PCB

DC controller PCB

BD block

Laser driver/BD PCB

Photosensitive drum