Brother International HL-2400C Service Manual - Page 70

1.2 Scanning System This printer employs a semiconductor laser diode as a light source. This laser diode is switched according to the transmitted image data (video signal). The generated laser light scans over the OPC belt through a polygon mirror and lens, by which method electrostatic latent images will be formed on the OPC belt. (1) Structure of the Scanning System (Refer to Fig.4-24.) The scanner unit is located as shown in Fig.4-8. The scanner unit consists of the following parts;
Laser Unit:  Cylinder Lens:  Polygon Mirror:  F-θ Lens:  Scanner Motor:  Mirror:  LDC:  PD: BTD Mirror: Light emitting source incorporating a laser diode. Condenser for the laser beam. Hexahedral mirror for scanning the laser beam. Focus lens for the laser beam. Motor to rotate the polygon mirror. Reflecting mirror for the laser beam path. Laser diode control circuit. Beam detector. Beam timing detector mirror to guide the laser beam to the PD sensor. 9 2 6 4 8 7 5 1 2' 3 Fig.4-24 IV-21