Brother International HL-2400C Service Manual - Page 60

2 Exposing The exposing process means that the OPC belt surface is exposed to the laser beam to form an electrostatic latent image. (1) Structure of Scanner Unit i) The scanner unit is located as shown in Fig.4-8. ii) The source of the laser beam is a semiconductor laser. iii) The laser light is scanned onto the OPC belt by converting the laser light to a beam of light through the lens and reflective mirror to form an electrostatic latent image. (2) Process of Exposing (Refer to Fig.4-13.) i) The OPC belt surface has been charged to the potential -Vo(V) in the charging process. ii) The laser light is scanned at right angles to the forward direction of the OPC belt. iii) High speed switching of the laser is made according to the transmitted image data. iv) The charge of the areas radiated by the laser light is reduced to the potential VR(V). v) An invisible electrostatic latent image is formed on the OPC belt as shown in Fig. 4-13. -VR -VO Charging Exposing Fig.4-13 IV-11