Brother International HL 1030 Service Manual - Page 67

CHAPTER 3 THEORY OF OPERATION 2.3.2 Toner sensor Detects if there is toner in the toner cartridge. The toner sensor at the left side emits light through the window on the left side of the toner cartridge, then the toner sensor at the right side receives it when the toner is low. They also detect whether or not the drum unit is installed. (The toner cartridge is installed in the drum unit.) Toner sensor (light emission) Toner sensor (light reception) Fig. 3-33 2.4 Drum Unit 2.4.1 Photosensitive drum Generates the latent electrostatic image and develops the image on the drum surface. 2.4.2 Primary charger Forms a uniform charge on the drum surface. (1) Corona wire Generates the ion charge on the drum. (2) Grid Spreads the ion charge evenly over the drum surface. 2.4.3 Transfer roller Transfers the toner image to the paper from the drum surface. 2.4.4 Cleaner Removes the paper dust or dirt on the surface of the photosensitive drum. 2.5 Toner Cartridge Develops the electrostatic latent image on the photosensitive drum with toner and forms the visible image. 3-25