Brother 1240, HL-1030, 1250 service manual Drum Unit, Toner Cartridge

CHAPTER 3 THEORY OF OPERATION

2.3.2Toner 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 reception)

Toner sensor (light emission)

Fig. 3-33

2.4Drum Unit

2.4.1Photosensitive drum

Generates the latent electrostatic image and develops the image on the drum surface.

2.4.2Primary 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.

2.4.3Transfer roller

Transfers the toner image to the paper from the drum surface.

2.4.4Cleaner

Removes the paper dust or dirt on the surface of the photosensitive drum.

2.5Toner Cartridge

Develops the electrostatic latent image on the photosensitive drum with toner and forms the visible image.

3-25