Brother HL-1260 service manual Image Formation System, Outline, Printing Process

3. IMAGE FORMATION SYSTEM

3.1 Outline

The image formation system is the main part of the printer. The print information, after input from the video controller circuit into the engine controller circuit as a TVDO signal, forms a toner image on the photosensitive drum.

Then the toner image is transferred onto the paper by the transfer charging roller. The image formation system is composed of the photosensitive drum the charging unit, the developing unit and the cleaning unit.

3.2 Printing Process

The major part of the image formation system is contained in the cartridge, as shown in Figure 2.5.

Laser beam	Cartridge
Primary charging roller	Blade
Cleaning blade	Developing cylinder
Photosensitive drum	Paper
	Transfer charging roller

Static charge eliminator

Figure 2.5

The cartridge used by the printer has a seamless photosensitive drum with the structure shown in Figure 2.6. The outer layer of the drum consists of an organic photoconductor (OPC); the base is aluminum.

The printing process can be divided into five major stages:

Photoconductive layer

Base

Figure 2.6

1.Electrostatic latent image formation stage Step 1 Primary charge (-)

Step 2 Scanning exposure

2.Developing stage Step 3 Development

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