Pressure Contact And Release Unit; Developing - Brother HL-6050 Service Manual

2.6.3

Pressure contact and release unit

HL-6050 series printer has the pressure contact and release unit of the development roller. In
order to lengthen the service life of the toner unit, development roller of the toner unit is
brought into close contact with the photosensitive drum when necessary.
1. The toner unit is brought into close contact with the drum unit when the paper being fed
activates the registration sensor actuator.
2. When the paper exits from the fixing unit and activates the paper exit sensor, the toner
unit is released from the drum unit.
3. The toner unit is brought into close contact with the drum unit during the continuous
printing. When the job (continuous printing) is finished, the toner unit is released from the
drum unit.
2.6.4

Developing

Developing causes the toner to be attracted to the electrostatic image on the drum so as to
transform it into a visible image.
The developer consists of a non-magnetic toner. The development roller is made of
conductive rubber and the supply roller (which is also made of conductive sponge) rotate
against each other. The toner is charged and carried from the supply roller to the
development roller. The toner adheres to the development roller and is conveyed to the
photosensitive drum at an even thickness controlled by the blade. The toner is nipped
between the development roller and the drum and developed onto the latent image on the
drum. The electrostatic field between the drum and the development roller, which is DC-
biased from the high-voltage power supply, creates the electrostatic potential to attract toner
particles from the development roller to the latent image area on the drum surface.
Blade
Supply roller
Corona wire
Development roller
Transfer roller
Fig. 3-38
3-31
HL-6050/6050D/6050DN SERVICE MANUAL
Photosensitive drum