Toshiba 3511, 4511 manual Black Developer Unit, Functions

12

12.5 Black Developer Unit

12.5.1 Functions

a. Black developer material

The developer material consists of the carrier and toner. The carrier is made of electrically con- ductive ferrites which is 30-100 µm and the toner is made of the resin particle which is 5-20 µm. Since the developer material deteriorates after a long time use, periodic replacements are needed.

b. Mixer unit

The carrier and toner are frictionized each other when the developer material is stirred. Then the carrier is positively charged (+) and the toner is negatively charged (–), and the toner is adhered by the electrostatic force.

c. Developer sleeve (Magnetic roller)

These aluminum rollers have magnets inside. The developer material is pulled by these magnets to form a magnetic brush. The magnets are fixed at their position so only the sleeve rotates. By this rotation, the developer material is transported to the developer sleeve. Then the magnetic brush formed at the developer sleeve sweeps over the drum surface and thus development is performed.

d. Doctor blade

The doctor blade controls the amount of the developer material from the transport sleeve so that the magnetic brush of the developer material can contact with the drum surface properly.

e. Black auto-toner sensor

To print out a precise image, the proportion (toner density ratio) of the carrier and the toner in the developer material needs to be always constant. The magnetic bridge circuit in the auto-toner sensor detects the toner ratio in the developer material. This sensor supplies the toner from the toner cartridge.

e-STUDIO3511/4511 DEVELOPER UNIT 12 - 4 November 2003 © TOSHIBA TEC