Confidential

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3. The laser beams reflected by the reflection mirror go straight toward the exposure drum below

it, then expose the exposure drum.

The area exposed to the laser beam is the image to be printed. The surface potential of the

exposed area is reduced, forming the electrostatic image to be printed.

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 developer 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 developer roller. The toner adheres

to the developer roller and is conveyed to the exposure drum at an even thickness controlled by the

blade. The toner is nipped between the developer roller and the drum and developed onto the

latent image on the drum. The electrostatic field between the drum and the developer roller, which

is DC-biased from the high-voltage power supply, creates the electrostatic potential to attract toner

particles from the developer roller to the latent image area on the drum surface.

1 Cycle of dru
m
Surface
potential (V)
+897
+400
+150
Dru
m
sleeve 0
Time
1 23
(a)
(b)
1 Primary charging
2 Laser bea
m
exposure and developing
3 Transfer the image to pape
r
(a) Unexposed area
(Non image area)
(b) Exposed area
(Image area)
Suppl
y
rolle
r
Blade
Develope
r
rolle
r
Exposure dru
m
Corona wire
Transfer
olle
r