Oki OKIPAGE 12i Series, Service Handbook

Page: 34 / 226

2 - 17
(4) Developing
Toner is attracted to the electrostatic latent image on the image drum surface, converting it
into a visible toner image. Developing takes place through the contact between the image
drum and the developing roller.
1 As the toner supply roller rotates while rubbing on the developing roller, a friction charge
is generated between the developing roller and the toner, allowing the toner to be
attracted to the developing roller (the developing roller surface is charged positive and
the toner, negative).
2 The toner attracted to the developing roller is scraped off by the doctor blade, forming a
thin coat of toner on the developing roller surface.
3 Toner is attracted to the exposed portion (low-potential part) of the image drum at the
contact of the image drum and the developing roller, making the electrostatic latent
image visible.
Charge roller
Doctor blade
Developing roller
Image drum
Toner supply roller
-300V
-750V -100V -750V -750V
Developing roller
Toner
Image drum
-100V
Exposed
part
Exposed
part
An illustration of activities at the contact point of the image drum surface and
the developing roller (arrow marks denote the direction of the electrical field).
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+ + + + + + + + + + + + + + + + + + + + + + +