Canon NP-1010 Service Manual page 16

step 4 Development
Figure 2-8
As shown in Figure 2-8. the developing
assembly consists of a developing cylinder
and a magnetic blade; the developing cylinder
itself is made up of a magnet fixed in position
and a cylinder which rotates around the mag-
net.
The black developer is a single-composi-
tion developer of magnetite and resin. The de-
veloper has insulating properties and is
charged to a positive potential by friction
against the rotating cylinder.
Figure 2-10
During development, the toner is attracted
to the OPC drum by the work of the surface
potential of the drum and the developing bias
(at time of positive component) and turns the
electrostatic latent image to a visible image.
Excess toner is attracted back by the surface
potential of the drum and the developing bias
(at time of negative component).
The DC bias is known to affect copy den-
sity; the higher the DC bias, i.e., closer to OV,
the higher the density, but with an increased
likelihood of fogging.
Step 5
Transfer
Magnet
'
Figure 2-g
A concentrated magnetic field develops
between the magnet and the tip of the blade,
and the developer is attracted to the magnetic
field.
The magnetic field holds the developer it
has attracted virtually immobile and creates a
collection of developer particles hanging from
the tip of the blade. As the cylinder rotates,
the developer particles leave the magnetic
field to deposit themselves on the cylinder in a
thin, uniform layer.
J,
Figure 2-l 1
In this step, a negative corona is applied to
the back of the copy paper so as to attract
the positively charged toner to the copy paper.
Since both the developing cylinder and the
blade are given AC and DC biases (negative
component) at the same time, the resulting
wave form of the developing bias has a larger
negative component than positive.
COPYRIGHT 01ilAA CANON INC.
CANON HP-1010 AEY.0 DEC. 1988 PAINTED IN JAPAN IIMPAIME AU JAPONI 2-3