Image Processing Reference
In-Depth Information
The parameterized DMA Equation 10.30 suggests that a linear relationship between
the DMA and the development voltage exists when the toner tribo is held constant
throughout the printing process. Development physicists have shown that the Q
=
M of
toner in a two-component mixture degrades with time [16
18] and toner aging [20].
Ignoring toner aging, tribo and TC, T
c
, have the following relationship:
-
Q
M
¼
A
t
T
c
þ
k
0
(
10
:
31
)
where
A
t
is proportional to the carrier surface area that varies with time due to toner
attaching to the carrier
k
0
is a constant unaffected by the developer aging
Figure 10.19 shows a plot of toner tribo vs. TC for a test system.
A typical solid area curve is shown in Figure 10.20 for an experimental printer
for various values of TC. This is called the developability curve. Clearly, DMA is a
nonlinear function of development voltage at low development-voltage values.
Accordingly, the functional behavior of DMA captured by the
first principle model
120
Cyan
Magenta
Yellow
Black
110
100
90
80
70
60
50
40
0
1
2
3
4
5
6
7
8
9
Toner concentration (TC) in %
FIGURE 10.19
Toner tribo vs. TC relationships for cyan, magenta, yellow, and black toners
(note slight variations in the slopes among different toners).
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