Gestetner G060 Service Manual page 241

Step 2: ID Sensor Solid Pattern Generation
1 2 m m
1 5 m m
The machine agitates the developer for between 15 and 60 seconds until the
fluctuation in TD sensor output becomes less than 0.3V, and then makes a 10-
grade pattern (12 mm x 15 mm) on the transfer belt for each toner color. Each
grade of the pattern is a solid color, and is made by changing the development bias
and charge roller voltage. The difference between development bias and charge
roller voltage is always the same.
Step 3: Sensor Pattern Detection
The ID sensor detects the densities of the 10 solid patterns for each color. This
data goes to memory.
Step 4: Toner Amount Calculation
The amount of toner on the transfer belt (M/A, mass per unit area, mg/cm
calculated for each of the 10 grades of the sensor pattern from the ID sensor
output value from each grade of the pattern.
Step 5: V , V , VL Selection and V
D B
M / A
Target
M / A
B
The machine determines the relationship between the amount of toner on the
transfer belt and the development bias for each of the 10 grades. The machine
now selects the development bias and charge roller voltages for the target M/A for
each color by referring to a table in memory.
The way that the laser power (V
SM
Adjustment
REF
Development Bias
B
0
B
1
—
B
—
B
n-1
B
n
Development Bias
) is selected depends on the setting of SP3-125-2.
L
6-11
PROCESS CONTROL
G060D154.WMF
2
) is
Charge Bias LD Power
C L
0 0
C L
1 1
— —
C L
— —
C L
n-1 n-1
C L
n n
G060D002.WMF
G060