Step 6: Id Sensor Highlight Pattern Generation - Gestetner B147 Service Manual

Step 6: ID Sensor Highlight Pattern Generation

12 mm
15 mm
The machine makes a 10-grade pattern on the transfer belt for each toner color.
The pattern consists of 10 squares. Each of the squares is 12 mm x 15 mm, and is
a dot-pattern squares (not solid-color squares like in the process of step 2). They
are made using constant bias and charge roller voltages selected from one of the
types mentioned above, and the various grades are made by changing the LD
power.
Step 7: Sensor Pattern Density Detection
The ID sensor detects the densities of the 10 grade-pattern squares for each color.
This data goes to memory.
Step 8: V (LD Power) Selection
L
The machine determines the relationship
between the amount of toner on the transfer
belt and the laser power for each of the 10
grades. The machine now selects the laser
power to get the target M/A.
SM
Left
6-13
PROCESS CONTROL
Transfer belt
B146D504.WMF
M/A
Target
M/A
L
B147/B149/B190
LD Power
B146D505.WMF