Oki OKIPAGE 12i Series, Service Handbook

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The LED driver (MSM6731BWAF) corrects the LED illumination by controlling the LED current.
The LED illumination can be set in 16 steps, with 7 steps in the direction of illumination increase
in relation to the standard value, and 8 steps in the direction of decrease. For this reason, the LED
correction data is a 4-bit data for each dot.
The relationship between the LED correction data and LED current correction steps with the LED
driver (MSM6731BWAF) used in an LED head is shown below.
LED Correction Data
Correction Data
msb b3
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
b2
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
b1
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
lsb b0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Correction
Step
Correction
Mode
+16%
+14%
+12%
+10%
+8%
+6%
+4%
+2%
0%
-2%
-4%
-6%
-8%
-10%
-12%
-14%
Correction by
increasing
illumination
Correction by
decreasing
illumination
No correction