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.
msb b3
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
LED Correction Data
Correction Data
b2
b1
lsb b0
0
0
1
1
1
1
1
0
1
0
0
1
0
1
0
0
0
0
1
1
1
1
1
0
1
0
0
1
0
1
0
0
39
Correction
Correction
Step
Mode
0
+16%
1
+14%
0
+12%
Correction by
1
+10%
increasing
0
+8%
illumination
1
+6%
0
+4%
1
+2%
0
0%
No correction
1
-2%
0
-4%
1
-6%
Correction by
0
-8%
decreasing
1
-10%
illumination
0
-12%
1
-14%