<< Click to Display Table of Contents > Optimize Contrast |
After marking the first bitmap, the contrast (Black Level and White Level) has to be adjusted.
Black Level Adjustment:
Find a good Black Level (laser time per area) by adjusting the Mark Speed and the Dither Step.
Picture |
|||
Black Level Effect |
Not dark enough |
Good dark value |
Too dark |
Laser time per area [ms/mm²] |
6.25 |
10.0 |
12.5 |
Mark Speed [mm/s] |
4000 |
3161 |
2828 |
Distance between dots [mm] [*] |
0.04 |
0.03161 |
0.02828 |
Dither Step [mm] |
0.04 |
0.03161 |
0.02828 |
Solution |
Increase the Laser time per area to 160%, by decreasing the Mark Speed and the Dither Step to 79% of the current values. |
- |
Decrease the Laser time per area to 80%, by increasing the Mark Speed and the Dither Step to 112% of the current values. |
Table 28: Optimize Black Level by adjusting Mark Speed and Dither Step
[*]: Frequency = 100 kHz
White Level Adjustment:
Find a good trade-off between being able to distinguish between different bright areas and the invisibility of pure white by adjusting the "Out" bit value corresponding to "In 255" bit (white) of the System PixelMap.
Picture |
|||
White Level Effect |
Pure white is invisible, but different bright areas are indistinguishable. |
A good trade-off between being able to distinguish of different bright areas and pure white invisibility. |
Different bright areas are distinguishable, but pure white is too dark. |
PixelMap white value [bit] |
255 |
200 |
150 |
Table 29: Optimize White Level by adjusting Out bit value corresponding to "In 255" bit (white) of the System PixelMap