39 NED
XCM4040SAT4 UME-0002-04
4.9
Setting Offset
In the diagram below, the horizontal axis indicates the volume of light and
vertical axis indicates the output.
Fs shows the output at saturation. Dd shows the output at darkness. (Both
Fs and Dd are digital.) Se shows for the saturation current, or the amount of
exposure when the output saturates.
Figure 4-9-1 Saturation Exposure and Dark Current Output
By setting the offset, you can set the Y-intercept arbitrarily. DF shows the
digital offset value. The gradients of lines do not change.
Figure 4-9-2 Offset Adjustment
Adjust gain and offset to meet your system’s requirements.
Ｄｄ
Ｆｓ
Ｓｅ
Volume of Light
(lx
・
s)
Output
Fs : Saturation Output
Dd : Dark Current
Se : Saturation Exposure
Output
DF : Offset Value
ＤＦ
Volume of
Light
(lx
・
s)
