8.Features
© China Daheng Group, Inc. Beijing Image Vision Technology Branch 118
The global shutter sensors of MER-U3 series camera are as follows models:
Model
Sensor Type
MER-031-860U3M/C(-L)/MER-031-860U3M(-L) NIR/MER-041-436U3M/C(-L)
/MER-050-560U3M/C(-L)/MER-050-560U3M(-L) NIR/MER-051-120U3M/C(-L)
/MER-131-210U3M/C(-L)/MER-131-210U3M(-L) NIR/MER-132-43U3M/C(-L)
/MER-131-210U3M/C(-L)/MER-134-93U3M/C(-L)//MER-160-227U3M/C(-L)
/MER-230-168U3M/C(-L)/MER-231-41U3M/C(-L)/MER-301-125U3M/C(-L)/
MER-302-56U3M/C(-L)/MER-502-79U3M/C(-L)/MER-502-79U3M(-L) POL/
MER-503-36U3M/C(-L)
Global Shutter
Table 8-6 Global Shutter camera models
Because all the lines of electronic rolling shutter camera are exposed not at the same time, it is difficult to
use flash light. The strobe is light only during all the lines at the same time exposure and no photons into
the sensor at the other time, the camera can get consistent brightness image. If the strobe is light too early,
the image above will be bright, if the strobe is delay to extinguish, the image below will brighter. The width
of the flash signal can be obtained by the following formula:
T
strobe
= T
exposure
− (𝑁 − 1) ∗ T
row
The following figure identifies the moment when the MER-500-14U3M/C(-L) electronic rolling shutter
camera exposing:
Strobe
Exposure line by line
Readout after exposure
Strobe output
1
N
Figure 8-21 The relationship between strobe width and exposure time in rolling shutter mode
The MER-500-14U3M/C(-L) camera output a strobe signal when all the lines are exposed at the same
time, and does not output the strobe signal at other stages. Therefore, when the exposure time is less than
the preset frame period (approximately equal to readout time), there is no strobe output, and the flash light
is off.
Example:
When the camera is at the full resolution, the bandwidth limit is closed, if set the exposure time as 100ms,
then the preset frame period is about 71.5ms, the signal width of strobe is 28.5ms, if change the exposure
time to 70ms, then no strobe signal output, because all the lines are not exposed at the same time.
