8.Features
© 2023 China Daheng Group, Inc. Beijing Image Vision Technology Branch 138
The MER-G-P/MER-G series camera supports two exposure modes: overlap exposure and non-overlap
exposure. The user cannot assign the overlap exposure or non-overlap exposure directly, it depends on
the frequency of trigger signal and the exposure time. The exposure modes are described as below.
Non-overlap exposure
In non-overlap exposure mode, after the exposure and readout of the current frame are completed, then
the next frame will expose and read out. As shown in the Figure 8-14, the N
th
frame is read out, after a
period of time, the N+1
th
frame to be exposed.
The formula of non-overlap exposure frame period:
non-overlap exposure frame period > exposure time + readout time
Sensor
Exposure
Time
Non-overlap
Non-overlap
Frame N
Frame N+1
Frame N+2
Frame N
Frame N+1
Sensor
Readout
Blank
Blank
Figure 8-14 The exposure sequence diagram in non-overlap exposure mode
Trigger acquisition mode
If the interval between two triggers is greater than the sum of the exposure time and readout time, it will
not occur overlap exposure, as shown in Figure 8-15.
Sensor
Exposure
Time
Frame N
Frame N+1
Frame N+2
Frame N
Frame N+1
Sensor
Readout
Trigger
Trigger
Trigger
Figure 8-15 The trigger acquisition exposure sequence diagram in non-overlap exposure mode
Overlap exposure
In overlap exposure mode, the current frame image exposure process is overlap with the readout of the
previous frame. That is, when the previous frame is reading out, the next frame image has been started
exposure. As shown in the Figure 8-16, when the N
th
frame image is reading out, the N+1
th
frame image
has been started exposure.
The formula of overlap exposure frame period:
