Matrix Vision mvBlueFOX, Техническое руководство, Страница: 252 / 255

21.5 mvBlueFOX-[Model]205 (5.0 Mpix [2592 x 1944]) 245
Note
Moving objects together with a rolling shutter can cause a shear in moving objects.
The
global reset release shutter
, which is only available in triggered operation, starts the exposure of all rows
simultaneously and the reset to each row is released simultaneously, too. However, the readout of the lines is equal
to the readout of the rolling shutter: line by line:
Note
This means, the bottom lines of the sensor will be exposured longer! For this reason, this mode will only make
sense, if there is no extraneous light and the flash duration is shorter or equal to the exposure time.
Furthermore, the sensor offers two operating modes:
• free running mode (Overlapping exposure and readout)
• snapshot mode (Sequential exposure and readout) in triggered operation
21.5.2.1 Free running mode
In free running mode, the sensor reaches its maximum frame rate. This is done by overlapping erase, exposure and
readout phase. The sensor timing in free running mode is fixed, so there is no control when to start an acquisition.
This mode is used with trigger mode
Continuous .
To calculate the maximum frames per second (FPS
max
) in free running mode you will need following formula:
FrameTime = (Imag 900) * ((Image 9) / PixelClock)
If exposure time is lower than frame time:
FPS_max = 1
----------------------
FrameTime
If exposure time is greater than frame time:
FPS_max = 1
------------------------
ExposureTime
21.5.2.2 Snapshot mode
In snapshot mode, the image acquisition process consists off several sequential phases:
21.5.2.2.1 Trigger
Snapshot mode starts with a trigger. This can be either a hardware or a software signal.
The following trigger modes are available:
MATRIX VISION GmbH