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21.4 mvBlueFOX-[Model]202d (1.2 Mpix [1280 x 960]) 241
21.4 mvBlueFOX-[Model]202d (1.2 Mpix [1280 x 960])
21.4.1 Introduction
The CMOS sensor module (MT9M024) incorporates the following features:
• resolution to 1280 x 960 gray scale or RGB Bayer mosaic
• supports window AOI mode with faster readout
• programmable analog gain (0..12 dB)
• progressive scan sensor (no interlaced problems!)
• high dynamic range (p. 165) 115 dB (with gray scale version)
• rolling shutter
• programmable readout timing with free capture windows and partial scan
• many trigger modes (free-running, hardware-triggered)
21.4.2 Details of operation
The sensor uses following acquisition mode:
•
rolling shutter
( ShutterMode = "ElectronicRollingShutter" ) With the
rolling shutter
the lines
are exposed for the same duration, but at a slightly different point in time.
Note
Moving objects together with a rolling shutter can cause a shear in moving objects.
Furthermore, the sensor offers following operating modes:
• free running mode (Overlapping exposure and readout)
• snapshot mode (Sequential exposure and readout)
21.4.2.1 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 = (ImageHeight * (1650 / PixelClock)) + (25 * (1650 / 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
MATRIX VISION GmbH