Dalsa 1M28-SA, User Manual

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24 PRELIMINARY 1M28 and 1M75 User’s Manual
03-32-00525-03 DALSA
Figure 12: Free Running Mode, Constant Image Data Rate
Frame Timer
Integration Readout Integration Reset
Figure 13: Free Running Mode, Variable Image Data Rate
Integration Readout
Integration
Readout
Global Shutter Timing
With a global shutter, the sensor starts with a global reset of all pixels. Then during the
integration time, photo-generated electrons are collected in the pixels. After the exposure
time, the collected electrons are transferred to a storage node, and sequential readout of
the sensor matrix begins. As a result, all pixels are exposed to light for the same amount
of time, resulting in crisp images that do not suffer from the time displacement artefacts
characteristic of rolling shutter CMOS cameras.
Figure 14: Global Shutter Timing
Reset
Data
Global shutter
Reset Integration
Frame Readout
Freerunning Mode
The freerunning mode is the factory set timing mode at power up and captures images
without the need for an external control signal. The sensor data is read out after the set
integration time. After the sensor is finished reading out, the sensor resets and the
sequence begins again. The date is output on the rising edge of the pixel clock.
The signals FRAME_VALID (FVAL) and LINE_VALID (LVAL) mask valid image
information. The number of clock pixels after exposure CPRE is defined by the calculation
of the frame time