Readout Time; Figure 5-24: Full Frame At Full Resolution - Teledyne ProEM Series System Manual

Chapter 5

Figure 5-24: Full Frame at Full Resolution

Readout of the CCD begins with the simultaneous shifting of all pixels one row toward
the shift register, in this case the row on the top. The shift register is a single line of
pixels along the edge of the EMCCD, not sensitive to light and used for readout only.
Typically the shift register pixels hold twice as much charge as pixels in the imaging area
of the CCD.
After the first row is moved into the shift register, the charge now in the shift register is
shifted toward the output node, located at one end of the shift register. As each value is
emptied into this node it is digitized. Only after all pixels in the first row are digitized is
the second row moved into the shift register. The order of shifting in our example is
therefore A1, B1, C1, D1, A2, B2, C2, D2, A3.... After charge is shifted out of each pixel,
the remaining charge is zero, meaning that the array is immediately ready for the next
exposure.
A subsection of the CCD can be read out at full resolution, sometimes dramatically
increasing the readout rate while retaining the highest resolution in the Region Of
Interest (ROI).
5.4.7

Readout Time

In WinX/32, readout time can be obtained by going to the Acquisition menu and
selecting Readout Time....
In LightField, it is reported on the Sensor expander.
Readout Time is calculated based on the current ROI/Binning/Vertical shift rate
settings.
Operation 87