Pco Edge 3.1, Руководство пользователя

Страница: 17 / 59

17
6.2 GLOBAL SHUTTER
First, all pixels are globally reset and these reset values are shifted
into so-called diffusion nodes. From there, they are non-destructively
read out into memory as reset dark images. The exposure starts after
transfer of the reset dark image to the diffusion nodes, where they are
stored on the chip. The exposure is stopped by global charge transfer
to the diffusion nodes. Then, the exposure image is read out to the
memory, where the former reset dark image is subtracted to perform
an external correlated double sampling, which reduces the noise.
Since two images have to be read out to yield one valid image, the
sCMOS image sensor’s
Global Shutter mode has only half of the
frame rate of the Rolling Shutter mode.
Timing
The exposure and delay time can be adjusted in steps of one line
time (see
1.2
).
Camera (Global Shutter) Exposure time Delay time
pco.edge 3.1
USB 3.0
20 µs … 100 ms
0 µs … 1 s
pco.edge 5.5 USB 3.0
20 µs … 100 ms
pco.edge 5.5 Camera Link
10 µs … 100 ms
pco.edge 5.5 Camera Link HS 10 µs … 100 ms
NOTE
Not available for
pco.edge 4.2
RESET EXPOSURE READOUT