Bonito Technical Manual
V2.4.0
53
Parameters and commands
Basic working principle of the CMOS sensor
A basic familiarity with the CMOS sensor‘s working principle is required to recog-
nize how the PIV mode of the Bonito camera operates. For that reason, a simpli-
fied short explanation is included below.
Each pixel of the sensor is a shutter pixel that includes a photo detector, a pixel
memory, and a number of gates.
The photo detector accumulates the charge produced by light (exposure).
When the electronic shutter gate is open, the charge accumulated in the photo
detector is removed, and the photo detector is reset. During exposure, the elec-
tronic shutter gate is closed.
When the transfer gate opens, the charge is transferred internally from the
photo detector to the pixel memory. The photo detector keeps charging while
the transfer takes place.
During the readout, the charge from the pixel memory is converted into a digital
signal that is output to the Camera Link connection via the readout and control
architecture.
When PIV mode is active, the electronic shutter gate is always closed. The trans-
fer gate is opened regularly to transfer the accumulated charge to the pixel
memory.
The PIV sequence - overview
Range
Either
0
(PIV mode off) or
4
(PIV mode on)
Default
0
Related
Parameter
J
Example
M=4
Figure 27: Simplified diagram of the CMOS pixel architecture
