KAC−12040
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19
Frame Time
The frame time is defined in units of Line Time. 1 Line
Time unit = 2 output rows. To first-order the frame rate is not
directly impacted by selection of Global Shutter, Rolling
Shutter, Dual-Scan, or Tri-Scan.
The Frame Time is made up of three phases:
1. Integration Phase
2. Readout Phase
3. Frame Wait Phase (Vertical Blanking, V
BLANK
)
By default the Integration Phase overlaps the Readout and
Frame Wait Phases. If the Integration Phase is larger than the
R Frame Wait time, then the Integration Phase will
determine the video frame rate. Otherwise the frame rate
will be set by the R Frame Wait time. In other words,
if the programmed integration time is larger than the
minimum readout time (and vertical blanking) then extra
vertical blanking will be added and the frame rate will slow
to accommodate the requested integration time.
Figure 15. Default Frame Time Configuration (Frame A)
Single Frame of Video Overhead
Integration Phase Frame m
Integration Phase Frame m+1
Integration Phase Frame m+2
Readout Phase Frame m
Readout Phase Frame m+1
Frame
Wait
Frame
Wait
13.80 ms by Default
Video Frame Time = R Wait
8.34 ms by Default (952 Line Times)
13.79 ms by Default
(1576 Line Times)
~0.01 ms
(1 Line Time)
If the Integration Phase is less than the Readout Phase then
the start of integration is automatically delayed to minimize
the storage time and dark current.
Figure 16. Frame Time with Extended Integration Time
Integration Phase Frame m+2
Readout Phase Frame m+1
Frame
Wait
Video Frame Time = Integration Time
Integration Phase Frame m+1
Readout Phase Frame m
Frame
Wait
Integration Phase Frame m
If the Readout Phase (+ V
BLANKING
) is less than the
Integration Phase, then the readout occurs as soon the
integration is complete to minimize the storage time and
dark current.
See the KAC−12040 User Guide for detailed calculation
of the Integration Phase, Readout Phase, and Frame Wait.
To first-order the Readout Phase is equal to the number of
rows
⋅
row_time.