VCC-16MV02
Rev.905-0163-00
©2018 CIS Corporation. All rights reserved.
21
7.11.
Pulse Width Trigger Shutter Mode
□
This is the mode to start exposure with external input trigger signals, and set the exposure time with pulse width of
the trigger signals.
□
Trigger operation is H Cycle, and V-sync Restart system.
The delay time (Exposure Time Delay
①
) from
detecting trigger edge in the camera to actually starting exposure is
2H~3H. The delay time (Exposure Time Delay
②
) from
detecting trigger edge in the camera to end exposure is
2H+14.26μs ~ 3H+14.26μs.
□
Since the external trigger signals synchronize with camera internal H signals, approx. 1H jitter occurs to Exposure
Time Delay
①
and
②
. In case of pulse width trigger mode, jitters may occur at both start and end edges of
exposure. At this time, exposure time would change so that flicker might be noticeable in the image, especially when
high-speed shutter is set. This flicker sometimes can be eliminated when fixed trigger shutter mode is used.
However, this problem can be solved by inputting a trigger pulse with synchronizing it to the camera internal H cycle
(LVAL).
□
Pulse width is min. 1H to approx. two frames. Functionally, there is no upper limitation, but noises such as dark
noises shadings may be noticeable at long time exposure.
□
There is an exposure time period for approx. 14.26μs at the edge right after exposure output.
□
Trigger input during exposure time shall be ignored in the camera. However, a trigger shorter than 1 frame cycle
should not be used.
□
Triggers can be accepted while outputting video output images. However, please be noted that a trigger signal to
start the next video outputting should not be input before completion of outputting the prior images. (Please refer to
(A) in the drawing below).
Effective Line : 3000H
Effective Line
～ ～
Exposure Out
3
0
0
0
1
TRIG IN
LVAL Out
FVAL Out
Video Out
DVAL Out
～ ～
3
0
0
0
1
Effective Line
Trigger input ignore period
Exposure Time
Exposure Time Delay
①
Exposure Time Delay
②
(A)
TRIG IN
Exposure Out
(SP Out)
Exposure time delay
①
②
