Linea HS Series Camera User's Manual
Camera Performance and Features
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69
Establishing the Optimal Response
An important camera performance characteristic is its responsivity and associated noise level at the
system’s maximum line rate and
with the required illumination and lens configuration.
Responsivity and noise performance can be assessed using a stationary, plain white target under
bright field illumination. However, to accurately evaluate
the camera’s
real-life performance, it is
important that the setup is representative of the final system configuration.
The ideal test setup meets the following conditions:
•
The lens is in focus, at the desired magnification and with the desired aperture.
•
The illumination intensity is equal to that of the inspection system and aligned with the
camera
’s
field of view.
•
The camera is operated with an exposure time that will allow the maximum line rate of the
system to be achieved. The camera’s internal line rate generator and exposure control can
be used for a stationary target.
Exposure Control by Light Source Strobe
Relevant Features:
Note:
TDI sensors do not have exposure control built in. Pixels continuously
convert photons to electrons.
After receiving a line trigger, the camera instructs the sensor to execute the
analog read operation. During this time incoming photons are still detected and
may associate with the current or subsequent line. This effect is negligible when
constant lighting is used.
When using strobed lighting, assure a minimum delay of 1.4
s between the rising
edge of EXSYNC and powering-on of the light source.
Using the GPIO controls the camera can be set up to strobe a light source effectively giving
exposure control. Figure 38 shows an example of an output signal used as a strobe signal.
Camera Trigger
Sensor Trigger
Output Line
3,4,5 or 6
Trigger Delay
Output Delay
Set to
Trigger Delay + 1.6 µs
Output Duration
Output Strobe Control Example
Figure 38: Strobe Timing
