Datalogic A30, Руководство по оборудованию

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A30™ HARDWARE GUIDE
40
7
7 IMAGE CAPTURE FEATURES
7.1 MAXIMUM LINE SPEED AND EXPOSURE TIME CALCULATIONS
The Exposure Time (or Shutter ) parameter defines the time during which the image will be
exposed to the image sensor to be acquired. This parameter depends heavily on the
environmental conditions (external lighting system, image contrast etc.).
In general, a longer time corresponds to a lighter image but is susceptible to blurring due to the
part movement; a shorter exposure time corresponds to a darker image.
Assuming:
• X : Part Resolution (mm)
• T
exp
: Exposure Time (s)
• LS : Line Speed (mm/s)
The essential condition to avoid blurring effects between two adjacent elements in a dynamic
inspection application is:
LS ∗ T
exp
≤ X
The maximum (theoretical) line speed LS can be calculated as follows:
X / T
exp (max)
= LS
(max)
Example:
Using:
Lighting Mode = Very High Power Strobe
Exposure Time (x10
µ
s) = 10 (100
µ
s)
Part Resolution (X) = 0.254 mm (10 mils)
has a maximum line speed of:
0.254 (mm) / 0.0001 (s) = 2540 mm/s
Likewise, T
exp (max)
is the maximum Exposure Time value that can be used without blurring for
the given application line speed and code resolution. Therefore:
X / LS
(max)
= T
exp (max)