VI User Manual - 第39页
Maintenance mode Vision 2007 4.10 User Manua l Rev 01 2 - 3 2.1.1.1 Gray level calibrat io n with Vi-800 gray tool The calibration with gray tool me asures the gr ay plate for each lighting to calibr ate the lighting pow…
Maintenance mode
2 - 2 Vision 2007 4.10 User Manual Rev 01
2.1 Test machine
When you click on Test machine button, the opposite screen appears with the calibration functions of
the AOI system.
2.1.1 Gray levels
Calibration of the gray levels ensures the same degree of light intensity and performance of the
lighting head is obtained for every machine by selection of a reference gray level (120).
Consequently, any lighting combination on any machine placed on any production lines through-
out the world will provide the same lighting ranges.
The gray levels is cali-
brated using the gray
tool supplied with the
machine.
Two tool versions are
available.
The standard gray paper used to create the tool have a life time of 1 year, if it is kept
away from light and humidity.
Contact support to change the standard gray paper each year.
On completion of gray level calibration, the focus may have changed as a result of gray
level adjustment.
Maintenance mode
Vision 2007 4.10 User Manual Rev 01 2 - 3
2.1.1.1 Gray level calibration with Vi-800 gray tool
The calibration with gray tool measures the gray plate for each lighting to calibrate the
lighting power.
1. Click Gray levels button in TEST MACHINE window for automatic adjustment of con-
veyor width.
2. Insert the calibration tool in the machine.
3. Once the gray tool is inside the machine
and the camera is automatically placed
above, the Light adjustments window is
brought up. The AOI system then mea-
sures the gray level for each lighting type.
4.
Manually adjust the lens opening (top ring) of
the camera and click
Start test
to obtain the
new value of measurement for each lighting.
5.
Repeat this operation until the value of gray
level measured is equal (+/- 10) to the reference value (120) for the weakest lighting (Val-
ues out of range are underlined in red). Then the
Auto Calibration
button is activated.
6. Click Auto Calibration. Auto calibration of gray levels begins: this procedure may take
more than 2 minutes.
2.1.1.2 Gray level calibration with Vi-800G gray scale
The calibration with gray scale compensates for gamma variations from one camera to
another. The calibration includes 3 passes:
First pass calibrates the lighting power. The machine measures the gray plate for each
lighting.
Second pass calibrates the camera’s gamma response. The machine measures 20
different shades of gray.
Third pass calibrates the lighting power with the gamma correction active.
1. Click Gray levels button in TEST MACHINE window for automatic adjustment of con-
veyor width.
2. Insert the calibration tool in the machine.
3. Once the gray tool is inside the machine and the camera is automatically placed
above, the Gamma correction window is brought up. The AOI system then measures
the gray level for each lighting type.
Test machine
Maintenance mode
2 - 4 Vision 2007 4.10 User Manual Rev 01
4. Manually adjust the lens opening (top ring) of the camera and click Start test to obtain
the new value of measurement for each lighting.
5. Repeat this operation until the value of gray level measured is equal (+/- 10) to the
reference value (120) for the weakest lighting (Values out of range are underlined in
red). Then the Auto Calibration button is activated.
6. Click Auto Calibration. Auto calibration of gray levels begins: this procedure may take
more than 2 minutes.
2.1.1.3 Calibration results
Once the calibration is over, the Gamma correction window displays the calibration
values and graphs:
The gray scale (A) displays, for each shade of gray, the measured values, used for gam-
ma correction.
Delta GL max (B) indicates the maximum difference in gray levels between the theoret-
ical gamma values and the corrected values. This value should be less than 8 gray levels
if the gamma correction is successful.
Used GL (C) indicates the number of distinct gray levels available when the gamma cal-
ibration is active. This value should be at least 225 (which is the number of distinct gray
levels available without gamma correction).
The different graphs (D) represent the measured and computed values at different stag-
es of the calibration process.
Cameras
The Vi-3K Series and Vi-5000 Series camera lens is accessible
from the rear of the machine.
A Top: lens opening ring.
B Bottom: focus ring.
A
D
B
C
A
B
A
Test machine