PerkinElmer
Optoelectronics
24
7.2 Sample Imaging Setup
The following example assumes that you have determined the following:
•
Target width X
•
Image resolution # of pixels (By choice of camera)
•
Required feature resolution. i.e. the smallest feature
dimension “D” to be detected.
Example:
To image a feature .020” dia. on an 18” web using a LD3523 Camera.
Satisfying the Nyquist criterion, the effective y sample size
eff
y
=0.01”.
Since the maximum line rate corresponding to the minimum line period from
Table 1 is
sec
9
.
105
µ
, the web velocity to assure contiguous y samples must be
such that the web moves 0.010” during the line period.
min
/
1
.
472
min
sec/
60
*
/
"
12
sec
/
"
42
.
94
sec
/
"
42
.
94
sec
10
*
9
.
105
"
010
.
0
6
ft
ft
V
web
=
=
=
=
−
The required exposure
exp
t
is then computed as follows:
sec
10
*
8
.
12
42
.
94
*
2048
18
2048
*
010
.
*
#
*#
6
exp
−
=
−
=
−
=
web
eff
V
pixels
of
X
pixels
of
y
t
Note 1.
The calculated exposure time guarantees the effective spatial resolution of 0.010”
at the maximum line period. Reliable imaging will require adjustment of the web
light source and/or camera gain.
Summary of Contents for RETICON LD3500 Series
Page 5: ...v PerkinElmer Optoelectronics ...
Page 6: ......
Page 8: ...PerkinElmer Optoelectronics 2 Figure 1 LD3500 Series Camera Block Diagram ...
Page 34: ...PerkinElmer Optoelectronics 28 APPENDIX B Front Plate Detailed Mechanical Drawing ...
Page 36: ...PerkinElmer Optoelectronics 30 W Warranty ii Working Distance Estimating 17 ...
