AMIS-710627-A4, AMIS-710628-A4, AMIS-710629-A4:
Data Sheet
600dpi CIS Modules
10.0 Depth of Focus
Figure 4 shows the typical MTF versus Distance, which can be used to define the working depth of focus. Two curves indicate the
spread among the modules. Note that the MTF is greater than 40 percent out to a distance greater than 0.3mm from the glass surface.
Since this module is a 600dpi module, a pixel density of 600 pixels per inch, the MTF was measured with a 300dpi or a 150 line-pair per
inch optical bar pattern. The test was conducted with pixel rate set to 5.0MHz.
The effective algorithm used in the measurements is as described by the following equation:
MTF={[Vp(n)+Vp(n+1)]/2-[Vp(n+2)+Vp(n+3)]/2}/{[Vp(n)+Vp(n+1)]/2+[Vp(n+2)+Vp(n+3)]/2}
Where n is 1, 2, .....5184th, Vp(n) is the signal amplitude of the nth pixel.
Figure 4: Typical MTF versus Distance
TYPICAL MTF VS DEPTH OF FOCUS
60
50
M
TF
IN
40
30
20
10
0
%
0
0.2
0.4
0.6
DEPTH FROM THE WINDOW SURFACE(mm)
AMI Semiconductor – Jan. 06, M-20493-001
8
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