AMIS-710401 Datasheet, PDF (6/9 Pages) AMI SEMICONDUCTOR – 400dpi CIS Module

AMIS710401-A4: 400dpi CIS Module
Red 600nm LED Light Source
Data Sheet
10.0 Depth of Focus
Figure 4 shows two graphs of typical MTF versus Distance, which can be used to define the working depth-of-focus (DOF). The two
curves indicate the spread among the production modules. Note that the MTF is greater than 50 percent between the 0.0mm and
0.1mm depth. Distances greater than 0.1mm from the glass surface are still usable, but discretion must be used in its application. Since
this module is a 400dpi module, the MTF was measured with a 400dpi or a 200 line-pair per inch optical bar pattern. The test was
conducted with the 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, .....3456^th, Vp(n) is the signal amplitude of the n^th pixel.
MTF vs depth focus
PI401MC-A4 STANDARD
55
50
45
40
35
30
25
20
15
10
0 0.1 0.2 0.3 0.4 0.5 0.6
Depth (mm) From The Window
Surface
SN2028
SN60
Figure 4: Typical MTF versus Distance
AMI Semiconductor – Jun. 06, M-20589-001
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