IR Transparent Window
Appendix D: Window Designs for
HSDL-3209
OPAQUE MATERIAL
Optical Port Dimensions for HSDL-
3209
To ensure IrDA compliance,
some constraints on the height
and width of the window exist.
The minimum dimensions
ensure that the IrDA cone
angles are met without
vignetting. The maximum
dimensions minimize the
effects of stray light. The
minimum size corresponds to a
cone angle of 30° and the
maximum size corresponds to
a cone angle of 60°.
Y
IR Transparent Window
OPAQUE MATERIAL
X
K
Z
A
In the figure above, X is the
width of the window, Y is the
height of the window and Z is
the distance from the HSDL-
3208 to the back of the
D
window. The distance from the
center of the LED lens to the
center of the photodiode lens,
K, is 5.1mm. The equations for The depth of the LED image
is 15° and the maximum is
computing the window
dimensions are as follows:
inside the HSDL-3208, D, is
3.17mm. ‘A’ is the required
half angle for viewing. For
30°. Assuming the thickness of
the window to be negligible,
the equations result in the
X = K + 2*(Z+D)*tanA
Y = 2*(Z+D)*tanA
IrDA compliance, the minimum following tables and graphs:
Module Depth
(z) mm
Aperture Width (x, mm)
Aperture height (y, mm)
The above equations assume
that the thickness of the
Max
8.76
min
6.80
Max
3.66
Min
1.70
2.33
2.77
3.31
3.84
4.38
4.91
5.45
5.99
6.52
window is negligible compared
to the distance of the module
from the back of the window
(Z). If they are comparable, Z’
replaces Z in the above
0
1
2
3
4
5
6
7
8
9
9.92
7.33
4.82
11.07
12.22
13.38
14.53
15.69
16.84
18.00
19.15
7.87
5.97
8.41
7.12
equation. Z’ is defined as
8.94
8.28
Z’=Z+t/n
9.48
9.43
where ‘t’ is the thickness of
the window and ‘n’ is the
refractive index of the window
material.
10.01
10.55
11.09
11.62
10.59
11.74
12.90
14.05
AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
