ISL29001_14 Datasheet, PDF (9/11 Pages) Intersil Corporation – Light-to-Digital Sensor

ISL29001
k = 7.5. This is a scaling factor for the IR sensitive Diode 2.
Flat Window Lens Design
A window lens will surely limit the viewing angle of the
ISL29001. The window lens should be placed directly on top
of the ISL29001. The thickness of the lens should be kept at
minimum to minimize loss of power due to reflection and
also to minimize loss of loss due to absorption of energy in
the plastic material. A thickness of t = 1mm is recommended
for a window lens design. The bigger the diameter of the
window lens the wider the viewing angle is of the ISL29001.
Table 4 shows the recommended dimensions of the optical
window to ensure both 35° and 45° viewing angle. These
dimensions are based on a window lens thickness of 1.0mm
and a refractive index of 1.59.
WINDOW LENS
t
∅
D_TOTAL
D1
ISL29001
D_LENS
∅ = Viewing angle
FIGURE 12. FLAT WINDOW LENS
TABLE 4. RECOMMENDED DIMENSIONS FOR A FLAT
WINDOW DESIGN
D_TOTAL
1.5
D1
0.50
D_LENS @ 35°
VIEWING ANGLE
2.25
D_LENS @ 45°
VIEWING ANGLE
3.75
2.0
1.00
3.00
4.75
2.5
1.50
3.75
5.75
3.0
2.00
4.30
6.75
3.5
2.50
5.00
7.75
t=1
D1
D_LENS
D_TOTAL
Thickness of lens
Distance between ISL29001 and inner edge of lens
Diameter of lens
Distance constraint between the ISL29001 and lens
outer edge
* All dimensions are in mm.
9
FN6166.7
November 17, 2011