ISL29003 Datasheet, PDF (11/15 Pages) Intersil Corporation – Light-to-Digital Output Sensor with High Sensitivity, Gain Selection, Interrupt Function and I2C Interface

ISL29003
Window with Light Guide Design
If a smaller window is desired while maintaining a wide
effective viewing angle of the ISL29003, a cylindrical piece of
transparent plastic is needed to trap the light and then focus
and guide the light on to the device. Hence, the name light
guide or also known as light pipe. The pipe should be placed
directly on top of the device with a distance of D1 = 0.5mm
to achieve peak performance. The light pipe should have
minimum of 1.5mm in diameter to ensure that whole area of
the sensor will be exposed. See Figure 5.
TABLE 16. RECOMMENDED DIMENSIONS FOR A FLAT
WINDOW DESIGN
D_TOTAL
1.5
D_LENS @ 35°
D_LENS @ 45°
D1
VIEWING ANGLE VIEWING ANGLE
0.50
2.25
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.
D_LENS
D₂ >1.5mm
LIGHT PIPE
t
L
D₂
D_LENS
ISL29003
FIGURE 5. WINDOW WITH LIGHT GUIDE/PIPE
11
FN7464.5
August 8, 2008