Fig. 3.

Schematic view of LEDFLEX. 1 Heating resistors, 2 Glass window, 3 Excitation LEDs, 4 Fresnel lens, 5 Low-pass filter (λ < 800 nm), 6 High-pass filter (λ > 660 nm). 7 10 mm x10 mm Photodiode, 8 Detector housing, 9 Fan