Abstract:
An optical measurement apparatus (10) comprises a photon detection unit (12) that detects incident photons, a time signal output unit (14) that outputs a time signal, and a storage unit (16) where the time signal outputted from the time signal output unit (14) is stored when photons are detected by the photon detection unit (12). The photon detection unit (12) comprises an HPD (24) having a photo-cathode (24a) and an APD (24b), a TZ amplifier (26), a peak-holding circuit (28), and an A/D converter (30). The time signal output unit (14) comprises a timer (32) and a counter (34). The storage unit (16) comprises a comparator (36) and a memory (38). When photons impinge on the HPD (24), a trigger signal is outputted from the comparator (36), and the photon count outputted from the A/D converter (30) and the time information outputted from the counter (34) are stored in the memory (38).
Abstract:
Presented here are devices and methods to correct ambient light measurements made in the presence of optical elements, such as the curved edge of the cover glass associated with the mobile device. In one embodiment, a film with optical properties is placed within the ambient light sensor to diffuse the high-intensity light beam coming from the optical element. In another embodiment, an aperture associated with the ambient light sensor is disposed to prevent the high-intensity light beam from entering the ambient light sensor. In another embodiment, a processor coupled to the ambient light sensor smooths the peak associated with the high intensity light beam produced by the optical element.