Optical sensors are used to detect various things using visible light and invisible light. ROHM manufactures light emitting devices with various wavelengths such as infrared light emitting diodes and VCSELs, high sensitivity and high reliability phototransistors, light receiving devices such as transmissive photo-interrupters, and light receiving and emitting modules such as reflective photosensors (photo-reflectors) to meet the diverse needs of the market.