Accurate detection of the position of a light spot projected onto its active area is performed by the OSM910 position sensing detector. The analog silicon photodiode offers a high degree of linearity, resolution and fast response time, it’s claimed.The detector can be configured with an appropriate infrared LED, lens and detection circuitry to accurately detect the location of objects over distances from less than 1/4” to 10 feet. It has a common cathode and two anode contacts with high resistance between them. A spot of light projected on the active area produces a current from each anode that’s proportional to the spot’s relative position. A change in spot position causes the current from each anode to change, allowing accurate position tracking. Applications include auto-focus and safety mechanisms and media detection in printers, among others.