EETimes quotes Ilan Splillinger, CVP of HoloLens and silicon at Microsoft, revealing the company's AR glasses hardware details:
"The HoloLens sensor bar (above) packs four environmental cameras for tracking head movements and gestures used to control the display. A depth sensor is a Kinect scaled to a fraction of its size and power consumption. It supports a short range mode for tracking gestures within a meter and a long range mode for mapping the room. A 2MPixel high def video camera projects images the user sees."