Real-life applications of terahertz (THz) systems often require fast imaging of large field of view of opaque scenes. Such features have been demonstrated by the development of a complete reflection active THz imaging system that combines QCLs as sources and antenna & cavity coupled micro-bolometer as THz video camera. While better than 5 mm resolution images of 40×60 mm² illuminated surfaces are acquired in real-time, a rotating planar mirror provides fast scanning of large areas, e.g. 20×30 cm² in less than 10 seconds. This paper gives an overview of the developed system and video demonstrations.