NaviCam is a computer device equipped with photographing and displaying functions. It recognizes markers placed in the virtual world, on which relevant information appears. With NaviCam, a user can tag information to real world scenes and execute navigation.
Jun Rekimoto and Katashi Nagao, "The World through the Computer:Computer Augmented Interaction with Real World Environments", ACM User Interface Software and Technology (UIST '95) , 1995