Indirect real-time measurement of the penpoint in an interactive projector-camera system

Abstract

Real-time interactive on documents can enhance effectiveness of learning in modern education. A pen capable of locating on a screen is one significant choice. Some products have been developed and the nib of pen is used as the emitter. However, the pen might fail to be located while our body or hand would block the light wherever the photo detector is. In this paper, we have proposed a scheme to solve the problem. It will detect the nib of pen indirectly. Meanwhile, for the realization of real time, we choose PSD(position sensitive detector) as the detector to track the light of the LEDs. And by using the method of coding, multiple light points detected by one PSD could be achieved.