Generating a Television Picture 3 We have seen that the only effective way to transmit an optical image at a distance is to "dissect" or scan it, thereby transforming a simultaneous phenomenon into a sequential succession of individual pieces of optical information. On the receiving end, these individual pieces of optical information are transformed back into electric signals whose succession is sufficiently rapid to blend into one continuous signal. 3.1 Picture Scanning The first scanning device used by television pioneers was the Nipkow disk (as shown in Figure 1.1), which undoubtedly played a crucial role in the development of television. It allowed the practical realization of the transmission of moving images and proved the feasibility of a television system. However, as a mechanical device, it was very much limited in its capacities and development potential, and it had no future in the system it helped to create. The Nipkow disk had a number of problems inherent in its mechanical nature: