Physicist, born in Murom, W Russia. He studied at the St Petersburg Institute of Technology and the Collège de France in Paris, emigrated to the USA in 1919, and became a US citizen in 1924. He joined the Radio Corporation (1929), becoming director of electronic research (1946) and vice-president (1947). In 1923–4 he patented an all-electronic television system using a scanned camera-tube (the iconoscope), in 1929 demonstrated a cathode-ray display (the kinescope), and in later years contributed to the development of colour television and the electron microscope. He is regarded as ‘the father of modern television’.