 In April 1925, German professor Max Dieckmann and his student Rudolf Hell applied for a patent for a device named Lichtelektrische Bildzerlegerröhre für Fernseher (Photoelectric Image Dissector Tube for Television).A patent was issued in October 1927, and their experiments were announced in the magazines "Discovery" and "Popular Radio", but they failed to reduce it to practice.In 1951, Hell claimed that he had made a tube but could not get it to function, since at the time there was an insufficient knowledge of electron optics, the manipulation of an electron beam by electric or magnetic fields.