What is "image dissector"

An image dissector, also called a dissector tube, is a video camera tube in which photocathode emissions create an " electron image" which is then scanned to produce an electrical signal representing the visual image. The term may apply specifically to a dissector tube employing magnetic fields to keep the electron image in focus, and an electron multiplier to scan the electrons. Dissectors were used only briefly in television systems before being replaced by the much more sensitive iconoscope during the 1930s.

American television pioneer Philo T. Farnsworth invented the first functional image dissector in 1927. Earlier, German Professor Max Dieckmann and his student Rudolf Hell filed in 1925 a patent for a device named Lichtelektrische Bildzerlegerröhre für Fernseher (Photoelectric Image Dissector Tube for Television) that worked along the same principles, but failed to reduce it to practice.