Frequency Divider Circuit (U.S. Patent No. 3,619,646) Eric Andre Vittoz, 1971

Granted in 1971, Eric Vittoz's patent for the first binary frequency divider was used in the first prototypes of the electronic watch. His frequency divider circuit included at least one logical structure complying with certain Boole Relations including two complementary input quantities and two output quantities. The logical structure comprised three pairs of field effect transistors, such as MOS-transistors having isolated gates. A cascade of such binary frequency divider circuits could be made as an integrated circuit. The SSCS News includes pages 1-2 of this patent.