a mail-processing machine for automatic facing of letters according to addresses and stamps and for printing a postmark and wavy lines on the envelope to cancel the stamp. They are used primarily in post offices that process more than 300,000 letters per day.
Various methods exist for recognizing the face side of a standard letter. In the USSR it is done by color contrast of the envelope or postcard and code markings printed on the envelope or postcard during their manufacture; in the USA, Great Britain, the Federal Republic of Germany, and other countries, phosphorescent or fluorescent stamps are used; and in Japan the method is based on the color contrast of the envelope and stamp. As each letter moves into the facer-canceler, it passes photoelectric indicators, which control the facing mechanism by reacting to a recognition sign, causing each envelope to assume a single position (with the stamp in the upper right-hand corner) of the four possible before cancellation. After cancellation the letters or postcards are automatically placed in accumulators, which form horizontal or vertical packs. The productivity of facer-cancelers is 20,000–30,000 letters per hour.
I. A. LAMM and K. V. BOROZDIN