At least one controlling unit of a controlling unit for controlling a bending driving motor bending driving a bendable portion, a controlling unit for controlling an advancing and retreating driving motor advancing and retreating moving an insert section and a controlling unit for controlling a rotating...http://www.google.com.au/patents/US5159446?utm_source=gb-gplus-sharePatent US5159446 - Electronic endoscope system provided with a separate camera controlling unit and motor controlling unit
