An endoscope system comprises first and second endoscopes each of which includes an elongated insertion tube and an imaging device, a light source for supplying illumination light to the endoscopes, a function for processing a signal originating from one of the imaging devices, and a video processor...http://www.google.com/patents/US5196928?utm_source=gb-gplus-sharePatent US5196928 - Endoscope system for simultaneously displaying two endoscopic images on a shared monitor
