An endoscopic adapter assembly for coupling a video camera head and an endoscope having a proximal end, the adapter includes an ocular adapter for engaging securely the proximal end of the endoscope. An endoscope-engageable portion engages the coupler adapter and a focusing portion is rotatably secured...http://www.google.ca/patents/US4807594?utm_source=gb-gplus-sharePatent US4807594 - Adapter assembly for endoscopic video camera
