Cleaning device for an observation window of an endoscope

An endoscope comprising an elongated sheath having two ends, an operation section having two ends, one end being connected to one end of the sheath, a distal end section having a proximal end connected to the other end of the sheath and a distal end and a nozzle chamber formed in the distal end section, and an observation window provided on the distal end of the distal end section and having an outer surface, a cleaning device comprising:

• a hollow cylindrical nozzle reciprocatingly disposed in the nozzle chamber and having a distal end portion adapted to project from the distal end of the distal end section and recede into the distal end section according to reciprocation of the nozzle, said distal end portion having a blind end extending from the distal end of the distal end section;
• a nozzle opening formed in the distal end portion of the nozzle directed to the outer surface of the observation window when the nozzle projects from the distal end of the distal end section;
• nozzle opening and closing means provided in the distal end section for closing the nozzle opening when the nozzle recedes into the distal end section;
• a fluid passage extending through the sheath and having two ends, one end communicating with the nozzle and the other end being disposed in the operation section and connected to fluid supplying means disposed outside the operation section;
• nozzle retracting means provided in the endoscope for retracting the nozzle into the distal end section;
• and
• nozzle projecting means provided in the endoscope for projecting the distal end portion of the nozzle from the distal end of the distal end section when the observation window is cleaned.