Iris diaphragm device and endoscope having the same

An iris diaphragm device comprising:

• an objective optical system for imaging incidental light beams;
• iris diaphragm means which is disposed on the optical path of said objective optical system and which is displaced, so as to change the diameter of a diaphragm aperture;
• operating means including a shape-memory material which is deformed in accordance with temperatures, so as to displace said iris diaphragm means;
• and
• temperature changing means for changing the temperature of said shape-memory material of said operating means.

An endoscope comprising:

• a holding portion disposed adjacent to an operator;
• an elongated insertion portion extending in front of said holding portion;
• an objective optical system disposed at the front portion of said insertion portion and arranged to image incidental light beams;
• an iris diaphragm device including iris diaphragm means which is disposed on the optical path of said objective optical system and which is deformed so as to change the diameter of a diaphragm aperture and operating means having a shape-memory material which is deformed in accordance with temperatures so as to displace said iris diaphragm means;
• and
• temperature control means for controlling the temperature of said shape-memory material.

An endoscope comprising:

• a holding portion disposed adjacent on an operator;
• an elongated insertion portion extending in front of said holding portion;
• an objective optical system disposed at the front portion of said insertion portion and arranged to image incidental light beams;
• an iris diaphragm device including iris diaphragm means which is disposed on the optical path of said objective optical system and which is deformed so as to change the diameter of a diaphragm aperture, operating means having a shape-memory material which is deformed in accordance with temperatures so as to displace said iris diaphragm means and an heating element for heating said shape-memory material of said operating means;
• and
• temperature control means for controlling said heating element.