Lens barrel assembly having iris diaphragm device and projector

A projector for projecting an image, including a stationary barrel, a rotatable barrel for rotating in said stationary barrel relative thereto, to move an incorporated lens system along an optical axis, and an iris diaphragm device, contained in said rotatable barrel, for changing a size of an aperture opening by rotating a driving portion rotatable about said optical axis, said projector comprising:

• a first groove, formed in said stationary barrel to extend in a circumferential direction defined about said optical axis, and having a length equal to or more than a rotatable range of said rotatable barrel;
• a second groove, formed in said rotatable barrel to extend along said first groove, and having a length according to a combination of said rotatable range of said rotatable barrel and a rotatable range of said driving portion;
• a diaphragm control plate portion, disposed in said rotatable barrel in a rotatable manner in said circumferential direction, having an end portion from which said driving portion extends;
• an engaging groove formed in said diaphragm control plate portion to extend along said optical axis;
• an operable unit disposed outside said stationary barrel in a rotatable manner about said optical axis;
• and
• a pin device, having first and second end portions, said first end portion being secured fixedly to said operable unit, said second end portion being inserted through said first and second grooves and said engaging groove, for operating upon rotation of said operable unit to cause said engaging groove to rotate said diaphragm control plate portion about said optical axis to actuate said iris diaphragm device with said driving portion.