AUTO IRIS DEVICE PROVIDED WITH LOCK MECHANISM

PURPOSE:To constitute a titled device so that an aperture is not varied not only at the time of locking but also after locking, by pressing in advance a diaphragm ring by a spring in the same direction as a lock lever presses the diaphragm ring, so than no gap is made between the diaphragm ring and a guide part. CONSTITUTION:As for a spring 28, one end is fixed and supported by a screw 19, and the other end is fixed and supported by a shaft 4. Accordingly, a diaphragm ring 2 pushed by the spring 28 becomes a one-sided state, the inside circumferential surface of the diaphragm ring 2 in the vicinity of an arm part 2b contacts by pressing to the side face of a guide groove 1c, and no gap is made. Accordingly, even if a lock lever 13 is turned counterclockwise against a spring 15 and a circular arcuate surface 13b is pressed against a ring 3, the diaphragm ring 2 does not move, therefore, it can be locked in a state of an aperture in that case, and a diaphragm aperture can be set exactly.