| 摘要 |
PROBLEM TO BE SOLVED: To provide a diaphragm device for a camera equipped with a diaphragm ring made inexpensive and light in weight. SOLUTION: The diaphragm ring 3 can rotate with an optical axis as center, and has seven cam grooves 3a and a tooth part 3b. Seven diaphragm blades 4 can rotate on a bottom board 1 and their engaging pins 4b are fitted in the cam grooves 3a. A reduction gear 5i rotated by the rotor 5c of a motor 5 is meshed with the tooth part 3b. Since the ring 3 is manufactured by injection molding by using synthetic resin material, it is manufactured more inexpensively than the conventional diaphragm ring made of metal. Since the ring 3 is light in weight, its rotation is quickened, and when the ring 3 is driven by the motor, power consumption is made low and noise produced in the meshing part is restrained to be quiet in comparison with the conventional one. COPYRIGHT: (C)2005,JPO&NCIPI
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