| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens barrel improved in terms of the degree of freedom on the design of a lens by realizing the moving form of what is called a discontinuous function by which extreme bent movement is realized in the straight advance moving function of the lens with reference to the rotation of the lens barrel. SOLUTION: A straight advance barrel 2 is provided with a plurality of cam grooves A and B and a plurality of guide pins A and B respectively fit in the cam grooves so as to switch the effective acting areas of cam grooves 4 and 5 and guide pins 6 and 7 following the cam grooves in the straight advance actuation of the barrel 2 obtained by the rotation of a rotary barrel 3. The cam grooves 4 and 5 have bent shape where cam grooves 4a and 5b taking charge of positive straight advance movement and cam grooves 4b and 5a taking charge of negative straight advance movement are separated from each other, and are provided with switching levers 8 and 9 at the respective bent positions of the cam grooves. The guide pins 6 and 7 fit in the cam grooves 4 and 5 by the rotating action of the lens barrel are switched by the switching levers 8 and 9 so as to follow the effective cam grooves 4a and 5b taking charge of the positive straight advance movement and the effective cam grooves 4b and 5a taking charge of the negative straight advance movement. COPYRIGHT: (C)2004,JPO&NCIPI
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