| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens device capable of preventing a nick from being caused in a groove for guiding a roller by supporting the roller in a moving barrel through an elastic member and forming the outer peripheral surface of the roller so that its cross section may be circular-arc-shaped. SOLUTION: The 2nd and the 3rd rollers 16b and 16c of a roller train 16 are supported in the moving barrel 14 through the elastic members 50 and 56. The outer peripheral surfaces of the rollers 16a to 16b are formed to be circular-arc-shaped. Even when the rollers 16b and 16c give impact to the inner wall surface of a straight advance groove 20, the elastic members supporting the rollers 16b and 16c are elastically deformed to absorb the impact force. In such a case, the rollers 16b and 16c come into contact with the inner wall surface of the groove 20 along an outer peripheral surface formed to be circular- arc-shaped, so that they do not exert unnatural force on the inner wall surface of the groove 20 and the nick is not caused on the inner wall surface of the groove 20.
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