| 摘要 |
PROBLEM TO BE SOLVED: To provide a device by which a guide member is prevented from coming off from a guide groove to guide a lens barrel to straight advance by a simple constitution by forming the bottom part of the guide groove so as to make a width larger that that of an aperture part and also forming the top end part of the guide member so as to make the width larger than that of a base end part. SOLUTION: A straight advance guide groove 27 is formed along an optical axis on the inner peripheral surface of a first lens barrel 13, and also a straight advance guide protrusion 30 is engaged with the straight advance guide groove 27, so that the first lens barrel 13 is guide to straight advance in an optical axis direction. The bottom part 27C of the straight advance guide groove 27 is formed so ads to have a large width by forming a tapered part 27a on both wall surfaces 27A, and the top end part 30C of the straight advance guide protrusion 30 is formed so as to have the large width by forming a tapered part 30a on both wall surfaces 30A. Thus, even though twisting force is applied to the straight advance groove 27 and the straight advance protrusion 30, the straight advance guide protrusion 30 is prevented from easily coming off from the straight advance guide groove 27.
|
