| 摘要 |
PURPOSE:To simplify the cam shape of a cam ring and to miniaturize the whole of a zoom lens without reducing the strength by allowing the area for zoom photographing of a cam means to include the area for macro photographing. CONSTITUTION:At the time of zoom operation, a pin 12b of an operation ring is moved back and forth in a first part 20 of a guide hole 10c of a fixed ring 10, and simultaneously, a pin 13a of a lens holding member 13 is moved back and forth in a cam hole 11c of a cam ring (from a telephoto position A to a wide position B). At the time of macro operation, the pin 12b of the operation ring is moved back and forth in a second part 21, and simultaneously, the pin 13a of the lens holding member 13 is moved back and forth in the cam hole 11c of the cam ring (from the wide position B to a macro terminal position C). That is, the zoom area of the cam hole is between positions A and B, and a part between positions B and C of the zoom area is the macro area. Since the area for macro photographing is included in the area for zoom photographing with respect to cam holes 11a-11c, cam holes for macro are not especially necessary.
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