To provide compact constitution with a small number of part items and to select a power transmission path (between automatic focusing and manual focusing, for instance) without special switching operation.
A second input member 8 to which manual operating force or the like is inputted, is rotatably fitted to the outer periphery of a shaft part 6b of a first input member 6 to which motor-driving force or the like is inputted. An inner race 7 is fitted to the outer periphery of the shaft part 6b so as to be rotatable integrally with the first input member 6. Ball members 9 for transmitting revolving force to an output member 10 rotatably fitted to the outer periphery of the shaft part 6b, axially in line with the second input member 8, are held by a tapered face, facing obliquely inward in the radial direction, of the second input member 8, and a parallel face 7b to a shaft and an orthogonal face 7c to the shaft, facing radially outward, of the inner race 7.
TAMURA MASAHISA
SUZUKI TAKASHI
