| 摘要 |
A lens barrel has a telescopic structure in which an inner cylinder and an outer cylinder move relative to each other. At different positions between the inner cylinder (11) and the outer cylinder (12) in the optical axis direction, a plurality of ring-shape retainers (201, 202) is disposed to support multiple bearing balls (30) such that the bearing balls rotate in contact with an inner cylinder (11) and an outer cylinder (12) while the retainers being supported floating in a direction parallel to the optical axis in accordance with the rotation of the bearing balls (30). The inner cylinder (11) and the outer cylinder (12), which move relative to each other, are supported by the ball bearings. |
