| 摘要 |
PROBLEM TO BE SOLVED: To provide an encoder device capable of detecting the moving position of a zoom lens, etc., with a simple constitution. SOLUTION: This encoder device for the zoom lens has a first frame (fixed frame) having a contact point moving around the optical axis of the lens and a guide part 2d guiding the contact point around the optical axis, and has a second frame (outside zoom ring) which has a guide part 5f integrally moving the contact point around the optical axis and relatively moving the contact point in an optical axis direction, and can relatively move with the first frame around the optical axis and in the optical axis direction. |
