Patent ID: 8454250

Claim:
A lens device attached to a camera, the lens device comprising: a lens barrel that holds a lens system; a mount ring that has a tubular fitted portion which establishes coupling with the camera and a flange portion which is provided around the fitted portion, the mount ring being attached to the lens barrel; a plurality of pins that is provided on the lens barrel and positions a central axis of the mount ring with respect to an optical axis of the lens system; a plurality of through holes that is formed on the flange portion; a positioning ring that has an outer diameter smaller than a hole diameter of the through holes and provided with an opening where the pins are fitted; and a fixing member that fixes the positioning ring inside the through holes, wherein the pins are restricted by the opening of the positioning ring fixed by the fixing member under a condition where the mount ring is positioned, in order to position the lens barrel and the mount ring with respect to each other.