| 摘要 |
<p>The purpose of the present invention is to provide a lens system whereby it is possible to change the magnitude of torque needed for the rotation of an operation ring depending on whether a drive unit is attached to a lens barrel. Another purpose of the present invention is to provide a lens barrel and a drive unit. When a drive unit is not attached to a lens barrel, a torque adjustment mechanism operates and a friction member presses against an operation ring by means of the biasing force from a biasing member. Once the drive unit is attached to the lens barrel, a stopping member provided to the drive unit passes through a path formed on a fixed ring and acts on the torque adjustment mechanism, thereby stopping the biasing action of the biasing member.</p> |
