| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens barrel enabling a user to easily set to the focal distance of a circumferential fisheye or a diagonal fisheye even when the zoom lens barrel is attached to a camera whose imaging device size is different, and eliminating the need of a lock release operation when a zoom operation is performed again. <P>SOLUTION: The lens barrel includes a zoom operation ring, a fixed cylinder rotatably holding the zoom operation ring, and a rotation restriction means restricting the rotation of the zoom operation ring with respect to the fixed cylinder. Zooming is performed by operating the zoom operation ring, and the focal distance range of the lens barrel is such that the image circle is smaller than that of the focal distance corresponding to a field angle of a circumferential fisheye or a diagonal fisheye in at least one imaging device size. By operating the rotation restriction means, the rotation of the zoom operation ring to a wide side is restricted to the focal distance corresponding to the field angle of the circumferential fisheye or the diagonal fisheye in the imaging device size. <P>COPYRIGHT: (C)2012,JPO&INPIT |
