| 摘要 |
An optical apparatus for setting any one of a plurality of lenses in a certain operating position and for setting the opening of at least one of the lenses comprises a lens turret rotatable around an axis and having the lenses mounted thereon at locations spaced apart about the same axis, a gear on at least one of the lenses and turnable relative to the turret for adjusting the lens opening, and a drive system including a shaft coaxial with and rotatable in either direction about the axis and carrying a drive gear engaging each adjusting gear for turning the lens turret and each adjusting gear. At least one of the adjusting gears has a limited range of rotation relative to the lens turret in at least one direction so that the turret is rotatable by the drive gear through an adjusting gear when the latter is at a limit of its range of relative rotation. Preferably each lens is provided with an adjusting gear and only one drive gear is employed, which at any moment drivably engages all the adjusting gears. |
