| US 7,603,030 B2 | ||
| Optical apparatus for correcting the movement of a focusing lens in accordance with a change in focal length | ||
| Seiichi Kashiwaba, Utsunomiya (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Oct. 04, 2005, as Appl. No. 11/243,880. | ||
| Claims priority of application No. 2004-300378 (JP), filed on Oct. 14, 2004. | ||
| Prior Publication US 2006/0083505 A1, Apr. 20, 2006 | ||
| Int. Cl. G03B 17/00 (2006.01) | ||
| U.S. Cl. 396—86 [396/79; 396/85; 396/101; 396/121; 396/529; 359/694; 359/699; 359/700; 359/701] | 9 Claims |
| 1. An optical apparatus comprising:
a zoom optical system including a focusing lens unit;
a first cam member that rotates around the optical axis and moves along the optical axis in a magnification-changing operation,
the first cam member including a focus cam portion for driving the focusing lens unit; and
a speed-changing mechanism that changes the relative rotational speed between the focusing lens unit and the first cam member
in accordance with a change of the focal length of the zoom optical system in the magnification-changing operation,
wherein all parts of the speed-changing mechanism move along the optical axis in the magnification-changing operation, and
wherein the speed-changing mechanism includes a transmission member that is rotatable around the optical axis with respect
to the first cam member and that includes a speed-changing cam portion for changing at least one of the rotational speed and
the rotational direction of the focusing lens unit.
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