| US 7,532,812 B2 | ||
| Lens apparatus | ||
| Ryuji Nurishi, Utsunomiya-shi (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Sep. 12, 2006, as Appl. No. 11/531,021. | ||
| Claims priority of application No. 2005-266060 (JP), filed on Sep. 13, 2005. | ||
| Prior Publication US 2007/0058963 A1, Mar. 15, 2007 | ||
| Int. Cl. G03B 17/00 (2006.01); G03B 3/00 (2006.01) | ||
| U.S. Cl. 396—82 [396/71; 396/73; 396/124] | 8 Claims |
| 1. A lens apparatus comprising:
an imaging optical system including a focus lens unit;
a branching optical unit disposed at the image side of the focus lens unit;
a focus-state detecting unit including a focus detecting element having a focus detection area that receives light beams from
the branching optical unit, the focus-state detecting unit detecting a focus state using the focus detecting element;
an actuator that drives the focus lens unit in the optical axis direction of the focus lens unit;
a controller that controls the actuator, in accordance with an output from the focus-state detecting unit; and
a movable image-side optical unit disposed at the image side of the branching optical unit,
wherein the controller changes the size of the focus detection area of the focus detecting element within a range in accordance
with the position of the image-side optical unit.
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