Patent ID: 7532812
Filing Date: 2009-05-12
Classification: G02B,G03B

Abstract:
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.