Focus adjustment device and imaging apparatus

Abstract

An imaging apparatus includes an imaging device that captures an image by an optical system and outputs a signal, the optical system having an aperture and a lens that is driven in an optical axis direction; and a mode setting unit that sets a motion picture imaging mode in which the image is captured as a motion picture and a still picture imaging mode in which the image is captured as a still picture. An aperture size of the aperture is changed at a first speed when the still picture imaging mode is set and the aperture size of the aperture is changed at a second speed slower than the first speed when the motion picture imaging mode is set.

What is claimed is: 
     
         1 . An imaging apparatus comprising:
 an imaging device that captures an image by an optical system and outputs a signal, the optical system having an aperture and a lens that is driven in an optical axis direction; and   a mode setting unit that sets a motion picture imaging mode in which the image is captured as a motion picture and a still picture imaging mode in which the image is captured as a still picture, wherein   an aperture size of the aperture is changed at a first speed when the still picture imaging mode is set and the aperture size of the aperture is changed at a second speed slower than the first speed when the motion picture imaging mode is set.   
     
     
         2 . The imaging apparatus as recited in the  claim 1 , further comprising
 a focused state determination unit that determines whether or not the image of an object is focused on an image plane of the imaging device, wherein   the focused state determination unit prohibits a focused state determination during driving of the aperture when the still picture imaging mode is set.   
     
     
         3 . The imaging apparatus as recited in the  claim 1 , further comprising
 a focused state determination unit that determines whether or not the image of an object is focused on an image plane of the imaging device, wherein   the focused state determination unit performs a focused state determination regardless of a driving condition of the aperture when the motion picture imaging mode is set.   
     
     
         4 . The imaging apparatus as recited in the  claim 2 , further comprising
 a display unit that performs an indication of the focused state when the focused state determination unit determines that the image of the object is focused on the image plane of the imaging device.   
     
     
         5 . The imaging apparatus as recited in the  claim 3 , further comprising
 a display unit that performs an indication of the focused state when the focused state determination unit determines that the image of the object is focused on the image plane of the imaging device.   
     
     
         6 . The imaging apparatus as recited in the  claim 1 , further comprising
 a detection unit that detects a position of the lens where the image of an object is focused on an image plane of the imaging device, wherein   the detection unit detects repeatedly the position of the lens where the image of the object is focused on the image plane of the imaging device while the lens is driven to the position detected by the detection unit.