Blur detection device, imaging device, lens device, imaging device main body, blur detection method, and blur detection program

Abstract

Provided are a blur detection device, an imaging device, a lens device, an imaging device main body, a blur detection method, and a blur detection program capable of appropriately detecting blurring of an imaging device. An angular velocity of a digital camera and a posture of the digital camera with respect to an Earth's rotation axis are detected. An Earth's rotation angular velocity component superimposed on a detection result of the angular velocity is calculated. The Earth's rotation angular velocity component is subtracted from the detection result of the angular velocity, and a blur amount of the digital camera is calculated based on the subtracted angular velocity.

What is claimed is: 
     
         1 . A blur detection device comprising:
 an angular velocity detector that detects an angular velocity of an imaging device;   a first high pass filter that eliminates an influence of zero variation of an output of the angular velocity detector; and   a blur amount calculator that calculates a blur amount of the imaging device based on an output of the first high pass filter.   
     
     
         2 . The blur detection device according to  claim 1 , wherein a cutoff frequency of the first high pass filter is set to be a value lower than a frequency of blurring caused by Earth's rotation. 
     
     
         3 . The blur detection device according to  claim 2 , further comprising:
 a posture detector that detects a posture of the imaging device with respect to an Earth's rotation axis;   a rotation angular velocity component calculator that calculates an Earth's rotation angular velocity component superimposed on the output of the angular velocity detector based on the posture of the imaging device detected by the posture detector; and   a subtractor that subtracts the Earth's rotation angular velocity component calculated by the rotation angular velocity component calculator from the output of the angular velocity detector.   
     
     
         4 . The blur detection device according to  claim 1 , further comprising a switcher that switches an output destination of the angular velocity detector, to the blur amount calculator or the first high pass filter based on whether or not there is the zero variation of the output of the angular velocity sensor. 
     
     
         5 . The blur detection device according to  claim 1 , further comprising:
 a second high pass filter, a cutoff frequency of the second high pass filter being set to be a value lower than a cutoff frequency of the first high pass filter; and   a switcher that switches an output destination of the angular velocity detector, to the first high pass filter or the second high pass filter based on an imaging condition of the imaging device.   
     
     
         6 . The blur detection device according to  claim 5 , wherein:
 the imaging condition is an exposure time of the imaging device; and   the switcher sets the output destination of the angular velocity detector based on whether or not the exposure time is equal to or less than a threshold value.   
     
     
         7 . The blur detection device according to  claim 6 , wherein the threshold value is set with consideration for an influence of an Earth's rotation on detection of blurring of the imaging device. 
     
     
         8 . The blur detection device according to  claim 5 , further comprising a subtractor that subtracts an Earth's rotation angular velocity component from the output of the angular velocity detector, wherein:
 the imaging condition is an exposure time of the imaging device; and   the switcher sets the output destination of the subtractor based on the exposure time and a zero output of the subtractor.   
     
     
         9 . The blur detection device according to  claim 5 , wherein the switcher determines whether or not a mode in which long-time exposure is performed is selected as an imaging mode, sets the output destination of the angular velocity detector to the first high pass filter in a case where the mode in which the long-time exposure is performed is not selected, and sets the output destination of the angular velocity detector to the second high pass filter in a case where the mode in which the long-time exposure is performed is selected.