| 摘要 |
PROBLEM TO BE SOLVED: To shorten a convergence time for converged into a focus and improving the looking performance of an image plane to the focus by changing the moving speed of a camera lens according to the quotient obtained by dividing a value obtained by subtracting a first evaluation value from a second evaluation value by a value obtained by adding the second evaluation value to the first evaluation value. SOLUTION: An AF block 137 is provided with an automatic focus integrated circuit(AF-IC) 139 and a CPU 138 for AF and this AF-IC 139 is provided with a luminance signal generation circuit and evaluation value generation circuits prepared according to respective evaluation values. A first evaluation value formed by extracting high frequency components of a first shielding frequency or more in a specific region of image signals is calculated and then a second evaluation value formed by extracting high frequency components of a second shielding frequency or more, which is lower than the first shielding frequency in the specific region of the image signals is calculated. The first evaluation value is subtracted from the second evaluation value and the moving speed of the camera lens is changed according to the quotient obtained by dividing it by the sum of the first and the second evaluation value. |
