| 摘要 |
PROBLEM TO BE SOLVED: To perform high-speed focus detection with simple constitution and to provide the focus detection technique being free from parallax. SOLUTION: Subject light from a subject at a subject distance L is formed into an image on a CCD 5 through a photographing optical system 3 as shown by the subject light 7, and formed into the image on a line sensor 4 through a light receiving lens 6 as shown by the subject light 11. A phase difference between an output signal 10 from the CCD 5 and an output signal 12 from the line sensor 4 at such a time becomes S+x. The subject distance L becomes L=Sa/x from L:S=a:x. S and (a) are known and (x) is obtained by the phase difference, so that the subject distance L is obtained. The focusing position of a focus lens is obtained according to the obtained subject distance L, the moving direction and the moving amount are obtained based on a present focus lens position, and the focus lens is moved to a focusing position based on the moving direction and the moving amount. |
