| 摘要 |
PURPOSE:To decide a correct deviation quantity speedily among deviation quantities according to slight lens driving, plural detection optical systems, or the state of the optical systems and to enable secure focusing by detecting a coincident deviation quantity among image deviation quantities on an optical axis. CONSTITUTION:The focus detecting device consists of, for example, a correlation calculating circuit 28, a calculating circuit 29 for a deviation quantity on a sensor surface, a calculating circuit 32 for the deviation quantities on the optical axis, an image deviation quantity decision circuit 33, etc. In the 1st state of a lens, plural image deviation quantity is detected, and in the 2nd state of the lens, at least one image deviation quantity is detected to detect the quantity of a shift in lens position between 1st and 2nd states. Thus, the quantity of variation between image deviation quantities corresponding to the 1st and 2nd states is detected and compared with the quantity of the shift in lens position to select the image deviation quantity corresponding to the variation quantity coincidence among the image shift quantities. Consequently, the correct deviation quantity can be decided speedily among the deviation quantities according to the slight lens driving, plural detection optical systems, or the state of the optical systems to enable the secure focusing. |
