| 摘要 |
PROBLEM TO BE SOLVED: To improve predicting accuracy of a moving body by changing a rangefinding interval and an average frequency in accordance with reliability and luminance when the reliability of a focus detecting signal or the luminance of an object is low. SOLUTION: The focusing state of an object image formed by a photographic lens is repeatedly detected at predetermined time intervals by a focus detecting part 1 and the focus detecting signals are outputted in time sequence. The movement of the object in the optical axial direction of the photographic lens is detected by a moving body deciding part 5 and the luminance of the object is measured by a photometric part 8. Further, the reliability of the signal outputted from the focus detecting part 1 is evaluated by a reliability deciding part 7. When that the object is moved in the axial direction of the photographic lens is detected by the moving body deciding part 5, the signal for focusing the photographic lens is predictively calculated by a moving body predicting arithmetic part 2, after a change is attained for making the specified time intervals longer, based on the outputs of the photometric part 8 and the reliability deciding part 7, when the luminance and reliability are lower than respective fixed values. |
