| 摘要 |
PROBLEM TO BE SOLVED: To improve a tracking performance to a moving subject by statistically calculating an average detecting time, image surface position and image surface velocity, based on the defocusing amount of a photographing lens, its detecting time and the position of the lens, and further statistically calculating the image surface velocity and the image surface position at a predetermined time. SOLUTION: The defocusing amount is inputted from a defocusing amount detection device 3, and the position of the lens at this point and the time are inputted from a position detection device 2 and a clock 5. For instance, data from a present time to 300ms past is viewed in perspective to select the data. The result by statistical calculation is stored in a 2nd storage device 7. When the number of data exceeds a specified value, regression calculation is performed. The tilt of a positional regression expression is found as the change per unit time of the image surface velocity from the regression calculation. By performing the calculation including an intercept, the image surface velocity at a certain time is estimated. Then, the image surface velocity optimum for focusing at exposure time and the defocusing amount at the present time are calculated, and the data is transmitted to a lens having driving ability so as to obtain focusing. |
