| 摘要 |
PURPOSE:To perform speedy and smooth focusing operation by an easy method by finding a distance by an arithmetic processing method from the ratio of the varying component and mean component of an image with the photoelectric conversion output signal of a subject image. CONSTITUTION:The light from a subject 1 is imaged on a photoelectric converting means (image sensor) 4 through the stop member 3 of an optical system 2. Then the output of the sensor 4 is detected as the varying component by a varying component detection part 5 and detected as the mean component by a mean component detection part 6. Then a ratio calculation part 7 compares the varying component of the detection part 5 with the mean component of the detection part 6. An arithmetic part 8 controls the stop member 3 and also drives the lens group of an optical system 2 through the lens driving part 9 according to the output of the calculation part 7 and the output of a system processor to calculate a defocusing quantity. Thus, the speedy and smooth focusing operation is easily performed. |
