| 摘要 |
PURPOSE:To provide a distance measuring device for an autofocusing apparatus which can surely focus even when there exist a plurality of subjects, prevent mismeasurement even when an error occurs in spatial quantization in image- formation on a light-receiving sensor and can measure a distance to the subject accurately and rapidly. CONSTITUTION:A subject is caught by a light-receiving sensor constituted by three line sensors 10b, 20b and 30b, and a zero-cross point for a secondary difference of its luminance distribution is calculated and detected. And a coincidence point of three zero-cross behaviors concerning these three line sensors 10b, 20b and 30b is detected with making one of the three line sensors 10b, 20b and 30b as a reference and displacing the other two alternately one after another, and a distance to the subject is measured by a displacement amount of the zero-cross behaviors of two line sensors at coincidence. |
