| 摘要 |
PURPOSE:To provide the phase difference detection type distance detecting method which has high precision even when right-left variation in the minimum value of the degree of correlation is asymmetrical. CONSTITUTION:A reference photosensor and a reference photosensor which have plural photodetecting elements respectively are arranged on the focal plane of an optical system and images of the same subject are formed on both the sensors and a reference light signal while varied in phase is compared with a standard light signal to calculate the degree of correlation, thereby detecting the distance to the object from the phase wherein the degree of correlation has an extremal value. If the variation in the degree of correlation across the extremal value y0 is asymmetrical, the value obtained by subtracting a ratio beta of variation in the degree of correlation with the phase varying in units from the other ratio alpha of variation and dividing the result by a constant (c) is added to the degree y1 of correlation at a sample point adjoining to the extremal value on the side where the former variation ratio is obtained to obtain a value v1 as the corrected degree of correlation, which is used for interpolative arithmetic to find the phase where the degree of correlation has the extremal value. |
