| 摘要 |
PROBLEM TO BE SOLVED: To appropriately eliminate such a harmful effect as visual field mask vignetting as to focal point detector and a method for adjusting the same in a phase difference detecting system. SOLUTION: This device is provided with a visual field mask 1, a separator optical system 2 dividing a luminous flux passing the mask 1 to form image, an image sensor 3 photoelectrically converting a set of light images obtained by the system 2, a photodetecting area storage means 4, a mask means 5 masking the photoelectric output of the sensor 3 in accordance with the information of the photodetecting area written in the means 4, and a focal point calculating means 6 calculating defocusing amount from the photoelectric output masked by the means 5. As for this adjusting method, the photodetecting area at which the vignetting does not occur when irradiation of uniform illumination is performed on the sensor 3 through the mask 1 and the system 2 is written in the means 4. |
