Automatic focus detecting device

Abstract

Abstract PURPOSE:To execute an exact focusing by irradiating uniform light to an image sensor, deriving a reciprocal of an output signal in that case, multiplying the output signal for a focusing detection by its reciprocal, and correcting the output signal. CONSTITUTION:In case of the figure (a), a pupil and a pupil splitter coincide with each other, therefore, the quantity of a light passing through the pupil to each image height (h), (i) and (j) is all equal to (a). In case of the figure (b), the pupil and the pupil splitter do not coincide with each other, therefore, the quantity of a light passing through the pupil to each image height (h), (i) and (j) becomes (b), (a) and (c), respectively, are made ununiform, and the light quantity is made uneven. If a light quantity difference or the uneven light quantity exists in this way, a similarity of two images of picture data A, B are deteriorated, and an accuracy of a correlation processing result drops remarkably, therefore, when the picture data A, B are obtained by a uniform light passing through a focusing optical system, the picture data A, B become data having the uneven light quantity by eccentricity, etc. Accordingly, by executing the processing by making a correction coefficient by its reciprocal, the influence of the uneven light quantity and the light quantity difference can be eliminated.

Inventors

• 👤 Yoshiaki Horikawa
• 👤 嘉明 堀川

Bibliographic Details