Method and system for detecting sharpness of an object image

摘要

The present invention relates to a method and a system for detecting the sharpness of the object image by detecting the amount of the component of a certain specified frequency, whereby the object image formed by means of an image forming optical system is detected by an image sensitive element consisting of a number of fine photo sensitive elements arranged respectively integrated on one plane, while the outputs of the above mentioned photo sensitive elements are delivered out one after another in accordance with the arrangement order of the above mentioned elements by means of a signal time series means so as to carry out an electrical scanning of the above mentioned object image in such a manner that the then obtained scanning outputs of the object image are successively converted by means of an A - D (analogue-digital) converting means into digital signals which are put in a small computer in which an estimation function for estimating the amount of the component of a certain specified frequency in the spectrum of the spacial frequencies of the object light beam forming the above mentioned object image is programmed in advance.