| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic focus detecting device which can perforfn high-accurate and stable focus detection and for which image evaluation function is used. SOLUTION: The optical image of a sample 1 is fetched in an image sensor 4 through an objective lens 2 and an image formation lens 3, the image data fetched in the sensor 4 are stored in a memory 7, pixel data within the specified range of the memory 7 are read out to a contrast evaluation calculating means 8, the sum of the adjoining plural pixels of the pixel data is defined as one pixel block, the total sum of the difference of the adjoining pixel blocks or the square of the difference is calculated as the contrast value of the image, also the contrast value of the image is found plural times while changing the combination of the pixel data included in the pixel block in the case of each image input, and focusing degree is found while the sum of those is defined as the image evaluation function. |
