JPS644716A - Autofocusing system - Google Patents

Abstract

PURPOSE:To attain accurate focusing even on an object in motion by executing detection for focusing with an optical image on a two-dimensional CCD and driving the light receiving surface of the two-dimensional CCD into blocks in a matrix shape so that focusing is executed as for the block whose movement following the passage of time is the least. CONSTITUTION:The change coupled element (CCD) 2 has a structure where image elements are arrayed in two dimensions and sets two areas which receives the respective image formations of separation lenses 10 and 11. Moreover the respective areas are set to be vertically and horizontally divided into the blocks in a matrix shape in the corresponding positions each other. And the existence of the movement of an image following the passage of time is detected every block. If the movement exists, the block whose movement is the least is selected and it the movement does not exist, the specified block is selected. Thereafter, as for the selected block correlation calculations are sequentially executed between the image signals in two areas. A distance (l) between two optical images on the CCD 2 is calculated from the combination of correlation which gives the highest correlation and the quantity of defocusing is calculated to shift the control of driving an image pickup lens. Thus, the accurate focusing an be possible even in case of photographing the object in motion.