Patent ID: 7719603

Claim:
An automatic focusing method for a camera in which scanning is performed to find a position of a focus lens having a largest focus value proportional to an amount of high frequency components in an image signal, and a final position of the focus lens is set according to the result of the scanning, the method comprising: in a first stage of a scan: initializing digital signal processor (DSP) values controlling the first stage of the scan including a boundary position, which is the start of a boundary region, dependent on whether a macro mode or a normal mode is set by a user; scanning entirely and solely in a first region within a first distance if the macro mode is set by the user; scanning entirely and solely in a second region beyond the first distance if the normal mode is set by the user; determining if a focal lens position is within the boundary position; and if the focal lens position is within the boundary region, then initializing digital signal processor (DSP) values controlling a second stage of the scan and advancing to the second stare of the scan; in the second stage of the scan: performing additional scanning in the second region if it is determined that the position of the focus lens found when scanning in the first region does not have the largest focus value when the macro mode is set by the user and while in the macro mode and without the user selecting a proper mode between the macro or the normal modes; and performing additional scanning in the first region if it is determined that the position of the focus lens found when scanning in the second region does not have the largest focus value when the normal mode is set by the user and while in the normal mode and without the user selecting a proper mode between the macro or the normal modes.