Patent ID: 8059956

Claim:
An auto focus method in a camera, the method comprising the steps of: detecting, by an encoder, an encoder initial value corresponding to a driving current value required for a lens unit to start to initially move and receiving the encoder initial value by an image signal processor, wherein the encoder initial value is one of encoder values corresponding to a position being equal to where the lens unit starts to initially move as a starting point of an auto focus operation, and each of the encoder values corresponds to a position value by which the lens unit is to be moved; performing the auto focus operation by starting from the detected encoder initial value, and dividing a distance that the lens unit is to be moved into sections corresponding to a preset number of steps; comparing a position value by which the lens unit is to be moved in each step of the preset number of steps with a position value by which the lens unit has actually moved in said each step; detecting an edge value that shows a brightness change for a contour of a subject in said each step; and completing the auto focus operation by moving the lens unit to a position corresponding to the edge value having a maximum brightness change for the contour of the subject selected from among the edge values detected for the preset number of steps.