Patent ID: 7693405

Claim:
An image pickup device comprising: an auto focus control unit sampling contrast values of an image of an object while driving a lens in an optical axis direction, calculating a focused focal position based on the contrast values, and driving the lens to the focused focal position; a shake detecting unit detecting an amount of shake in the optical axis direction; and a selection judging unit selecting ones of the sampled contrast values based on the amount of shake detected at the time of sampling, wherein the auto focus control unit calculates the focused focal position based on the selected ones of the sampled contrast values, wherein the selection judging unit: selects one of the sampled contrast values when the amount of shake detected at the time of sampling the one of the sampled contrast values is less than or equal to a first reference amount of shake, discards the one of the sampled contrast values when the amount of shake detected at the time of sampling the one of the sampled contrast values is greater than or equal to a second reference amount of shake that is larger than the first reference amount of shake, and selects the one of the sampled contrast values when the amount of shake detected at the time of sampling the one of the sampled contrast values is greater than the first reference amount of shake and less than the second reference amount of shake, and assigns the one of the sampled contrast values to a selected one of: a lens position at the time of sampling the one of the sampled contrast values, a lens position at the time of sampling a sample contrast value immediately prior to the one of the sampled contrast values, and a lens position at the time of sampling a sample contrast value immediately subsequent to the one of the sampled contrast values, wherein the selection judging unit generates a corrected lens position by correcting the lens position at the time of sampling the one of the sampled contrast values based on the amount of shake, and selects the selected one of the lens positions to minimize a difference between the selected one of the lens positions and the corrected lens position.