Patent ID: 7697058

Claim:
An autofocus adjustment device, comprising: a distance-measuring device which measures a distance from an object; an image pickup device which converts an optical image of the object taken in through an image pickup lens to an image signal; a focus adjustment device of a contrast system which adjusts a focus position of the image pickup lens using a high frequency component of the image signal outputted from the image pickup device; and a focus position range setting device which sets a first range of the focus position for adjusting the focus position of the image pickup lens in the contrast system according to image pickup conditions, wherein: the image pickup lens is driven according to a measurement result of the distance-measuring device, and then the focus adjustment device adjusts the focus position according to the image signal outputted from the image pickup device within the range of the focus position set by the focus position range setting device, and if the focus position is failed to be found as a result of focus adjustment in the contrast system within the first focus position range set by the focus position range setting device, then the focus position range setting device automatically changes the focus position range to a second focus position range that does not overlap with the first focus position range and the focus adjustment device adjusts the focus position within the range of the focus position changed by the focus position range setting device.