Image scanning device having a system for determining distance to a target

摘要

An image scanning device is provided which includes a system for determining the distance to a target to be scanned. The image scanning device includes an optical system and an image sensor array for focusing a light beam and imaging the target. The device preferably includes an automatic focusing system for adjusting the position of the optical system in order to adjust the focal point, and thereby focus the image of the target onto the image sensor array. In one embodiment of the image scanning device, the distance is determined by analyzing a collimated aiming pattern formed by collimating the light beam. In another embodiment, the distance is determined by analyzing a speckle pattern caused by the speckle effect upon the light beam hitting the target.