Autofocusing optical imaging device

摘要

An optical imager includes: an image sensor for capturing images of targets and outputting image signals; a lens for focusing the target on the image sensor as a function of lens position; a memory for storing predetermined lens positions determined from predetermined target sizes; and a controller for determining current target size based on captured images and positioning the lens at a predetermined lens position by correlating current target size with predetermined target sizes.

主权项

1. A method of operating an optical imager comprising:
(a) capturing an image of a target in a set up mode with an image sensor; (b) determining the proper focus setting of a lens to bring a target in focus with the image sensor; (c) storing a position of the lens for the determined proper focus setting; (d) repeating steps (a) through (c) until a desired number of lens positions have been stored, wherein lens positions that have been stored include minimum and maximum recorded lens positions; (e) capturing an operating image in an autofocus mode; (f) moving the lens between the minimum and maximum previously recorded lens positions to obtain the proper focus setting for the operating image; (g) capturing a focused image at the proper focus setting; and, (h) processing the focused image, wherein the minimum and maximum recorded lens positions represents a motion range which is less than the maximum possible optical imager lens motion range.