Method of driving focusing element in barcode imaging scanner

摘要

A method includes the following: (1) detecting light from a target object to capture multiple images of the target object while substantially maintaining the distance between the target object and the imaging lens arrangement that is configured to have a focus position thereof changed with a lens-driving-parameter; (2) processing the at least one of the multiple images to determine a feature-size in an aiming pattern; (3) processing at least two of the multiple images to find an optimal lens-driving-parameter that results in the maximum image sharpness; and (4) storing both the feature-size and the optimal lens-driving-parameter into a memory.

主权项

1. A method comprising:
detecting light from a target object through an imaging lens arrangement with an imaging sensor having photosensitive elements to capture multiple images of the target object while substantially maintaining the distance between the target object and the imaging lens arrangement, wherein the imaging lens arrangement is configured to change a focus position thereof with a lens-driving-parameter, and wherein at least one of the multiple images is captured during a time period when an extended-aiming-pattern having at least one line of visible illumination is generated on the target object by projecting visible light through an aiming pattern generating element; processing the at least one of the multiple images to determine a feature-size measuring a size of the at least one line of visible illumination on the same focus plane in the at least one of the multiple images; processing at least two of the multiple images to find an optimal lens-driving-parameter that results in the maximum image sharpness; and storing both the feature-size and the optimal lens-driving-parameter into a memory for changing a calibration table.