CHROMATIC ABERRATION CORRECTION IN IMAGING SYSTEM INCLUDING VARIABLE FOCAL LENGTH LENS

摘要

An image acquisition system is operated to provide an image that is relatively free of the effect of longitudinal chromatic aberration. The system includes a variable focal length lens (e.g., a tunable acoustic gradient index of refraction lens) that is operated to periodically modulate a focus position. First, second, third, etc., wavelength image exposure contributions are provided by operating an illumination system to provide instances of strobed illumination of first, second, third, etc., wavelengths (e.g., green, blue, red, etc.) timed to correspond with respective phase timings of the periodically modulated focus position which focus the respective wavelength image exposure contributions at the same focus plane. The respective phase timings of the periodically modulated focus position compensate for longitudinal chromatic aberration of at least the variable focal length lens. An image is produced that is relatively free of the effect of longitudinal chromatic aberration by combining the image exposure contributions.

主权项

1. A method for operating an image acquisition system to provide an image that is relatively free of an effect of longitudinal chromatic aberration in one or more lenses of the image acquisition system, the image acquisition system comprising an imaging system including a variable focal length lens, an illumination system, and a controller, the method comprising:
operating the variable focal length lens to periodically modulate a focus position of the imaging system over a plurality of focus positions along a Z-height direction; providing a first wavelength image exposure contribution by operating the illumination system to provide an instance of strobed illumination of a first wavelength timed to correspond with a first phase timing of the periodically modulated focus position which focuses the first wavelength image exposure contribution at a first focus plane; and providing a second wavelength image exposure contribution by operating the illumination system to provide an instance of strobed illumination of a second wavelength timed to correspond with a second phase timing of the periodically modulated focus position which compensates for longitudinal chromatic aberration of at least the variable focal length lens and focuses the second wavelength image exposure contribution at the first focus plane.