System and method for continuous, asynchronous autofocus of optical instruments using multiple calibration curves
AssigneeApplied Precision, LLC
InventorsJeremy Cooper, Paul Goodwin, Stephen G. Goodson
Life of this patent
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Abstract
The current application is directed to autofocus subsystems within optical instruments that continuously monitor the focus of the optical instruments and adjust distances within the optical instrument along the optical axis in order to maintain a precise and stable optical-instrument focus at a particular point or surface on, within, or near a sample. Certain autofocus implementations operate asynchronously with respect to operation of other components and subsystems of the optical instrument in which they are embedded. The described autofocus subsystems employ multiple calibration curves to precisely adjust the z-position of an optical instrument.
Claims20
An autofocus subsystem included within an optical instrument, the autofocus subsystem comprising:
- an autofocus light path through which the autofocus subsystem receives electromagnetic radiation backscattered from an optical interface of the optical instrument;
- an autofocus rotor including two or more autofocus-rotor elements through each of which the backscattered electromagnetic radiation passes, when the autofocus rotor is aligned with the autofocus light path, onto an autofocus detector that produces a corresponding autofocus signal;
- and
- an autofocus processing component including an electronic memory and a processing component that
- controls positioning of one or more instrument components in optical-instrument position space with coordinate axes x and y perpendicular to an optical-instrument optical axis and coordinate axis z along the optical-instrument optical axis,
- acquires and stores, in memory, two or more calibration curves, each representing autofocus signal magnitudes associated with a particular autofocus-rotor element with respect to optical-instrument position, and
- uses the two or more calibration curves to monitor and adjust optical-axis position during data collection.
A method for adjusting the position of an optical instrument during data collection at a point of interest by an autofocus subsystem within an optical instrument, the method comprising:
- acquiring, prior to data collection, two or more calibration curves, each calibration curve representing autofocus-signal magnitude detected through a particular autofocus-rotor element with respect to optical-instrument position;
- storing data for the two or more calibration curves in an electronic memory;
- during data collection, determining a current autofocus-signal magnitude through two or more autofocus-rotor elements;
- using the two or more determined current autofocus-signal magnitudes associated with two or more autofocus-rotor elements and the data for the two or more calibration curves stored in memory to determine a directed distance from a current optical-instrument position and the point of interest;
- and
- adjusting the optical-instrument position by the determined directed distance.
An autofocus subsystem comprising:
- an autofocus rotor with two or more autofocus-rotor elements through each of which backscattered electromagnetic radiation passes, when the autofocus rotor is aligned with an autofocus light path through which the autofocus subsystem receives electromagnetic radiation backscattered from an optical interface of an optical instrument, onto an autofocus detector that produces a corresponding autofocus signal;
- and
- an autofocus processing component including an electronic memory and a processing component that
- controls positioning of one or more instrument components in optical-instrument position space,
- acquires and stores, in memory, two or more calibration curves, each representing autofocus signal magnitudes associated with a particular autofocus-rotor element with respect to optical-instrument position, and
- uses the two or more calibration curves to monitor and adjust optical-axis position during data collection.
Dependencies are inferred from the claim text.