Patent ID: 8558154

Claim:
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.