摘要 |
A positioning apparatus comprises a controller for controlling a driving device, and positions a measurement portion of an optical element. The controller displaces a drive portion of the optical element by a specific operation of the driving device, and calculate a displacement of the optical element as a first displacement based on an output from a position measuring device, calculate a displacement of the optical element caused by the specific operation as a second displacement, based on an output from a wavefront measuring device configured to measure a wavefront of light directed by the optical element, based on a difference between the first displacement and the second displacement, calibrate a position of the optical element calculated from the output from the position measuring device, and store a result of the calibration, and control the driving device based on the stored calibration result and an output from the position measuring device.
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