| 摘要 |
For the autofocus, an auxiliary illumination, which consists of two light sources (17, 18) which are arranged next to one another in the pupil and switched in an alternating fashion, is reflected into the beam path of the microscope. A parallax effect occurs in the event of defocusing, and the image of the object (2) or of a mark (15) projected onto the object in the light of the auxiliary illumination begins to oscillate in the rhythm of the switching frequency. This movement of the image generates on detectors (21, 22) arranged in the image plane an AC signal which is used for refocusing. <IMAGE>
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