| 摘要 |
<p>TITLE: CONTACT FREE MEASURING APPARATUS HAVING AN FTHETA-CORRECTED OBJECTIVE AND METHOD FOR USING THE SAME An apparatus for the non-contacting measurement of rod shaped objects contains a telecentric, F-thetacorrected objective which comprises two catadioptric elements. The first catadioptric element is a Mangin mirror and the second catadioptric element is a plane plate mirror-coated at the front, while a third optical element is a meniscus lens . The use of catadioptric elements permits a simplified and inexpensive form of construction which is also compact, as a result of which objects with large dimensions can be measureed quickly and accurately. Such an apparatus serves, in particular, for the continuous control of the production of filament-shaped objects.</p> |
