| 摘要 |
<p>PURPOSE:To eliminate the unstableness of optical axes at parts of an optical system due to a geometric change or the like caused by mechanical vibration and aging of material of apparatus, by fastening on a box frame body a collimator section and a telescope section optically connected with a retroreflector. CONSTITUTION:Light from a light source 2 is condensed onto a slit 6 via a condenser lens 3 and a small reflection mirror 4 and passes through a collimator section 8 to emit a parallel light beam. This parallel light beam is turned back reversely with a retroreflector (corner cube) 13 maintaining parallelism with an outgoing light and incident into a telescope objective mirror 9 via a differential section 18 with a V-block prism 16 which carries a reference sample or a sample 17 to be inspected on a sample base 15 to form an image of the slit 6. The position of the image is measured with a light position detector 19. It should be noted that a telescope section 11 provided with the collimator section 8, a lens section 9 and an opening 10 is fastened on a one-piece stainless steel box frame body 5 divided vertically in two inside along an optical path thereof.</p> |
