| 摘要 |
<p>The optical method is for flatness measurement and involves the use of a measurement beam from a collimator or photoelectric autocollimator telescope tube for contactless measurement of deviations from flatness of an optically plane surface. A constant beam deflection angle is achieved by double reflection using mirrors and prisms, e.g. pentagonal prisms, and dispersion-free prisms through which the beam passes symmetrically. The measurement beam is incident perpendicular or inclined to sections of the surface and is "shifted along one or more crossed paths on the surface and received after reflection. Direction changes are derived and integrated. In one embodiment, the light emerges from a collimating tube (1) through an aperture stop(2) as a parallel beam (3) impinging on a pentagonal prism (4) with internal reflection and retro-reflection from the optical flat (5).</p> |
