| 摘要 |
PURPOSE:To make it possible to measure the angle of a prism at a high speed with high accuracy in a non-contact state by rough positional setting, by mounting a beam source emitting parallel beam, a prism to be inspected, a beam reflection means, a beam refraxing means, a beam reversal means and an angle detection means. CONSTITUTION:Parallel beam 21 emitted from an automatic collimator 11 is reflected by a prism 13 and subsequently reflected by the surface 20 of a prism 14 to be inspected and again reflected by the prism 13 to be returned to the collimator 11. Similarly, parallel beam 16 is reflected by the surface 19 of the prism 14 to be inspected and again reflected by a flat mirror 17. When the beam 18 reflected by the mirror 17 is allowed to be incident to a prism 21, the direction of beam is reversed and inclined by 2{(alpha-alpha')+beta}. If the angle to be measured of the prism 14 to be inspected is a desired angle alpha', that is, alpha=alpha', the beams 15, 22 are incident to the colimator 11 at an equal angle 2beta. If said angle is shifted from the desired angle alpha', the beams 15, 22 are shifted by the angle two times the shift amount alpha-alpha'. Therefore, if the angular difference of two beams is read, the shift of the prism 14 to be inspected from the desired angle can be detected. |
