| 摘要 |
<p>PURPOSE:To maintain accuracy of a measuring device at the highest level, by arranging a detection mechanism for detecting a deviation from the optical axis of reflected light incident on a lens from a sample to always maintain the optical axis at the normal position with the correction thereof. CONSTITUTION:A half mirror 2 is set in the body tube between an objective lens 3 and an eyepiece lens 4 at an angle to the optical axis, slits 5a-5d which are positioned in vertical and horizontal ways within a branch tube 8 extended in the direction of reflection of the mirror 2 are provided parallel with the optical axis and photoelectric sensors 9a-9d are set facing the respective slits 5a-5d. Then, a part of the reflected light from a sample 7 is changed in the direction with the half mirror 2 and received with the photoelectric sensor 9a-9d via the slits 5a-5d. Detection outputs of the photoelectric sensors 9a-9d changes according to a deviation of the optical axis to generate a voltage corresponding to vertical and horizontal deviations of the optical axis and detection outputs thereof are compared with a comparator circuit 6. Thus, the vertical and horizontal deviations of the optical axis are displayed on displays 10ab and 10cd.</p> |
