| 摘要 |
<p>PURPOSE:To obtain a scanning type position detector which can produce two slit-like beams having the same optical path length and intersecting each other at right angles with a simple constitution by providing first reflecting means which reflect a beam in a first optical path by an even number of times and second reflecting means which reflect a beam in a second optical path by an odd number of times. CONSTITUTION:A lighting means is provided with a first splitter 2 which branches a luminous flux from a light source 1 to a first and second optical paths (c) and (d), second beam splitter 7 which again combines the two optical paths into one optical path, and beam transforming member which transforms the two luminous fluxes into slit-like beams. Then, by respectively providing first reflecting means M1 and M2 which reflect a beam by an even number of times and second reflecting means 3, 4d, and 5d which reflect a beam by an odd number of times in the first and second optical paths (c) and (d), the two slit-like beams intersecting each other at right angles are formed by making the optical path lengths of the first and second optical paths (c) and (d) the same. Therefore, the optical system of this scanning type position detector can be easily designed and, at the same time, the cost of the detector can be reduced.</p> |
