| 摘要 |
PURPOSE:To correct reflected light to a proper position even if it is displaced owing to the displacement of a body to be measured by irradiating the pattern of the object body with light from a light source through a deflecting means and controlling the deflecting means with the output of a line image detecting means. CONSTITUTION:The laser light emitted by a laser light source 2 is incident slantingly on the body 1 to be measured through the deflecting means 5 and a cylindrical lens 6 and its reflected light is supplied to the 1st and the 2nd line image detecting means 4 and 8. If the object body 1 is displaced in the direction of the optical axis of reflected light to a position 1', the reflected light from the light source 2 does reach a detecting means 4. Then, the beam of the reflected light is detected by a detecting means 8. Displacement from a light intensity distribution at a reference position A is detected by a peak position detecting circuit 9 and a displacement-voltage converting means 10 and fed back to the deflecting means 5 to adjust the laser light as shown by a broken line, so the reflected irradiation light is incident on the detecting means 4 all the time to obtain a pattern image of the object body 1. |
