| 摘要 |
PURPOSE:To control the position and the speed of a load table with high precision by detecting the position of the spot of reflected light reflected by a reflecting plate and a reflecting mirror, and controlling the direction of the reflecting plate. CONSTITUTION:Light generated by a light source 6 passes a half mirror 10, is reflected by a reflecting plate 7 reflective in an arbitrary direction, is further reflected by a semispherical reflecting mirror 8 fitted to a load table 1, and returns in the same route. The light is reflected by the reflecting board 7 again, reflected by the half mirror 10, and enters a light spot position detecting means 9. The light spot position detecting means 9 detects the spot position of the reflected light, and outputs a reference position set in the spot position detecting means 9 and information on the light spot to a reflecting plate controlling part 11. The reflecting plate controlling part 11 controls the direction of the reflecting plate 7 so as to coincide the spot position of the reflected light with the reference position, by using the information obtained by the light spot position detecting means 9. |
