| 摘要 |
PURPOSE:To enable a positioning of high accuracy and high speed even if a comparatively inexpensive XY stage is used by making the objective lens part equivalent to the reference light side of a laser measuring machine movable. CONSTITUTION:The laser light 9 of two wavelength output of f1, f2 is separated by the polarizing prism of the interferometer 4 inside and the f1 measures the movement of an XY stage by the interferometer made in the space with the mirror 6 fitted to the XY stage 8. On the other hand, f2 is made incident on the interferometer made between the total reflection mirror 3 fitted to an objective lens 1 by the total reflection mirror 3 as a reference light. The position variation of the objective lens can be detected at the reference light side even in case of the objective lens 1 being relatively slipped to the XY stage 8 by a temp. change, etc., and the relative position of the objective lens 1 and XY stage 8 can always be measured correctly by reading the difference in the positional changes of f1 and f2 sides. |
