| 摘要 |
PURPOSE:To obtain a shape measuring method being capable of detecting interference fringe information with high resolution, by measuring the interference fringe of a reflected light from the surface to be measured and the reference surface, by an interference fringe sensor by moving relatively the interference fringe sensor and the surface to be measured, and measuring the shape of the surface to be measured. CONSTITUTION:A laser beam L emitted from a laser oscillating device 1 is reflected by a total reflection mirror 2, widened by a space filter 3, becomes parallel rays through collimator lens 4 and divided into two by a semi-transparent mirror 5. Its reflected light L1 passes through a condensing lens 6 and made incident on the surface to be measured 7, and also, the transmission light is made incident on a reference mirror 8. The reflected light from the surface to be measured 7 and the reference mirror 8 reaches the semi-transparent mirror 5, passes through a image forming lens 9, and an interference fringe is formed on a linear image sensor 10. Under the control of a control part 14, a moving table 11 brings the sensor 10 to a step movement, and also, the reference mirror 8 is moved by 1/4 of an interference fringe distance through a piezo-element 16. Interference fringe information is derived by processing the output of the sensor 10 in this case by a processing part 13, and a shape of the surface to be measured 7 is measured.
|
