| 摘要 |
PROBLEM TO BE SOLVED: To stabilize a measured result with respect to fluctuations in the distance or inclination of a measuring object in a film thickness measuring instrument for measuring the film thickness of a membrane in-line in the two-dimensional region of the measuring object. SOLUTION: The light horizontally emitted from a light source 50 is allowed to be incident on a half mirror 52 through a floodlight projection lens 51. The light reflected by the half mirror 52 is coaxially illuminated on the object 43 vertically by an object lens 53. The light reflected by the object lens 53 is formed into an image on an imaging part 56 through a telecentric optical system on a matter side comprising the object lens 53 and an aperture iris 54. The light incident on the imaging part 56 is spectrally diffracted by the spectral filter provided to a multispectral filter 55. Herein, the light source 50 and the aperture iris 54 are set to an imaging relation, and an object 43 and the imaging part 56 are also set to an imaging relation. Further, the number of apertures on an image side in a floodlight projection optical system is larger than that on the matter side in a light detecting optical system and the light source 50 has an expanse of a certain degree at the position of the aperture iris 54 to form an image of a uniform luminosity. COPYRIGHT: (C)2005,JPO&NCIPI
|
