| 摘要 |
<p>PURPOSE:To measure, in a noncontact manner and with high accuracy, the deformed state of a plane to be measured and to easily adjust a focus by confining a part corresponding to a masked region within a prescribed range by a method wherein a reference lattice is projected on the plane to be measured, an obtained real image is projected additionally on a standard lattice and a generated moire interference fringe is analyzed. CONSTITUTION:Reflected light of the real image of a reference lattice 12 projected on a plane 35 to be measured is projected on a standard lattice 16; a real image is formed. A moire interference fringe which is generated by the real image and the standard lattice 16 is input to a CCD 19. Its output signal is subjected to a required treatment. Bright and dark pitches are analyzed as contour lines of the unevenness of the plane to be measured. Thereby, they can be measured in a noncontact manner and with high accuracy. When a part corresponding to a masked region in a picture image is confined within a prescribed range, the distance to the plane 35 to be measured and to a projection optical system 13 is confined within a prescribed region and a focus can be adjusted easily.</p> |
