Determination of small angular displacement by moiré fringes of matched radial-parallel gratings.
We investigate the properties of the moiré fringes of matched radial-parallel (MRP) gratings that are useful for the fine visual indication of angular displacements. Moiré patterns formed by overlapping two different MRP gratings of angular pitches, P(theta) and P(theta)? (<P(theta)), can provide a simple fringe-counting method for determining both the angle and the direction of the relative angular displacement of the gratings within the accuracy of (P(theta)?/M(theta)), where M(theta) is the angular magnification for radial vernier fringes.
Kim
B J
BJ
Song
J S
JS
Kim
J T
JT
Jo
J H
JH
Chang
S
S
Yuk
K C
KC