Moire´ minimization condition in three-dimensional image displays

A moire´ minimization condition is found analytically for the contact-type three-dimensional (3-D) imaging systems by approximating 3-D displays as four superposed sine gratings. Finding maximization conditions for two-dimensional (2-D) waves in this structure provides minimization of moire´s. The global extremum was found at a certain angle which does not depend on the period. Experiments confirm the analytical findings. Practical advantage of using that angle is in its wide areas of applications: 3-D displays can be made to have almost invisible moire´s with using this angle without regards to other specific parameters like pixel size and pitch of the screen.