Moire Pattern in Color Television

The overlapping of two periodic line patterns of the same general magnitude can produce larger scale visible patterns called moire fringes. In shadow mask picture tubes a design objective is to prevent such unsought patterns from being produced by the interaction of the scan line pattern with the pattern of mask holes or phosphor dots. This goal is the subject of this paper, although a broader examination of moire in color television would include other spurious patterns in the reproduced picture. These could be caused by interference between two or more patterns such as the original subject, the target grid of the image orthicon, scan line pattern, mask-screen pattern, and carrier color signal periodicity.