Patent ID: 6564486
Filing Date: 2003-05-20
Classification: G02B,G09F

Abstract:
Apparatus for displaying a plurality of still images, forming an animated display, to a viewer moving substantially at a known velocity relative to said still images substantially along a known trajectory substantially parallel to said still images, said apparatus comprising:a backboard having a backboard length along said trajectory, said still images being mounted on a surface of said backboard, each of said still images having an actual image width and having an image center, image centers of adjacent images being separated by a frame-to-frame distance; and a slitboard positioned substantially parallel to said backboard, facing said surface thereof and separated therefrom by a board-to-board distance, said slitboard being mounted at a viewing distance from said trajectory, said board-to-board distance and said viewing distance totaling a backboard distance, said slitboard having a slitboard length along said trajectory, and having a plurality of slits substantially perpendicular to said slitboard length, each said slit corresponding to one of said images and having a slit width measured along said slitboard length and a slit center, respective slit centers of adjacent ones of said slits being separated by said frame-to-frame distance; wherein: in order to display each said image with an apparent image width, said board-to-board distance, said viewing distance and said actual image width are selected so that the product of (a) said actual image width and (b) the quotient of (i) said viewing distance and (ii) said board-to-board distance substantially equals said apparent image width; in order to project each said image substantially without blurring, said slit width is selected to be at most about one-tenth of said actual image width; said images are illuminated to an image luminance; and when said viewer is in an environment illuminated to an ambient luminance, said slit width is at least about equal to one-tenth the product of (a) said actual image width, (b) the square of the quotient of said backboard distance and said viewing distance, and (c) the quotient of said ambient luminance and said image luminance.