G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
G09F19/00—Advertising or display means not otherwise provided for
G09F19/12—Advertising or display means not otherwise provided for using special optical effects
G09F19/14—Advertising or display means not otherwise provided for using special optical effects displaying different signs depending upon the view-point of the observer
Visionneuse pliable en carton, permettant d'observer des anaglyphes ou des stereogrammes, images doubles donnant la sensation de relief, ces images etant reproduites sur un support opaque