Abstract: A device displaying a changeable image. The device includes a screen having a viewing plane, and platelets thereon. The platelets cast shadows of different sizes. The shadows, when viewed collectively, form images on the viewing plane. The platelets are made of a rigid opaque material and are attached immovably to the viewing plane, the platelets are disposed in parallel rows extending in two mutually perpendicular directions, each forming an angle of 45.degree. with the horizon. The platelets extending in the respective directions are different in both size and shape, such sizes and shapes being determined so as to form a different image in each direction by the shadows cast by the platelets.

Abstract: A display device wherein a pleated sheet is retained in a carrier defining opposed pockets receiving the opposite ends of the pleated sheet. Stops are provided at opposite sides of the carrier for engagement by opposite side portions of the pleated sheet for limiting lateral expansion of the pleated sheet. The spacing between the stops is preselected to maintain the folds of the pleated sheet suitably compressed to have a height substantially equal to the depth of the pockets.

Abstract: A valuable document is protected from counterfeiting by applying an extremely thin layer of metal to the document at predetermined locations. The thin layers of metal form a "ghost image" which changes in appearance as the angle of view is varied, making the valuable document easily recognizable by a lay observer. The portions of the valuable document covered by the thin layers of metal reflect ultra-violet and infra-red light making a photocopy of the valuable document strikingly different in appearance than the original document. Counterfeiting the document by any method is extremely difficult as the process of applying the thin layers of metal is one of high technology, not readily available to the public.

Abstract: A visual display in which written, pictorial or combination thereof may be presented for viewing in an appealing manner for any of a variety of purposes, and apparatus for developing changes and/or animation in the display utilizing specially prepared transparent media by which the subject matter is presented and means to control the visual presentation of that subject matter and obtain change and/or animation effects.

Abstract: A decorative display, including a shallow box mounted in a picture frame, a first picture being on the front side of the box rear wall, and which is visible from a directly front direction by the line of sight passing through a grate inside the box, the grate consisting of a series of spaced-apart thin strips, one side of the strips having sections of a second picture, so as to form a composite picture when viewed from an angle, and the other side of the strips being likewise illustrated with sections of a third picture for view from an opposite angle, and the display including electric lamps for the picture illumination. A fourth and fifth picture is provided by a slidable grate over the strips.

Abstract: A point of purchase advertising display device has a front element and a rear element which are spaced a short distance apart and back illuminated. Primary copy is transparent or translucent on the front element and is repeated on the rear element in translucent form in register with that on the front element. A front fine pattern of transparent and opaque areas occupies the rest of the front element and defines the margins of each character in the primary copy. Translucent secondary copy on the rear element is viewed through parts of the front pattern, and the rest of the rear element consists of a rear fine pattern of translucent and opaque areas which is dissimilar from the front pattern but cooperates with the front pattern to produce a field of changing visual effects as a person moves relative to the display device. The rear fine pattern defines the margins of each character in the copy on the rear element.

Abstract: A sign is fabricated which presents different messages depending on the angle of view. The fabricated sign has walls, different sides having parts of different messages. The method of fabrication includes taking at least two images, cutting them into strips of equal width and combining successive strips alternatively from the two images in order to form a third image, which is printed on a plastic sheet. This sheet is laid upon a wave-formed mold surface so that the tops of the waves coincide with the borders between the strips. The plastic sheet is softened and stretch-deformed, e.g., by vacuum deformation, while the borders are held against movement into the form of the waved mold surface.

Abstract: A kit of multiple parts to be assembled for fabricating a multiple view pictorial display device that provides displays of different images when viewed frontally from different angles relative to the plane of the device.

Abstract: A method of producing a graphic pattern and a graphic pattern for imprinting substrates, such as documents, especially paper currency, stamps or the like, with lines in the form of lengthwise extending color mounds or peaks is disclosed. There is provided a line grid or pattern which is substantially uniform at least in given field sections and comprises relatively closely juxtaposed non-intersecting and non-contacting lines. The ratio between the height and the spacing of the color mounds forming the lines is selected such that when viewing the pattern below a predetermined boundary inclination angle the base of the valleys between the color mounds or peaks is not visible.