Flat form device for creating illuminated patterns

A flat form graphic device for displaying light in a pattern of graphic shapes, alpha-numeric characters or ideographic symbols, the device comprising the combination of a first plate, said first plate being shaped with a base portion extending along a given plane together with at least one shaped portion which extends over an area having a predetermined graphic, alpha-numeric or ideographic symbol shape, said base portion and shaped portions each having inner surfaces, said shaped portion further being light-transmissive along selected areas thereof said shaped portion being shaped to project in a first direction from said given plane with the shaped portion defining a predetermined graphic pattern, a second plate having a planar surface, means for mounting the second plate with its planar surface extending along the first plate in juxtaposed relationship with at least certain portions of the inner surface of said base portion with at least one cavity being formed between said inner surface of the shaped portion and a portion of said planar surface of the second plate, means tier filling said cavity with an ionizable gaseous medium which is capable of being excited into an electric discharge for radiating light through said selected areas of the shaped portion, means for exciting said ionizable gaseous medium for causing light to be produced within and emitted from the cavity, and a light-transmitting, electrically-conductive coating means on a predetermined area of said shaped portion for shielding undesirable portions of emf energy being radiated from the cavity.