Signalling method for back-lit advertising, information board, or decorative display

摘要

The method involves engraving a transparent panel or plate (A) of e.g. plastic or glass on the back (B) of it with an angle of cut of about 20 degrees. The engraving (D) is then covered by an opaque screen (E). Light sources (F) are placed behind and on the sides of the panel. The rays (G) projected on the panel sides are reflected to the observation side, thus highlighting the engraving borders. The ray projected from the rear of the panel illuminate the whole panel except the engraving. Alternative embodiments have engravings cut at 50 or 90 degrees or on the front from which rays are reflected on the screen.