A long-range house number identification panel has its number indicia
mounted on an illuminated viewing screen, being individually readable
with the naked eye from up to 200 feet distance. An electrically
energizable phosphorescent screen behind the indicia serves to illuminate
the numbers at night. The identifying indicia may consist of
transparencies through the surface of a blanking screen. A photocell
switches off the screen in daylight; and the level of screen illumination
may be limited below the optimum, by operating at a reduced voltage so as
to extend the service life of the screen. A u/v barrier coat may be used
to protect the phosphor of the screen against solar degradation.