Controlling light discharged by a phosphorescent material

#This invention relates generally to phosphorescent materials.

#Materials that are phosphorescent glow in the dark after being exposed to an energy source generating sufficient energy to create phosphorescence. Phosphorescence is the result of electrons associated with molecules changing orbitals in a fashion, which results in the generation of light. Some phosphorescent materials glow after being exposed to energy in the ultraviolet range. Since sunlight may include sufficient ultraviolet energy, sunlight exposure may be sufficient to cause some materials, such as zinc sulfide, to glow.

#As one example, zinc sulfide, after having been exposed to ultraviolet light, may emit a pale green light for a period of up to eight hours. Thus, zinc sulfide is utilized in a variety of products including children's glowing toys and dolls, as well as a variety of non-toy products including signs and safety equipment.

#FIG. 1 is a perspective view of one embodiment of the present invention;

#FIG. 2 is an enlarged cross-sectional view taken generally along the line 2-2 in FIG. 1;

#FIG. 3 is a depiction of the display screen of the device shown in FIG. 1 in one situation in accordance with one embodiment of the present invention; and

#Referring to FIG. 1, one application of the principles set forth herein is in connection with a wide variety of toys. As a toy example, shown in FIG. 1, a drawing toy 10 may include a housing 12 with an inclined drawing surface 13. A child may use an erasable marker 18 to draw on the drawing surface 13. However, in this embodiment, the child's drawing may be guided by a pattern 14 that has been formed on the drawing surface 13 to guide the child's depiction of the object. Thereby, the child may simply trace over the pattern 14 to create a suitable design on the toy 10.

#Turning to FIG. 2, the child's eye, indicated as E, may view the drawing surface 13 from one side. On the opposite side of the surface 13 may be coated a phosphorescent layer or film 20. In one embodiment, the layer 20 may be opaque. The layer 20 may be formed of any phosphorescent material that glows for an extended amount of time in one embodiment. In one embodiment, the surface 13 may be formed of a transparent material such as a plastic sheet having the phosphorescent layer 20 merely coated on one side.

#When the phosphorescent layer 20 is exposed to a sufficient energy source, it will emit light as indicated at L. The layer 20 will continue to glow, enabling the surface 13 to glow in the dark. As one example, the layer 20 may be zinc sulfide.