PHOTOLUMINESCENT COASTER

Field of the Invention The present invention relates to devices for protecting surfaces. More specifically, the present invention is a photoluminescent coaster.

Background of the Invention Use of coasters is a well-known way to avoid damage to tabletops and other furniture from the temperature variances of glasses, cups, or bottles, from condensation or other moisture on their exterior, or even from scratches and abrasions from hard or sharp surfaces. Comedy routines have been written about compulsive hosts who keep putting coasters under their guests' drinks, or who use two coasters in case one doesn't work or is not enough. Coasters come in many forms and shapes: wood, metal, plastic, cloth, cardboard or paper; squares, circles, flowers, hearts, diamonds, cup-shapes, hat- shaped, virtually any planar figure which approximates the size of the bottom of a glass, a bottle, a cup, or a saucer. Restaurants, bars, breweries, and distilleries have recognized the advertising utility of coasters, imprinting messages and advertisements on their surfaces, touting their wares and services. Coasters have become so pervasive that they are hardly noticed any longer.

There is a need for a coaster, or coaster-like device, which provides the protective function of a coaster, but draws attention to itself and its message. One way of doing so is to provide a coaster which lights up, which glows in the dark. As coasters are often used in dimly lit bars and restaurants, or on a romantically set table

for two, a glowing coaster will stand out; it will be easy to locate; it will provide an exclamation point to its message, even if that message is nothing but the implicit "use me." However, as a coaster is of necessity a highly portable item, and an often wet item, a traditional power source, be it battery or household outlet, is generally contraindicated. Rather, a self-contained, self-generating, light source is preferable, such as an integrated phosphorescence. A coaster with a photoluminescent surface, revealing a message, a logo, or just a location, will be noticed, easily located, and provide a unique advertising medium when used in the proper environs.

Summary of the Invention

A coaster device includes a substrate having an upper surface and a lower surface. In an optional embodiment, the substrate may be formed from a moisture absorbent material, such as paper, cardboard, or other pulp-based material, sandstone, or the like. In another optional embodiment, the substrate may be formed from a moisture resistant material, such as plastic, wax, or the like. In a further optional embodiment, the coaster may include a substrate formed from a moisture absorbent material with a moisture resistant material applied to the lower surface of the substrate.

The substrate has a brightening agent on at least the upper surface of the substrate. The brightening agent could be applied to the upper surface of the substrate or integrated into the material of at least the upper surface of the substrate.

A photoluminescent layer on the upper surface absorbs radiant energy and emits radiant energy in the form of light when the level of radiant energy available for absorption falls below a predetermined level. The photoluminescent layer may be applied to the upper surface or may be impregnated into the upper surface.

Optionally, the photoluminiscent layer may form a moisture resistant layer over the substrate. Optionally, a transparent or translucent case is provided to at least partially receive and encase the substrate.

Brief Description of the Drawings

FIG. l is a top view of an optional embodiment of a device according to the present invention;

FIG. 2 is a cutaway side view of the optional embodiment of FIG. 1 taken along section line A — A; FIG. 3 is a top view of an optional embodiment of a device according to the present invention;

FIG. 4 is a side view of the optional embodiment of FIG. 3.

Description Reference is now made to the figures wherein like parts are referred to by like numerals throughout. The device of the present invention is a photoluminescent coaster that absorbs light and glows in the dark. Referring to FIGS. 1 and 2, a coaster device according to an embodiment of the present invention consists of a substrate 110 with an upper surface and a lower surface. In an optional embodiment, the substrate 110 may be formed from a moisture absorbent material. Examples of moisture absorbent material could include paper, cardboard, or other pulp materials, wood, cotton or polyester cloth or other natural or synthetic textile material, sandstone, or any other material that tends to absorb water on contact. In another optional embodiment, the substrate 110 could be formed from a moisture resistant material, such as plastic or other polymer, or other materials that

tend to resist moisture. In yet another optional embodiment, the substrate 110 could be formed from a material with a moisture resistant surface. In such an optional embodiment, the photoluminescent layer 120 (described in greater detail below) may be applied over the moisture resistant surface, under the moisture resistant surface, or may form the moisture resistant surface, at least in part. For example, the photoluminescent layer 120 may form a coating over the substrate 110, at least in the places where it is applied. Those places where the photoluminescent layer 120 is not applied may remain uncoated or may be coated using a sealant or other material. At least the upper surface of the substrate 110 includes a brightening agent. The brightening agent could include colorants, dyes, pigments, or optical brightening agents. The brightening agent may be integrated into the material forming the substrate 110 or may be applied to the upper surface of the substrate 110. For example, in one optional embodiment the substrate 110 may be a heavy paper stock with a brightening agent integrated into the substrate during the manufacturing process. In an alternate optional embodiment, the brightening agent may be applied to the upper surface of the foundation substrate component 110 as a coating, a dye, or a stain, or otherwise integrated into at least the upper surface of the substrate.

A photoluminescent layer 120 is on the upper surface of the substrate 110. In an optional embodiment, the photoluminescent layer 120 may be applied to the upper surface of the substrate, such as through printing, or otherwise depositing the photoluminescent layer 120 to the upper surface. In another optional embodiment, the photoluminescent layer 120 is impregnated into the upper layer. In an optional embodiment, a photoluminescent layer 120 may form a textual or graphical display that is illuminated by the photoluminescent layer 120.

The photoluminescent layer 120 may be formed from any photoluminescent material that absorbs radiant energy and emits light energy. For example, any number of non-radioactive photoluminescent materials could be used including various aluminum oxide ceramic pigments, such as alkaline earth metal aluminate oxide europium doped and alkaline earth metal sulfide europium doped, zinc sulfide, strontium aluminate, or the like. Optionally the photoluminescent material is selected from a photoluminescent material that permits multiple uses, i.e. can absorb radiant energy and discharge light energy over multiple cycles. hi an optional embodiment illustrated in FIGS. 3 and 4, the substrate 110 may be received into a case 130. The case 130 may be substantially transparent or translucent such as acrylics or plastic through which emitted light may pass. The case 130 at least partially receives and encases the substrate. In an optional embodiment, the case may include a graphical or textual display to complement the photoluminescent layer 120 and cooperate to form a composite graphical or textual display by selectively permitting or blocking the emission of light ^" from the photoluminescent layer. In a further optional embodiment, the case may include a photoluminescent layer to replace or complement the photoluminescent layer on the substrate. In an optional embodiment, the case 130 may include a formed image to capture, diffuse, and redirect emitted light from the photoluminescent layer 120. Such formed image could be created by many different processes including, but not limited to, etching, embossing, debossing, cutting, or any other process where material is removed or added through mechanical, electrical, or optical (e.g. laser) means.

Referring generally to FIGS. 1-4, a coaster device is utilized by exposing the photoluminescent layer 120 to a source of radiant energy, such as a light source.

When the light source is extinguished, the photoluminescent layer 120 emits light energy to glow to make the coaster device, and any object resting on the coaster device such as a drinking glass, visible. In an optional embodiment in which the photoluminescent layer 120 forms a graphical or textual display, the display may be illuminated. Similarly, in an optional embodiment in which the substrate 110 is received into a case 130, any graphical or textual display on or in the case 130 is illuminated.

While certain embodiments of the present invention have been shown and described it is to be understood that the present invention is subject to many modifications and changes without departing from the spirit and scope of the claims presented herein.