초록 ▼

Ultraviolet luminescent retroreflective sheeting includes a retroreflective portion containing retroreflective elements and an ultraviolet luminescent portion to facilitate nighttime viewing by persons not located at or near a source of light being retroreflected by the retroreflective portion. At l

Ultraviolet luminescent retroreflective sheeting includes a retroreflective portion containing retroreflective elements and an ultraviolet luminescent portion to facilitate nighttime viewing by persons not located at or near a source of light being retroreflected by the retroreflective portion. At least part of the ultraviolet luminescent portion is provided as the bonding lines for bonding the transparent cover sheet to the support sheet to form a series of sealed cells in which the retroreflective elements, which may be of the encapsulated lens-type or the encapsulated cube-corner-type, are disposed. The ultraviolet luminescenct portion includes fluorescent agent which emits light when irradiation by ultraviolet irradiation. The ultraviolet luminescent retroreflective sheeting may be used in a display device, such as a roadside sign, in combination with a source of ultraviolet radiation means which may be formed integrally with the sheeting or spaced therefrom and which will, in operation, emit ultraviolet rays in the direction of the retroreflective sheeting.

대표청구항 ▼

[ We claim:] [1.] Ultraviolet luminescent retroreflective sheeting comprising a retroreflective region having retroreflective elements and an ultraviolet luminescent region which emits light under ultraviolet radiation;wherein the retroreflective region comprisesan encapsulated lens retroreflective

[ We claim:] [1.] Ultraviolet luminescent retroreflective sheeting comprising a retroreflective region having retroreflective elements and an ultraviolet luminescent region which emits light under ultraviolet radiation;wherein the retroreflective region comprisesan encapsulated lens retroreflective region comprising a support layer, a substantial monolayer of transparent microspheres partially embedded in one surface of the support layer, a light reflective layer coating on the portion of the transparent microspheres which are embedded in the one surface of the support layer, a transparent surface protective film facing in spaced relationship to the one surface of the support layer, and a series of bonding lines bonding the protective film to the one surface of the support layer to thereby form a plurality of sealed, small compartment cells, each of the sealed cells containing therein a part of the substantial monolayer of transparent microspheres, the non-embedded portions of which are exposed to the atmosphere within the sealed cell, orsaid retroreflective region comprisesan encapsulated cube-corner retroreflective region comprising a support layer; a light-transmitting cover layer spaced apart from the support layer; a layer of cube-corner retroreflective elements disposed on one surface of the cover layer facing the support layer, a series of bonding lines bonding the surface layer to the layer of cube-corner retroreflective elements and forming a plurality of sealed, small compartment cells, each of the sealed cells containing therein cube-corner retroreflective elements which are exposed to the atmosphere within the sealed cell, andwherein the bonding lines comprise a fluorescent agent which emits light under ultraviolet radiation and a resin, wherein said bonding lines form at least a portion of the ultraviolet region, and,wherein when the ultraviolet luminescent region is illuminated with a fluorescent lamp which emits near-ultraviolet rays of main wavelength around 360 nm at a light-receiving intensity of 0.8 mW/cm.sup.2, the luminance is at least 10 cd/m.sup.2.