Patent ID: 8375613
Filing Date: 2013-02-19
Classification: G02B

Abstract:
1. An edge-lit, electrically illuminated signboard formed as an assembly that is viewed from a first direction and configured to project a luminous halo onto a support member which supports the signboard, comprising: a first light guide having a body in the form of substantially planar sheet, the first light guide have a first face, a second face, and a reverse bevel, the first and second faces being substantially parallel to one another and the reverse bevel being disposed intermediate to outer peripheral edges of said first and second faces, the first light guide having an internal light entry well formed therein for introduction of light from within a bounds of the first light guide, the internal light entry well interrupting at least one of the faces of the first light guide such that light is introduced edgewise from within bounds of the first light guide; a second light guide having a body in the form of a substantially planar sheet, the second light guide having a first face, a second face, the first and second faces being substantially parallel to one another, the second light guide having an edge intermediate between the first and second faces thereof such that light is introduced edgewise from outside the bounds of the first light guide; a first light emitting diode (LED) array including at least one set of outward-facing LEDs, wherein the first LED array is disposed within the internal light entry well in the first light guide; a second light emitting diode (LED) array including at least one set of inward-facing LEDs, wherein the second LED array is disposed within a region external to the second light guide; a reflective sheet disposed between the first light guide and the second light guide for optically isolating the first LED array from the second LED array, the reflective sheet having a reflective surface such that any light escaping the second light guide is collected and rebounded back toward the second light guide, thereby isolating the first LED array from the second LED array; a first means for diffusing light from a front and a rear of the reverse bevel formed upon the first light guide such that light directed from the front of the reverse bevel exits the first face of the first light guide in the form of an illuminated perimeter and light diffused from the rear of the reverse bevel forms the luminous halo; and a second means for diffusing light from the front face of the second light guide; wherein the first light guide, the first LED array, and an opaque backing panel define a signboard subassembly, the opaque backing panel being formed of a substantially light-absorbing material, the opaque backing panel being located against a back of the first light guide, and an opaque housing, the housing extending from the back of the first light guide and overlaying an area corresponding to a location of the first LED array; wherein the second light guide, the second LED array, the reflective sheet, the second light diffusing means, and a printed image define a header subassembly, the header subassembly collectively being disposed over and in front of the first LED array and against the first face of the first light guide which is a planar external face; wherein the signboard subassembly and the header subassembly define a header signboard assembly that allows sufficient area upon the first planar external face of the first light guide for a message to be written by a diffusive, optically coupling writing instrument; wherein light emitted from the first LED array within the first light guide is projected obliquely by the reverse bevel onto the support structure to form the luminous halo upon the support structure such that the projection of light visibly exceeds and surrounds the bounds of the header signboard assembly and light from the first LED array forms the illuminated perimeter; wherein light emitted from the second LED array within the second light guide is projected diffusely forward through the printed image; whereby the signboard assembly provides two operationally and structurally independent illuminated display systems oriented in a common first direction while providing differing illumination effects.