Abstract: A method of making a waveguide illumination system. More specifically, in a specific embodiment, an optically transmissive sheet having a light coupling area located at or near its light input edge and a two-dimensional light extraction area located on at least one of the first and second broad-area surfaces and at a distance from the first edge is provided. An LED strip having a strip of heat-conducting printed circuit and a linear array of electrically interconnected side-emitting LED packages is further provided. The LED strip is aligned parallel to the light input edge and positioning at or near the light input edge such that a major surface of the heat-conducting printed circuit extends generally parallel to the optically transmissive sheet and at least a substantial portion of the major surface is disposed in a space between the light input edge and an opposite edge of the optically transmissive sheet.

Abstract: A method of making a waveguide illumination system. More specifically, in a specific embodiment, an optically transmissive sheet having a light coupling area located at or near its light input edge and a two-dimensional light extraction area located on at least one of the first and second broad-area surfaces and at a distance from the first edge is provided. An LED strip having a strip of heat-conducting printed circuit and a linear array of electrically interconnected side-emitting LED packages is further provided. The LED strip is aligned parallel to the light input edge and positioning at or near the light input edge such that a major surface of the heat-conducting printed circuit extends generally parallel to the optically transmissive sheet and at least a substantial portion of the major surface is disposed in a space between the light input edge and an opposite edge of the optically transmissive sheet.

Abstract: A waveguide illumination system employing an optically transmissive sheet, which is used to guide light using a total internal reflection, and a strip of heat-conducting printed circuit located near an edge of the sheet and having a major surface which portion is located in a space between two opposite edges of the sheet. The waveguide illumination system further includes a linear array of electrically interconnected side-emitting LED packages mounted to a major surface of the strip of heat-conducting printed circuit and optically coupled to the optically transmissive sheet within a light coupling area. A two-dimensional pattern of light extraction features is formed in at least one surface of the optically transmissive sheet such that a density of the light extraction features within the two-dimensional pattern increases with a distance from the light coupling area.

Abstract: A waveguide illumination system employing an optically transmissive sheet, which is used to guide light using a total internal reflection, and a strip of heat-conducting printed circuit located near an edge of the sheet and having a major surface which portion is located in a space between two opposite edges of the sheet. The waveguide illumination system further includes a linear array of electrically interconnected side-emitting LED packages mounted to a major surface of the strip of heat-conducting printed circuit and optically coupled to the optically transmissive sheet within a light coupling area. A two-dimensional pattern of light extraction features is formed in at least one surface of the optically transmissive sheet such that a density of the light extraction features within the two-dimensional pattern increases with a distance from the light coupling area.

Abstract: A face-lit waveguide illumination system employing a planar sheet of an optically transmissive material. A strip of side-emitting LEDs is positioned adjacent to a major surface of the planar sheet and optically coupled to the planar sheet. The planar sheet is configured to guide light using optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the planar sheet and emit the light towards a surface normal direction.

Abstract: A face-lit waveguide illumination system employing a planar sheet of an optically transmissive material. A strip of side-emitting LEDs is positioned adjacent to a major surface of the planar sheet and optically coupled to the planar sheet. The planar sheet is configured to guide light using optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the planar sheet and emit the light towards a surface normal direction.

Abstract: A face-lit waveguide illumination system employing a planar slab or plate of an optically transmissive material. A light source is optically coupled a linear optical element which is formed in or attached to a face of the waveguide and is configured to inject light at an angle permitting for light propagation by means of a total internal reflection. Light is propagated through the waveguide towards a predetermined direction in response to optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the waveguide and emit such light towards a surface normal direction.

Abstract: A face-lit waveguide illumination system employing a planar slab or plate of an optically transmissive material. A light source is optically coupled a linear optical element which is formed in or attached to a face of the waveguide and is configured to inject light at an angle permitting for light propagation by means of a total internal reflection. Light is propagated through the waveguide towards a predetermined direction in response to optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the waveguide and emit such light towards a surface normal direction.

Abstract: A face-lit waveguide illumination system employing a planar slab or plate of an optically transmissive material. A light source is optically coupled a linear optical element which is attached to a face of the waveguide and is configured to inject light at an angle permitting for light propagation by means of a total internal reflection. Light is propagated through the waveguide towards a predetermined direction in response to optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the waveguide and emit such light towards a surface perpendicular. In one embodiment, the planar waveguide includes a window pane which provides light transport from one location, where light is injected through the face of the pane, to another location where light is extracted. Additional embodiments of the face-lit waveguide illumination system are also disclosed.

Abstract: A face-lit waveguide illumination system employing a planar slab or plate of an optically transmissive material. A light source is optically coupled a linear optical element which is attached to a face of the waveguide and is configured to inject light at an angle permitting for light propagation by means of a total internal reflection. Light is propagated through the waveguide towards a predetermined direction in response to optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the waveguide and emit such light towards a surface perpendicular. In one embodiment, the planar waveguide includes a window pane which provides light transport from one location, where light is injected through the face of the pane, to another location where light is extracted. Additional embodiments of the face-lit waveguide illumination system are also disclosed.

Abstract: Retroreflective lenticular systems employing a focusing array and a retroreflector array optically coupled to the focusing array. The focusing array is provided on a first surface and the retroreflector array is provided on an opposing second surface. The retroreflector array includes an array of retroreflective elements alternating with separation areas and disposed in energy exchange relationship with respect to the focusing array. The focusing array includes a plurality of focusing lenses configured to illuminate only the retroreflective elements with focused beams at least at some angles and to focus the incident beam only onto the separation areas at other angles. The intermittent illumination of retroreflective elements provides variable retroreflectivity of at least portions of the system and enhances the system visibility and conspicuity in the reflected light.

Abstract: Light directing films employing at least two layers forming a continuous corrugated boundary between major surfaces of the film. Light received by a major surface of the film is internally redirected by interacting with the facets of the corrugated inter-layer boundary and is emitted from the opposing major surface towards a new propagation direction which is different from the original propagation direction by up to 90 degrees. Light directing films may have additional layers and/or layer boundaries which may provide additional bend angles to light rays or otherwise diffuse the emitted beam.

Abstract: A face-lit waveguide illumination system employing a planar slab or plate of an optically transmissive material. A light source is optically coupled a linear optical element which is attached to a face of the waveguide and is configured to inject light at an angle permitting for light propagation by means of a total internal reflection. Light is propagated through the waveguide towards a predetermined direction in response to optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the waveguide and emit such light towards a surface perpendicular. In one embodiment, the planar waveguide includes a window pane which provides light transport from one location, where light is injected through the face of the pane, to another location where light is extracted. Additional embodiments of the face-lit waveguide illumination system are also disclosed.

Abstract: A light trapping optical cover employing an optically transparent layer is described. The transparent layer has at least one corrugated surface formed by a plurality of isosceles right-angle prismatic corrugations configured to internally retroreflect light into the transparent layer. The corrugated surface also includes optical windows configured for inputting or outputting light to or from the transparent layer. The optical cover may further employ a focusing array of light collectors being pairwise associated with the respective optical windows.

Abstract: An illumination system employing a waveguide. Light received from an edge or an end of a waveguide is propagated in response to transmission and total internal reflection. Light deflecting elements distributed along the propagation path of light continuously change the out-of-plane propagation angle of light rays and cause decoupling of portions of the propagated light from the core of the waveguide at different distances from the light input edge or end. Light escapes from the waveguide into an intermediate layer at low out-of-plane angles and is further redirected by light extraction features out of the system. In one embodiment, the illumination system is configured to emit collimated light. In one embodiment, the illumination system includes shallow surface relief features. In one embodiment, the light deflecting elements include forward-scattering particles distributed throughout the volume of the waveguide. Additional collimating and non-collimating illumination units and methods are also disclosed.

Abstract: Light directing films employing at least two layers forming a continuous corrugated boundary between major surfaces of the film. Light received by a major surface of the film is internally redirected by interacting with the facets of the corrugated inter-layer boundary and is emitted from the opposing major surface towards a new propagation direction which is different from the original propagation direction by up to 90 degrees. Light directing films may have additional layers and/or layer boundaries which may provide additional bend angles to light rays or otherwise diffuse the emitted beam.

Abstract: An illumination system employing an elongated waveguide having a non-round transversal cross-section and having at least a portion of its surface shaped in the form of a linear collimating element. The waveguide further employs at least one array of light extracting features distributed along a longitudinal axis of the waveguide and disposed in the focal area of the respective linear collimating element. Each light extracting feature has an active aperture which is substantially less than the light receiving aperture of the linear collimating element and is configured to redirect light propagating in the waveguide generally towards a normal direction with respect to the longitudinal axis of the waveguide. Light rays redirected by the light extracting features are further collimated by the linear collimating element and exit from the waveguide in the form of a directional beam.

Abstract: A light trapping optical cover employing an optically transparent layer with a plurality of light deflecting elements. The transparent layer is configured for an unimpeded light passage through its body and has a broad light input surface and an opposing broad light output surface. The light deflecting elements deflect light incident into the transparent layer at a sufficiently high bend angle with respect to a surface normal and direct the deflected light toward a light harvesting device adjacent to the light output surface. The deflected light is retained by means of at least TIR in the system formed by the optical cover and the light harvesting device which allows for longer light propagation paths through the photoabsorptive layer of the device and for an improved light absorption. The optical cover may further employ a focusing array of light collectors being pairwise associated with the respective light deflecting elements.