Abstract:
Disclosed herein is an optical device having a light source, a viscoelastic lightguide and a retroreflective film suitable for retroreflecting light. Light from the light source enters the viscoelastic lightguide and is transported within the lightguide by total internal reflection. The optical device may have a “front lit” configuration such that light being transported within the lightguide is extracted and retroreflected by the film toward a viewer. The optical device may have a “back lit” configuration such that light being transported within the lightguide is extracted and transmitted through the film toward a viewer. The retroreflective film may comprise beaded retroreflective sheeting such as that used in traffic signs and markings.
Abstract:
A light engine having an array of light horns. Each light horn has a narrow end, an open wide end, and side walls extending from the narrow end to the wide end with the side walls shaped as truncated pyramids. One or more LEDs are located at the narrow end of each of the light horns with each of the light horns providing substantially collimated light from the LEDs at the wide end.
Abstract:
Variable index light extraction layers (100) that contain a plurality of microreplicated posts (120) are described. The variable index light extraction layers contain a plurality of microreplicated posts (120), a first region including a first lower-index substance (130) and a second region including a second higher-index substance (140). Optical films can use the variable index light extraction layers (100) in front lit or back lit display devices.
Abstract:
Optical devices include a light source and an optical article, where the optical article is an acid-free, non-yellowing pressure sensitive adhesive light guide. The light source is optically coupled to the light guide such that light emitted by the light source enters the light guide and is transported within the light guide by total internal reflection. The light guide includes a plurality of features oriented to extract light being transported within the light guide.
Abstract:
Hybrid signage capable of self illumination and having an active backlight. The signage includes a turning film having a structured surface for redirecting light in order to passively illuminate a printed graphic or shaped sign when the backlight is off. In the shaped sign, the shape provides the content, such as letters, to be conveyed to the viewer instead of a graphic. The signage can be actively illuminated when the backlight is on to supplemental the passive illumination.
Abstract:
A backlight is disclosed and includes a visible light transmissive body primarily propagating light by TIR with a light input surface and a light output surface and a light guide portion and a light input portion. The light guide portion has a light reflection surface and a light emission surface. The light input portion has opposing side surfaces that are not parallel. One of the opposing surfaces is co-planar with either the light emission surface or the light reflection surface. A light source is disposed adjacent to the light input surface. The light source emits light into the light input portion. A reflective layer is disposed adjacent to or on the opposing side surfaces.
Abstract:
A driver circuit is configured for connection to a power source and includes a plurality of light emitting diodes (LEDs) having at least one performance characteristic that varies according to different performance categories ranging between higher performance and lower performance. The driver circuit also includes a plurality of LED sections each populated with at least one LED of a different one of the different performance categories. Circuitry is coupled to the LED sections and configured to activate and deactivate the LED sections based on LED performance.
Abstract:
The present disclosure is generally directed to illumination devices, and methods for making the same. The device, in particular, includes a first conductor layer, a first insulator layer disposed on the first conductor layer and having at least one first aperture defined therein through the first insulator layer, a second conductor layer disposed on the first insulator layer and having at least one second aperture defined therein through the second conductor layer and positioned to align with the at least one first aperture, and a light manipulation layer disposed on the second conductor layer and having at least one pair of apertures defined therein through the light manipulation layer including a third aperture and a fourth aperture, where the third aperture is positioned to align with the at least one second and first apertures.
Abstract:
This application describes a back-lit transmissive display including a transmissive display (620) and a variable index light extraction layer (640) optically coupled to a lightguide (630). The variable index light extraction layer has first regions (140) of nanovoided polymeric material and second regions (130) of the nanovoided polymeric material and an additional material. The first and second regions are disposed such that for light being transported at a supercritical angle in the lightguide, the variable index light extraction layer selectively extracts the light in a predetermined way based on the geometric arrangement of the first and second regions. The transmissive display may be a transmissive display panel or a polymeric film such as a graphic.