WO2010078316A1

WO2010078316A1 - Lighting assembly

Info

Publication number: WO2010078316A1
Application number: PCT/US2009/069676
Authority: WO
Inventors: Karl M. Kropp; John A. Wheatley
Original assignee: 3M Innovative Properties Company
Priority date: 2008-12-30
Filing date: 2009-12-29
Publication date: 2010-07-08

Abstract

Lighting assemblies lighting assembly comprising: an enclosure having an interior surface and a first transmissive area, the interior surface comprising a first surface area region and a second surface area region generally opposite the first surface area region, wherein the first transmissive area is within second surface area region, and wherein the interior surface is at least one of semi-specularly reflective or specularly reflective and has an on-axis average reflectivity of at least 98% for visible light of any polarization; a first light emitting diode lighting output source positioned to introduce light into the enclosure, wherein when light is emitted from the first light emitting diode lighting output source, the light is reflected multiple times by the interior surface; and a light guide disposed within the enclosure and between the first and second surface area regions, wherein the light guide comprises light extraction features, and wherein there is a gap between the light guide and the first light emitting diode lighting output source, wherein when a portion of the light enters the light guide and the light is transported throughout the light guide and extracted by the light extraction features. Light assemblies described herein are useful as functional or decorative elements, for example, in displays, signs, and vehicles (e.g., automobile, trucks, etc.). Useful embodiments of light assemblies described herein for vehicles include automobile and truck (vehicle) lighting, dash lighting, instrument cluster lighting, door sill lighting, dome lighting, and under cabinet lighting.

Description

LIGHTING ASSEMBLY

Background

[0001] Light emitting diodes ("LEDs") (also sometimes referred to as "solid state lamps"), including those having Lambertian light emission pattern and having a light emission collimated to a range from 20° to 30° in at least one direction (e.g., the thickness direction of an enclosure, as well as in a cone), are well known in the art. One limitation of lighting with LEDs is providing uniform illumination over an output surface. The ratio between the size of the LED die and illuminated area typically ranges from several 100 to several 1,000 to 1, to even more than 10000 to 1 (i.e., size of the lighted area vs. the size of the LED die). One technique for trying to obtain more uniform lighting from LEDs is to utilize numerous, relatively closely spaced LEDs, which is an approach that is inefficient from both a cost standpoint having to use numerous LEDS, as well as the sensitivity of these systems to drift or failure of an individual LED.

[0002] LEDs are used in a variety of applications. Distributing light from LEDs is a common need shared by signs, displays, and liquid crystal displays. Here, a light distribution enclosure is placed behind an element which can be a colored panel, a graphic, or an LCD panel. Often, the goal is to achieve uniform illumination in a thin form factor, and with the fewest possible light sources.

[0003] LEDs have been used to light vehicle sill plates, but tend to lack desired efficiency, brightness, and uniformity. Current lighted sill plate designs can use multiple LEDs directly coupled to a light distribution assembly. Generally this is a sheet of clear plastic, but it could also be a bundle of plastic optical fibers. Typically these approaches lack lighting uniformity, sufficient brightness, or both.

[0004] One approach to try to provide a more efficient distribution of light is to use multiple LEDs directly attached to the edge of a light guide.

Summary

[0005] In one aspect, the present disclosure describes a lighting assembly comprising: an enclosure having an interior surface and a first transmissive area, the interior surface comprising a first surface area region and a second surface area region generally opposite the first surface area region, wherein the first transmissive area is within second surface area region, and wherein the interior surface is at least one of semi- specularly reflective or specularly reflective and has an on-axis average reflectivity of at least 98% (in some embodiments at least 95%, 98%, 99%, or more) for visible light of any polarization; a first light emitting diode lighting output source positioned to introduce light into the enclosure, wherein when light is emitted from the first light emitting diode lighting output source, the light is reflected multiple times by the interior surface; and a light guide disposed within the enclosure and between the first and second surface area regions, wherein the light guide comprises light extraction features on a major surface of the light guide facing the second surface area region, wherein there is a gap between the light guide and the first light emitting diode lighting output source, and wherein when a portion of the light enters the light guide and the light is transported throughout the light guide and extracted by the light extraction features. In some embodiments, the first light emitting diode lighting output source is a first light emitting diode (e.g., light emitting diode having Lambertian light emission pattern) positioned within the enclosure adjacent a portioned of the interior surface and at least one of within the first surface area region or between the first and second surface area regions.

[0006] In some embodiments, lighting assemblies described herein further comprise a second light emitting diode lighting output source positioned to introduce light into the enclosure, when light is emitted from the second light emitting diode lighting output source, and generally opposite the first light emitting diode lighting source. In some embodiments, the second light emitting diode lighting output source is a second light emitting diode (e.g., light emitting diode having Lambertian light emission pattern) positioned within the enclosure adjacent a portioned of the interior surface and at least one of within the first surface area region or between the first and second surface area regions.

[0007] It is understood that all the reflectivity values encompass all visible light reflected into a hemisphere (i.e., such values include semi-specular, specular, and diffuse reflections). The term "transmissive" as used herein means at least 50% (optionally, at least 60%, 70%, 75%, 80%, 85%, or even at least 90%) of the photons for at least one wavelength in the of light (e.g., in the visible spectrum) striking the area/film/element/etc, are transmitted through and exit the area/film/element/etc., as applicable.

[0008] In some embodiments, and typically desirably, the light emitting diode lighting output sources, when energized have a uniform lumens output.

[0009] Light assemblies described herein are useful as functional or decorative elements, for example, in displays, signs, and vehicles (e.g., automobile, trucks, etc.). Useful embodiments of light assemblies described herein for vehicles include automobile and truck (vehicle) lighting, dash lighting, instrument cluster lighting, door sill lighting, dome lighting, and under cabinet lighting.

Brief Description of the Drawings

[0010] FIG. 1 is a cross-sectional view of an exemplary lighting assembly described here.

[0011] FIGS. 2-4 are schematic side views of backlights containing a hollow recycling enclosure, comparing the effects of specular, Lambertian, and semi-specular reflectors.

Detailed Description

[0012] Referring to FIG. 1, exemplary lighting assembly 110 has enclosure 111 having interior surface 112 and first transmissive area 113. Interior surface 112 comprises first surface area region 114 and second surface area region 115 generally opposite first surface area region 114, wherein first transmissive area 113 is within second surface area region 115. First and second (optional) light emitting diodes 117, 118 each having Lambertian light emission pattern are positioned generally opposite each other within enclosure 111. Light guide 120 is disposed within enclosure 111 and within first surface area region 114. Light guide 120 has light extraction features 121. Gaps 122, 123 are between light guide 120 and first and second light emitting diodes, 117, 118, respectively.

[0013] The enclosure can be made of any of a variety of materials, including plastic, metal, wood, etc. The shape of the enclosure may be any of a variety of shapes including generally rectangular and triangular (including with squared off edges (internal and/or external), as well as those with oblong or rounded edges (internal and/or external)), as well as elliptical, and other Euclidean geometrical shapes.

[0014] Desirable length to width ratios of the enclosure are, for example, in a range from 1 :1 to 40:1 (in some embodiments, 10:1 to 40: 1, 15:1 to 40:1, 20:1 to 40:1, 25:1 to 40:1, or even 30:1 to 40:1). Desirable length to height (i.e., first surface area region to generally opposed, second surface area region) ratios of the enclosure are, for example, in a range from 20:1 to 150:1 (in some embodiments, in a range from 50:1 to 100:1).

[0015] Suitable light emitting diodes are known in the art, and are commercially available. Such light emitting diodes include those having Lambertian light emission pattern. In some embodiments, the LED may be used with a wedge-shaped reflector so that light may be emitted into the enclosure with a restricted or partially collimated angular distribution. Further, in some embodiments, light sources that at least partially collimate the emitted light may be preferred. Such light sources can include lenses, extractors, shaped encapsulants, or combinations thereof of optical elements to provide a desired output into the enclosure. Further, the lighting output sources can include injection optics that partially collimate or confine light initially injected into the enclosure to propagate in directions close to a transverse plane (the transverse plane being parallel to the output area of the lighting output source) (e.g., an injection beam having an average deviation angle from the transverse plane in a range from 0° to 45°, or 0° to 30°, or even 0° to 15°).

[0016] LEDs are available in a variety of power usage ratings, including those ranging from less than 0.1 watt to 5 watts (e.g., power usage ratings up to 0.1, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, or even up to 5 watts) per LED. LEDs are available in colors ranging from violet (about 410 nm) to deep red (about 700 nm). Basic colors of LEDs are blue, green, red, and amber, although other colors, such, as white, are also available. Ultraviolet LEDs can also be used. These can be used, for example, with a down converting phosphor to convert their emitted light to visible light.

[0017] Light from a light emitting diode lighting output source can be introduced into the enclosure in a variety of ways. For example, LED (chip) itself can be placed inside the enclosure. A lens connected to an LED can protrude into the enclosure even though the LED itself is outside the enclosure. In some cases, the LED can be located a meter away or more and have its light transported to the enclosure by, for example, a light fiber system. Light fiber systems use total internal reflection to propagate light from the injection end of the fiber to an exit point. The exit end of the fiber can be inserted into the enclosure, and optionally used with collimation technique (e.g., lenses or an external collimating wedge). Techniques of transporting light in a solid medium include low absorption solids (e.g., low loss glass fiber or acrylic fiber). It is often preferable to use a lower refractive index cladding surrounding the glass or acrylic core. The low index cladding prevents or reduces accidental light leakage that may occur from scratching, or objects physically touching the core. Further, for example, it is possible to use a hollow technique for light transport rather than solid. In this case a cavity comprised of a low-loss omnidirectional specular, or semi-specular mirror can be used. Light, preferably collimated, is injected into one end of this transport cavity, and by multiple reflections is transported to an extraction point which may be, in the case of a tube, the opposite end. The extraction end of this transport system can be positioned proximate the enclosure so as to introduce light into the enclosure.

[0018] The light emitting diode lighting output sources (in some embodiments, light emitting diodes themselves) are typically placed in the first surface area region and/or one of the sides (typically a narrow side). Typically, the light emitting diode lighting output source(s) (in some embodiments, light emitting diodes themselves) are positioned, with respect to an interior surface, within a range from 0.5 cm to 2.5 cm (in some embodiments, 0.75 cm to 1.5 cm) and/or, with respect to the first surface area region, within 50 (in some embodiments, 25) percent of the distance between the first and second surface area regions.

[0019] Optionally, the lighting assembly further comprises at least one additional (e.g., a second, third, fourth, fifth, or more) light emitting diode lighting output source(s) (in some embodiments, light emitting diodes themselves) within the enclosure (e.g., adjacent a portion of the interior surface and at least one of within the first surface area region or between the first and second surface area regions). For example, the lighting assembly may further comprise an additional light emitting diode lighting output source (in some embodiments, a light emitting diode itself positioned within the enclosure adjacent a portion of the interior surface and at least one of within the first surface area region or between the first and second surface area regions, and generally opposite the first light emitting diode lighting output source (in some embodiments, light emitting diodes themselves), wherein when light is emitted from the first and additional light emitting diode lighting output source(s) (in some embodiments, light emitting diodes themselves), the light is reflected multiple times by the interior surface to provide diffuse light, and wherein there is a also gap between the light guide and the additional light emitting diode lighting output source (in some embodiments, a light emitting diode itself).

[0020] Suitable light guides and light extraction devices are known in the art and are commercially available. Exemplary discontinuities that provide a light extraction features, which may be in the form of alphanumerics and/or trademark indicia, include abrasions, etching (e.g., acid etching, laser etching, etc.), printings (e.g., ink jet printing, screen printing, etc.) mechanical material removal (e.g., drillings, routings, etc.); transfer processes, labels (e.g., labels in the shape of circles), coatings, including coatings (e.g., paints) with particles (e.g., opaque particles, glitter particles, etc.), embossed patterns, and coated bead gain diffusers. In some embodiments, the light guide extraction features may be in random or non-random patterns. In some embodiments, discontinuities of the light guide extraction features cover in a range from 10 to 90 percent (in some embodiments, 15 to75 percent) of the surface area they are on and/or have discrete areas in a range from 0.1 mm² to 1 mm² (in some embodiments, 0.1 mm² to 0.75 mm²). For example, in some embodiments, the discontinuities is a coating (e.g. paint) that covers in a range from 10 to 90 percent (in some embodiments, 15 to 75 percent) of the surface area they are on and/or have discrete areas in a range from 0.1 mm² to 1 mm² (in some embodiments, 0.1 mm² to 0.75 mm²), although the specific amount of coverage may depend, for example, on the desired optical effect. In some embodiments, for example, when paint is sprayed onto a major surface of the light guide, the discontinuities may be in the shape of beads, or half- beads.

[0021] Although not wanting to be bound by theory, it is believed the gap, which is typically air, between light guide and an LED(s) aid in promoting homogeneity of the light. Typically, the size of the gap between light guide and an LED(s) is as small as about 2-3 mm to significantly larger gaps, depending on the size of the enclosure. The placement of the light guide relative to the LED can be determined by one of ordinary skill in the art so as to allow light from the LED to be uniformly distributed before entering the guide.

[0022] A "specular" reflector, sometimes referred to as a mirror, performs according to the optical rule that "the angle of incidence equals the angle of reflection." This is seen in the hollow enclosure 816 of FIG. 2. There, the front and back reflectors, 812, 814 are both specular. A small portion of an initially launched oblique light ray 850 is transmitted through the front reflector 812, but the remainder is reflected at an equal angle to the back reflector 814, and reflected again at an equal angle to the front reflector 812, and so on as illustrated. This arrangement provides maximum lateral transport of the light across the enclosure 816, since the recycled ray is unimpeded in its lateral transit of the enclosure 816. However, no angular mixing occurs in the enclosure, since there is no mechanism to convert light propagating at a given incidence angle to other incidence angles.

[0023] A "Lambertian" reflector, on the other hand, redirects light rays equally in all directions. This is seen in the hollow enclosure 916 of FIG. 3, where the front and back reflectors 912, 914 are both Lambertian. The same initially launched oblique light ray 950 is immediately scattered in all directions by the front reflector 912, most of the scattered light being reflected back into the enclosure 916 but some being transmitted through the front reflector 912. Some of the reflected light travels "forward" (generally to the right as seen in the figure), but an equal amount travels "backward" (generally to the left). By forward scattering, we refer to the lateral or in-plane (in a plane parallel to the scattering surface in question) propagation components of the reflected light. When repeated, this process greatly diminishes the forward directed component of a light ray after several reflections. The beam is rapidly dispersed, producing minimal lateral transport.

[0024] A "semi-specular" reflector provides a balance of specular and diffusive properties. In the hollow enclosure 1016 of FIG. 4, the front reflector 1012 is purely specular but the back reflector 1014 is semi-specular. The reflected portion of the same initially launched oblique light ray 1050 strikes the back reflector 1018, and is substantially forward-scattered in a controlled amount. The reflected cone of light is then partially transmitted but mostly reflected (specularly) back to the back reflector 1014, all while still propagating to a great extent in the "forward" direction. [0025] Specularly reflective surfaces having an on-axis average reflectivity of at least 98% for visible light by the light source(s) of any polarization can be provided, for example, by a fϊlm(s) such as those described in U.S. Pat. Nos. 5,882,774 (Jonza et al.) and 6,641,880 (Deyak et al.), the disclosures of which are incorporate herein by reference; additional details regarding such films can also be found in said patents. Embodiments of such films are marketed by 3M Company, St. Paul, MN, under the trade designation "VIKUITI ENHANCED SPECULAR REFLECTOR FILM." Other suitable reflective materials include those marketed by Alanod Aluminum- Veredlung GmbH & Co., Ennepetal, Germany, under the trade designation "MIRO-2 ANODIZED ALUMINUM FILM").

[0026] Semi-specular reflective surfaces can be provided, for example, by (1) a partial transmitting specular reflector plus a high reflectance diffuse reflector; (2) a partial Lambertian diffuser covering a high reflectance specular reflector; (3) a forward scattering diffuser plus a high reflectance specular reflector; or (4) a corrugated high reflectance specular reflector. Additional details regarding semi-specular reflective materials, can be found, for example, in PCT Application No. US2008/864115 (Attorney Docket No. 63032WO003), the disclosure of which is incorporated herein by reference.

[0027] Optionally, light assemblies described herein further comprising additional transmissive areas (e.g., one two, three, four, five, six, seven, eight, nine, ten, or more additional transmissive areas) within the second surface area region. Optionally, the transmissive area(s) are in the shape of, or otherwise include, both alphanumerics and trademark indicia. The transmissive area can be made of any material suitable for the particular light assembly desired, which may include acrylic, polycarbonate, plastics, and glass, as well as a material described below for the transmissive element.

[0028] Films for constructing lighting assemblies described herein may be supported, for example, by a transmissive substrate. Suitable transmissive substrates can include optical films, sheets, or plates. Suitable materials include glass, transmissive engineering thermoplastics (e.g., polycarbonate, polystyrene, acrylic, styrene acrylonitrile, cyclo olefin polymer ("COP"; available from Zeon Chemicals L.P., Louisville, KY), polyethylene terephthalate, polyethylene 2,6-naphthalate, and fluoropolymers). [0029] Optionally, lighting assembly described herein further comprising a comprising a tinted transmissive element(s) (e.g., a film(s)) disposed between the light guide and the first surface area region, the light guide and the transmissive area(s) (e.g., adhered to the transmissive area(s)) and/or the other side of the transmissive area(s)). Suitable films are known in the art and include tinted (e.g., dyed or pigmented) films and color shifting films. Transmissive tinted and color shifting films are available, for example, from 3M Company under the trade designation "SCOTCHCAL 3630" in about 60 different colors.

[0030] "Color shifting film" as used herein refers to a film comprising alternating layers of at least a first and second layer type, wherein the first layer type comprises a strain hardening polymer (e.g., a polyester), wherein the film has at least one transmission band and one reflection band in the visible region of the spectrum, the transmission band having an average transmission of at least 70%, and wherein at least one of said transmission band and reflection band varies at normal incidence by less than about 25 nm over a square inch. Optionally, the film comprises alternating polymeric layers of at least a first and a second layer type, wherein the film has at least one transmission band and at least one reflection band in the visible region of the spectrum, and wherein at least one of the transmission band and reflection band has a band edge that varies at normal incidence by no more than 8 nm over a distance of at least 2 inches along each of two orthogonal axes in the plane of the film. Optionally, at least one of the transmission band and the reflection band has a bandwidth at normal incidence that varies by no more than 2 nm over a surface area of at least 10 cm². Optionally, the film has exactly one transmission band in the visible region of the spectrum. Optionally, the film has exactly one reflection band in the visible region of the spectrum. Color shifting films can be made, for example, as described in U.S. Pat. No. 6,531,230 (Weber et al.), the disclosure of which is incorporate herein by reference; additional details regarding such films can also be found in said patent.

[0031] Films typically have a major surface covered with adhesive. Suitable adhesives are well known in the art (e.g., pressure sensitive adhesives) will generally be found on one surface of the film (continuous or portions depending on the embodiment involved) and allows the film to be attached to another surface. [0032] Suitable light assembly configurations can be designed and assembled using known techniques by one skilled in the art after reviewing the instant disclosure.

[0033] Light assemblies described herein are useful as functional or decorative elements, for example, in displays, signs, and vehicles (e.g., automobile, trucks, etc.). Useful embodiments of light assemblies described herein for vehicles include automobile and truck (vehicle) lighting, dash lighting, instrument cluster lighting, door sill lighting, dome lighting, and under cabinet lighting.

[0034] Advantages and embodiments of this invention are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. All parts and percentages are by weight unless otherwise indicated.

Example

[0035] A lighting assembly as generally shown in FIG. 1 was constructed as follows. A 39.4 cm (15.5 inches) long, 4.5 cm (1.8 inch) wide, 6 mm (0.25 inch) deep (high) tray was made from 0.1 cm (0.04 inch) sheet metal. An adhesive backed film that was specularly reflective and had an on-axis average reflectivity of 98.5% (available from 3M Company, St. Paul, MN, under the trade designation "VIKUITI ENHANCED SPECULAR REFLECTIVE FILM") was tightly fitted and applied to the bottom of the tray.

[0036] An adhesive backed film that was specularly reflective and had an on-axis average reflectivity of 98.5% ("VIKUITI ENHANCED SPECULAR REFLECTIVE FILM") was also tightly fitted and applied to the perpendicular (interior) sides of the tray.

[0037] Two surface mount LEDs (obtained from Philips Lumileds Corporation, San Jose, CA, under the trade designation "LUXEON REBEL") were positioned one on each end of the bottom of the tray, each from 1.3 cm (0. 5 inch) and centered between the width of the tray. The LEDs were attached to the adhesive backed film ("VIKUITI ENHANCED SPECULAR REFLECTIVE FILM") with an acrylic foam tape (available from 3M Company under the trade designation "VHB 4920"), and were wired in parallel.

[0038] A cover plate having slightly longer and wider dimensions than the tray was also made from 0.1 cm (0.04 inch) thick sheet metal to fit tightly on the top of the tray. An adhesive backed film that was specularly reflective and had an on-axis average reflectivity of 98.5% ("VIKUITI ENHANCED SPECULAR REFLECTIVE FILM") was tightly fitted and applied to the interior major surface of the cover plate. A decorative design was then milled through the major surfaces of the cover plate (and film).

[0039] An acrylic strip about 4.45 cm (1.75 inch) by 36.6 cm (14 inches) was cut from a 6 mm thick (0.25 inch) cast acrylic sheet (obtained under the trade designation "CYRO ACRYLITE" from Midwest Sign & Graphics, St. Paul MN, using a fine tooth saw. One of the 4.45 cm edge was polished to eliminate scratches and other artifacts related to the cutting.

[0040] A semi-white solvent-based aerosol paint (obtained under the trade designation "KRYLON" from Sherman- Williams (Rrylon Products Group), Cleveland, OH) was lightly sprayed on the polished 4.45 cm edge of the acrylic guide. The paint can had a spray nozzle with the designation "EZ TOUCH 360° DIAL NOZZLE." The paint can was nearly empty, causing the paint to spatter more than a full can would have. The paint covered about 15% of the top surface of the guide in a generally uniform pattern, although more paint covered the middle of the top surface as compared to the ends of the top surface. After the paint dried, the painted surface was placed face up in the tray between the LEDs, but not covering either one.

[0041] The cover plate was placed over the tray and light guide.

Lighting Assembly Embodiments

1. A lighting assembly comprising: an enclosure having an interior surface and a first transmissive area, the interior surface comprising a first surface area region and a second surface area region generally opposite the first surface area region, wherein the first transmissive area is within second surface area region, and wherein the interior surface is at least one of semi-specularly reflective or specularly reflective and has an on-axis average reflectivity of at least 98% for visible light of any polarization; a first light emitting diode lighting output source positioned to introduce light into the enclosure, wherein when light is emitted from the first light emitting diode lighting output source, the light is reflected multiple times by the interior surface; and a light guide disposed within the enclosure and between the first and second surface area regions, wherein the light guide comprises light extraction features on a major surface of the light guide facing the second surface area region, there is a gap between the light guide and the first light emitting diode lighting output source, and when a portion of the light enters the light guide, the light is transported throughout the light guide and extracted by the light extraction features.

2. The lighting assembly according to embodiment 1, wherein the first surface area region is semi-specularly reflective.

3. The lighting assembly according to embodiment 1, wherein the first surface area region is specularly reflective.

4. The lighting assembly according to any preceding embodiment, wherein the first light emitting diode lighting output source is a first light emitting diode positioned within the enclosure adjacent a portioned of the interior surface and at least one of within the first surface area region or between the first and second surface area regions.

5. The lighting assembly according to embodiment 4, wherein the first light emitting diode has Lambertian light emission pattern.

6. The lighting assembly according to any preceding embodiment, further comprising a second light emitting diode lighting output source positioned to introduce light into the enclosure, when light is emitted from the first light emitting diode lighting output source, and generally opposite the first light emitting diode lighting source.

7. The lighting assembly according to any preceding embodiment, wherein the second light emitting diode lighting output source is a second light emitting diode positioned within the enclosure adjacent a portioned of the interior surface and at least one of within the first surface area region or between the first and second surface area regions.

8. The lighting assembly according to embodiment 7, wherein the second light emitting diode has Lambertian light emission pattern.

9. The lighting assembly according to any preceding embodiment, wherein the extraction features include abrasions. 10. The lighting assembly according to any of embodiments 1 to 8, wherein the extraction features include etchings.

11. The lighting assembly according to any of embodiments 1 to 8, wherein the extraction features include an embossed pattern.

12. The lighting assembly according to any of embodiments 1 to 8, wherein the extraction features include a printed pattern.

13. The lighting assembly according to any of embodiments 1 to 8, wherein the major surface of the light guide include paint.

14. The lighting assembly according to embodiment 13, the paint covers in a range from 10 to 90 percent of the major surface

15. The lighting assembly according to any preceding embodiment, wherein light extraction features comprise discrete areas in a range fromθ.1 mm² to 1 mm².

16. The lighting assembly according to any preceding embodiment, wherein the specular reflectance of the interior is provided by at least one film.

17. The light assembly according to any preceding embodiment, wherein the enclosure is generally rectangular in shape.

18. The light assembly according to any preceding embodiment, wherein the first transmissive area is in the shape of at least one alphanumeric.

19. The light assembly according to any preceding embodiment, wherein the first transmissive area is in the shape of at least one trademark indicia.

20. The light assembly according to any preceding embodiment, further comprising additional transmissive areas within the second surface area region.

21. The light assembly according to embodiment 25, wherein the transmissive areas are in the shape of alphanumerics.

22. The light assembly according to embodiment 25, wherein the transmissive areas include both alphanumerics and trademark indicia.

23. The lighting assembly according to any preceding embodiment, wherein the first light emitting diode lighting output source has a power usage rating up to 1 watt.

24. The lighting assembly according to any of embodiments 1 to 25, wherein the first light emitting diode lighting output source has a power usage rating up to 0.75 watt. 25. The lighting assembly according to any of embodiments 1 to 25, wherein the first light emitting diode lighting output source has a power usage rating up to 0.5 watt.

26. The lighting assembly according to any preceding embodiment, further comprising a film that is at least transmissive disposed between the light guide and the transmissive area.

27. The lighting assembly according to any preceding embodiment having a length, wherein the first light emitting diode lighting output source is positioned, with respect to an interior surface, within a range from 0.5 cm to 2.5 cm.

28. The lighting assembly according to any preceding embodiment having a distance between the first and second surface area regions, wherein the first light emitting diode lighting output source is positioned, with respect to the first surface area region, within 50 percent of the distance between the first and second surface area regions.

29. The lighting assembly according to any preceding embodiment that is a door sill lighting assembly.

30. A vehicle comprising the lighting assembly according to any preceding embodiment.

[0042] Foreseeable modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention. This invention should not be restricted to the embodiments that are set forth in this application for illustrative purposes.

Claims

What is claimed is:

1. A lighting assembly comprising: an enclosure having an interior surface and a first transmissive area, the interior surface comprising a first surface area region and a second surface area region generally opposite the first surface area region, wherein the first transmissive area is within second surface area region, and wherein the interior surface is at least one of semi- specularly reflective or specularly reflective and has an on-axis average reflectivity of at least 98% for visible light of any polarization; a first light emitting diode lighting output source positioned to introduce light into the enclosure, wherein when light is emitted from the first light emitting diode lighting output source, the light is reflected multiple times by the interior surface; and a light guide disposed within the enclosure and between the first and second surface area regions, wherein the light guide comprises light extraction features on a major surface of the light guide facing the second surface area region, there is a gap between the light guide and the first light emitting diode lighting output source, and when a portion of the light enters the light guide, the light is transported throughout the light guide and extracted by the light extraction features.

2. The lighting assembly according to claim 1, wherein the first surface area region is semi-specularly reflective or specularly reflective.

3. The lighting assembly according to any preceding claim, wherein the first light emitting diode lighting output source is a first light emitting diode positioned within the enclosure adjacent a portioned of the interior surface and at least one of within the first surface area region or between the first and second surface area regions.

4. The lighting assembly according to claim 3, wherein the first light emitting diode has Lambertian light emission pattern.

5. The lighting assembly according to any preceding claim, further comprising a second light emitting diode lighting output source positioned to introduce light into the enclosure, when light is emitted from the first light emitting diode lighting output source, and generally opposite the first light emitting diode lighting source.

6. The lighting assembly according to claim 5, wherein the second light emitting diode lighting output source is a second light emitting diode positioned within the enclosure adjacent a portioned of the interior surface and at least one of within the first surface area region or between the first and second surface area regions.

7. The lighting assembly according to claim 6, wherein the second light emitting diode has Lambertian light emission pattern.

8. The lighting assembly according to any preceding claim, wherein the extraction features include at least one of abrasions, etchings, an embossed pattern, and a printed pattern.

9. The lighting assembly according to claim 8, the paint covers in a range from 10 to 90 percent of the major surface

10. The lighting assembly according to any preceding claim, wherein light extraction features comprise discrete areas in a range fromθ.1 mm² to 1 mm².

11. The light assembly according to any preceding claim, further comprising additional transmissive areas within the second surface area region.

12. The lighting assembly according to any preceding claim, wherein the first light emitting diode lighting output source has a power usage rating up to 1 watt.

13. The lighting assembly according to any preceding claim, further comprising a film that is at least transmissive disposed between the light guide and the transmissive area.

14. The lighting assembly according to any preceding claim having a length, wherein the first light emitting diode lighting output source is positioned, with respect to an interior surface, within a range from 0.5 cm to 2.5 cm.

15. The lighting assembly according to any preceding claim having a distance between the first and second surface area regions, wherein the first light emitting diode lighting output source is positioned, with respect to the first surface area region, within 50 percent of the distance between the first and second surface area regions.