Patent Description:
Luminaires (or light fixtures) often include multiple components, such as a housing, a light source, a reflector, a lens, and a trim. Among the various components of luminaires, sellers can offer customers options for the various components. For example, a seller of luminaires can offer customers different types of trims that provide different appearances. Sellers of luminaires also can offer different types of lenses that provide different distributions of light. For instance, the seller can offer customers a first type of lens that provides a wide distribution of light from the luminaire. However, if a customer wants or a specific environment calls for a more narrow distribution of light, the seller can offer a second type of lens that modifies the light exiting the luminaire to achieve a more narrow distribution of light. In some cases, the seller may offer a variety of lenses with each luminaire to provide a variety of different distributions.

However, offering a variety of different lenses for sale with a luminaire adds expense because the manufacturer must create tooling for making each variety of lens. Additionally, offering a variety of lenses for sale with a luminaire adds supply chain costs and challenges because the seller must keep each variation of the lens in stock. Accordingly, it would be beneficial to provide a solution that allows customers to choose different light distributions while also minimizing the number of different lenses that are required to be manufactured and held in stock for sale to customers.

<CIT> discloses an LED lighting device having a polygon surface shaped light-pervious plate is disposed at the open side and light emitted from the LED is capable of being spread outward through the polygon surface shaped light-pervious plate. <CIT> discloses a light fixture structure comprises a housing defining an opening and an first attachment element comprising a nose element, a hook element and a connection region, and optionally further comprising a diffuser engaging a first portion of the hook element, and/or an accessory which engages a second portion of the hook element. Japanese patent publication <CIT> discloses an LED lighting device with a lens located at the end of a reflector to close the opening, where the lens member includes a protruding part, which controls light distribution, protruding toward the LED light source and disposed at a periphery of the lens member. Japanese patent publication <CIT> discloses an LED lighting apparatus with a lens cassette holder with multiple slits to relocate a lens, or install the lens upside down.

The present disclosure relates generally to luminaires, and more particularly to a lens that provides two different distributions of light for the luminaire. In one example embodiment, a luminaire comprises a housing, a light emitting diode light source disposed within the housing, a reflector disposed within the housing, and a lens disposed within the housing. The reflector is oriented within the housing to reflect a portion of light emitted from the light emitting diode light source. The lens comprises a first side and a second side, wherein at least one of the first side and the second side comprises a pattern of optical features. The lens further comprises an attachment feature configured to attach the lens to the luminaire either in a first position with the first side facing the light emitting diode light source or in a second position with the second side facing the light emitting diode light source.

In another example embodiment, a luminaire comprises a housing, a light emitting diode light source disposed within the housing, and a lens disposed within the housing. The lens comprises a first side and a second side, wherein at least one of the first side and the second side comprises a pattern of optical features. The lens further comprises an attachment feature configured to attach the lens to the luminaire either in a first position with the first side facing the light emitting diode light source or in a second position with the second side facing the light emitting diode light source.

These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims.

The drawings illustrate only example embodiments and are therefore not to be considered limiting in scope. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or placements may be exaggerated to help visually convey such principles. In the drawings, the same reference numerals used in different drawings designate like or corresponding but not necessarily identical elements.

In the following paragraphs, example embodiments will be described in further detail with reference to the figures. In the description, well-known components, methods, and/or processing techniques are omitted or briefly described. Furthermore, reference to various feature(s) of the embodiments is not to suggest that all embodiments must include the referenced feature(s).

The example embodiments described herein relate to a luminaire having a housing and a lens disposed within the housing. The lens comprises two different broad surfaces. When the lens is oriented in the luminaire housing with the first broad surface facing the light source, the lens emits light having a first distribution. However, when the lens is removed, flipped over, and inserted back into the luminaire housing so that the lens is oriented with the opposite second broad surface facing the light source of the luminaire, the lens emits light having a second distribution that is different from the first distribution. The example embodiments illustrated in the attached figures pertain to a recessed luminaire. However, it should be understood that the example embodiments described herein are representative and the disclosure can be applied to other types of light fixtures, including but not limited to surface mounted light fixtures, pendant light fixtures, troffer light fixtures, highbay light fixtures, outdoor light fixtures, and flood light fixtures.

In certain example embodiments, the example light fixtures are subject to meeting certain standards and/or requirements. For example, the National Electric Code (NEC), the National Electrical Manufacturers Association (NEMA), the International Electrotechnical Commission (IEC), the Federal Communication Commission (FCC), and the Institute of Electrical and Electronics Engineers (IEEE) set standards as to electrical enclosures (e.g., light fixtures), wiring, and electrical connections. As another example, Underwriters Laboratories (UL) sets various standards for light fixtures, including standards for heat dissipation. Use of example embodiments described herein meet (and/or allow a corresponding device to meet) such standards when required.

Any light fixture components (e.g., housings, reflectors, lenses, trim assemblies), described herein can be made from a single piece (e.g., as from a mold, injection mold, die cast, <NUM>-D printing process, extrusion process, stamping process, or other prototype methods). In addition, or in the alternative, a luminaire (or components thereof) can be made from multiple pieces that are mechanically coupled to each other. In such a case, the multiple pieces can be mechanically coupled to each other using one or more of a number of coupling methods, including but not limited to epoxy, welding, fastening devices, compression fittings, mating threads, and slotted fittings. One or more pieces that are mechanically coupled to each other can be coupled to each other in one or more of a number of ways, including but not limited to fixedly, hingedly, removeably, slidably, and threadably.

An attachment feature (including a complementary attachment feature) as described herein can allow one or more components and/or portions of an example lens, reflector, housing or other component of a light fixture to become coupled, directly or indirectly, to another portion or other component of a light fixture. An attachment feature can include, but is not limited to, a flange, a snap, Velcro, a clamp, a portion of a hinge, an aperture, a recessed area, a protrusion, a slot, a spring clip, a tab, a detent, and mating threads. One portion of an example lens can be coupled to a light fixture by the direct use of one or more attachment features.

In addition, or in the alternative, a portion of a light fixture can be coupled using one or more independent devices that interact with one or more attachment features disposed on a component of the lens, light fixture, or other component of a light fixture. Examples of such devices can include, but are not limited to, a pin, a hinge, a fastening device (e.g., a bolt, a screw, a rivet), epoxy, glue, adhesive, tape, and a spring. One attachment feature described herein can be the same as, or different than, one or more other attachment features described herein. A complementary attachment feature (also sometimes called a corresponding attachment feature) as described herein can be a coupling feature that mechanically couples, directly or indirectly, with another coupling feature.

Terms such as "first", "second", "top", "bottom", "side", "distal", "proximal", and "within" are used merely to distinguish one component (or part of a component or state of a component) from another. Such terms are not meant to denote a preference or a particular orientation, and are not meant to limit the embodiments described herein. In the following detailed description of the example embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the invention.

Referring now to <FIG>, an example luminaire <NUM> comprising a dual distribution lens is illustrated. <FIG> shows a perspective view of luminaire <NUM> with a view up into the light emitting aperture <NUM>. <FIG> shows a cross-sectional view of luminaire <NUM> with the cross section taken along a vertical plane passing through the luminaire <NUM>. <FIG> shows another cross-sectional view of luminaire <NUM> with the cross section taken along another vertical plane passing through the luminaire <NUM>. The example luminaire <NUM> is a recessed luminaire for installation in a ceiling. Although not shown in <FIG>, the recessed luminaire <NUM> can be mounted using any of a variety of known methods including but not limited to fasteners, torsion springs, friction clips, and mounting brackets.

The primary components of the example luminaire <NUM> comprise a housing <NUM>, a light source <NUM>, a reflector <NUM>, and a lens <NUM>. The housing <NUM> comprises an interior surface <NUM> which can be reflective so as to reflect light incident on the interior surface <NUM>. The lower edge of the interior surface <NUM> defines the light emitting aperture <NUM>. The housing <NUM> further comprises a housing flange <NUM> extending from the lower edge of the interior surface <NUM> of the housing <NUM>. The housing flange <NUM> can cover any gaps which may exist between the luminaire <NUM> and the surface (e.g., a ceiling) in which the luminaire <NUM> is mounted. The housing <NUM> of example luminaire <NUM> also comprises an optional service aperture <NUM>. The service aperture <NUM> provides access to the interior of the housing <NUM> and can be used, for example, to make wiring connections when installing the luminaire <NUM>.

The light source illustrated in <FIG> is a chip on board LED light source <NUM>, which is mounted to the interior upper surface of housing <NUM>. It should be understood that in alternate embodiments other types of light sources can be implemented including but not limited to a single LED, an array of LEDs, and one or more organic LEDs. Additionally, in alternate embodiments, the light source can be located in other positions within the luminaire.

In the example of <FIG>, the reflector <NUM> is mounted within the housing <NUM> near the interior upper surface and near the light source <NUM>. The reflector <NUM> is generally conical in shape and comprises an entrance opening proximal to the light source <NUM> and an exit opening distal from the light source <NUM>. The reflector <NUM> receives some of the light emitted by the light source <NUM> and reflects the incident light down toward the light emitting aperture <NUM>. Although the housing <NUM> and the reflector <NUM> are shown as distinct components in the example of <FIG>, it should be understood that the dual distribution lens can be implemented in a variety of luminaires which may have different housings and may or may not include a reflector. As one example, in an alternate embodiment, the separate reflector can be omitted and the interior of the housing can comprise a reflective surface. In yet other alternate embodiments, a reflective surface within the luminaire may be unnecessary.

In the example luminaire <NUM> illustrated in <FIG>, the reflector <NUM> comprises a reflector flange <NUM> which extends outward from the bottom edge of the reflector <NUM>. The reflector flange <NUM> retains the dual distribution lens <NUM> within the housing <NUM>. As shown in <FIG>, the dual distribution lens <NUM> comprises a first broad surface (or first side) <NUM>, a second broad surface (or second side) <NUM>, and a rim <NUM> about the perimeter of the lens <NUM>. The rim <NUM> of the lens <NUM> comprises one or more attachment features for securing the lens <NUM> within the housing <NUM>. In the example of <FIG>, the attachment features are tabs <NUM> and <NUM> disposed along the interior surface of the rim <NUM>.

As shown in <FIG>, the reflector flange <NUM> comprises one or more gaps <NUM> through which tabs <NUM> or tabs <NUM> can fit. In a first orientation, the tabs <NUM> of the rim <NUM> are inserted into the gaps <NUM> of the reflector flange <NUM> and the lens <NUM> is rotated so that the tabs <NUM> rest on the upper side of the reflector flange <NUM>. Once the lens <NUM> is positioned with the tabs <NUM> passing through the gaps <NUM> and the lens <NUM> is rotated, the lens <NUM> is secured by the reflector flange <NUM> within the luminaire in the first orientation.

The first broad surface <NUM> of the lens comprises a pattern of optical features which makes the first broad surface <NUM> different from the second broad surface <NUM>. As such, in the first orientation, the lens <NUM> provides a first distribution of light created by the light from the light source <NUM> encountering the pattern of optical features on the first broad surface <NUM> before the light passes through the lens <NUM>. The lens <NUM> can comprise an indicator <NUM>, such as the word "WIDE", on one or both of the first broad surface <NUM> and the second broad surface <NUM> indicating the type of light distribution associated with the orientation of the lens <NUM>.

The light distribution emitted by the luminaire <NUM> can be changed by reorienting or flipping over the same lens <NUM> without the need for another lens. In other words, instead of providing two lenses with different light distributions, two different light distributions can be achieved with the single lens having different surfaces on the opposite broad surfaces of the lens. Continuing with the lens <NUM> in the first orientation described in the previous paragraph, the lens <NUM> can be rotated so that the tabs <NUM> pass back through the gaps <NUM> in the reflector flange <NUM> and so that the lens <NUM> can be removed from the housing <NUM>. Once removed, the lens <NUM> can be flipped over so that the second broad surface <NUM> faces upward toward the light source <NUM>. The lens <NUM> can then be inserted back into the housing <NUM> so that the tabs <NUM> on the second side of the lens <NUM> are inserted into the gaps <NUM> in the reflector flange <NUM>. Once the tabs <NUM> are inserted into the gaps <NUM>, the lens <NUM> is rotated so that the tabs <NUM> rest on top of the reflector flange <NUM> and the lens <NUM> is retained in place in a second orientation within the luminaire <NUM>. The second broad surface <NUM> is different than the first broad surface <NUM> so that a different light distribution is emitted by the luminaire <NUM> when the lens <NUM> is in the second orientation.

It should be understood that the tabs <NUM> and <NUM> and the reflector flange <NUM> are merely one example of attachment features for securing the lens <NUM> within the luminaire <NUM> according to the invention. As one example, in alternate embodiments not according to the invention, instead of a plurality of tabs <NUM> proximal to the first side <NUM> and a plurality of tabs <NUM> proximal to the second side <NUM> of the lens <NUM>, there may be only a single attachment feature on each side of the lens. In another alternate embodiment, the tabs can be located on the outer surface of the rim <NUM> and the tabs can attach to a ledge on the interior surface of the housing <NUM>. In yet another example, the bottom of the reflector can be wider than the lens with a reflector flange extending inward and the tabs can be located on the outer surface of the rim <NUM> such that they rest on the inward extending reflector flange. In yet other examples not according to the invention, the tabs can be replaced by threads, detents, or a variety of other types of attachment features that allow the lens to be easily attached to and detached from the luminaire so that the lens can be easily flipped over from the first orientation to the second orientation. It should also be understood that in alternate embodiments and alternate types of light fixtures, the lens can be located at different positions with respect to the luminaire. For example, while the example of <FIG> shows the lens <NUM> recessed in the housing <NUM>, in other embodiments, the lens can be located adjacent the housing flange <NUM> at the light emitting aperture <NUM>.

Referring now to <FIG> and <FIG>, two ray trace diagrams are provided illustrating the different light distributions that can be achieved by reorienting the lens <NUM> from the first orientation to the second orientation. For purposes of clarity, the ray trace diagrams shown in <FIG> and <FIG> have been simplified from the example luminaire of <FIG> in that the housing <NUM>, reflector <NUM>, and lens rim <NUM> are not shown, the light source <NUM> has been simplified to a point source, and only a portion of the light rays are shown. <FIG> shows lens <NUM> with the first broad surface <NUM> facing the light source <NUM> and the second broad surface <NUM> facing away from the light source <NUM>. An axis <NUM> is shown passing through the center of the lens <NUM>. The pattern of optical features on the first broad surface <NUM> causes a substantial portion of the light rays emitted from the light source <NUM> to diverge. In the example shown in <FIG>, the diverging light rays <NUM> constitute a majority of the light rays and the converging light rays <NUM> a minority of the light rays, thereby producing a relatively wide light distribution.

In contrast, <FIG> shows lens <NUM> after being reoriented or flipped over, as described above, so that the first broad surface <NUM> faces away from the light source <NUM> and the second broad surface <NUM> faces the light source <NUM>. In the second orientation shown in <FIG>, the light rays emitted from the light source <NUM> do not encounter the pattern of optical features on the first side <NUM> until after the light rays pass through the lens <NUM>. As a result of this second orientation, there are more converging light rays <NUM> than diverging light rays <NUM> and the lens <NUM> provides a more narrow light distribution relative to the first orientation shown in <FIG>.

The example dual distribution lens <NUM> illustrated in <FIG> has a pattern of optical features on the first broad surface <NUM> and a smooth surface on the second broad surface <NUM>. The pattern of optical features on the first broad surface <NUM> has features with the shape of a four-sided pyramid. However, to achieve other light distributions, the features can have other shapes including but not limited to conic, tetrahedral, or hexagonal. Additionally, in other example embodiments, instead of a smooth surface, the second broad surface <NUM> of the lens <NUM> can have a pattern of optical features that is different from the pattern of optical features on the first broad surface <NUM>. The differing patterns of optical features on opposite sides of the lens can also be used to achieve different light distributions. While the pattern of optical features on the first broad surface <NUM> are shown extending from the lens <NUM>, it should be understood that in other embodiments, other types of features affecting light distribution can be embedded within the lens proximal to one or both of the first side and the second side of the lens.

Claim 1:
A luminaire (<NUM>) comprising:
a housing (<NUM>);
a light emitting diode light source (<NUM>) disposed within the housing;
a reflector (<NUM>) disposed within the housing and oriented to reflect a portion of light from the light emitting diode light source; and
a lens (<NUM>) disposed within the housing, the lens comprising a first side (<NUM>) and a second side (<NUM>), at least one of the first side and the second side comprising a pattern of optical features, wherein the lens comprises an attachment feature that attaches the lens to the reflector, wherein the attachment feature is configured to attach the lens to the luminaire in a first position with the first side facing the light emitting diode light source and in a second position with the second side facing the light emitting diode light source, characterized in that the attachment feature comprises: a first plurality of tabs (<NUM>) proximate to a first edge of a rim (<NUM>) of the lens, wherein when the lens is attached to the luminaire in the first position, the first plurality of tabs fit into corresponding recesses (<NUM>) in the reflector; and
a second plurality of tabs (<NUM>) proximate to a second edge of the rim of the lens, wherein when the lens is attached to the luminaire in the second position, the second plurality of tabs fit into the corresponding recesses (<NUM>) in the reflector.