The present disclosure relates generally to lighting fixtures, and in particular to a uniform lens illumination in downlight fixtures.
Conventional downlight fixtures with backlit illumination may create visual hot spots of light on a lens that covers the light sources, resulting in a non-uniform brightness or an undesirable glare across the lens. For example, when a person looks up at the light fixture that uses light emitting diode (LED) light sources, they may see point sources created by the light being emitted by each of the LEDs. This problem is generated by the significant contrast in the amount of light being generated by the LED when compared to the immediate area around the LED, which is not emitting any light. The high contrast between the portions of the fixture emitting light (the LEDs and lens) and the non-light emitting portions can generate unpleasant glare. Existing solutions to reduce the contrast between the light being emitted by the light sources and the remaining portion of the light fixture facing the environment to be illuminated may include increasing a thickness of the downlight fixtures to provide a larger distance between the light sources and the lens. Alternatively, a very thick diffusing lens may be used. However, both the existing solutions mentioned above may diminish light output efficiency of the downlight fixtures. Further, a downlight fixture that incorporates the above-mentioned solutions may have a thick profile which may undesirable in terms of the aesthetics of the downlight fixture. Thus, there remains a need for a back lit downlight fixture that can provide a substantially uniform illumination of the lens while maintaining a thin profile.
In one aspect, the present disclosure can relate to a downlight fixture. The downlight fixture includes a mounting plate configured to mount the downlight fixture to a mounting surface. Further, the downlight fixture includes a housing reflector member coupled to and disposed below the mounting plate. The housing reflector member includes a top edge that defines a first aperture, a bottom edge that defines a second aperture disposed below and opposite the first aperture, and a reflector body extending between the top edge and the bottom edge and having an inner surface and an outer surface that is opposite to the inner surface. Furthermore, the downlight fixture includes a top reflector panel coupled to the housing reflector member such that at least a portion of the top reflector panel covers the first aperture. A lens is coupled to the housing reflector member such that at least a portion of the lens covers the second aperture. Additionally, the downlight fixture includes a plurality of light sources disposed on a surface of the top reflector panel facing the lens and adjacent a perimeter of the top reflector panel such that the plurality of light sources are: (a) outside a perimeter of the lens, and (b) above the reflector body of the housing reflector member.
In another aspect, the present disclosure can relate to a downlight fixture. The downlight fixture includes a housing reflector member. The housing reflector member includes a curved portion having a substantially concave inner profile and extending from a top edge of the housing reflector member to an intermediate edge of the housing reflector member. Further, the housing reflector member includes a stairway shaped portion disposed below the curved portion and extending substantially laterally inwards from the intermediate edge of the housing reflector member to a bottom edge of the housing reflector member. A top reflector panel is coupled to the curved portion of the housing reflector member such that at least a portion of a perimeter of the top reflector panel is disposed on the top edge of the housing reflector member. Further, a lens is coupled to the stairway shaped portion of the housing reflector member adjacent the bottom edge of the housing reflector member. Furthermore, the downlight fixture includes a plurality of light emitting diodes (LEDs) disposed on a surface of the top reflector panel facing the lens and adjacent the perimeter of the top reflector panel such that the plurality of LEDs are positioned: (a) outside a perimeter of the lens, and (b) above the curved portion of the housing reflector member.
In yet another aspect, the present disclosure can relate to a downlight fixture. The downlight fixture includes a mounting plate configured to mount the downlight fixture to a mounting surface. Further, the downlight fixture includes a housing reflector member coupled to and disposed below the mounting plate. The housing reflector member includes a top edge, a bottom edge that defines an aperture, and a reflector body extending between the top edge and the bottom edge and having a reflective inner surface and an outer surface that is opposite to the reflective inner surface. Further, the downlight fixture includes a top reflector panel coupled to the top edge of the housing reflector member, and a lens coupled to the housing reflector member such that at least a portion of the lens covers the aperture. Furthermore, the downlight fixture includes a plurality of light sources disposed on the housing reflector member adjacent the bottom edge of the housing reflector member such that the plurality of light sources are outside a perimeter of the lens.
These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims.
The foregoing and other features and aspects of the disclosure are best understood with reference to the following description of certain example embodiments, when read in conjunction with the accompanying drawings, wherein:
The drawings illustrate only example embodiments of the disclosure and are therefore not to be considered limiting of its scope, as the disclosure may admit to other equally effective embodiments. 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 positioning may be exaggerated to help visually convey such principles.
In the following paragraphs, the present disclosure will be described in further detail by way of examples with reference to the attached drawings. In the description, well known components, methods, and/or processing techniques are omitted or briefly described so as not to obscure the disclosure. As used herein, the “present disclosure” refers to any one of the embodiments of the disclosure described herein and any equivalents. Furthermore, reference to various feature(s) of the “present disclosure” is not to suggest that all embodiments must include the referenced feature(s).
The present disclosure is directed to an example uniform lens illumination downlight fixture (herein downlight fixture′) that includes at least a plurality of light sources and a lens that covers the plurality of light sources. In particular, the plurality of light sources are disposed at a distance above the lens and positioned outside a perimeter of the lens to reduce an amount of direct light exiting the downlight fixture through the lens. Further, the plurality of light sources are positioned such that an inner profile of the downlight fixture's housing receives the light emitted by the plurality of light sources and/or operates in concert with a reflector panel of the downlight fixture to reflect the light towards the lens and/or a space (e.g., luminous cavity) between the reflector panel and the lens (above the lens), thereby increasing a reflected or indirect light exiting the downlight fixture through the lens. Stated another way, the plurality of light sources have a vertical position that is directly above the inner profile of the downlight fixture's housing to minimize the visibility of point sources of light when looking up at the fixture. That is, the example downlight fixture of the present disclosure provides a more uniform illumination of the lens by reducing the amount of direct light exiting the downlight fixture and increasing an amount of indirect or reflected light exiting the downlight fixture. Additionally, the above-mentioned arrangement of the lens and the plurality of light sources allows the example downlight fixture of the present disclosure to have a thin profile, i.e., reduce a distance between a surface on which the plurality of the light sources are disposed and the lens.
The technology of the present disclosure can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the technology to those having ordinary skill in the art. Furthermore, all “examples” or “example embodiments” given herein are intended to be non-limiting and among others supported by representations of the present technology.
Further,
Referring to
As illustrated in
In addition to the top cover 210, the mounting plate 102 may include a downward extending flange 211 extending along the perimeter/boundary of the top cover 210 of the mounting plate 102. In certain example embodiments, the downward extending flange 211 may have: (i) a first side wall 204 that extends substantially perpendicular to the top cover 210 from the top edge 203 to an outer bottom edge 205 of the mounting plate 102, (ii) a second side wall 209 that extends substantially parallel to the top cover 210 from the outer bottom edge 205 to an inner bottom edge 207 of the mounting plate 102, and (iii) a third side wall 213 that extends substantially perpendicular to the top cover 210 and parallel to the first side wall 204 from the inner bottom edge 207 to the top cover 210 of the mounting plate 102. As illustrated in
Further, the mounting plate 102 may include a plurality of blind apertures 202 located on the downward facing flange 211. In particular, each blind aperture 202 may extend from a portion of the third side wall 213 (adjacent the top cover 210) towards the first side wall 204. Alternatively, in other example embodiments, the apertures 202 may be through apertures. In certain example embodiments, the plurality of blind apertures 202 may be configured to attach a housing reflector member 120 of the downlight fixture 100 to the mounting plate 102 as will be described below in greater detail in association with
Referring to
In certain example embodiments, as illustrated in
In addition to the curved portions (306a, 306b), the housing reflector member 120 may include a stairway shaped portion 317 that extends substantially horizontally/laterally and inward (direction of the inner surface 321) from the intermediate edge 304 of each curved portion (306a, 306b), as illustrated in
In particular, the stairway shaped portion 317 may include a first planar seat portion 308, a side wall 715 (shown in
Further, the stairway shaped portions 317 that extend laterally inward from the intermediate edge 304 of each curved portion (306a, 306b) may be arranged such that the bottom edges 323 of stairway shaped portions 317 may define a second substantially square shaped aperture 319 that is configured to receive a lens 122 as will be described in greater detail below in association with
As illustrated in
According to certain example embodiments, the housing reflector member 120 may be fabricated using a reflective material, such as aluminum or highly reflective white plastic; or may be fabricated using a non-reflective material and subsequently made to be reflective. For example, an inner profile of the housing reflector member 120, i.e., the inner surface 321 of the curved portion 306 and an inner surface of the stairway shaped portion 317 (facing the mounting plate 102 and/or the light sources 132), may be polished or may be painted to be made reflective so that light emitted from the plurality of the light sources 132 and directed towards the inner profile of the housing reflector member 120 may be reflected to a desired area, such as the lens 122, the luminous cavity above the lens 122, and/or the top reflector panel 402, as will be described below in greater detail in association with
Even though the present disclosure describes the apertures defined by the top edges and the bottom edges of the housing reflector member as being substantially square shaped, one of ordinary skill in the art can understand and appreciate that in other example embodiments, the housing reflector member may be configured to define apertures having any other appropriate geometric or non-geometric shape without departing from a broader scope of the present disclosure. Further, the first aperture 391 may have a different shape from that of the second aperture 319. Furthermore, even though the present disclosure describes the housing reflector member as having a curved portion and a stairway shaped portion, one of ordinary skill in the art can understand and appreciate that in other example embodiments, the housing reflector member may have any other shape that allows majority of the light from the light sources to be reflected without departing from a broader scope of the present disclosure. In some embodiments, the housing reflector member may have fewer or lesser portions than that described herein without departing from a broader scope of the present disclosure. For example, in some embodiments, the housing reflector member 120 may not include the stairway shaped portion 317.
Furthermore, even though the present disclosure describes each top edge of the housing reflector member as having one or more tabs, one of ordinary skill in the art can understand and appreciate that in other example embodiments, not all the top edges may have tabs. For example, only two of the opposite top edges 302 may have the tabs 312. Additionally, even though the present disclosure describes coupling the housing reflector member to the mounting plate using the one or more tabs, one of ordinary skill in the art can understand and appreciate that in other example embodiments, any other appropriate coupling mechanism may be used without departing from a broader scope of the present disclosure. For example, the housing reflector member 120 may be coupled to the mounting plate 102 using fasteners, such as screws, rivets, clamps, etc. In another example, the housing reflector member 120 and the mounting plate 102 may be formed together as a single piece, that is, they may be integral.
Even though the present disclosure describes the housing reflector member 120 as having a curved portion and a stairway shaped portion, one of ordinary skill in the art can understand that the housing reflector member 120 is a single component where the curved portion and a stairway shaped portion are integral to the housing reflector member 120. That is, the housing reflector member 120 may include the top edge 302 that defines the first aperture 391, the bottom edge 323 that defines the second aperture 319, and a body (306, 321) that extends from the top edge 302 to the bottom edge 323. The body may include an inner surface and an outer surface, where the inner surface is made reflective. Further, the body may include a curved or sloped portion 306 that extends from the top edge 302 to the intermediate edge 304, and a stairway shaped portion 321 that extends from the intermediate edge 304 to the bottom edge 323.
Referring to
In certain example embodiments, the lens 122 may be fabricated from an acrylic material and may be substantially clear or translucent. Alternatively, the lens 122 may be formed using other suitable materials, such as glass, and can be, or made to be, opaque, if desired.
As described above, in certain example embodiments, the lens 122 may be coupled to the housing reflector member 120 such that at least a portion of the lens 122 fits within and covers the second substantially square shaped aperture 319 defined by the bottom edges 323 of the housing reflector member 120, as illustrated in
Even though the present disclosure describes a specific mechanism of coupling the lens to the housing reflector member, one of ordinary skill in the art can understand appreciate that in other example embodiments, the lens may be coupled to the housing reflector member or any other portion of the downlight fixture using any other appropriate mechanism without departing from a broader scope of the present disclosure. For example, the lens 122 may be coupled to the housing reflector member 120 using fasteners, clamps, etc.
Referring to
In certain example embodiments, the top reflector panel 402 may be coupled to or positioned on top of the housing reflector member 120 such that: (a) the second surface 405 of the top reflector panel 402 rests on the top edge 302 of the housing reflector member 120 along the perimeter of the top reflector panel 402 and covering the first substantially square shaped aperture defined by the top edges 302 of the housing reflector member 120, and (b) the notches 404 of the top reflector panel 402 align with, receive, and accommodate the respective one or more tabs 312 of the housing reflector member 120.
In particular, as illustrated in
In certain example embodiments, the top reflector panel 402 may be fabricated using a reflective material, such as aluminum or highly reflective white plastic; or may be fabricated using a non-reflective material and subsequently made to be reflective. For example, the second surface 405 of the top reflector panel 402 facing the lens 122 may be polished or may be painted to be made reflective in order to reflect light back towards the lens 122.
Referring to
Furthermore, as illustrated in
Further, the circuit board 130 and the LEDs 132 disposed thereon are positioned on the top reflector panel 402 such that the inner profile of the housing reflector member 120, i.e., the inner surface 321 of the curved portion 306 and an inner surface of the stairway shaped portion 317, reflects a majority of the light emitted by the LEDs 132 and reduces the amount of direct light directed towards the lens 122. For example, the LEDs 132 are positioned on the top reflector panel 402 within the downlight fixture 100 such that light emitted by the LEDs within a certain range of vertical angles (angle from a vertical axis that is normal to the LED) is reflected by the inner profile, and light emitted outside the said range of vertical angles may be emitted as direct light from the downlight fixture. In said example, light emitted by an example LED may increase in luminous intensity up to 60 degrees from a vertical/normal axis to the LED and then the luminous intensity may drop substantially beyond 60 degrees, i.e., from 60 to 90 degrees. Accordingly, the LEDs may be positioned on the top reflector panel 402 such that light emitted within the 60 degree vertical angle range (on either side) may be reflected by the inner profile of the housing reflector member 120 and light emitted outside of the 60 degree vertical angle may be directed towards the lens 122 to exit the lens 122 as direct light. Since the direct light exiting the lens 122 is light that is outside the 60 degree vertical angle, the intensity of direct light may be lower, thereby, mitigating the visual hot spot effect. Another way to ensure that most of the light having higher luminous intensity is captured and reflected by the inner profile of the housing reflector member 120 is to: (a) vary the curvature of the curved portion 306 of the housing reflector member 120 and/or (b) reduce the distance between the top reflector panel 402 and the lens 122, thereby, making the profile of the downlight fixture 100 thinner.
One of ordinary skill in the art can understand and appreciate that the above-mentioned LED example is provided only for explanatory purposes and is not limiting. That is, the downlight fixture 100 described herein may use LEDs having any other appropriate light distribution characteristics or patterns without departing from a broader scope of the present disclosure. Furthermore, even though the present disclosure describes the light source as being an LED, one of ordinary skill in the art can understand and appreciate that in other embodiments, any other appropriate point or non-point light source may be used without departing from a broader scope of the present disclosure. For example, the light source may be fluorescent tube light, bulb, etc.
In particular, the plurality of light sources 132 of the downlight fixture 100 may be powered by running electrical wires from an external power source to the plurality of light sources 132 of the downlight fixture 100 through the wiring/mounting cavity 604 of the downlight fixture 100. Alternatively, the downlight fixture 100 may be configured to hold a backup/independent power source, such as a battery, that may be used to power the plurality of light sources 132.
Referring to the example embodiment shown in
In one example embodiment, the secondary/indirect light 706 may have a lower intensity than the direct light 704 that is output through lens 122. The lower intensity secondary/indirect light 706 may serve to reduce the contrast between the light emitted by the LEDs 132 and the areas of the downlight fixture 100 surrounding the LEDs 132 thereby providing an appearance of uniform illumination of the lens 122. Furthermore, the second portion of light 706 that is reflected into the luminous cavity 602 and/or bounces back and forth in the luminous cavity 602 may interact with the first portion of the light 702 that is reflected into the luminous cavity 602 and/or the direct light 704 to produce good color mixing before exiting through the lens 122. Further, as discussed above, the lens 122 may be a diffuse lens that is capable of scattering light, such as between the top and bottom surfaces (522, 524) of the lens 122 to cause the lens 122 to be uniformly illuminated 122.
In another example embodiment, as illustrated in
As illustrated in
Although the disclosures provides example embodiments, it should be appreciated by those skilled in the art that various modifications are well within the scope of the disclosure. From the foregoing, it will be appreciated that an embodiment of the present disclosure overcomes the limitations of the prior art. Those skilled in the art will appreciate that the present disclosure is not limited to any specifically discussed application and that the embodiments described herein are illustrative and not restrictive. From the description of the example embodiments, equivalents of the elements shown therein will suggest themselves to those skilled in the art, and ways of constructing other embodiments of the present disclosure will suggest themselves to practitioners of the art. Therefore, the scope of the present disclosure is not limited herein.
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