Patent Application
20110121709
The present invention relates generally to high intensity discharge (“HID”) luminaries, and more particularly, to an optical system of a HID luminaire that eliminates the gravity effect and wire shadow typically associated therewith.
Examples of the HID lamp 100 include mercury vapor lamps, metal halide lamps, high and low pressure sodium vapor lamps, xenon short-arc lamps, and ultra-high performance mercury arc lamps. The HID lamp 100 produces light by generating an electric arc across two spaced-apart electrodes 120 and 130 housed inside the arc tube 140. The arc tube 140 can be a translucent or a transparent fused quartz or fused alumina arc tube. The electrodes 120 and 130 are typically fabricated using tungsten, but other materials can be used.
The arc tube 140 is suspended within an outer protective envelope 110 using the support wire 150. The support wire 150 is fabricated using an electrically conductive material that carries electricity to and from the arc tube 140. The support wire 150 also provides support for the arc tube 140 to be suspended within the outer protective envelope 110. The outer protective envelop 110 is fabricated using a transparent or translucent material that allows the light generated within the arc tube 140 to be emitted to a desired area for illumination.
The arc tube 140 also includes an arc tube cavity 141 having a top surface 144 and a bottom surface 146. The top surface 144 is the highest elevated portion of the arc tube cavity 141, while the bottom surface 146 is the lowest elevated portion of the arc tube cavity 141. The arc tube cavity 141 can be vertically oriented, horizontally oriented, or oriented at any angle therebetween. In
The arc tube cavity 141 is typically filled with gas or a mixture of gas and metals. For example, the arc tube cavity 141 may be filled under pressure with pure xenon, a mixture of xenon-mercury, sodium-neon-argon, sodium-mercury-neon-argon, or some other mixture such as argon, mercury, and one or more metal halide salts. A metal halide salt is a compound of a metal and a halide, such as bromine, chlorine, or iodine. Some of the metals that have been used in metal halide lamps include scandium, sodium, thallium, and indium. Typically, xenon, neon, or argon gas is used in HID lamps because they are easily ionized and provide some level of light. These gases facilitate the striking of an arc between the two electrodes 120 and 130 when voltage is first applied to the HID lamp 100. Once the arc is started, the arc heats up and evaporates the metal salts thereby forming a plasma, which greatly increases the intensity of the light produced by the arc and reduces the power consumption.
The HID lamp 100 typically requires a ballast (not shown) to regulate the arc current flow and to deliver the proper voltage to the arc. Some HID lamps include a third electrode (not shown) within the arc tube that initiates the arc when the HID lamp is first lit. Alternatively, other HID lamps 100, such as the one shown in
In the past, some manufactures have attempted to minimize the wire shadow 220 by fabricating the support wire 220 using thinner and smaller wire sizes. Alternatively, manufactures have attempted to address both the gravity effect 210 and the wire shadow 220 by completely blocking the light emitting portion that includes the gravity effect 210 and the wire shadow 220 or by spreading out the entire light emission so that the gravity effect 210 and the wire shadow 220 are mixed with the rest of the emitted light. These solutions typically use a material having a highly diffusive finish on either or both of the reflector and the lens. The conventional lens is typically fabricated with prismatic elements formed across the entire surface of the lens. Alternatively or additionally, the reflector is typically fabricated as a pillow style reflector, which has numerous tiny bumps that are formed onto the entire reflector's inner surface. The use of a highly diffuse type of lens or a diffuse finish on the reflector's inner surface allows the light to be mixed and spreads the emitted light so that the gravity effect 210 and the wire shadow 220 is reduced or eliminated. However, the efficiency of the emitted light is substantially decreased when using these conventional solutions, because some of the generated light is reflected multiple times before being transmitted through the lens, while other portions of the generated light are never transmitted through the lens. Each time a ray of light bounces (or reflects) off the reflector's inner surface, the light emitting efficiency is reduced due to a loss of energy. In most conventional fixtures, approximately ten percent of the light's energy is absorbed each time the beam of light bounces off the reflector's inner surface. Thus, if the light bounces twice off the reflector's inner surface before being transmitted through the lens, the light efficiency is eighty-one percent, or (0.9)*(0.9)*(100%).
In view of the foregoing, there is a need in the art for providing a HID luminaire that reduces or eliminates the wire shadow and/or the gravity effect while improving lighting efficiency.
According to one exemplary embodiment, a HID luminaire can include a HID lamp and a reflector. The reflector can have a proximal end, a distal end and an internal surface extending from the proximal end to the distal end. The HID lamp can be disposed within the reflector near the proximal end. The internal surface of the reflector can include a first portion, an intermediate area, and a second portion. The first portion can extend from the proximal end to the intermediate area and the second portion can extend from the intermediate area to the distal end. The second portion can be less light reflective than the first portion.
According to another exemplary embodiment, a HID luminaire can include a HID lamp, a reflector, and a lens. The reflector can have a proximal end, a distal end and an internal surface extending from the proximal end to the distal end. The HID lamp can be disposed within the reflector near the proximal end. The lens can be coupled to the distal end of the reflector. The lens can have a center portion and an outer portion that surrounds the center portion. The center portion can be substantially clear and the outer portion can be substantially more diffuse than the center portion. The outer portion produces outgoing light rays having a beam spread angle of greater than 2.5 degrees when an incoming light ray enters the outer portion at a perpendicular angle.
According to another exemplary embodiment, a HID luminaire can include a HID lamp, a reflector, and a lens. The lamp can include an arc tube that can have an arc tube cavity positioned between two electrodes. The arc tube cavity can have a top surface and a bottom surface. The reflector can have a proximal end, a distal end and an internal surface extending from the proximal end to the distal end. The internal surface of the reflector can include a first portion, an intermediate area, and a second portion. The first portion can extend from the proximal end to the intermediate area and the second portion can extend from the intermediate area to the distal end. The second portion can be less light reflective than the first portion. The lens can be positioned near the distal end of the reflector. The lens can have a center portion and an outer portion that surrounds the center portion. The center portion can be substantially clear and the outer portion can be substantially more diffuse than the center portion. The inner diameter of the center portion can range from about 87.5 percent to about 112.5 percent of the diameter of the intermediate area. The intermediate area can be positioned at an elevational level that ranges from the bottom of the arc tube to the top of the arc tube.
According to another exemplary embodiment, a HID luminaire can include a HID lamp, a reflector, and a lens. The reflector can have a proximal end, a distal end and an internal surface extending from the proximal end to the distal end. The lens can be positioned adjacent the reflector. The lens can have a first portion and a second portion that surrounds the first portion. Each of the first portion and the second portion of the lens can have different diffusion rates.
According to another exemplary embodiment, a HID luminaire can include a HID lamp, a reflector, and a substantially circular lens. The reflector can have a proximal end, a distal end and an internal surface extending from the proximal end to the distal end. The lens can be disposed adjacent the reflector. The lens can have a first portion and a second portion that can be disposed around the first portion. The first portion can be substantially clear portion and the second portion can have at least one frosted surface.
The foregoing and other features and aspects of the invention may be best understood with reference to the following description of certain exemplary embodiments, when read in conjunction with the accompanying drawings, wherein:
The drawings illustrate only exemplary embodiments of the invention and are therefore not to be considered limiting of its scope, as the invention may admit to other equally effective embodiments.
The present invention is directed to high intensity discharge (“HID”) luminaries. Although the description of exemplary embodiments is provided below in conjunction with a particular type of HID lamp, alternate embodiments of the invention may be applicable to other types and configurations of HID lamps.
The invention is better understood by reading the following description of non-limiting, exemplary embodiments with reference to the attached drawings, wherein like parts of each of the figures are identified by like reference characters, and which are briefly described as follows.
The HID lamp 100 represents any type of HID lamp including, but not limited to, mercury vapor lamps, metal halide lamps, high and low pressure sodium vapor lamps, xenon short-arc lamps, and ultra-high performance mercury arc lamps. Although one exemplary type of HID lamp 100 has been described with reference to
In one exemplary embodiment, the reflector 310 is parabolic-shaped and has a proximal end 312 and a distal end 314. As shown in this exemplary embodiment, the proximal end 312 is coupled to a mounting member 305 that is used to mount the HID luminaire 300 within a housing (not shown) that is coupled to a ceiling, wall, or other type of suitable structure. In one exemplary embodiment, the distal end 314 forms a flange 319 that bends outwardly from the reflector 310. In certain exemplary embodiments, the creation of a flange 319 is done to facilitate the coupling of the lens 350 to the distal end 314 of the reflector 310. The parabolic-shaped reflector 310 focuses the light emitted by the lamp 100 to create a beam of light. Although this exemplary embodiment depicts a parabolic-shaped reflector 310, other geometric shaped reflectors known to those of ordinary skill in the art are within the scope and spirit of the exemplary embodiment.
The reflector 310 is disposed around the HID lamp 100 and includes an internal surface 315 having a first portion 320 and a second portion 330. The first portion 320 extends from the proximal end 312 to an intermediate area 328. The second portion extends from the intermediate area 328 to the distal end 314. In one exemplary embodiment, the first portion 320 is a reflective smooth arcuate surface, while the second portion 330 is a reflective surface that includes multiple facets 332. In this exemplary embodiment, the second portion 330 is less reflective than the first portion 320 because the efficiency of the light emitted to an illuminated surface based upon light reflecting off of the second portion 330 is less than the efficiency of the light emitted to the illuminated surface based upon light reflecting off of the first portion 320. Although this exemplary embodiment depicts facets 332 on the inner surface of the second portion 330, other types of reflective surface patterns can be used in the alternative on the inner surface of the second portion 330 without departing from the scope and spirit of the exemplary embodiment.
Referring back to
½*W3≦W1≦W2≦2*W3
In this exemplary embodiment, the facets 332 are flat-shaped, substantially flat, or planar, and smooth. In alternative embodiments, the facets 332 are arc-shaped, or curvilinear, having a smooth surface. Further, the curvilinear surface alternatively includes convex-shaped or concave-shaped surfaces. According to an exemplary embodiment, the first portion 320 and the second portion 330 are integrally formed. However, in alternate exemplary embodiments, the first portion 320 and the second portion 330 are formed separately and thereafter coupled to one another using methods known to people having ordinary skill in the art. The configuration for the exemplary reflector 310 provides a light emission efficiency of up to eighty percent. In other exemplary embodiments, the facets 332 include prismatic elements.
When light from the HID lamp 100 travels to the distal end 314 of the reflector 310, the light is reflected at the edges of the distal end 314 and forms striations and yellowish color on the area to be illuminated. In the exemplary embodiment of
Referring back to
The exemplary lens 350 is coupled to and disposed below the reflector 310 Alternatively, the lens 350 is positioned adjacent to a reflector but not directly coupled thereto. The lens 350 includes a center portion 360 and an outer portion 370 surrounding the center portion 350. In one exemplary embodiment, the center portion 360 is clear and has a lens inner diameter 365. Furthermore, in this exemplary embodiment, the outer portion 370 is diffuse and extends from the lens inner diameter 365 to a lens outer diameter 375. Although the outer portion 370 is diffuse, the outer portion 370 allows some light to be transmitted therethrough to a desired area that is intended to be illuminated. The outer portion 370 eliminates the gravity effect 210, the wire shadow 220, and the striations and yellowish color caused by the light reflecting off the edges of the distal end 314 by mixing the light and blending the portion of light forming the yellowish color, the portion of the light forming the wire shadow, and the portion of the light forming the striations with the rest of the light prior to emitting the light onto the illuminated surface.
According to some exemplary embodiments, the outer portion 370 is frosted. A frosted outer portion is used to mean an outer portion of a lens which has been rendered translucent through a process which roughens or obscures the clear surface of the outer portion. In alternative exemplary embodiments, the outer portion 370 includes a micro-pattern. According to some of these alternative embodiments, the micro-patterns are formed by molding the lens 350 with the prismatic patterns or dimpled patterns also molded into the outer portion 370. According to an alternative exemplary embodiment, the micro-patterns are formed by molding the lens 350, covering the center portion 360 with a protective material, and sandblasting the lens 350, so that micro-patterns are formed onto the surface of the outer portion 370. In an exemplary embodiment, the micro-patterns are formed onto the surface of the outer portion that faces the illuminated area; however, alternate exemplary embodiments can have the micro-patterns formed onto the surface of the outer portion that faces away from the illuminated area without departing from the scope and spirit of the exemplary embodiment. Although examples of the outer portion 370 are described as being either frosted or micro-patterned, other types of diffuse surfaces that allow at least portions of the light to be transmitted therethrough are usable without departing from the scope and spirit of the exemplary embodiment. Although some exemplary methods have been described for diffusing the outer portion 370, other methods known to people having ordinary skill in the art can be used without departing from the scope and spirit of the exemplary embodiment.
The reflector 310 includes the first portion 320, the second portion 330, and the intermediate area 328, which defines the transition point between the first portion 320 and the second portion 330. As previously mentioned, the first portion 320 extends from the proximal end 312 to the intermediate area 328, while the second portion 330 extends from the intermediate area 328 to the distal end 314. In certain exemplary embodiments, the intermediate area 328 is positioned at or substantially near the same elevational level as the arc tube cavity's bottom surface 146. However, in alternative exemplary embodiments, the intermediate area 328 is positioned at any elevational level ranging from the elevational level of the bottom of the arc tube 140 to about the elevational level of the top of the arc tube 140. The distal end 314 has a distal end diameter 415. The intermediate area 328 has an intermediate diameter 428, which, in this exemplary embodiment, is less than the distal end diameter 415.
As shown in the example of
D
2=(1±0.125)*D1
Although the exemplary outer portion 370 is diffuse, the outer portion 370 allows at least a portion of the light to be transmitted therethrough to an area to be illuminated.
Although each exemplary embodiment has been described in detail, it is to be construed that any features and modifications that are applicable to one embodiment are also applicable to the other embodiments. Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons of ordinary skill in the art upon reference to the description of the exemplary embodiments. It should be appreciated by those of ordinary skill in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures or methods for carrying out the same purposes of the invention. It should also be realized by those of ordinary skill in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. It is therefore, contemplated that the claims will cover any such modifications or embodiments that fall within the scope of the invention.
