1. Field
The present disclosure relates to an extended source light module.
2. Description of Related Art
LEDs have been developed for many years and have been widely used in various light applications. As LEDs are light-weight, consume less energy, and have a good electrical power to light conversion efficacy, they have been used to replace conventional light sources, such as incandescent lamps and fluorescent light sources. LEDs may be utilized in an array. An extended light source includes an LED array. Light from an extended light source is distributed by a reflector. However, there is a need in the art to improve the light distribution from an extended light source and to provide a predetermined light distribution as a function of the properties of the extended light source.
In one aspect of the disclosure, a light source includes an extended light source, a first optical element, and a second optical element. The first optical element is coupled to the extended light source. The second optical element is coupled to the first optical element. The second optical element has a central reflective member and a refractive member surrounding the central reflective member.
In one aspect of the disclosure, an apparatus configured to provide a predetermined light distribution includes a solid state light source, a first optical element, and a second optical element. The first optical element is coupled to the solid state light source. The first optical element has a first optical element input aperture, a first optical element output aperture, and side walls approximately symmetric with respect to a first optical axis. The solid state light source is located in the first optical element input aperture in a plane perpendicular to the first optical axis. The first optical element output aperture is configured to provide transformed light and untransformed light in a first predetermined light distribution. The transformed light is light reflected off the side walls. The untransformed light is light unreflected off the side walls. The side walls have a curvature to provide the transformed light at the first optical element output aperture such that the transformed light in superposition with the untransformed light has the first predetermined light distribution at the first optical element output aperture. The second optical element is coupled to the first optical element. The second optical element is located parallel to the plane. The second optical element has a secondary optical axis coaxial to the first optical axis. The second optical element has a second optical element input and a second optical element output. The second optical element output provides a second predetermined light distribution. The second optical element input has a reflective member located around the secondary optical axis and a refractive member located around the reflective member. The reflective member has a profile configured with respect to the first predetermined light distribution to reflect light towards the refractive member. The refractive member has a plurality of prismatic facets. Each of the prismatic facets has an individual inclination angle relative to the plane. Each individual inclination angle is configured as a function of an intensity of the transformed light, an intensity of light incident the reflective member, and an intensity of the untransformed light to produce the second predetermined light distribution with a predetermined light pattern. Light emitted by the solid state light source is transformed by the first optical element, the reflective member of the second optical element, and the refractive member of the second optical element to produce the second predetermined light distribution with the predetermined light pattern. The second predetermined light distribution is the predetermined light distribution.
In an aspect of the disclosure, a light emitting apparatus includes a solid state light source, a first optical element, and a second optical element. The first and second optical elements are configured to direct light emitted from the solid state light source to the second optical element. The second optical element includes a first member and a second member. The first member is configured to reflect at least a portion of the light to the second member. The second member is configured to refract at least a portion of the reflected light.
In an aspect of the disclosure, a light emitting apparatus includes a first optical element, a second optical element having a first member and a second member, and a solid state light source. The solid state light source is arranged with the first and second optical elements such that light emitted from the light source is directed by the first optical element to the second optical element where at least a portion of the light is reflected by the first member towards the second member and at least a portion of the reflected light is refracted by the second member.
Various aspects of the present invention will be described herein with reference to drawings that are schematic illustrations of idealized configurations of the present invention. As such, variations from the shapes of the illustrations as a result, for example, manufacturing techniques and/or tolerances, are to be expected. Thus, the various aspects of the present invention presented throughout this disclosure should not be construed as limited to the particular shapes of elements (e.g., regions, layers, sections, substrates, etc.) illustrated and described herein but are to include deviations in shapes that result, for example, from manufacturing. By way of example, an element illustrated or described as a rectangle may have rounded or curved features and/or a gradient concentration at its edges rather than a discrete change from one element to another. Thus, the elements illustrated in the drawings are schematic in nature and their shapes are not intended to illustrate the precise shape of an element and are not intended to limit the scope of the present invention.
It will be understood that when an element such as a region, layer, section, substrate, or the like, is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will be further understood that when an element is referred to as being “formed” on another element, it can be grown, deposited, etched, attached, connected, coupled, or otherwise prepared or fabricated on the other element or an intervening element. In addition, when a first element is “coupled” to a second element, the first element may be directly connected to the second element or the first element may be indirectly connected to the second element with intervening elements between the first and second elements.
Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the drawings. It will be understood that relative terms are intended to encompass different orientations of an apparatus in addition to the orientation depicted in the drawings. By way of example, if an apparatus in the drawings is turned over, elements described as being on the “lower” side of other elements would then be oriented on the “upper” side of the other elements. The term “lower” can therefore encompass both an orientation of “lower” and “upper,” depending of the particular orientation of the apparatus. Similarly, if an apparatus in the drawing is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The terms “below” or “beneath” can therefore encompass both an orientation of above and below.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this disclosure.
As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The term “and/or” includes any and all combinations of one or more of the associated listed items.
Various aspects of an LED array module may be illustrated with reference to one or more exemplary configurations. As used herein, the term “exemplary” means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other configurations of an LED array module disclosed herein.
Furthermore, various descriptive terms used herein, such as “on” and “transparent,” should be given the broadest meaning possible within the context of the present disclosure. For example, when a layer is said to be “on” another layer, it should be understood that that one layer may be deposited, etched, attached, or otherwise prepared or fabricated directly or indirectly above or below that other layer. In addition, something that is described as being “transparent” should be understood as having a property allowing no significant obstruction or absorption of electromagnetic radiation in the particular wavelength (or wavelengths) of interest, unless a particular transmittance is provided.
A solid state component is a device built entirely from solid materials in which the electrons are entirely confined within the solid material. The solid state component may be a light source. The light source may be constructed from an array of light emitting semiconductor cells. One example of a light emitting semiconductor cell is an LED. The LED is well known in the art, and therefore, will only briefly be discussed to provide a complete description of the invention.
Referring to
The electrodes 106 and 108 may be formed on the surface of the epitaxial-layer structure 104. The p-type semiconductor region 118 is exposed at the top surface, and therefore, the p-type electrode 106 may be readily formed thereon. However, the n-type semiconductor region 114 is buried beneath the p-type semiconductor region 118 and the active region 116. Accordingly, to form the n-type electrode 108 on the n-type semiconductor region 114, a portion of the active region 116 and the p-type semiconductor region 118 is removed to expose the n-type semiconductor region 114 therebeneath. After this portion of the epitaxial-layer structure 104 is removed, the n-type electrode 108 may be formed.
As discussed above, one or more light emitting cells may be used to construct a light emitting element. A light emitting element may be constructed in a 2-dimensional planar fashion. One example of a light emitting element will now be presented with reference to
The light emitting element may be configured to produce white light. White light may enable the light emitting element to act as a direct replacement for conventional light sources used today in incandescent, halogen and fluorescent lamps. There are at least two common ways of producing white light. One way is to use individual LEDs that emit wavelengths (such as red, green, blue, amber, or other colors) and then mix all the colors to produce white light. The other way is to use a phosphor material or materials to convert monochromatic light emitted from a blue or ultra-violet (UV) LED to broad-spectrum white light. The present invention, however, may be practiced with other LED and phosphor combinations to produce different color lights.
An example of a white light emitting element will now be presented with reference to
In an alternative configuration of a white light emitting element, each LED may have its own phosphor layer. As those skilled in the art will readily appreciate, various configurations of LEDs and other light emitting cells may be used to create a white light emitting element. Moreover, as noted earlier, the present invention is not limited to solid state lighting devices that produce white light, but may be extended to solid state lighting devices that produce other colors of light.
The module 400 provides a predetermined light distribution from the extended light source 402. As discussed supra, the module 400 includes an extended light source 402, a primary optical element 404, and a secondary optical element 412. The extended light source 402 has a predetermined spatial light distribution. The primary optical element 404 collects, redirects, and redistributes portions of the light emitted from the extended light source 402. The extended light source 402 is located in the input aperture 406 in a plane perpendicular to an optical axis of the primary optical element 404. The primary optical element 404 creates in superposition with an untransformed portion of the emitted light a precalculated intensity distribution across the output aperture 408 through a calculation of a profile of the side wall 410, located between the input aperture 406 and the output aperture 408, as a function of a given specific extended light source 402.
The secondary optical element 412 is located in a plane of the output aperture 408 of the primary optical element 404 with an optical axis coaxial to the optical axis of the primary optical element 404. The secondary optical element 412 has a lower surface and an upper surface. The lower surface receives light and the upper surface emits the received light. The secondary optical element 412 creates a predetermined light pattern. The secondary optical element 412 includes a first member 414 and a second member 416. The first member 414 is located around the optical axis of the secondary optical element 404. The first member 414 has a reflective surface with a profile calculated as a function of the intensity distribution across the output aperture 408. The first member 414 redistributes and redirects light received from the primary optical element 404 towards the second member 416, which is disposed around the first member 414. The second member 416 includes a number of prismatic facets 418. Each of the prismatic facets 418 has an individual inclination angle relative to a reference plane disposed perpendicular to the optical axis. The individual inclination angle for each of the prismatic facets is calculated as a function of the actual intensity of the direct incident light from the primary optical element 404, an intensity of light reflected from the first member 414, and the desired intensity of the outgoing light in a preselected/predetermined direction.
Accordingly, the module 400 provides a triple transformation of light, with the primary optical element providing a first transformation as a function of the curvature of the side wall 410 and the size of the input aperture 406 and the output aperture 408, the secondary optical element first member 414 providing a second transformation as a function of its size and the curvature of its reflective lower surface 422, and the secondary optical element second member 416 providing a third transformation as a function of the individual inclination angle of its prismatic facets 418. The triple transformation of the module 400 produces a predetermined light envelope and creates a predetermined light pattern.
The extended light source 402 may be a multi-chip LED array. The module 400 may include a phosphor layer on the extended light source 402 or a remote phosphor located remote from the extended light source 402. The secondary optical element 412 may be rotationally symmetrical around the optical axis and the prismatic facets 418 may be in circular relation. Alternatively, the secondary optical element 412 may be asymmetrical around the optical axis and the prismatic facets 418 may be in non-circular relation. The outer surface of the secondary optical element second member 416 may be shaped to be rotationally symmetric around the optical axis. Alternatively, the outer surface of the secondary optical element second member 416 may have an arbitrary shape with a shape asymmetric with respect to the optical axis.
The secondary optical element 412 may be a light shaping element and therefore may shape the light that passes through the secondary optical element 412. A simple glass cover is an example of an element that is not a light shaping element. The secondary optical element 412 may be a non-Lambertian diffuser, and therefore the radiant intensity of the light is not directly proportional to the cosine of the angle between an observer's line of sight and the normal to the surface. As such, when the secondary optical element 412 is a non-Lambertian diffuser, the light from the secondary optical element 412 does not appear to have the same radiance from different observer angles.
The secondary optical element 412 is coupled to the primary optical element 404. The secondary optical element is located parallel to the plane of the primary optical element input aperture 404I. The secondary optical element 412 has a secondary optical axis 820 coaxial to the primary optical axis 820 (i.e., the axes are the same). The secondary optical element 412 has a secondary optical element input 412I and a secondary optical element output 412O. The secondary optical element output 412O provides the predetermined light distribution 808. The secondary optical element input 404I has a reflective member 414 located around the secondary optical axis 820 and a refractive member 416 located around the reflective member 414. The reflective member 414 has a profile (e.g., approximately conically shaped) configured with respect to the primary predetermined light distribution 802/804 to reflect light 806 towards the refractive member 416. The refractive member 416 has a plurality of prismatic facets 418. Each of the prismatic facets 418 has an individual inclination angle relative to the plane of the primary optical element input aperture 404I. Each individual inclination angle is configured as a function of an intensity of the transformed light 804, an intensity of light 806 incident the reflective member 414, an intensity of the untransformed light 802, and an intensity of light exiting the secondary optical element output 808.
The light 810 emitted by the solid state component 402 is transformed by the primary optical element 404, the reflective member 414, and the refractive member 416 of the secondary optical element 412 to produce the predetermined light distribution with a predetermined light pattern 808.
The various aspects of this disclosure are provided to enable one of ordinary skill in the art to practice the present invention. Modifications to various aspects of an LED array module presented throughout this disclosure will be readily apparent to those skilled in the art, and the concepts disclosed herein may be extended to other applications. Thus, the claims are not intended to be limited to the various aspects of an LED array module presented throughout this disclosure, but are to be accorded the full scope consistent with the language of the claims. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”
Pursuant to 35 U.S.C. §119(e), this application claims the benefit of U.S. Provisional Application Ser. No. 61/242,221 filed on Sep. 14, 2009, the contents of which are hereby incorporated by reference herein in their entirety.
Number | Date | Country | |
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61242221 | Sep 2009 | US |