Laser diode pumped white light emitter module
10374380 ยท 2019-08-06
Inventors
Cpc classification
H01S3/08054
ELECTRICITY
H01S5/02469
ELECTRICITY
H01S5/02212
ELECTRICITY
H01S3/09415
ELECTRICITY
H01S5/0071
ELECTRICITY
H01S5/0087
ELECTRICITY
H01S3/005
ELECTRICITY
H01S5/4025
ELECTRICITY
H01S5/02
ELECTRICITY
International classification
H01S3/00
ELECTRICITY
H01S3/08
ELECTRICITY
Abstract
An apparatus includes a thermally conductive housing including a reflective chamber, the reflective chamber including a reflective surface on a first side of the reflective chamber and an orifice on a second side of the reflective chamber. The reflective surface includes a converging surface annularly surrounding a central recirculating surface. The apparatus includes a phosphor converter at the orifice of the reflective chamber. The apparatus further includes a plurality of laser diodes arranged annularly around the orifice, the plurality of laser diodes configured to emit laser beams towards the converging surface.
Claims
1. An apparatus comprising: a thermally conductive housing comprising a reflective chamber, the reflective chamber comprising a reflective surface on a first side of the reflective chamber and an orifice on a second side of the reflective chamber, wherein the reflective surface comprises a converging surface annularly surrounding a central recirculating surface, wherein the reflective chamber is formed by a heat sink and a reflector coupled to the heat sink, wherein the reflector comprises the reflective surface and the heat sink comprises the orifice; a phosphor converter at the orifice of the reflective chamber; a plurality of laser diodes arranged annularly around the orifice, the plurality of laser diodes configured to emit laser beams towards the converging surface.
2. The apparatus of claim 1, wherein the converging surface is a parabolic surface configured to converge the laser beams at the phosphor converter.
3. The apparatus of claim 1, wherein the recirculating surface is a spherical surface configured to reflect back recirculating light from the phosphor converter.
4. The apparatus of claim 1, the heat sink comprising a conical cavity below the orifice.
5. The apparatus of claim 1, the heat sink comprising a plurality of apertures arranged annularly around the central orifice to receive the plurality of laser diodes.
6. The apparatus of claim 1, the heat sink comprising a protruding rim on a first side of the heat sink, the protruding rim annularly surrounding the plurality of apertures.
7. The apparatus of claim 6, the heat sink comprising a plurality of projections extending out a second side of the heat sink.
8. The apparatus of claim 1, the heat sink comprising: a conical cavity below the orifice; a plurality of apertures arranged annularly around the central orifice to receive the plurality of laser diodes; a protruding rim on a first side of the heat sink, the protruding rim annularly surrounding the plurality of apertures; and a plurality of projections extending out a second side of the heat sink.
9. The apparatus of claim 1, the apparatus comprising an odd number of laser diodes.
10. The apparatus of claim 9, wherein the odd number of laser diodes are equally spaced around the orifice.
11. The apparatus of claim 1, wherein the reflective chamber comprises a conical cavity, a cylindrical cavity, and a cup-shaped cavity, and wherein the conical cavity is between the orifice and the cylindrical cavity, and wherein the cylindrical cavity is between the cup-shaped cavity and the conical cavity.
12. The apparatus of claim 1, the apparatus comprising an even number of laser diodes.
13. The apparatus of claim 12, wherein the even number of laser diodes are unequally spaced around the orifice.
14. The apparatus of claim 1, wherein the plurality of laser diodes arranged annularly around the orifice are aligned with the converging surface.
15. The apparatus of claim 1, wherein: the converging surface is a parabolic surface configured to converge the laser beams at the phosphor converter; and the recirculating surface is a spherical surface configured to reflect back recirculating light from the phosphor converter.
16. A method comprising: projecting laser beams from a plurality of laser diodes onto a converging surface of a reflective chamber of an emitter module, wherein the reflective chamber is formed by a heat sink and a reflector coupled to the heat sink; reflecting the laser beams to converge on a phosphor converter at an orifice of the reflective chamber, wherein the reflector comprises the reflective surface and the heat sink comprises the orifice; and recirculating reflected light and recirculated light from the phosphor converter back to the phosphor converter.
17. The method of claim 16, wherein the converging surface annularly surrounds a central recirculating surface.
18. The method of claim 17, wherein the central recirculating surface is a spherical surface.
19. The method of claim 16, wherein projecting laser beams from a plurality of laser diodes onto a converging surface comprises projecting collimated light onto the converging surface.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) In order that the advantages of the subject matter may be more readily understood, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the subject matter and are not therefore to be considered to be limiting of its scope, the subject matter will be described and explained with additional specificity and detail through the use of the drawings, in which:
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DETAILED DESCRIPTION
(26) Reference throughout this specification to one embodiment, an embodiment, or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Appearances of the phrases in one embodiment, in an embodiment, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. Similarly, the use of the term implementation means an implementation having a particular feature, structure, or characteristic described in connection with one or more embodiments of the present disclosure, however, absent an express correlation to indicate otherwise, an implementation may be associated with one or more embodiments.
(27) The following description supplies specific details in order to provide a thorough understanding. Nevertheless, the skilled artisan would understand that the apparatus and associated methods of using the apparatus can be implemented and used without employing these specific details. Indeed, the apparatus and associated methods can be placed into practice by modifying the illustrated apparatus and associated methods and can be used in conjunction with any other apparatus and techniques conventionally used in the industry.
(28) As demands for beam control become more stringent, the need for higher illuminance is required. Increases in luminous density allows for luminaries to be smaller and more efficient. Laser diode-pumped emitters, or (LDPEs), are a new and evolving technology. Elements conventionally needed to make LDPEs reliable and efficient, combined with the higher cost of the laser diodes themselves, makes the overall system complex and expensive. Some conventional LDPEs utilize an arrangement of mirrors and optical fibers to transmit the laser light to the phosphor converter, increasing cost and system size. Others conventional LDPEs consist of one or more laser diodes pointed directly at a phosphor converter where the divergent beam creates undesirable emission profiles. Others conventional LDPEs contain no effective method of recycling light emitted back into the LDPE. Embodiments described herein effectively combine multiple elements into a holistic assembly which keeps the laser diodes and light-converting phosphor cool.
(29) Referring to
(30) The emitter module 100 includes a housing 102. In some embodiments, the housing 102 is thermally conductive. Components of the emitter module 100 produce heat which if not controlled or dissipated can lead to performance issues. The housing 102 may include features that aid in the dissipation of heat. In some embodiments, the housing 102 may be formed by coupling a plurality of parts. For example, in the embodiment depicted in
(31) The housing 102 forms an internal reflective chamber 110. The reflective chamber 110 is an enclosed cavity with an orifice 130. The reflective chamber 110 includes a reflective surface 120 on a first side of the reflective chamber 110. In some embodiments, the reflective chamber 110 includes an orifice 130 on a second side of the reflective chamber 110. In some embodiments, the first side is opposite the second side. As depicted in
(32) The housing 102 may be made of a reflective material. In some embodiments, the housing 102 is a thermally conductive material that includes a reflective coating. In some embodiments, the reflective coating is applied to the surfaces of the reflective chamber 110.
(33) In some embodiments, the reflective surface 120 includes a first portion and a second portion. In some embodiments, the reflective surface 120 includes a converging surface 122 that annularly surrounds a recirculating surface 124. The converging surface 122 is configured to reflect and converge light towards the orifice 130. The converging surface 122 is adjacent to the recirculating surface 124 and encircles the recirculating surface 124.
(34) The emitter module 100 further includes at least one laser diode 150. In some embodiments, the emitter module 100 includes a plurality of laser diodes 150. The laser diodes 150 are configured to emit laser beams into the reflective chamber 110. In some embodiments, the laser diodes 150 are configured emit light towards the converging surface 122. The laser diodes 150 are powered and emit diverging light into the reflective chamber 110 where the beam is first incident on a reflective surface (e.g., the converging surface, which may be a parabolic surface) and is reflected into a converging beam which is directed and incident to the centrally-located phosphor converter 140. In some embodiments, the laser diodes 150 are configured to emit blue or violet light. Other embodiments may be configured to emit different light on the spectrum.
(35) The emitter module 100 further includes a printed circuit board 160 or other electronic circuitry configured to control and activate the emitter module 100 and/or the laser diodes 150. In the illustrated embodiment, the printed circuit board 160 is coupled to the top of the housing 102. When the emitter module 100 is coupled to a fixture, the circuitry of the fixture and the printed circuit board 160 work cooperatively to operate and control the emitter module 100.
(36) The emitter module 100 further includes a phosphor converter 140 at the orifice 130. In some embodiments, the phosphor converter 140 is a monocrystalline structure. In some embodiments, the phosphor converter 140 is a polycrystalline structure. In some embodiments, the phosphor converter 140 is a monocrystalline or polycrystalline structure containing a proportionately-small amount of Cerium suspended in a Yttrium Aluminum Garnet matrix (YAG:Ce). In some embodiments, the Cerium is the absorbing element that causes the incident blue or violet light to be absorbed and Stokes-shifted into a lower energy colors such as yellow, green, and red. In another embodiment, the phosphor converter 140 is a sintered ceramic containing (YAG:Ce), red nitrides, and alumina, in such concentrations to cause a wider spectrum of light to emitted from the phosphor convertor 140. Other embodiments of the phosphor converter 140 are contemplated herein.
(37) Referring to
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(40) In the event light is incident to the recirculating surface, the recirculated light 180d is reflected to the phosphor converter 140. The emitter module 100 is configured to repeat the same absorption-reflection-transmission cycle described herein until all or mostly all light is emitted out through the phosphor converter 140.
(41) In the event light is incident to the parabolic reflector or non-ideal angles to other surfaces in the reflective chamber 110 such as the surface of the conical cavity 112 or the surface of the cylindrical cavity 114, the light continues to reflect off the surfaces of the reflective chamber 110 until mostly all of the light escapes through the phosphor converter 140.
(42) Referring now to
(43) The emitter module 100 is a modular assembled unit. The illustrated embodiment includes a heat sink 103. The heat sink 103 is a monolithic solid material capable of transferring heat from the printed circuit board 160 and the phosphor converter 140, and the laser diodes 150 to the surrounding atmosphere. The heat sink 103 includes a circular primary disc 222. On a front side of the primary disc 222, the heat sink 103 includes a protruding rim 240. The protruding rim 240 is a circular raised annular surface that includes an outer rim surface, a front rim surface, and an inner rim surface. The protruding rim 240 forms a cavity into which the printed circuit board 160 is bonded to the heat sink 103.
(44) The heat sink 103 further includes a plurality of projections 224 extending out a rear side of the primary disc 222 (see, for example,
(45) The bayonet slot 230 is an L-shaped or J-shaped curved slot that allows the emitter module 100 to be inserted into a receptacle and twisted slightly to secure the emitter module 100 to a fixture. In some embodiments, the heat sink 103 further includes indentations 238 (see
(46) Referring again to
(47) The heat sink 103 further includes an annular ring 225 that forms a cylindrical cavity 114. Referring to
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(49) The printed circuit board 160, in some embodiments, may be directly bonded to the heat sink 103. In some embodiments, there are no air gaps between the printed circuit board 160 and the heat sink 103. In some embodiments, the printed circuit board 160 is soldered to the heat sink 103. In some embodiments, the printed circuit board 160 is adhered to the heat sink 103 by an adhesion medium. The printed circuit board 160 is in thermal communication with the heat sink 103. Some embodiments may include thermal grease or a thermal pad between the printed circuit board 160 and the heat sink 103 to enhance heat transfer.
(50) In some embodiments, the printed circuit board 160 is not adhered to the heat sink 103 to allow access to the laser diodes 150. Referring to
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(55) In some embodiments, the converging surface annularly surrounds a central recirculating surface. In some embodiments, the central recirculating surface is a spherical surface. In some embodiments, projecting laser beams from a plurality of laser diodes onto a converging surface comprises projecting collimated light onto the converging surface.
(56) Although described in a depicted order, the method may proceed in any of a number of ordered combinations.
(57) In the above description, certain terms may be used such as up, down, upper, lower, horizontal, vertical, left, right, over, under and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But, these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an upper surface can become a lower surface simply by turning the object over. Nevertheless, it is still the same object. Further, the terms including, comprising, having, and variations thereof mean including but not limited to unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms a, an, and the also refer to one or more unless expressly specified otherwise. Further, the term plurality can be defined as at least two.
(58) Additionally, instances in this specification where one element is coupled to another element can include direct and indirect coupling. Direct coupling can be defined as one element coupled to and in some contact with another element. Indirect coupling can be defined as coupling between two elements not in direct contact with each other, but having one or more additional elements between the coupled elements. Further, as used herein, securing one element to another element can include direct securing and indirect securing. Additionally, as used herein, adjacent does not necessarily denote contact. For example, one element can be adjacent another element without being in contact with that element.
(59) As used herein, the phrase at least one of, when used with a list of items, means different combinations of one or more of the listed items may be used and only one of the items in the list may be needed. The item may be a particular object, thing, or category. In other words, at least one of means any combination of items or number of items may be used from the list, but not all of the items in the list may be required. For example, at least one of item A, item B, and item C may mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, at least one of item A, item B, and item C may mean, for example, without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.
(60) Unless otherwise indicated, the terms first, second, etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, e.g., a second item does not require or preclude the existence of, e.g., a first or lower-numbered item, and/or, e.g., a third or higher-numbered item.
(61) As used herein, a system, apparatus, structure, article, element, component, or hardware configured to perform a specified function is indeed capable of performing the specified function without any alteration, rather than merely having potential to perform the specified function after further modification. In other words, the system, apparatus, structure, article, element, component, or hardware configured to perform a specified function is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the specified function. As used herein, configured to denotes existing characteristics of a system, apparatus, structure, article, element, component, or hardware which enable the system, apparatus, structure, article, element, component, or hardware to perform the specified function without further modification. For purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as being configured to perform a particular function may additionally or alternatively be described as being adapted to and/or as being operative to perform that function.
(62) The present subject matter may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.