ES2441515A1 - Lighting module for led type luminaires and corresponding luminaire (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Lighting module (1) for luminaires (100) of led type and corresponding luminaire. The lighting module comprises an integrated circuit (4), a plurality of leds (2) mounted on the integrated circuit and a heat sink capable of dissipating the heat generated in the integrated circuit. The integrated circuit (4) and the dissipator are a single piece as a support sheet (6) of a material highly conductive of heat. In addition, the plurality of leds (2) of the lighting module (1) is in thermal contact with said support sheet (6). The invention also relates to a luminaire (100) that incorporates the lighting module (1). (Machine-translation by Google Translate, not legally binding)

Description

Lighting module for LED type luminaires and corresponding luminaire.

Field of the Invention

The invention is in the lighting sector, more specifically in the high power lighting sector, such as outdoor lighting.

In particular, the invention relates to a lighting module for LED type luminaires comprising an integrated circuit, a plurality of LEDs mounted on the integrated circuit and a heat sink capable of dissipating the heat generated in the integrated circuit.

Also, the invention relates to a luminaire incorporating said lighting module.

State of the art

In recent years, luminaires equipped with light emitting diodes, better known in the art for their English acronym LED (Light Emitting Diode), have been imposed on outdoor lighting technology. The advantage of LED lighting lies in high energy efficiency, compared to traditional lighting systems, coupled with its high durability.

In this type of outdoor luminaires, for example, urban luminaires or high-power non-urban luminaires, the number of LEDs used can be high. Although the energy efficiency is higher and the consumption is lower than that of traditional luminaires, problems associated with the heat generated by the LEDs also appear.

To solve this problem, it is usual to provide a heat sink adjacent to the face of the integrated circuit opposite to the one that supports the LEDs. The heatsinks are usually pieces of conductive material provided with a plurality of fins that are attached to the integrated circuit through a paste or thermal blanket that facilitates the transmission of heat from the circuit to the heatsink.

US 2009/0262533 A1 discloses an example of a heatsink for this type of high power luminaires. In this luminaire, the heatsink consists of a plurality of vertical fins that protrude from the face of the printed circuit opposite to the face on which the LEDs are provided. This solution is complicated, expensive and very bulky.

Another common problem in the state-of-the-art luminaires that have the aforementioned fins is that normally the LED module is unique, so that the maintenance of the luminaire is complicated.

Summary of the invention

The purpose of the invention is to provide a lighting module for LED type luminaires of the type indicated at the beginning, which is more compact than those of the prior art and which also facilitates the maintenance tasks of the luminaire. In addition, the module must use less material and fewer components, making assembly and manufacturing easier and making the system more reliable.

This purpose is achieved by means of a lighting module for LED type luminaires of the type indicated at the beginning, characterized in that the integrated circuit and the heatsink are a single piece as a backing sheet of a material highly conductive to heat and because said plurality of LEDs are in thermal contact with said support sheet.

Thanks to the highly conductive material the heat transmission of the LEDs to the integrated circuit / heatsink assembly in the form of a support sheet is direct. That is to say that there are not so many losses because being a single support sheet there is no longer an interface between the circuit and the heatsink that causes a thermal resistance that hinders the evacuation of heat. On the other hand, this simplifies the module, since the support sheet performs both the power supply function, normally assumed by the circuit, and the dissipation function, normally assumed by the heatsink. Obviously this also contributes to the improvement of reliability since the number of necessary components is reduced and assembly operations are avoided in which errors can occur that cause increases in thermal resistance between interfaces. Among the highly conductive materials of heat it is preferred to use metallic materials such as aluminum, copper, or non-metallic materials such as ceramics or others.

The shape of the support sheet also ensures that despite not having the fins an important radiating and heat exchange surface is achieved by convection, which allows the lack of fins to be cushioned.

Furthermore, the invention encompasses a series of preferred features that are the subject of the dependent claims and whose usefulness will be highlighted later in the detailed description of an embodiment of the invention.

Another of the problems associated with LED type luminaires is the diffuser that covers them that makes it difficult to exchange heat with the environment. In the state of the art the luminaires, on the side that emit the light, are protected in a sealed manner with a polycarbonate (PC), polymethacrylate (PMMA), glass or similar cover, known in the art as a diffuser. The diffuser protects the luminaire and allows modifying the pattern of emitted light.

This coating protects the entire face on which the LEDs are provided in such a way that it hinders the evacuation of heat by radiation and convection and therefore hinders the cooling of the luminaire. Therefore, optionally, in order to improve the cooling of the luminaire, the invention aims to further increase the heat exchange surface with the environment. Thus, preferably the lighting module also comprises a plurality of diffusers, each diffuser covering said plurality of diffusers groups of LEDs formed by one

or several of said LEDs such that the face of said support sheet on which the LEDs are mounted is partially exposed to the environment. With this, it is achieved that part of the highly conductive material support sheet, on the face on which the LEDs are provided, is exposed to the environment, instead of being covered by the diffuser. This further increases the radiant surface especially through the surface of the integrated circuit exposed to the environment.

Another objective of the invention is to provide a module that improves the tightness of the luminaire. For this purpose, in a particularly preferred embodiment, each LED is covered by an individual diffuser, the area of said support foil being around said diffuser in contact with the environment.

On the other hand, in the state of the art LEDs are usually coated with a lens to improve their light performance. Thus, with the aim of further simplifying the module according to the invention in one embodiment, each LED has a lens that covers it and said lens and said diffuser are a single piece, said single piece of lens / diffuser type attached to said support sheet through sealing means.

This feature has the effect that the radiating surface of the support sheet is as large as possible, since it is only covered in the area surrounding each LED, while the rest of the support face of the LEDs is free. Sealant bonding means, such as epoxy based adhesives or the like, allow the LEDs to be tightly encapsulated.

This configuration also maximizes the surface of heat exchange by convection with respect to the luminaires with conventional diffuser, since as explained, the amount of support sheet of the LEDs that is exposed to the environment, is maximized, but also each of the lens / diffuser type parts have a surface that exchanges heat by convection with the environment. Thus, the coating of each LED with a lens / diffuser assembly acts similarly to a fin. Despite this, this configuration does not imply giving up the correct tightness of the state-of-the-art luminaires that comprise a single large diffuser.

In another embodiment of the module, the support sheet comprises a plurality of through-through spacing slots between said LEDs. These slots further increase the radiation surface, but also allow interrupting the direct transmission of heat by conduction between adjacent LEDs separated by a sheet.

On the other hand, in a particularly preferred embodiment, each of the slots is provided so that each LED of said plurality of LEDs is separated from each of the adjacent LEDs through a slot, so that said slot interrupts the direct transmission of heat by conduction between said adjacent LEDs.

It is also provided in the invention that said support sheet is coated with a paint with particles of a highly heat-conductive metallic material.

Finally, particularly preferably, the module according to the invention comprises quick connection means, the connection means being moisture-tight.

Particularly preferably, the luminaire according to the invention comprises a housing and the luminaire is free of a diffuser that is mounted tightly directly on said housing.

Likewise, the invention also encompasses other detail features illustrated in the detailed description of an embodiment of the invention and in the accompanying figures.

Brief description of the drawings

Other advantages and features of the invention can be seen from the following description, in which, without any limitation, a preferred embodiment of the invention is mentioned, mentioning the accompanying drawings. The figures show:

Fig. 1, a bottom perspective view of a lighting module for LED type luminaires according to the invention. Fig. 2, a side view of the module of figure 1. Fig. 3, a bottom view of the module of figure 1. Fig. 4, a bottom perspective view of a luminaire with three lighting modules for type luminaires LED according to the invention. Fig. 5, a top perspective view of the luminaire of Figure 4, with the housing open.

Detailed description of an embodiment of the invention

As can be seen in Figures 1 to 3, the lighting module 1 for LED-type luminaires 100 according to the invention comprises an integrated circuit 4 and a heat sink capable of dissipating the heat generated in said integrated circuit which are a single piece support foil mode 6 in the form of a rectangular parallelepiped of a highly heat conductive material. In the context of the invention, other sheet-shaped shapes such as square, circular, conceivable without affecting the scope of the invention are conceivable. It is also not an essential requirement that the sheet be flat. Being arched or wavy, it could perform the same function satisfactorily.

On its lower face, the support sheet 6 has a plurality of LEDs 2 that is in thermal contact with the sheet. Being the support sheet 6 of highly conductive material, such as aluminum, the heat of the LEDs 2 can be easily transferred by conduction and then evacuated by radiation or convection through the free surfaces of the support sheet 6. Also To further favor this heat conduction effect generated by the LEDs 2, it is preferably provided that the support sheet 6 is coated with a paint with particles of a highly heat-conductive metallic material.

As already mentioned, outdoor luminaries typically incorporate a diffuser that on one hand protects the luminaire from moisture and dust and on the other hand distributes the light generated by LEDs. On the other hand, in the invention it is especially preferred that the lighting module 1 incorporates a plurality of diffusers 8 that cover one or more LEDs leaving the free surface 14 partially uncovered and therefore exposed to the environment.

As can be seen in the figures, in this case, it is provided that each LED 2 is covered by an individual diffuser 8. With this, the entire area of the support sheet 6 around the diffuser 8 in contact with the environment. This characteristic makes practically the entire surface of the support sheet 6 function as a radiating surface, while the lower face is left with the entire free surface 14 as a convection heat exchange surface, which has been indicated by wavy arrows coming out of the upper and lower faces of the support sheet 6 of Figure 2. But in addition, each individual diffuser 8 exposes its entire exterior surface to the environment, acting similarly to that of a fin of a heatsink, thanks to the increased heat exchange surface by convection.

In this embodiment it is also appreciated that the lens 12 covering the corresponding LED and the diffuser 8 itself are a single piece. This is again a considerable advantage, since the union of both pieces in one, also eliminates a heat exchange interface, a thermal resistance and on the other hand reduces the number of necessary parts. These diffusers 8 are duly sealed on the support sheet 6 by sealing means such as epoxy resin or similar adhesives.

Another feature that makes it possible to further improve the cooling of the module according to the invention is to provide that the support sheet 6 has a plurality of pass-through slots 10 between the LEDs

2. These slots 10 have a triple function. On the one hand, they suppose an interruption of material that prevents two adjacent LEDs from easily transferring heat by conduction. This can be seen by the dashed lines A, B and C of Figure 3, which as seen pass exactly above the slots 10 and therefore there is no direct union between the LEDs. On the other hand, these through slots 10 also increase the vertical radiating surface 16 of the lighting module 1. Finally, once the lighting module 1 is mounted on the luminaire 100, these slots 10 facilitate the heat output from the housing 102 of the luminaire 100 and the humidity outlet.

Although not essential to the invention, in this embodiment each of the slots 10 is arranged to isolate each LED 2 from the adjacent LEDs 2 through slots 10. That is, the more slots isolate a LED from the adjacent LEDs, more radiant surface is obtained, the evacuation of heat improves and more heat conduction between LEDs becomes more difficult.

It should also be noted that the grooves 10 may have any desired shape, that is, linear, curved, wavy circular or others without affecting the scope of the invention.

Figures 4 and 5 show a luminaire 100 incorporating three lighting modules 1 according to the invention. As can be seen, the luminaire 100 has a main housing 102 comprising a cover 104 articulated by one of its ends 110 to allow access to the luminaire 100 from above. This obviously facilitates considerably the maintenance of the luminaire 100 since the operator can work from the top which ergonomically is much more comfortable.

Inside, the luminaire 100 comprises a second housing 106 intended to contain the control electronics. Thanks to a seal 108, the second housing 106 is completely sealed. On the other hand, and in a non-watertight manner, in the case 102 three lighting modules are provided in this case 1. As the number of modules increases the replacement costs of damaged modules are reduced, since it is not necessary to change all the LEDs at once.

The lighting modules 1 also have quick connection means 16 which are watertight. These quick connect means 16 facilitate the assembly and maintenance of the luminaire 100. These connection means 16 are a waterproof connector of the IP67 or similar type that is connected directly to the socket provided in the second housing 106. In the figures, it is also possible It is appreciated that the luminaire is free of a diffuser mounted tightly directly on said housing, as is usual in the state of the art.

Thanks to this non-watertight assembly in the luminaire of the lighting modules, regardless of a single common diffuser that forms part of the luminaire as those of the prior art, the air can circulate freely through the lighting modules 1 further favoring the Convection cooling of the luminaire 100. In contrast, in the prior art luminaires the diffuser that covers the lighting modules reduces the surface of heat exchange by convection from below and facilitates the accumulation of moisture and dust inside of the luminaire.

Claims (11)

1.- Lighting module (1) for LED-type luminaires (100) comprising an integrated circuit (4), a plurality of LEDs (2) mounted on said integrated circuit and a heat sink capable of dissipating the heat generated in said integrated circuit, characterized in that said integrated circuit (4) and said heatsink are a single piece as a support sheet (6) of a highly heat conductive material and because said plurality of LEDs (2) is in thermal contact with said support sheet (6). 2. Lighting module (1) according to claim 1, characterized in that it further comprises a plurality of diffusers (8), each diffuser (8) covering said plurality of diffusers (8) groups of LEDs (2) formed by one or several of said LEDs (2) such that the face of said support sheet (6) on which said LEDs (2) are mounted is partially uncovered. 3. Lighting module (1) according to claim 2, characterized in that each LED (2) is covered by an individual diffuser (8) with the area of said support sheet (6) around said diffuser (8) in contact With the environment. 4. Lighting module (1) according to claim 3, characterized in that each LED (2) has a lens (12) that covers it and that said lens (12) and said diffuser (8) are a single piece, said being single piece attached to said support sheet (6) through sealing means. 5. Lighting module (1) according to any one of claims 1 to 4, characterized in that said support sheet (6) comprises a plurality of slots (10) for separating through said LEDs (2). 6. Lighting module (1) according to claim 5, characterized in that each of the slots (10) is provided so that each LED (2) of said plurality of LEDs (2) is separated from each of the LEDs (2) adjacent through a slot (10), such that said slot (10) interrupts the direct transmission of heat by conduction between said adjacent LEDs (2). 7. Lighting module (1) according to any of claims 1 to 6, characterized in that said support sheet (6) is coated with a paint with particles of a highly heat-conductive metallic material. 8. Lighting module (1) according to any of claims 1 to 7, characterized in that it comprises quick connection means (16), said connection means (16) being moisture tight. 9.- LED type luminaire, characterized in that it comprises at least one lighting module (1) according to any of claims 1 to 8. 10.- LED type luminaire, characterized in that it comprises a housing (102) and that said luminaire (100) is free of a diffuser mounted tightly directly on said housing (102). SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 201331550 SPAIN Date of submission of the application: 22.10.2013 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: See Additional Sheet RELEVANT DOCUMENTS

Category

56 Documents cited Claims Affected

X

CN 201568775 U (FOSHAN NATIONSTAR OPTOELECTRONICS CO LTD) 01.09.2010, Summary of the WPI database. Recovered from EPOQUE, figure 1. 1-10

X

US 2010 110660 A1 (BRUKILACCHIO THOMAS JOHN) 06.05.2010, Summary of the WPI database. Recovered from EPOQUE, figure 1. one

TO

US 2009 290348 A1 (VAN LAANEN PETER et al.) 11.26.2009, Summary of the WPI database. Recovered from EPOQUE, figures 7-8. 2.3

TO

ES 2051292 T3 (PHILIPS NV) 16.06.1994, the whole document; figure 4. 4

TO

US 2010039815 A1 (JHENG KUN HUANG) 18.02.2010, Summary of the WPI database. Recovered from EPOQUE, figure 3. 5.6

TO

EN 2414555 A1 (ELAUSA ELECTRONICA I AUTOMATISMES S L) 07/19/2013, the whole document; figures 1-2. 1-10

TO

WO 2009091233 A1 (VARGAS MACIEL LAURA PATRICIA) 23.07.2009, Summary of the WPI database. Recovered from EPOQUE, figure 1. 1-10

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 27.01.2014

Examiner R. Molinera de Diego Page 1/5

REPORT OF THE STATE OF THE TECHNIQUE CLASSIFICATION OBJECT OF THE APPLICATION F21V29 / 00 (2006.01) F21S2 / 00 (2006.01) F21V5 / 04 (2006.01) H05K1 / 18 (2006.01) H05K7 / 20 (2006.01) H05K3 / 00 (2006.01) F21V7 / 20 (2006.01) H01L33 / 00 (2010.01) Minimum documentation sought (classification system followed by classification symbols) H05K, H01L, F21V Electronic databases consulted during the search (name of the database and, if possible, search terms used) INVENTIONS, EPODOC  WRITTEN OPINION Date of Written Opinion: 27.01.2014 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 2-10 1 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-10 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published. WRITTEN OPINION  1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

CN 201568775 U (FOSHAN NATIONSTAR OPTOELECTRONICS CO LTD) 01.09.2010

D02

US 2009 290348 A1 (VAN LAANEN PETER et al.) 11.26.2009

D03

US 2010 110660 A1 (BRUKILACCHIO THOMAS JOHN) 06.05.2010

D04

US 2009 290348 A1 (VAN LAANEN PETER et al.) 11.26.2009

D05

ES 2051292 T3 (PHILIPS NV) 16.06.1994

D06

US 2010039815 A1 (JHENG KUN HUANG) 02-18-2010

D07

EN 2414555 A1 (ELAUSA ELECTRONICA I AUTOMATISMES S L) 07/19/2013

D08

WO 2009091233 A1 (VARGAS MACIEL LAURA PATRICIA) 07/23/2009

 2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement The claims of the application are then compared with the cited documents.  First claim: Document CN201568775U shows a lighting module for LED type luminaires comprising an integrated circuit, a plurality of LEDs mounted on said integrated circuit and a heat sink capable of dissipating the heat generated in said integrated circuit, and because said integrated circuit and said heatsink is a single piece as a support sheet of a highly heat conductive material and because said plurality of LEDs is in thermal contact with said support sheet. Therefore, document D1 presents all the characteristics of the first claim, lacking in novelty as defined in Article 6 of the Spanish Patent Law, Law 11/1986 of March 20.  Second claim: Although document D1 does not disclose exactly that the face of the support sheet on which the LEDS are mounted is partially uncovered, this characteristic is simply evident to a person skilled in the art who would like to improve the heat dissipation of an element, however we find for example, document US2009290348 that leaves openings in the form of channels just to improve the heat dissipation generated by the LEDS, allowing the transmission of heat by convection. Therefore, the object of the second claim seems to imply no inventive activity, as defined in Article 8 of the Spanish Patent Law, Law 11/1986 of March 20.  Third claim: The diffusers of document D1 do not leave the area of the support sheet that is around them in contact with the environment, however the purpose is to improve the heat dissipation generated by the LEDS, this problem is well known, as well as Convection heat transfer. We find a multitude of documents in the State of the Art that have openings just for this purpose, for example, in this report, the document US2009290348 which discloses this characteristic is cited. However, it is known that open and ventilated luminaires have replaced the non-ventilated type. In addition, these applications are recommended in high-rise locations, except for those where the air is heavily loaded with dust or fumes may affect the reflector. Therefore, the object of claim three seems to imply no inventive activity.  Fourth claim: The fact that diffuser and lens are a single piece does not confer to the request for inventive activity, since it is a very common characteristic in the field of luminaires, an example of this is found in document ES2051292T. Therefore, the object of claim four seems to imply no inventive activity. WRITTEN OPINION  Fifth, sixth and seventh claims: The fact of counting the support sheet of: -through separation slots between LEDS -strips, so that each slot interrupts the direct transmission of heat between adjacent LEDs -a paint coating with particles of a highly conductive metallic material does not provide significant differences with respect to the technique described in the cited documents, so they would be considered obvious to an expert in the field. Therefore, the fifth, sixth and seventh claims do not seem to imply inventive activity.  Claims eighth, ninth and tenth: The details contained in these claims are either explicitly found in the aforementioned documents, or are implicitly found in said documents, or would be mere obvious particular executions for an expert in the field starting from D1 as of the date on which That the application was submitted. None of these claims are considered to contain a relevant difference with respect to document D1. Therefore, these claims would lack inventive activity. As indicated in article 5.2.c of Regulation 2245/1986 on the execution of the Patent Law, and in order to obtain a better understanding of the invention, it is suggested that an indication of the document be included in the description in subsequent stages of the procedure D1, commenting on the most important contribution they make to the state of the art. Said indication cannot extend the object of the invention, as originally presented.