HK1140003A - Shield member in led apparatus - Google Patents

Description

Shielding member in LED apparatus

Technical Field

[01] The present invention relates generally to the field of lighting systems, and more particularly to a lighting device for illuminating an area with a predetermined light intensity pattern towards a preferred side with an LED (light emitting diode) source.

Background

[02] There is a continuing need for low cost and energy efficient lighting devices. LEDs provide energy efficient light sources, and advances in LED technology are providing greater efficiency over time. One advantage of using LEDs as light sources is simply that the small size of such light sources translates into a low material usage in the luminaire containing such light sources, with the attendant cost benefits.

[03] The preferred performance requirements of lighting systems for various applications involve a degree of freedom with respect to "light spillage" in undesired lighting areas. For example, it is preferred that road and parking lot lighting systems have excellent light distribution over the area to be illuminated, but adjacent areas are as free of illumination as possible. More specifically, in providing lighting to a roadway or parking lot, it is desirable to be able to simultaneously direct light in a downward and preferably lateral direction while avoiding intrusive lighting on adjacent property. Such concerns may be difficult to address when utilizing LEDs as light sources, particularly where many LEDs are utilized in a single luminaire.

[04] Various LED light fixtures have been developed with light shields. Examples of such prior art luminaires are disclosed in the following U.S. patents: patent No.7,019,334(Yatsuda et al), patent No.6,972,439(Kim et al), and patent publications No. US 2006/0175626(Wall Jr.) and US 2006/0158080(Nakano et al).

[05] The prior art LED luminaire with shielding has certain drawbacks and deficiencies that the present invention addresses. In particular, there is a need for an improved LED luminaire with directional shielding that facilitates accurate manufacturing while having improved light distribution effects (including avoiding non-preferred side light distributions). It would be desirable to have an economically manufactured LED fixture with directional shielding that can provide high levels of output over a large illumination area in a preferred direction while minimizing light in non-preferred directions.

Disclosure of Invention

[06] It is an object of the present invention to provide an LED lighting device with directional shielding that overcomes some of the problems and disadvantages of the prior art, including those referred to above.

[07] It is another object of the present invention to provide an LED lighting device with directional shielding comprising a multi-LED luminaire, which directional shielding is inherently convenient for accurate manufacturing.

[08] It is a further object of the present invention to provide an LED lighting device with directional shielding having the above advantages and improved light distribution effects, including avoiding light distribution on non-preferred sides.

[09] It is a further object of the present invention to provide an LED lighting device with directional shielding that is particularly suitable for LED luminaires providing high levels of light output to large lighting areas such as roads and parking lots.

[10] It is another object of the present invention to provide an LED lighting device with directional shielding that has the above-mentioned advantages of directing light with a shield of the above-mentioned type in a cost-effective manner.

[11] These and other objects of the present invention will become apparent from the following description and the accompanying drawings.

[12] The present invention is an LED device for improved illumination in a downward and outward direction towards a preferred side. The apparatus is of the type comprising: mounting a plate; an LED package on the mounting board having a primary lens with a central axis; and a secondary lens member located above the primary lens and establishing an optical path therebetween. The improved apparatus of the present invention includes a shield member in the form of a layer over the mounting board, LED packages and secondary lens member, the shield member having a shield portion and a generally flat non-shield portion therearound.

[13] In certain preferred embodiments, the shield member has a shield member aperture aligned with the optical path, the shield portion defining the shield member aperture. Most preferably, the secondary lens member comprises a lens portion and a flange therearound; and the shield portion extends over a portion of the lens portion of the secondary lens member. It is highly desirable that the shield member has a shield member aperture aligned with the optical path, the shield portion defining the shield member aperture.

[14] Preferably, the secondary lens member is asymmetric and has an illumination pattern with a preferred side and a non-preferred side. The shield is positioned to intercept light on the non-preferential side. A preferred embodiment includes a cover that secures the shield member relative to the secondary lens member, the primary lens, and the LED package. The cover has an opening aligned with the light path.

[15] A preferred embodiment comprises a shield member sandwiched between the cover and the flange of the secondary lens member. Preferably, the flange of the secondary lens member abuts against the mounting plate. When the cover is fixed in place, the non-shielding portion of the shielding member and the flange of the sub-lens member are sandwiched.

[16] In some embodiments, an elastomeric gasket is disposed between the shield member and the secondary lens. Most preferably, the shield has a reflective surface facing the secondary lens.

[17] In a highly preferred embodiment, the LED packages, secondary lens members and shields are a plurality of LED packages, a plurality of secondary lens members and a plurality of shields. Preferably, the LEDs are packaged spaced apart on the mounting board. It is highly preferred that each secondary lens member is located above the primary lens of the corresponding LED package, each primary lens/secondary lens member pair establishing an optical path and having a central axis. It is also preferable that there are a plurality of shield portions of the shield member. Each shield is positioned partially over each primary lens/secondary lens member pair to intercept a portion of light emitted from the corresponding LED package.

[18] An LED apparatus for illuminating in a downward and outward direction toward a preferred side may in some embodiments include a mounting board and an LED package thereon having a primary lens with a central axis. The improved apparatus includes a shielding member in the form of a layer positioned over the mounting board and the LED packages. The shield member has a shield portion and a substantially flat non-shield portion around the shield portion.

[19] The term "downwardly" is used herein for convenience in describing the invention and aspects thereof, and does not in any way dictate the use of the apparatus in any orientation. In other words, "downward" is not limited by the direction of gravity. Thus, the term "downward" is intended to have such a meaning if the light fixture containing the inventive light-directing LED apparatus disclosed herein is oriented upward rather than downward, or in some laterally oriented direction. Since an important application of the inventive device is the illumination of the ground from a vertical light column, the term "downward" is used. Note that the figures essentially show such "downward" direction as generally upward, since the image of the compound outer lens surface of the secondary lens in perspective view is best seen clearly in such orientation.

[20] The term "LED package" as used herein refers to an assembly comprising a substrate, at least one LED (sometimes referred to as a "die") on the substrate, and a primary lens over the die. One or more, typically several, LED packages are disposed on a mounting board to form what is referred to as an "LED module". One or more LED modules are used as light sources for various innovative light fixtures.

[21] The most typical application of the inventive device is for the use of one or more LED modules in a luminaire to achieve the desired illumination when a plurality of such devices are arranged on so-called LED modules. Roads and parking lots are such applications, although many other applications for such devices exist.

Drawings

[22] The drawings illustrate preferred embodiments that incorporate the above-described features and characteristics of the present invention. The present invention will be readily understood from the specification and drawings. In the drawings:

[23] FIG. 1 is a perspective view of an LED lighting device of the present invention, which is part of a light fixture;

[24] fig. 2 is a front view of the lighting device of fig. 1;

[25] fig. 3 is an exploded perspective view of the lighting device of fig. 1;

[26] FIG. 4 is a top view of the lighting fixture of FIG. 1;

[27] FIG. 5 is a partial view of a shield portion of the shield member layer;

[28] FIG. 6 is a cross-sectional view taken along section 7-7 shown in FIG. 4;

[29] 7-8 are perspective views of one of the secondary lenses of the lighting device of FIG. 1, primarily showing the outer lens surface of the secondary lens;

[30] FIG. 9 is a schematic perspective view of a lamppost incorporating a light fixture incorporating the LED apparatus of the present invention; the lamppost is positioned along the side of the road.

[31] Fig. 10 is a two-dimensional light intensity distribution of a luminaire such as in fig. 9 with the above-described lighting device but without a shielding layer. This luminaire is not shown in the present invention but is not prior art.

[32] Fig. 11 is a two-dimensional light intensity distribution of a luminaire with the above-described lighting device and with a shielding layer, such as in fig. 9.

Detailed Description

[33] Fig. 1-4 and 9 show the LED device 10 for illumination in a downward direction 48 and an outward direction 49 toward the preferred side 36. The LED device 10 includes: a mounting plate 12; an LED package 14 on the mounting board having a primary lens 16, the primary lens 16 having a central axis 18; and a secondary lens member 20 positioned above the primary lens 16 and establishing an optical path 22 therebetween. As shown in fig. 1 and 2, mounting plate 12 is coupled to heat sink 54. One or more (typically several) LED packages 14 are arranged on the mounting board 12 to form a so-called LED module 58. One or more LED modules 58 are used as various innovative light fixtures.

[34] As shown in fig. 3, a shield member 24 in the form of a layer is located over the mounting board 12, the LED packages 14, and the secondary lens member 20. The shield member 24 has a shield portion 26 and a substantially flat non-shield portion 28 therearound, as seen in fig. 6. Fig. 5 and 6 show that the shield member 24 has a shield member aperture 30 aligned with the optical path 22, the shield portion 26 defining the shield member aperture 30.

[35] As shown in fig. 7 and 8, the secondary lens 20 includes a substantially transparent lens portion 32 and a flange portion 34 therearound. The lens portion 32 is adjacent to the flange portion 34 as shown in fig. 7 and 8. The shield 26 extends over a portion of the secondary lens member 20. The secondary lens member 20 is asymmetric and has an illumination pattern 50, the illumination pattern 50 having a preferred side 36 and a non-preferred side 38, as shown in fig. 9-11. The shield 26 is positioned to intercept light on the non-preferred side 38.

[36] In fig. 10 and 11, the secondary lens 20 defines a preferred side indicated by reference numeral 36. Fig. 10 and 11 also indicate with reference numeral 38 a direction toward the opposite non-preferred side 38.

[37] Fig. 10 and 11 show a two-dimensional light intensity distribution 50 for an embodiment comprising an LED package 14, a single primary lens 16, and a single secondary lens 20. The pattern 50 in fig. 10 and 11 was generated using ray tracing software to simulate the illumination emitted from the LED device 10.

[38] The brightness of illumination pattern 50 in fig. 11 shows the relative intensity distribution with shielding member layer 24, indicating that a significant proportion of the light emitted from device 10 is redirected by shielding member layer 24 of device 10 toward preferred side 36, and only a small amount of incoming light on non-preferred side 38. Fig. 10 shows the relative intensity distribution in the absence of the shield member layer 24, indicating that light from the device 10 is not blocked, resulting in a large amount of ingress light on the non-preferred side 38.

[39] Fig. 1-4 illustrate that the cover 40 secures the shield member 24 relative to the secondary lens 20, the primary lens 16, and the LED package 14. The cover 40 has an opening 42 aligned with the light path 22 as shown in fig. 1-3. The shield member 24 is sandwiched between the cover 40 and the flange 34 of the secondary lens member 20.

[40] As shown in fig. 6, when the cover 40 is fixed in place, the non-shielding portion 28 of the shielding member 24 and the flange 34 of the sub-lens member 20 are sandwiched. In some embodiments, the flange 34 of the secondary lens 20 is clamped against the mounting plate 12.

[41] In certain embodiments, as shown in fig. 6, the shield portion 26 of the shield member 24 has a reflective surface 44 facing the secondary lens member 20. In another embodiment of the LED device 10, a layer of an enclosing barrier member, such as a gasket 46, is sandwiched between the shield member 24 and the secondary lens member 20, as shown in fig. 3. In yet another embodiment of the LED device 10, an aluminum layer 56 is sandwiched between the mounting board 12 and the secondary lens 20, as seen in fig. 3.

[42] The LED device 10 may be constructed of only one LED package 14 and corresponding primary lens 16, secondary lens member 20, and shielding member 24 on the mounting board 12, or a plurality of LED packages 14 and corresponding primary lens 16, secondary lens member 20, and shielding member 24 on the mounting board 12.

[43] In some embodiments shown in fig. 3, a plurality of LED packages 14 are spaced apart from one another on the mounting board 12. There are also a plurality of secondary lens members 20 in some embodiments, as shown in fig. 3. Each secondary lens member 20 is positioned over the primary lens 16 of a corresponding LED package 14. Each primary lens/secondary lens member pair 52 establishes an optical path 22 and has a central axis 18, as shown in fig. 6. There are also a plurality of shield portions 26 of the shield member 24 in certain embodiments, as shown in fig. 3. As shown in fig. 3 and 6, each shield 26 is positioned partially over each primary lens/secondary lens member pair 52, thereby intercepting a portion of the light path 22 emitted from the corresponding LED package 14.

[44] The various components discussed and illustrated herein may be applied to a wide range of materials. While the principles of the apparatus have been described in terms of specific embodiments, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention.

Claims (25)

1. An LED apparatus for illumination in a downward direction and an outward direction towards a preferred side, the LED apparatus comprising: (a) mounting a plate; (b) an LED package on the mounting board having a primary lens with a central axis; and (c) a secondary lens member located above the primary lens and establishing an optical path therebetween,

characterized in that the LED device comprises a shielding member in the form of a layer over the mounting board, LED package and secondary lens member, the shielding member having a shielding portion and a substantially flat non-shielding portion therearound.

2. The LED apparatus of claim 1 wherein the shield member has a shield member aperture aligned with the light path, the shield portion defining the shield member aperture.

3. The LED apparatus of claim 1 wherein:

the secondary lens member includes a lens portion and a flange around the lens portion; and is

The shield portion extends over a portion of the lens portion of the secondary lens member.

4. The LED apparatus of claim 3 wherein the shield member has a shield member aperture aligned with the light path, the shield portion defining the shield member aperture.

5. The LED apparatus of claim 3 wherein:

the secondary lens member is asymmetric and has an illumination pattern with a preferred side and a non-preferred side; and is

The shield is positioned to intercept light on the non-preferential side.

6. The LED apparatus of claim 1 further comprising a cover that secures the shield member relative to the secondary lens member, the primary lens, and the LED package.

7. The LED apparatus of claim 6 wherein the cover has an opening aligned with the light path.

8. The LED apparatus of claim 6 wherein the shield member is sandwiched between the cover and the flange of the secondary lens member.

9. The LED apparatus of claim 8 wherein the flange of the secondary lens member abuts the mounting board.

10. The LED apparatus of claim 8 wherein the non-shielding portion of the shield member and the flange of the secondary lens member are clamped when the cover is secured in place.

11. The LED apparatus of claim 10 further comprising a resilient gasket disposed between the shield member and the lens member.

12. The LED apparatus of claim 1 wherein the LED apparatus comprises:

a plurality of LED packages spaced apart from each other on the mounting board;

a plurality of said secondary lens members, each secondary lens member being positioned above a primary lens of a corresponding LED package, each primary lens/secondary lens member pair establishing an optical path and having a central axis; and

a plurality of shielding portions of the shielding member, each shielding portion being partially located above each primary/secondary lens pair so as to intercept a portion of light emitted from the corresponding LED package.

13. The LED apparatus of claim 12 wherein for each shield portion of the shield member, a shield member aperture is aligned with a corresponding light path and the shield portion bounds the shield member aperture.

14. The LED apparatus of claim 12 wherein:

each sub-lens member includes a lens portion and a flange around the lens portion; and is

Each shield portion extends over a portion of the corresponding lens portion.

15. The LED apparatus of claim 14 wherein for each shield portion of the shield member, a shield member aperture is aligned with a corresponding light path and the shield portion bounds the shield member aperture.

16. The LED apparatus of claim 14 wherein:

each secondary lens member is asymmetric and has an illumination pattern with a preferred side and a non-preferred side; and is

Each respective shield is positioned to intercept light on the non-preferred side.

17. The LED apparatus of claim 12 further comprising a cover that secures the shield member relative to the secondary lens member, the primary lens, and the LED package.

18. The LED apparatus of claim 17 wherein the cover has an opening aligned with the light path.

19. An LED apparatus for illumination in a downward direction and an outward direction towards a preferred side, the LED apparatus comprising: (a) mounting a plate; and (b) an LED package on the mounting board having a primary lens with a central axis,

characterized in that the LED device comprises a shielding member in the form of a layer above the mounting board and the LED packages, the shielding member having a shielding portion and a substantially flat non-shielding portion therearound.

20. An LED apparatus for illumination in a downward direction and an outward direction towards a preferred side, the LED apparatus comprising: (a) mounting a plate; (b) an LED device on the mounting board; and (c) a lens member positioned over the LED device and establishing an optical path therebetween,

characterized in that the LED device comprises a shielding member in the form of a layer over the mounting board, LED arrangement and lens member, the shielding member having a shielding portion and a substantially flat non-shielding portion therearound.

21. The LED apparatus of claim 20 wherein:

the lens member includes a lens portion and a flange around the lens portion; and is

The shield portion extends over a portion of the lens member.

22. The LED apparatus of claim 21 wherein:

the lens member is asymmetric and has an illumination pattern with a preferential side and a non-preferential side; and is

The shield is positioned to intercept light on the non-preferential side.

23. The LED apparatus of claim 20 further comprising a cover that secures the shield member relative to the lens member and the LED device.

24. The LED apparatus of claim 20 comprising:

a plurality of LED devices spaced apart from each other on the mounting board;

a plurality of said lens members, each lens member being positioned over a corresponding LED device, each lens member/LED device pair establishing an optical path and having a central axis; and

a plurality of shields of the shield member, each shield being positioned partially over each lens member/LED device pair to intercept a portion of light emitted from the corresponding LED device.

25. An LED apparatus for illumination in a downward direction and an outward direction toward a preferred side, comprising: (a) mounting a plate; (b) an LED device on the mounting board; and (c) a lens member having a central axis,

characterized in that the LED device comprises a shielding member in the form of a layer over the mounting board, LED arrangement and lens member, the shielding member having a shielding portion and a substantially flat non-shielding portion therearound.