Patent Grant
8092042
The invention relates generally to the field of lighting systems and, more particularly, to apparatus for utilizing LED (light-emitting diode) sources for illuminating areas with a predefined pattern of light intensity toward a preferential side.
There is a continuing need for lighting apparatus which is low-cost and energy efficient. LEDs provide light sources which are energy efficient, and advances in LED technology are providing even greater such efficiencies over time. One advantage of using LEDs as light sources is simply that the smaller size of such sources translate into lower material usage within fixtures containing such sources, thus yielding the attendant cost-efficiency.
Preferred performance requirements for lighting systems for various uses involve freedom of “light spillage” into areas not intended to be lit. For example, it is preferred that roadway and parking lot lighting systems have excellent light distribution over areas which are to be lighted, but neighboring regions are as free of light as possible. More specifically, there is a need to be able to direct light in a downward and preferential lateral direction while avoiding so-called trespass lighting on neighboring property, while providing lighting to the roadways or parking lots. Satisfying such concerns can be difficult when LEDs are used as light sources, particularly given the fact that in such cases many LEDs are used in individual fixtures.
Various LED lighting fixtures with light shielding have been developed. Examples of such prior art fixtures are those disclosed in the following United States patents: U.S. Pat. No. 7,019,334 (Yatsuda, et al), U.S. Pat. No. 6,972,439 (Kim et al,) and Patent Publication Nos: US 2006/0175626 (Wall Jr.) and US 2006/0158080 (Nakano et al,).
LED fixtures in the prior art having shields have certain shortcomings and disadvantages to which this invention is addressed. In particular, there is a need for an improved LED light fixture with directional shield that facilitates accurate manufacture while having an improved effectiveness in light distribution, including avoidance of light distribution to a non-preferential side. It would be desirable that an LED light fixture with directional shielding which is cost-effective in manufacture be able to provide a high level of output for lighting large areas in a preferential direction while minimizing light in a non-preferential direction.
It is an object of this invention, to provide LED lighting apparatus with directional shielding which overcomes certain problems and shortcoming of the prior art including those referred to above.
Another object of this invention is to provide LED lighting apparatus with directional shielding which by its nature facilitates accurate manufacture, including of multi-LED fixtures.
Another object of this invention is to provide LED lighting apparatus with directional shielding having the above advantages and with improved effectiveness in light distribution, including avoidance of light distribution to a non-preferential side.
Another object of this invention is to provide LED lighting apparatus with directional shielding which is particularly adaptable for LED fixtures providing a high level of light output for lighting of large areas such as roadways and parking lots.
Yet another object of this invention is to provide an LED lighting apparatus with directional shielding having the above advantages which directs light using a shield in the above fashion in a cost-effective manner.
These and other objects of the invention will be apparent from the following descriptions and the drawings.
This invention is an LED apparatus for improved illumination toward a preferential side in a downward and outward direction. The apparatus is the type including a mounting board, and LED package thereon with a primary lens having a central axis and a secondary lens member over the primary lens which establishes a light path therebetween the improved apparatus of this invention includes a shield member in the form of a layer which is positioned over the mounting board, LED package and secondary lens member, the shield member having a shield portion and a substantially planar non-shield portion thereabout.
In certain preferred embodiments the shield member has a shield member aperture aligned with the light path and the shield portion borders the shield-member aperture. It is most preferred that the secondary lens member includes a lens portion and a flange thereabout; and the shield portion extends over a part of the lens portion of the secondary lens member. Highly desirable is where the shield member has a shield-member aperture aligned with the light path and the shield portion borders the shield-member aperture.
Preferably the secondary lens member is asymmetrical and has an illumination pattern with a preferential side and a non-preferential side. The shield portion is positioned to intercept light on the non-preferential side. Preferred embodiments include a cover which secures the shield member with respect to the secondary lens member, the primary lens and the LED package. The cover has an opening aligned with the light path.
Preferred embodiments have the shield member sandwiched between the cover and the flange of the secondary lens member. Preferably the flange of the secondary lens member is against the mounting board. The sandwiching is of the non-shield portion of the shield member and of the flange of the secondary lens member when the cover is secured in place.
In certain embodiments, a resilient gasket is disposed between the shield member and the secondary lens. It is most preferred that the shield portion has a reflective surface facing the secondary lens.
In highly preferred embodiments, the LED packages, secondary lens member and shield portion are a plurality of LED packages, secondary lens members and shield portions. Preferably the LED packages are spaced from one another on the mounting board. It is highly preferred that each secondary lens member is positioned over the primary lens of a corresponding LED package, each primary-lens/secondary-lens-member pair establishes a light path and has a central axis. Also preferred is where there is a plurality of shield portions of the shield member. Each shield portion is positioned partially over each primary-lens/secondary-lens-member pair thereby to intercept a portion of the light emitted from the corresponding LED package.
The LED apparatus for illumination toward a preferential side in a downward and outward direction, in some embodiments, may include a mounting board and an LED package thereon with a primary lens which has a central axis. The improvement comprises a shield member in the form of a layer positioned over the mounting board and an LED package. The shield member has a shield portion and a substantially planar non-shield portion thereabout.
The term “downward” is used herein for convenience in describing the invention and aspects thereof, but does not in any way mandate usage of the apparatus in any orientation. In other words, “downward” is not limited by the direction of gravity. Thus, it a light fixture incorporating the inventive light-directing LED apparatus disclosed herein is oriented upward rather than downward, or in some laterally-oriented direction, the term “downward” subsumes such meanings. The term “downward” has been used since one important application for the inventive apparatus is the lighting of ground surfaces from vertical light poles. Note that the figures primarily show such “downward” direction as generally upward since visualization of the compound outer lens surface of the secondary lens in perspective is best viewed for clarity in such orientation.
The term “LED package” as used herein means an assembly including a base, at least one LED (sometimes referred to as “die”) on the base, and a primary lens over the die. One or more, typically several, LED packages are arranged on a mounting board in forming that is referred to as an “LED module.” One or more LED modules are used as the light source for various innovative lighting fixtures.
The inventive apparatus will most typically be used in applications when a multiplicity of such devices are arranged on what is referred to as an LED module, one or more of which are used within a lighting fixture to achieve desired illumination. Roadway and parking lot lighting are such applications, although there are a great many other applications for such devices.
The drawings illustrate a preferred embodiment including the above-noted characteristics and features of the invention. The invention will be readily understood from the descriptions and drawings. In the drawings:
As shown in
As shown in
In
The brightness of illumination pattern 50 in
As illustrated in
In certain embodiments, as illustrated in
LED apparatus 10 can consist of only one LED package 14 on a mounting board 12 with a corresponding primary lens 16, secondary lens member 20 and shield member 24 or a plurality of LED packages 14 on a mounting board 12 with corresponding primary lenses 16, secondary lens members 20 and shield members 24.
In some embodiments, as shown in
A wide variety of materials are available for the various parts discussed and illustrated herein. While the principles of this apparatus have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4254453 | Mouyard et al. | Mar 1981 | A |
| 5274250 | Miyake et al. | Dec 1993 | A |
| 5617131 | Murano et al. | Apr 1997 | A |
| 5711890 | Hawkins et al. | Jan 1998 | A |
| 5796154 | Sano et al. | Aug 1998 | A |
| 5984494 | Chapman et al. | Nov 1999 | A |
| 6325524 | Weber et al. | Dec 2001 | B1 |
| 6414343 | Kondo et al. | Jul 2002 | B1 |
| 6502956 | Wu | Jan 2003 | B1 |
| 6630736 | Ignaut | Oct 2003 | B1 |
| 6635911 | Maruyama | Oct 2003 | B2 |
| 6635941 | Suda | Oct 2003 | B2 |
| 6730940 | Steranka et al. | May 2004 | B1 |
| 6837605 | Reill | Jan 2005 | B2 |
| 6876008 | Bhat et al. | Apr 2005 | B2 |
| 6893941 | Suda | May 2005 | B2 |
| 6969946 | Steranka et al. | Nov 2005 | B2 |
| 6972439 | Kim et al. | Dec 2005 | B1 |
| 7009213 | Camras et al. | Mar 2006 | B2 |
| 7019334 | Yatsuda et al. | Mar 2006 | B2 |
| 7078258 | Sakoh et al. | Jul 2006 | B2 |
| 7080932 | Keuper | Jul 2006 | B2 |
| 7102185 | Nichols et al. | Sep 2006 | B2 |
| 7141825 | Horio et al. | Nov 2006 | B2 |
| 7176070 | Lee et al. | Feb 2007 | B2 |
| 7182480 | Kan | Feb 2007 | B2 |
| 7281818 | You et al. | Oct 2007 | B2 |
| 7530711 | Bang | May 2009 | B2 |
| 7543953 | Chapman | Jun 2009 | B2 |
| 7566147 | Wilcox et al. | Jul 2009 | B2 |
| 7637624 | Chin | Dec 2009 | B2 |
| 7637630 | Wilcox et al. | Dec 2009 | B2 |
| 7654691 | Liu et al. | Feb 2010 | B2 |
| 7938558 | Wilcox et al. | May 2011 | B2 |
| 20040156209 | Ishida | Aug 2004 | A1 |
| 20040251469 | Yatsuda et al. | Dec 2004 | A1 |
| 20060158080 | Nakano et al. | Jul 2006 | A1 |
| 20060169878 | Kasano et al. | Aug 2006 | A1 |
| 20060175626 | Wall, Jr. | Aug 2006 | A1 |
| 20060176686 | McVicker | Aug 2006 | A1 |
| 20060187671 | Coushaine et al. | Aug 2006 | A1 |
| 20070070625 | Bang | Mar 2007 | A1 |
| 20070097684 | Obara et al. | May 2007 | A1 |
| Number | Date | Country |
|---|---|---|
| 94 17 326 | Feb 1995 | DE |
| 10 268800 | Mar 1997 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20080272380 A1 | Nov 2008 | US |
