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Title:
LENS AND LIGHTING DEVICE HAVING THE LENS
Document Type and Number:
WIPO Patent Application WO/2012/095242
Kind Code:
A1
Abstract:
The present invention relates to a lens for a lighting device. The lens comprises: a first lens portion (1) and a second lens portion (2) formed on the first lens portion (1), wherein at least a part of light from a lighting assembly (4) of the lighting device is deviated over a predetermined angle () to a side of the first lens portion (1) through the first lens portion (1), and remaining light from the lighting assembly (4) is deviated over the predetermined angle (α) to a side in the same deviation direction of the at least a part of light through the second lens portion (2). Moreover, the present invention further relates to a lighting device having the lens of the type above.

Inventors:
DAI, Chenglong (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
HE, Yubao (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
LUO, Yabin (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
WU, Hui (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
Application Number:
EP2011/073126
Publication Date:
July 19, 2012
Filing Date:
December 16, 2011
Export Citation:
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Assignee:
OSRAM AG (Hellabrunner Str. 1, München, 81543, DE)
DAI, Chenglong (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
HE, Yubao (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
LUO, Yabin (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
WU, Hui (5F Hantang Building, OCT Oversea Chinese TownShenzhen, Guangdong 3, 51805, CN)
International Classes:
G02B17/08; F21K99/00; F21V5/04; F21Y101/02
Foreign References:
DE102009021182A12010-11-18
EP2039985A22009-03-25
US20070201225A12007-08-30
Other References:
None
Download PDF:
Claims:
Patent claims

1 . A lens for a lighting device, wherein the lens comprises: a first lens portion (1 ) and a second lens portion (2) formed on the first lens portion (1 ), at least a part of light from a lighting assembly (4) of the lighting device being deviated over a predetermined angle (a) to a side of the first lens portion (1 ) through the first lens portion (1 ), and remaining light from the lighting assembly (4) being deviated over the predetermined angle (a) to a side in a deviation direction the same as that of the at least a part of light through the second lens portion (2).

2. The lens according to claim 1 , wherein the predetermined angle (a) is at least 10°.

3. The lens according to claim 1 , wherein the predetermined angle (a) is over 20°.

4. The lens according to claim 1 , wherein the first lens portion (1 ) consists of a first light incident surface (1 a), a first light out-going surface (1 b), a light reflection surface (3) and a connection surface (5) viewing from a transverse cross section of the lens, the at least a part of light is totally refracted to the light reflection surface (3) through the first light incident surface (1 a) and is refracted through the first light out-going surface (1 b) after it is totally reflected through the light reflection surface (3). 5. The lens according to claim 4, wherein the second lens portion (2) extends away from the first lens portion (1 ) in a direction of an optical axis (X) perpendicular to the lighting assembly on the connection surface (5) viewing from the transverse cross section of the lens. 6. The lens according to claim 4, wherein the first light incident surface (1 a) is spherical.

7. The lens according to claim 4, wherein the first light incident surface (1 a) is aspherical.

8. The lens according to claim 1 , wherein the first lens portion (1 ) forms a first concave portion (6) in a region where the optical axis (X) passes through, and a first convex portion (7) is formed at both sides of the first concave portion (6), respectively, viewing from a longitudinal cross section of the lens.

9. The lens according to claim 1 , wherein the second lens portion (2) has a second light incident surface (2a) and a second light out-going surface (2b) viewing from a transverse cross section of the lens, the remaining light comes in through the second light incident surface (2a) and is refracted through the second light out-going surface (2b).

10. The lens according to claim 1 , wherein the second lens portion (2) forms a second concave portion (8) in a region where an optical axis (X) passes through, and a second convex portion (9) is formed at both sides of the second concave portion (8), respectively, viewing from a longitudinal cross section of the lens.

1 1. The lens according to any one of claims 1 -10, wherein the first lens portion (1 ) and the second lens portion (2) are designed in such a manner that light going out from the first lens portion (1 ) and the second lens portion (2) at least partially overlaps.

12. A lighting device, wherein the lighting device has the lens according to any one of claims 1 -1 1 .

Description:
Description

Lens and Lighting Device having the Lens Technical Field

The present invention relates to a lens, and in addition, to a lighting device having the lens of the type above.

Background Art

Floodlight usually uses a reflector for distributing light in a rectangular area. The floodlight using the reflector, however, merely can provide low light distribution performance and low system efficiency. The reflector of such type only can be used for the traditional light source but cannot fit LED or similar small light source, while LED secondary optical lens, very popular nowadays, is usually applied to high or low power LED or similar light source. For the side backlight application, a light guide is a traditional solution for direct backlight, bare LED layout back of the backlight device and directly lighting the diffuser surface. But this solution still does not fit the small light source as its light distribution performance and system performance likewise are quite low.

Summary of the Invention Therefore, the object of the present invention lies in providing a lighting device, particularly, in providing a lens for a floodlight using LED as lighting assembly. The lens according to the present invention which is small in structure can be applied to small LED or similar light source and has good optical performance and high light distribution uniformity. The object of the present invention is realized by a lens for a lighting device as follow, i.e. the lens comprises: a first lens portion and a second lens portion formed on the first lens portion, at least a part of light from a lighting assembly, i.e. LED of the lighting device is deviated over a predetermined angle to a side of the first lens portion through the first lens portion, and the remaining light from the lighting assembly is deviated over the predetermined angle to a side in a deviation direction the same as that of the at least a part of light through the second lens portion. With application of the lens according to the present invention, all light from LED is deviated a predetermined angle towards one direction so as to assure projection of light into a predetermined region. In addition, the lens of such type is relatively small in structure as it can be used independently for LED as small lighting assembly. The light emitted by the lighting assembly should be refracted by the lens into a predetermined scope. In a preferred solution of the present invention, taking the optical axis running through the center of the lighting assembly as reference, all light from the lighting assembly is deviated through the lens over a predetermined angle with respect to the optical axis. The predetermined angle is at least 10°, preferably over 20°, so as to realize lighting to one side of the lighting device^

It is provided in the present invention that the first lens portion consists of a first light incident surface, a first light out-going surface, a light reflection surface and a connection surface viewing from a transverse cross section of the lens, wherein at least a part of light is totally refracted to the light reflection surface through the first light incident surface and is refracted through the first light out-going surface after it is totally reflected through the light reflection surface. At least a part of light from the lighting assembly thereby is projected to one side of the lens when going out from the first lens portion and being deviated over a predetermined angle.

Preferably, viewing from a transverse cross section of the lens, the second lens portion extends away from the first lens portion in a direction of an optical axis perpendicular to the lighting assembly on the connection surface, wherein the second lens portion is designed in such a manner that it enables the remaining light from the lighting assembly to be refracted through the second lens portion.

According to a preferred solution of the present invention, the first light incident surface is designed to be spherical when the lighting assembly is a point light source.

According to another preferred solution of the present invention, the first light incident surface is designed to be aspherical when the lighting assembly is a surface light source. It is provided in a preferred solution of the present invention, the first lens portion forms a first concave portion in a region where the optical axis of the lens passes through, and a first convex portion is formed at both sides of the first concave por- tion, respectively, viewing from a longitudinal cross section of the lens. At least a part of light going out from the first lens portion thereby is distributed more uniformly.

It is provided according to the present invention, the second lens portion has a second light incident surface and a second light out-going surface viewing from a transverse cross section of the lens, wherein the remaining light comes in through the second light incident surface and is refracted through the second light outgoing surface. All light from the lighting assembly therefore is deviated over a predetermined angle under cooperation of the second lens portion with the first lens portion and irradiates the same side of the lens.

According to a preferred solution of the present invention, the second lens portion forms a second concave portion in a region where the optical axis passes through, and a second convex portion is formed at both sides of the second concave portion, respectively, viewing from a longitudinal cross section of the lens. The re- maining light going out from the second lens portion thereby is distributed more uniformly.

Preferably, the first lens portion and the second lens portion are designed in such a manner that light going out from the first lens portion and the second lens portion at least partially overlaps. All regions in the location where lighting is needed will be lightened by light of the lighting assembly.

The other object of the present invention is realized by a lighting device having the lens of the type above. The lighting device of such type can use LED or similar small lighting assembly as light source, is small in structure and has good optical performance and uniform light distribution. Brief Description of the Drawings

The drawings constitute a portion of the Description for further understanding of the present invention. These drawings illustrate the examples of the present invention and explain the principle of the present invention together with the Description. In the drawings, the same element is represented by the same reference sign, wherein

Fig. 1 is a perspective solid view of a lens according to the present invention; Fig. 2 is a transverse cross section view of a lens according to the present invention;

Fig. 3 is a longitudinal cross section view of a lens according to the present invention; and Fig. 4 is a view of optical path of a lens according to the present invention. Detailed Description of the Embodiments

Fig. 1 is a perspective solid view of a lens according to the present invention. As seen from the figure, the lens according to the present invention has a first lens portion 1 and a second lens portion 2, wherein the second lens portion 2 is on one side of the first lens portion 1 and extends outwardly on the first lens portion. In addition, a lighting assembly 4 designed as LED is provided in an accommodating portion defined by the first lens portion 1 and the second lens portion 2.

Fig. 2 is a transverse cross section view of a lens according to the present invention. The cross sections of the first lens portion 1 and the second lens portion 2 can be observed from the figure, wherein the first lens portion 1 consists of a first light incident surface 1 a, a first light out-going surface 1 b, a light reflection surface 3 and a connection surface 5, and the second lens portion 2 consists of a second light incident surface 2a and a second light out-going surface 2b. The second lens portion 2 extends away from the first lens portion 1 in a direction of an optical axis X perpendicular to the lighting assembly on the connection surface 5 as seen from the figure. The lighting assembly 4 is provided in an accommodating portion surrounded by the first light incident surface 1 a and the second light incident surface 2a so as to enable all light from the lighting assembly 4 to go out through the lens. The lighting assembly 4 designed as point light source is used in one example, the first light incident surface therefore is designed to be spherical. The surface light source, of course, can be used as the lighting assembly 4, the first light incident surface then is correspondingly designed to be aspherical.

Fig. 3 is a longitudinal cross section view of a lens according to the present invention. As seen from a longitudinal cross section of the lens in the figure, the first lens portion 1 forms a first concave portion 6 in a region where the optical axis X passes through, and a first convex portion 7 is formed at both sides of the first concave portion 6, respectively, likewise, the second lens portion 2 forms a sec- ond concave portion 8 in a region where the optical axis X passes through, and a second convex portion 9 is formed at both sides of the second concave portion 8, respectively. Moreover, the first lens portion 1 and the second lens portion 2 extend to an installation surface (not shown in the figure) of the lens at two sides of the optical axis, respectively, as can be seen from the figure.

Fig. 4 is a view of optical path of a lens according to the present invention. At least a part of light from the lighting assembly 4 is totally refracted to the light reflection surface 3 through the first light incident surface 1 a and is refracted through the first light out-going surface 1 b after it is totally reflected through the light reflection sur- face 3, and the remaining light comes in through the second light incident surface 2a and is refracted through the second light out-going surface 2b, as seen from the figure. The refracted light is deviated over a predetermined angle a which is at least 10°, preferably 20°, in the present example. Moreover, it also can be seen from the figure that light going out from the first lens portion 1 and the second lens portion 2 at least partially overlaps.

The curved profiles of the first light out-going surface 1 b, the second light incident surface 2 and the second light out-going surface 2b in the present invention can be adjusted according to specification of the lighting assembly, i.e. LED light source, lens size, illumination distribution requirements, etc. The optimal free curve for a big power LED of 1 W is as follow, and actual curve is the free curve similar to this equation, wherein the center of the lighting assembly, i.e. LED, is origin of coordinates.

Wherein the calculating formulae of the curved profiles of respective surfaces are as follow: The first light out-going surface: y = -4Ε-05χ Λ 4 + 0.0009χ Λ 3 - 0.0344χ Λ 2 + 0.3848x

+ 20.69

The second light out-going surface: y = 0.0002x4 - 0.0036x3 - 0.0971x2 + 0.0542x + 5.9779

The second light incident surface: y = -0.0059x3 - 0.0865x2 + 0.0884x + 3.7999 The above is merely preferred examples of the present invention but not to limit the present invention. For the person skilled in the art, the present invention may have various alterations and changes. Any alterations, equivalent substitutions, improvements, within the spirit and principle of the present invention, should be covered in the protection scope of the present invention.

^

List of reference signs

1 first lens portion

1 a. first light incident surface

1 b first light out-going surface 2 second lens portion

2a second light incident surface

2b second light out-going surface

3 light reflection surface

4 lighting assembly (LED) 5 connection surface

6 first concave portion

7 first convex portion

8 second concave portion

9 second convex portion X optical axis of lighting assembly

predetermined angle