WO2014206756A1

WO2014206756A1 - Lens for illumination device and illumination device comprising the lens

Info

Publication number: WO2014206756A1
Application number: PCT/EP2014/062259
Authority: WO
Inventors: Jing BAO
Original assignee: Osram Gmbh
Priority date: 2013-06-26
Filing date: 2014-06-12
Publication date: 2014-12-31
Also published as: CN104251459A

Abstract

The present invention relates to a lens (100) for an illumination device, comprising a bottom surface (1) and an emergent surface (2) rising from the bottom surface (1), wherein a recessed region (3) is defined in a center of the bottom surface (1), a surface of the recessed region (3) forms an incident surface (4), and a light source (5) of the illumination device is disposed in the recessed region (3), wherein the emergent surface (2) comprises a first region (21) formed in a center of the emergent surface (2), and at least one second region (22) surrounding the first region (21), wherein the first region (21) is formed by a first refractive surface (211), and the second region (22) is formed by a reflective surface (221) and a second refractive surface (222). In addition, the present invention further relates to an illumination device (200) comprising the lens.

Description

Lens for Illumination Device and Illumination Device

Comprising the Lens

Technical Field

The present invention relates to a lens for an illumination device. In addition, the present invention further relates to an illumination device comprising the lens. Background Art

As technology advances, people more and more frequently re^¬ place conventional illumination devices with LED illumination devices. However, as an LED light source is a linear light source, it is necessary to use a specially designed lens to perform secondary optical processing on the light emitted from the LED light source, so as to achieve the desired illu^¬ mination effect. A conventional lens has a relatively large volume and size, which limits applications of the LED illumi^¬ nation devices in some occasions. In addition, in order to obtain the desired color temperature, red, blue, and yellow green LED chips are usually ar^¬ ranged in combination, so as to obtain the desired color temperature. A light-mixing lens is capable of favorably mixing the light emitted from these LED chips. However, in terms of light mixing, the size of the traditional lens is relatively large, and the light mixing effect thereof is just ordinary.

Summary of the Invention

In order to solve the above technical problem, the present invention proposes a lens for an illumination device, which has a relatively small size. Furthermore, the lens can also achieve superior light mixing effects. In addition, the pre^¬ sent invention further proposes an illumination device com- prising the lens.

The first object of the present invention is achieved by a lens for an illumination device, comprising a bottom surface and an emergent surface rising from the bottom surface, wherein a recessed region is defined in a center of the bot^¬ tom surface, a surface of the recessed region forms an inci^¬ dent surface, and a light source of the illumination device is disposed in the recessed region, characterized in that, the emergent surface comprises a first region formed in a center of the emergent surface, and at least one second re^¬ gion surrounding the first region, wherein the first region is formed by a first refractive surface, and the second re^¬ gion is formed by a reflective surface and a second refrac^¬ tive surface. In a design solution of the present invention, the emergent surface is configured to be zigzag, and in this case, the total emergent area of the emergent surface is not changed, but the distance between the emergent surface and the light source is correspondingly reduced, thereby reducing the overall thickness of the lens in the optical axis direc- tion.

According to a preferred design solution of the present invention, the incident surface is coated with scattering par^¬ ticles. This is especially advantageous for the lens for mixing light. The light mixing effect of an ordinary lens is not very satisfactory, but after the application of scattering particles to the incident surface, superior light mixing effects are achieved after the light is incident upon the in^¬ cident surface, thus further improving the light mixing prop^¬ erties of the lens according to the present invention. Preferably, the emergent surface and the incident surface are so configured that they are in rotational symmetry about an optical axis of the lens, and that a portion of light from the light source is incident upon the incident surface and emerges after being refracted by the first refractive sur- face, and the rest of the light from the light source is in- cident upon the incident surface, reflected by the reflective surface and refracted by the second refractive surface, and then emerges. A portion of the light is firstly reflected in the lens and then is refracted to the outside from the lens, and by adjusting the positional relationship between the refractive surface and the emergent surface, the beam angle of the emergent light can be specifically controlled.

Further preferably, viewing from a first cross section which is perpendicular to the bottom surface and through which the optical axis extends, the reflective surface and the second refractive surface form a predefined angle. By adjusting the angle between the reflective surface and the second refrac^¬ tive surface, the beam angle of the light emerging from the second refractive surface can be specifically adjusted. Advantageously, viewing from the first cross section, the re^¬ flective surface is inclined in a direction away from optical axis, and thereby light from the light source can be well re^¬ flected to the second refractive surface.

According to a preferred design solution of the present in- vention, the second refractive surface is configured as a plane. A planar refractive surface is easier to manufacture, which significantly reduces the manufacturing cost of the lens .

Preferably, the second refractive surface is parallel with the bottom surface, or is inclined in a direction away from optical axis. The arrangement of the second refractive sur^¬ face is entirely dependent on the light shape the designer wishes to obtain through the lens, and may be adjusted ac^¬ cording to specific requirements. Optionally, viewing from the first cross section, the reflec^¬ tive surface and the second refractive region form a serrated second region. The second region actually forms a reflec^¬ tive-refractive region, and in this region, the adjustment of beam angle of the light emerging from this region is achieved .

According to a preferred design solution of the present invention, the lens comprises three serrated second regions, wherein viewed in a direction from the bottom surface to the first region, diameters of the second regions successively become smaller. However, in other design solutions of the present invention, the lens may also comprise more than three serrated second regions, and the more the second regions, the finer the adjustment on the beam angle of the emergent light.

According to the present invention, the light from the light source exits through the first region in a manner of convergence. The light coming from the light source could be con^¬ vergent outside of the lens, instead of being divergent. Preferably, the contour of the first region is selected from any of hemispherical, semi-ellipsoidal or conical. Thus, the first region makes the light coming from the light source convergent .

Preferably, the contour of the recessed region is selected from any of hemispherical, semi-elliptic or conical. Thus, convergent light or divergent light could be achieved through the lens

The other object of the present invention is achieved by an illumination device, comprising a light source and a lens of the above type, wherein the light source is arranged in the recessed region of the lens. The overall structure of the illumination device according to the present invention is more compact, and the light spot formed by the light emerging from the illumination device is more uniform. Preferably, the light source is configured as an LED light source. The LED light source has the advantages of high lu^¬ minous efficiency, long lifespan and environmental protec- tion .

According to a preferred design solution of the present invention, the LED light source comprises a plurality of red, blue, and yellow green LED chips. It is to be understood that the features of the various exem^¬ plary embodiments described herein may be combined with each other, unless specifically noted otherwise.

Brief Description of the Drawings

The drawings constitute a portion of the Description for fur- ther understanding of the present invention. These drawings illustrate the embodiments of the present invention and ex^¬ plain the principle of the present invention together with the Description. In the drawings, the same part is repre^¬ sented by the same reference sign. In the drawings, Fig. 1 is a sectional view of the lens according to the pre^¬ sent invention;

Fig. 2 is an optical path diagram of the light emerging from the lens according to the present invention; and

Fig. 3 is a schematic diagram of the light source of the il- lumination device according to the present invention.

Detailed Description of the Embodiments

Fig. 1 is a sectional view of the lens 100 according to the present invention. As can be seen from the figure, the lens 100 according to the present invention comprises a bottom surface 1 and an emergent surface 2 rising from the bottom surface 1, wherein a recessed region 3 is defined in a center of the bottom surface 1, a surface of the recessed region 3 forms an incident surface 4. A light source 5 of the illumi- nation device shown in Fig. 3 is disposed in the recessed re^¬ gion 3.

In a design solution of the present invention, the emergent surface 2 comprises a first region 21 formed in a center of the emergent surface 2, and at least one second region 22 surrounding the first region 21, wherein the first region 21 is formed by a first refractive surface 211, and the second region 22 is formed by a reflective surface 221 and a second refractive surface 222. Fig. 1 merely shows a particularly preferred embodiment of the lens 100 according to the present invention. As can be seen from the figure, the lens 100 comprises three serrated second regions 22, wherein viewed in a direction from the bottom surface 1 to the first region 21, diameters of the se- cond regions 22 successively become smaller. However, in other unshown embodiments of the present invention, the lens 100 may also comprise two or more than three serrated second regions 22. The more the second regions 22, the finer the adjustment on the beam angle of the emergent light. Next, detailed description will be made on the lens 100 with reference to Fig. 1. As can be seen from Fig. 1, the emergent surface 2 and the incident surface 4 are configured to be in rotational symmetry about an optical axis X of the lens 100, and in this way, the light emerging from the lens 100 can form a circular light spot. As can be seen from the sectional view of Fig. 1, the reflective surface 221 and the se^¬ cond refractive surface 222 form a predefined angle. It is to be noted that, the sectional view of Fig. 1 is intercepted in the first cross section which is perpendicular to the bot- torn surface 1 and through which the optical axis X extends. In the design of the lens 100 according to the present inven^¬ tion, the designer can adjust the size of the angle according to the requirements, thereby controlling the beam angle of the emergent light. In the embodiment shown in Fig. 1, viewing from the first cross section, the reflective surface 221 is inclined in a direction away from optical axis X. The second refractive surface 222 is configured as a plane, and the second refrac- tive surface 222 is parallel with the bottom surface 1. How^¬ ever, in other embodiments not shown, the second refractive surface 222 may also be inclined in a direction away from the optical axis X. When the second refractive surface 222 is parallel to the bottom surface 1, the beam angle of the emer- gent light can be easily adjusted just by adjusting the angle of the reflective surface 221 with respect to the bottom sur^¬ face. As can be further seen in the first cross section, the reflective surface 221 is also a plane, and of course, in other embodiments, the reflective surface 221 can also be curved. However, it shall be emphasized that the curve shall be curved in a direction away from the optical axis X.

In addition, as can be visually seen in Fig. 1, viewing in the first cross section, the reflective surface 221 and the second refractive region 222 form serrated second regions 22. These serrated second regions 22 are arranged with one over^¬ lapping another, and just as previously described, the diame^¬ ters of these second regions 22 gradually become smaller from top to bottom. Further, the adjacent second regions 22 are connected in such a manner that the second refractive surface 222 of the lowermost second region 22 is connected with the reflective surface 221 of the adjacent second region 22, and the second refractive surface 222 of the uppermost second re^¬ gion 22 is connected with the first refractive surface 211 of the first region 21. The purpose of configuring the emergent surface of the lens 100 to be serrated is to reduce, to the maximum extent, the thickness of the lens 100 in the direc^¬ tion of the optical axis X, without changing the optical properties of the lens 100.

The top of the lens 100 is provided with a first region 21, the first region 21 is configured to make the light coming from the light source 5 convergent, and the contour of the first region 21 is selected from any of hemispherical, semi- ellipsoidal or conical, but not limited to those mentioned, the contour or shape that is capable of making light conver^¬ gent could be used to shape the first region 21. For example, when the first region 21 is configured to be in a conical shape, the first refractive surface 211 forms a conical sur^¬ face of the conical shape, and a top region of the conical shape is rounded.

A recessed region 3 is formed in the bottom surface 1 of the lens 100, the recessed region 3 is configured to be hemi^¬ spherical or conical. The recessed region 3 is hemispherical in the embodiment shown in Fig. 1. The surface of the hemi^¬ spherical recessed region 3 forms the incident surface 4.

In addition, the most important improvement of the lens 100 according to the present invention lies in that the incident surface 4 is coated with scattering particles. This is espe^¬ cially advantageous for the lens 100 for mixing light, as the light mixing effect of an ordinary lens is not very satisfac^¬ tory, but after the application of scattering particles to the incident surface 4, superior light mixing effects are achieved after the light is incident upon the incident sur^¬ face 4, thus further improving the light mixing properties of the lens 100 according to the present invention.

Fig. 2 is an optical path diagram of the light emerging from the lens 100 according to the present invention. As can be seen from the figure, a portion of light from the light source 5 (see Fig. 3) is incident upon the incident surface 4 and emerges after being refracted by the first refractive surface 211, and the rest of the light from the light source 5 is incident upon the incident surface 4, reflected by the reflective surface 221, refracted by the second refractive surface 222, and then emerges.

Fig. 3 is a schematic diagram of the light source 5 of the illumination device according to the present invention. As can be seen from the figure, the light source 5 is configured as an LED light source, and the LED light source comprises a plurality of red, blue, and yellow green LED chips 51. By arranging these LED chips in a combined manner, the illumina- tion device of the present invention can produce light with different color temperatures. Furthermore, the light source 5 shown in Fig. 3 shall be arranged in the recessed region 3 of the lens 100 shown in Fig. 1. Here, as the incident sur^¬ face 4 used as the surface of the recessed region is coated with scattering particles, light spots having different col^¬ ors cannot be clearly distinguished in the light spots formed by the light emerging from the lens 100 according to the pre^¬ sent invention. In addition, due to the use of the lens 100 according to the present invention, the overall thickness of the illumination device is also reduced.

The above is merely preferred embodiments of the present in^¬ vention but not to limit the present invention. For the per^¬ son skilled in the art, the present invention may have vari^¬ ous 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.

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List of reference signs

1 bottom surface

2 emergent surface

21 first region

211 first refractive surface

22 second region

221 second refractive surface

222 reflective surface

3 recessed region

4 incident surface

5 light source

51 red, blue, and yellow green LED chips

100 lens

X optical axis

Claims

Patent claims

1. A lens (100) for an illumination device, comprising a bottom surface (1) and an emergent surface (2) rising from the bottom surface (1), wherein a recessed region

(3) is defined in a center of the bottom surface (1), a surface of the recessed region (3) forms an incident surface (4), and a light source (5) of the illumination device is disposed in the recessed region (3) , charac- terized in that, the emergent surface (2) comprises a first region (21) formed in a center of the emergent surface (2), and at least one second region (22) sur^¬ rounding the first region (21), wherein the first region (21) is formed by a first refractive surface (211), and the second region (22) is formed by a reflective surface

(221) and a second refractive surface (222) .

2. The lens (100) according to Claim 1, characterized in that, the incident surface (4) is coated with scattering particles .

3. The lens (100) according to Claim 1, characterized in that, the emergent surface (2) and the incident surface

(4) are so configured that they are in rotational sym^¬ metry about an optical axis (X) of the lens (100), and that a portion of light from the light source (5) is in- cident upon the incident surface (4) and emerges after being refracted by the first refractive surface (211), and the rest of the light from the light source (5) is incident upon the incident surface (4), reflected by the reflective surface (221) and refracted by the second re- fractive surface (222), and then emerges.

4. The lens (100) according to any of Claims 1-3, charac^¬ terized in that, viewing from a first cross section which is perpendicular to the bottom surface (1) and in which the optical axis (X) extends, the reflective sur- face (221) and the second refractive surface (222) form a predefined angle.

5. The lens (100) according to Claim 4, characterized in that, viewing from the first cross section, the reflec^¬ tive surface (221) is inclined in a direction away from the optical axis (X) .

6. The lens (100) according to Claim 4, characterized in that, the second refractive surface (222) is configured as a plane.

7. The lens (100) according to Claim 6, characterized in that, the second refractive surface (222) is parallel with the bottom surface (1), or is inclined in a direc^¬ tion away from the optical axis (X) .

8. The lens (100) according to Claim 4, characterized in that, viewing from the first cross section, the reflec^¬ tive surface (221) and the second refractive region (222) form a serrated second region (22) .

9. The lens (100) according to Claim 8, characterized in that, the lens (100) comprises three serrated second re^¬ gions (22), wherein viewed in a direction from the bottom surface (1) to the first region (21), diameters of the second regions (22) successively become smaller.

10. The lens (100) according to any of Claims 1-3, charac^¬ terized in that, the light from the light source (5) ex^¬ its through the first region (21) in a manner of convergence .

11. The lens (100) according to Claim 10, characterized in that, the contour of the first region (21) is selected from any of hemispherical, semi-ellipsoidal or conical.

12. The lens (100) according to any of Claims 1-3, charac terized in that, the contour of the recessed region (3) is selected from any of hemispherical, semi-elliptic.

13. An illumination device, comprising a light source (5) , characterized in that, the illumination device further comprises a lens (100) according to any of Claims 1-11, wherein the light source (5) is arranged in the recessed region (3) of the lens (100) .

14. The illumination device according to Claim 12, characterized in that, the light source (5) is configured as an LED light source.

15. The illumination device according to Claim 13, characterized in that, the LED light source comprises a plu^¬ rality of red, blue, and yellow green LED chips (51) .