WO2015003851A1

WO2015003851A1 - Lens for light source

Info

Publication number: WO2015003851A1
Application number: PCT/EP2014/061043
Authority: WO
Inventors: Jing BAO; YingJun CHENG; Norbert Linder
Original assignee: Osram Gmbh
Priority date: 2013-07-12
Filing date: 2014-05-28
Publication date: 2015-01-15
Also published as: CN104279508A

Abstract

The present invention relates to a lens for a light source comprising an exit surface and an incident surface disposed opposite to the exit surface, wherein the lens comprises a first optical structure and a second optical structure, a through hole extending from the exit surface to the incident surface is defined by the first optical structure, and viewed from a section of the lens, the second optical structure comprises a first toothed structure disposed around the through hole and having a first thickness and a first width and at least one second toothed structure surrounding the first toothed structure and having a second thickness and a second width.

Description

Lens for Light Source Technical Field

The present invention relates to a lens for a light source.

Background Art

To adjust a light flux of light from, for example, an LED light source, it is necessary to use a complex optical lens to collect as much light from the light source as possible and direct the light to an exit to finally form a light dis^¬ tribution for illuminating an area to be illuminated. In general, light from a light source can be divided into two parts, one part of which is emitted at small angles and thus is close to a peak region of a light distribution of the emitted light in the light distribution, and the other part of which is emitted at large angles and thus is away from the peak region of the light distribution of the emitted light in the light distribution. For a directional illuminating device, a reflector or a total internal reflection lens is generally used. In case of the reflector, a first part of light from a light source is emit^¬ ted directly to a far field region, and a second part of the light from the light source is emitted to the far field re- gion after being reflected by the reflector. In case of the total internal reflection lens, the first part of the light from the light source is emitted to the far field region af^¬ ter being refracted, and the second part of the light from the light source is refracted and then emitted onto a total internal reflection surface so as to be reflected towards the far field region. However, optical lens devices according to these approaches generally need to be configured to have a large volume in order to satisfy optical characteristics thereof, which will certainly limit the application range of the lens devices and increase production cost.

Summary of the invention

To overcome the above technical problem, the present inven^¬ tion provides a novel lens for a light source, a spatial vol^¬ ume of which can be greatly reduced and which can appropriately achieve the collection of light from the light source, and as the lens has a toothed design and a hole-shaped de- sign, light absorption is avoided and a light efficiency is improved, thereby further improving an illumination effect for a far field region.

The object of the present invention is achieved by a lens for a light source comprising an exit surface and an incident surface disposed opposite to the exit surface, wherein the lens comprises a first optical structure and a second optical structure, a through hole extending from the exit surface to the incident surface is defined by the first optical struc^¬ ture, and viewed in a section of the lens the second optical structure comprises a first toothed structure disposed around the through hole and having a first thickness and a first width and at least one second toothed structure surrounding the first toothed structure and having a second thickness and a second width. According to such design, light from the light source is emitted through the first and second optical structures, respectively, it is achieved that the light from the light source is collected and emitted through a plurality of structures, and part of the light is emitted directly through the through hole while reducing the possibility that the light is absorbed, and the spatial volume of the lens is remarkably reduced by the design of the through hole and the toothed structures. According to a preferred embodiment of the present invention, the first optical structure is configured so that first light emitted from the light source through the first optical structure exits directly to a far field region. Thus, a first part of the light from the light source is emitted directly and achieves a centralized illumination effect with high ef^¬ ficiency in the far field region after being emitted.

According to a preferred embodiment of the present invention, the second optical structure is configured so that at least part of light emitted from the light source 1 through the se^¬ cond optical structure exits to a far field region after be^¬ ing refracted and reflected by the second optical structure. In this way, an effect of a tulip lens can be achieved and the thickness and volume are reduced, and moreover the other part of the light from the light source achieves a central^¬ ized illumination effect with high efficiency in the far field region after being emitted.

According to a preferred embodiment of the present invention, the through hole is configured to have a funnel-shaped con- tour. The funnel-shaped contour facilitates the collection of light from the light source, and part of the light from the light source can be emitted directly through the through hole without being emitted through the lens, thus the light effi^¬ ciency is less affected by light absorption by the material of the lens.

Preferably, the first optical structure comprises a first portion and a second portion, at least the first portion also forms a first refractive surface of the first toothed struc^¬ ture, second light from the light source enters the lens af- ter being refracted by the first refractive surface, and the second portion ensures direct emission of at least part of light from the light source to a far field region. The second light from the light source can enter the lens through the first toothed structure and exit outside the lens after being reflected, thus the possibility of collecting and using the light from the light source with high efficiency is achieved.

Preferably, viewed in the section of the lens, the first por^¬ tion is configured as a line shape and the second portion is configured as a convex curved shape. Thus, by the design of the first portion and the second portion, a process such as demolding can be facilitated during the manufacture and ma^¬ chining, and part of exit light can be formed according to specific requirements of the effect of light distribution of the exit light.

Preferably, viewed in the section of the lens, the first por- tion is configured as a line shape and the second portion is configured as a line shape. According to such design, the lens can be manufactured and machined simply, and the possi^¬ bility of meeting the requirements of different light distri^¬ butions of the exit light can be achieved. Preferably, viewed in the section of the lens, .the first portion and the second portion are configured in one piece with each other and configured into a curve shape According to such design, a process of machining and demolding the lens is facilitated, and the possibility of meeting the require- ments of different light distributions of the exit light can be achieved.

According to a preferred embodiment of the present invention, the first toothed structure and the second toothed structure form a Fresnel lens structure. Such design effectively allows the collection and use of the light from the light source with high efficiency, and allows the possibility of reducing the spatial volume of the lens.

Preferably, the first thickness and the second thickness are the same or different from each other. Therefore, when the first thickness and the second thickness are, for example, different from each other, the possibility of excellently collecting light from the light source is allowed, and the possibility of collecting the light from the light source in different manners can be achieved. Preferably, the first width and the second width are the same or different from each other. Therefore, the possibility of collecting the light from the light source in different man^¬ ners can be achieved.

Preferably, the first toothed structure comprises the first refractive surface and a first reflective surface, and the second light from the light source is emitted through the ex^¬ it surface after being refracted by the first refractive sur^¬ face and reflected by the first reflective surface. Thus, part of light from the light source is emitted from the exit surface of the lens after being refracted and reflected.

Preferably, the first refractive surface and the first re^¬ flective surface form a predetermined angle. The angle can be adjusted as required to achieve that light from the light source is collected in different manners and exits after be- ing reflected so as to finally form different light distribu^¬ tions of the exit light.

Preferably, viewed in the section of the lens, the first re^¬ flective surface is configured to be inclined away from an optical axis of the lens in a direction from the incident surface to the exit surface. Thus, one part of light from the light source is emitted, after being reflected, toward a di^¬ rection close to the optical axis to achieve an effect such as convergence so as to form an appropriate light distribu- tion of the exit light.

According to a preferred embodiment of the present invention, the second toothed structure comprises a second refractive surface and a second reflective surface, and third light from the light source is emitted through the exit surface after being refracted by the second refractive surface and reflect^¬ ed by the second reflective surface. Therefore, the other part of the light from the light source can be emitted after being refracted and reflected by the second toothed struc^¬ ture, thereby providing the possibility of collecting and us- ing the other part of the light from the light source with high efficiency.

Preferably, viewed in the section of the lens, the second re^¬ fractive surface and the second reflective surface form a predetermined angle. The angle can be adjusted as required to achieve that light from the light source is collected in dif^¬ ferent manners and exits after being reflected so as to fi^¬ nally form different light distributions of the exit light.

Preferably, viewed in the section of the lens, the second re^¬ flective surface is configured to be inclined away from an optical axis of the lens in a direction from the incident surface to the exit surface. Thus, the other part of the light from the light source is emitted, after being reflect^¬ ed, toward a particular direction to form an appropriate light distribution of the exit light. According to a preferred embodiment of the present invention, the lens is configured to be rotationally symmetrical with respect to an optical axis of the lens. Such design allows the possibility of enabling light from the light source pro^¬ cessed by the lens to have a rotationally symmetrical light distribution after exiting.

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 represent^¬ ed by the same reference numeral. In the drawings,

Fig. 1 is a sectional view of a lens according to a first em^¬ bodiment of the present invention; Fig. 2 is a three-dimensional view of the lens according to the first embodiment of the present invention;

Fig. 3 is a light path diagram of the lens according to the first embodiment of the present invention; and

Fig. 4 is a sectional view of a lens according to a second embodiment of the present invention.

Detailed Description of the Embodiments

Please refer to Fig. 1 which is a sectional view of a lens 100 according to a first embodiment of the present invention and Fig. 2 which is a three-dimensional view of the lens 100 according to the first embodiment of the present invention. According to such design, the illustrated lens 100 comprises an exit surface 2 as a top surface and an incident surface 3 as a bottom surface which is disposed opposite to the exit surface 2, and the illustrated incident surface 3 is provided with a light source which can be a light source using, for example, the LED technology to achieve the illumination ef^¬ fect of high efficiency and energy saving. As can be seen from Fig. 1, a first optical structure 4 by which a through hole 6 is defined is disposed at the center of the lens 100, the through hole 6 is defined in the exit surface 2 by the first optical structure 4 toward the incident surface 3, that is, the through hole 6 extends from the exit surface 2 to a direction of the incident surface 3, thus first light LI from the light source 1 can exit directly from the through hole 6 without being affected by the lens disposed in the exit path, and a light efficiency of the exit light can be avoided from being affected due to light absorption by the material of the lens.

Moreover, specifically, an inner wall of the through hole 6 can be configured to be composed of two portions 41, 42, wherein a first portion 41 is configured to be close to the light source 1, the second portion 42 is configured to be away from the light source 1, and a first refractive surface 511 of a first toothed structure 51 configured around the through hole 6 is formed by at least the first portion 41. When viewed in a section of the lens 100 as shown in Fig. 1, each of the first portion 41 and the second portion 42 can be configured into any shape selected from a line and a curve according to the design of the first portion 41 and the se^¬ cond portion 42 described above, that is, the second portion 42 can be configured to have a line-shaped section while the first portion 41 is configured to have a line-shaped section so that, for example, a broken line shape as shown in Fig. 1 is formed when viewed from the section of the lens 100, and second light L2 from the light source 1 enters the first toothed structure 51 after being refracted by at least one of the first portion 41 and the second portion 42. Of course, similarly, each of the first portion 41 and the second portion 42 can be configured to have other shapes (the details will be described hereinafter) . Further, Fig. 1 illustrates that the lens 100 further com^¬ prises a second optical structure 5 which is configured to have the first toothed structure 51 and a second toothed structure 52 as viewed in the section of the lens 100. Ac^¬ cording to the design of the first and second toothed struc- tures 51 and 52, an effect of the lens 100 such as a Fresnel lens is finally achieved. Of course, as for the number of the toothed structures, the lens 100 can not only have two toothed structures as shown in Fig. 1, but also can be con^¬ figured to have multiple, for example, three or more toothed structures according to different application environments and requirements of design so as to achieve the effect of, for example, a multistaged Fresnel lens.

It should be further noted that when viewed in the section of the lens 100, the first toothed structure 51 and the second toothed structure 52 have a first thickness hi and a first width wl and a second thickness h2 and a second width w2, re^¬ spectively, the first thickness hi may be configured to be the same as or different from the second thickness h2, and the first width wl and the second width w2 may be configured to be the same as or different from each other, thus the re^¬ spective thicknesses and widths can be changed according to different requirements of the efficiency of collection of light from the light source 1 to meet the requirements.

Please refer to Fig. 3 which is a light path diagram of the lens 100 according to the first embodiment of the present in^¬ vention. The first refractive surface 511 of the first toothed structure 51 is formed by at least the first portion 41, and the first toothed structure 51 further comprises a first reflective surface 512. By a cooperation of the first refractive surface 511 and the first reflective surface 512, the second light L2 from the light source 1 is incident into the first toothed structure 51 and emitted toward the first refractive surface 512 after being refracted by the first re^¬ fractive surface 511, and since the first reflective surface 512 can be configured to be inclined toward a direction away from an optical axis X of the lens 100 as viewed in the sec^¬ tion of the lens 100, the second light L2 exits toward a di^¬ rection away from the light source 1 (i.e., a direction of the exit surface 2) through the exit surface 2 after being reflected by the first reflective surface 512. Similarly, a second toothed structure 52 having a second refractive sur^¬ face 521 and a second reflective surface 522 is disposed in a direction around the first toothed structure 51, and after being refracted by the second refractive surface 521, third light L3 from the light source 1 is incident into the second toothed structure 52 and reflected by the second reflective surface 522 and then exits toward the exit surface 2. The first refractive surface 511 and the first reflective surface 512 can form a predetermined angle, and the second refractive surface 521 and the second reflective surface 522 can form a predetermined angle, thus it can be achieved that the third light L3 from the light source 1 is collected in different manners, and an angle at which the light from the light source exits toward the exit surface 2 can be adjusted ac^¬ cordingly. Please further refer to Fig. 4 which is a sectional view of a lens 100 according to a second embodiment of the present in^¬ vention. The lens 100 of the second embodiment is different from that of the first embodiment described above in that the first portion 41 and the second portion 42 of the first opti^¬ cal structure 4 can be configured to have a line-shaped sec^¬ tion and a curve-shaped section, respectively, and a differ^¬ ent effect of collecting part of light from the light source 1 can be achieved by the first optical structure 4 so config^¬ ured .

It should be noted that in an embodiment not shown, an inte^¬ gral section can be formed jointly by the first portion 41 and the second portion 42, that is, a shape such as a curve which can be particularly configured as a convex curve that is a curve convex toward the optical axis X of the lens 100 is formed jointly by the first portion 41 and the second por^¬ tion 42, such curve shape is smoothly transited and extends from the exit surface 2 to the incident surface 3, and such smooth section can accomplish the design of the smooth inner wall of the through hole 6.

The above are merely preferred embodiments of the present in^¬ vention but not to limit the present invention. It would be understood by those skilled in the art that the present in- vention may have various alterations and changes. Any altera^¬ tions, equivalent substitutions, and improvements, within the spirit and principle of the present invention, should be cov^¬ ered in the scope of the present invention.

, ^

Reference Numerals

1 light source

2 exit surface

3 incident surface

4 first optical structure

5 second optical structure

6 through hole

41 first portion

42 second portion

51 first toothed structure

52 second toothed structure

511 first refractive surface

512 first reflective surface 521 second refractive surface ₁

522 second reflective surface

X optical axis first light second light third light hi first thickness

h2 second thickness

wl first width

w2 second width

Claims

Patent claims

1. A lens (100) for a light source (1) comprising an exit surface (2) and an incident surface (3) disposed opposite to the exit surface (2), characterized in that the lens (100) comprises a first optical structure (4) and a second optical structure (5), a through hole (6) extending from the exit surface (2) to the incident surface (3) is defined by the first optical structure (4), and viewed from a section of the lens (100), the second optical structure (5) comprises a first toothed structure (51) disposed around the through hole (6) and having a first thickness (hi) and a first width (wl) and at least one second toothed structure (52) surrounding the first toothed structure (51) and having a second thick- ness (h2) and a second width (w2) .

2. The lens (100) according to claim 1, characterized in that the first optical structure (4) is configured so that first light (LI) emitted from the light source (1) through the first optical structure (4) exits directly to a far field region .

3. The lens (100) according to claim 1 or 2, characterized in that the second optical structure (5) is configured so that at least part of light emitted from the light source (1) through the second optical structure (5) exits to a far field region after being refracted and reflected by the second op^¬ tical structure.

4. The lens (100) according to claim 1 or 2, characterized in that the through hole (6) is configured to have a funnel- shaped contour.

5. The lens (100) according to claim 4, characterized in that the first optical structure (4) comprises a first por^¬ tion (41) and a second portion (42), at least the first por^¬ tion (41) forms a first refractive surface (511) of the first toothed structure (51), second light (L2) from the light source (1) enters the lens (100) after being refracted by the first refractive surface (511), and the second portion (42) direct emission of at least part of light from the light source (1) to a far field region.

6. The lens (100) according to claim 5, characterized in that viewed from the section of the lens (100), the first portion (41) is configured as a line shape and the second portion (42) is configured as a convex curved shape.

7. The lens (100) according to claim 5, characterized in that viewed from the section of the lens (100), the first portion (41) is configured as a line shape and the second portion (42) is configured as a line shape.

8. The lens (100) according to claim 5, characterized in that viewed from the section of the lens (100), the first portion (41) and the second portion (42) are configured as a continuous curve shape.

9. The lens (100) according to claim 1 or 2, characterized in that the first toothed structure (51) and the second toothed structure (52) form a Fresnel lens structure.

10. The lens (100) according to claim 9, characterized in that the first thickness (hi) and the second thickness (h2) are same or different from each other.

11. The lens (100) according to claim 9, characterized in that the first width (wl) and the second width (w2) are same or different from each other.

12. The lens (100) according to claim 5, characterized in that the first toothed structure (51) comprises the first re^¬ fractive surface (511) and a first reflective surface (512), and the second light (L2) from the light source (1) is emit^¬ ted through the exit surface (2) after being refracted by the first refractive surface (511) and reflected by the first re^¬ flective surface (512).

13. The lens (100) according to claim 12, characterized in that the first refractive surface (511) and the first reflec- tive surface (512) form a predetermined angle.

14. The lens (100) according to claim 12, characterized in that viewed from the section of the lens (100), the first re^¬ flective surface (512) is configured to be inclined away from an optical axis (X) of the lens (100) in a direction from the incident surface (3) to the exit surface (2) .

15. The lens (100) according to claim 1 or 2, characterized in that the second toothed structure (52) comprises a second refractive surface (521) and a second reflective surface (522), and third light (L3) from the light source (1) is emitted through the exit surface (2) after being refracted by the second refractive surface (521) and reflected by the se^¬ cond reflective surface (522) .

16. The lens (100) according to claim 15, characterized in that viewed in the section of the lens (100), the second re^¬ fractive surface (521) and the second reflective surface (522) form a predetermined angle.

17. The lens (100) according to claim 15, characterized in that viewed in the section of the lens (100), the second re- flective surface (522) is configured to be inclined away from an optical axis (X) of the lens (100) in a direction from the incident surface (3) to the exit surface (2) .

18. The lens (100) according to claim 1 or 2, characterized in that the lens (100) is configured to be rotationally sym^¬ metrical with respect to an optical axis (X) of the lens (100) .