Holding collimator elements in a lighting arrangement

Abstract

A lighting arrangement includes a plurality of light sources in spaced arrangement. Collimator elements are arranged in front of the light sources. A holder with a plurality of spaced openings is provided to hold the collimator elements within the openings in such a way that the openings are arranged to contact the collimator elements from at least two opposed sides, In order to allow exact positioning and easy manufacturing, the holder comprises at least a first portion and a second portion such that at least some of the openings are formed between the first and the second portions.

Claims

1. A lighting arrangement, including a plurality of light sources in spaced arrangement; a first plurality of collimator elements in front of the light sources arranged in a first collimator element row; a second plurality of collimator elements in front of the light sources arranged in a second collimator element row; a lens formed in one piece with the first and second pluralities of collimator elements, the lens being configured to project collimated light as a single beam; and a holder with a plurality of spaced openings, the first and second pluralities of collimator elements being arranged to be held within the openings, in such a way that the openings are arranged to contact the collimator elements from at least two opposed sides, the holder comprising at least a first portion and a second portion, at least some of the openings being formed between the first and the second portion; wherein a first group of the openings is arranged in a first opening row to receive the first collimator element row, and a second group of the openings is arranged in a second opening row to receive the second collimator element row, the second opening row being arranged at least substantially in parallel and at a distance to the first opening row, and the openings of the first and second group are arranged in offset arrangement.

2. The lighting arrangement according to claim 1, wherein the light sources are arranged on a carrier, and the holder being fixed to the carrier.

3. The lighting arrangement according to claim 2, wherein the holder and/or the carrier comprise positioning elements to obtain a fixed relative arrangement.

4. The lighting arrangement according to claim 1, wherein at least the first and/or the second portion is provided with a plurality of spaced, projecting wall elements, and wherein the openings are at least partially provided between the wall elements.

5. The lighting arrangement according to claim 1, wherein the holder comprises a third portion, wherein a first group of openings is arranged between the first and third portions, and a second group of openings is arranged between the second and third portions.

6. The lighting arrangement according to claim 1, wherein the holder comprises a plate portion arranged in a holding plane.

7. The lighting arrangement according to claim 1, wherein the openings are arranged at a distance from the light sources.

8. The lighting arrangement according to claim 1, wherein the first and second collimator elements are of elongated shape, and wherein an area of a second cross-section of the first and second collimator elements is larger than an area of a first cross-section of the first and second collimator elements, the first cross-section being arranged closer to the light sources than the second cross-section.

9. The lighting arrangement according to claim 1, wherein the collimator elements are solid elements of a transparent material.

10. The lighting arrangement according to claim 1, wherein the holder is arranged to hold the lens.

11. A method of manufacturing a lighting arrangement, the method comprising: arranging a plurality of light sources in a spaced arrangement; arranging first and second collimator element rows comprising first and second pluralities of collimator elements, respectively, in front of the light sources, all of the first and second pluralities of collimator elements being formed in one piece with a lens that is configured to project collimated light as a single beam; arranging the first and second pluralities of collimator elements between first and second portions of a holder comprising a plurality of spaced openings being formed between the first and second portions in such a way that the openings are arranged to contact the collimator elements from at least two opposed sides; arranging a first group of the openings in a first opening row to receive the first collimator element row, and a second group of the openings in a second opening row to receive the second collimator element row, the second opening row being arranged at least substantially in parallel and at a distance to the first opening row, and the openings of the first and second group are arranged in offset arrangement.

12. The method according to claim 11, wherein the holder comprises a third portion, wherein a first group of openings is arranged between the first and third portions, and a second group of openings is arranged between the second and third portions.

13. The method according to claim 11, wherein the holder is arranged to hold the lens.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 shows a perspective view of an embodiment of a lighting arrangement including a carrier;

(3) FIG. 2 shows a perspective view of a backside of the lighting arrangement of FIG. 1 without the carrier;

(4) FIG. 3 shows a sectional view of the lighting arrangement of FIG. 1, FIG. 2 with the section along A . . . A in FIG. 2;

(5) FIG. 4 shows a sectional view of the lighting arrangement of FIG. 1-3 with the section along B . . . B in FIG. 3;

(6) FIG. 5 shows the lighting arrangement of FIG. 1-4 in a perspective, exploded view;

(7) FIG. 6 shows the lighting arrangement of FIG. 1-5 in a perspective, exploded view from a backside, without the carrier.

(8) FIG. 7a-d show sectional views similar to FIG. 4 for different embodiments of lighting arrangements.

DETAILED DESCRIPTION OF EMBODIMENTS

(9) FIG. 1, FIG. 2 show in perspective views a lighting arrangement 10 including a carrier 12, a holder 14 mounted on the carrier 12, and an optical unit 16 held inside the holder 14.

(10) The optical unit 16 is comprised of individual elongate collimator elements 18 extending in the direction of an optical axis X and a lens 20. As will become apparent, several optical axes arranged in parallel may be defined for each collimator element. For ease of reference, one centrally arranged optical axis X will be referred to here. The collimator elements are arranged in parallel in spaced arrangement, i.e. at a distance to each other in a traverse direction, perpendicular to the optical axis X.

(11) In the embodiment shown, the lens 20 and collimator elements 18 are formed in one piece out of a solid, transparent material, for example, silicone.

(12) A plurality of LED elements as light sources 22 (shown e.g. in FIG. 5, not visible in FIG. 1, 2) are mounted on the carrier 12 arranged in a line, or row, extending perpendicular to the optical axis X.

(13) The arrangement of one light source 22 is visible from the sectional view of FIG. 3. The optical unit 16 including the collimator element 18 is arranged in front of the light source 22 such that light emitted from the light source 22 is received at a receiving surface 24 of the collimator element 18.

(14) The receiving surface 24 is of rectangular shape. The shape of the collimator element 18 may be described substantially as a pyramidal frustum extending between the receiving surface 24 and a rectangular light emitting portion 26. In the embodiment shown, the optical unit 16 with the collimator element 18 and lens 20 is formed in one piece such that the light emitting portion 26 is not separately visible. The collimator element 18 is shaped to widen with increasing distance from the light source 22 such that a second cross-section at a position distant from the light source 22, such as at the light emitting portion 26, is larger than a first cross-section closer to the light source 22, such as at the receiving surface 24.

(15) The collimator element 18 is a TIR reflector. Light received at the receiving surface 24 propagates internally within the transparent material of the collimator element 18. At the boundary surfaces to the surrounding air, total internal reflection occurs, as indicated for selected beams of light in FIG. 3. In consequence, the light emitted from the light source 22 broadly (Lambertian emitter) is collimated, i.e. the opening angle thereof reduced by the collimator element 18. The collimated light is then projected by the lens 20 as an emitted beam 28.

(16) As shown in FIG. 3, the collimator element 18 is arranged at a small distance d in front of the LED light source 22. While it is possible to arrange the light receiving surface 24 of the collimator 18 to directly contact the light emitting surface of the LED light source 22, it is preferable to provide a gap as shown in FIG. 3. However, the width d of the gap is in specific embodiments small, such as e.g. 50 μm.

(17) The optical unit 16 is held in front of the LED light sources 22 by the holder 14. As visible in particular from FIG. 3, the holder 14 encloses both the lens 20 and the individual collimator elements 18 to secure them in place relative to the carrier 12 and light sources 22. As visible e.g. from FIG. 1, FIG. 2, the holder 14 comprises screw holes to provide a screw connection to the carrier 12. Further, as shown in FIG. 2, the backside of the holder 14 comprises positioning protrusions 30 which fit into corresponding positioning holes in the carrier 12 (not shown) and ensure correct positioning of the holder 14 relative to the carrier 12 and light sources 22.

(18) The optical unit 16 is held within the holder 14, which comprises a front frame 32 surrounding and receiving the outer edges of the lens 20 in form-fitting manner (see FIG. 3). Further, the holder 14 comprises a back frame 34 in which the collimator elements 18 are held. The back frame 34 comprises a plurality of spaced openings 36 provided in a holding plate 38 arranged in a holding plane B . . . B.

(19) As visible from FIG. 3, the holding plate 38 and holding plane B . . . B are arranged at a distance along the optical axis X both from the light source 22 and from the receiving surface 24 of the collimator element 18. Thus, the back ends of the collimator elements 18 project from the holding plate 38 (FIG. 2).

(20) FIG. 4 shows a sectional view of the holding plane B . . . B. Collimator elements 18 are arranged within the openings 36 formed in the holding plate 38. As shown, the collimator elements 18 are surrounded by bordering portions of the openings 36 which contact the outer surfaces of the collimator element 18 to hold it securely in place.

(21) In the first embodiment shown, the holder 14 is comprised of two separate portions, a first, upper portion 14a and a second, lower portion 14b. A separation 40 between the first and second portions 14a, 14b is arranged mainly horizontally, i.e. in parallel to the row of light sources 22.

(22) The front frame 32 of the holder 14 is comprised of an upper front frame element 32a and a lower front frame element 32b which are joined together to form the front frame element 32 enclosing the lens 20. Likewise, the back frame 34 is separated into a first, upper back frame 34a to which a first, upper portion 38a of the holding plate 38 is attached and a second, lower back frame portion 34b, to which a second, lower portion 38b of the holding plate 38 is attached.

(23) The holder 14, which is arranged to accommodate the optical element 16 and in particular the collimator elements 18 inside, is therefore formed by two separate first and second portions 14a, 14b which are joined together, e.g. mechanically such as by clamping and/or screw connection, or by a material connection such as gluing, welding, etc.

(24) As shown e.g. in FIG. 2, FIG. 4, the separation surface 40 along which the first and second portions 14a, 14b, and in particular also the first and second portions 38a, 38b of the holding plate 38 are joined, is arranged in contact with each of the openings 36. Thus, the bordering portions surrounding the openings 36 are partially provided in the first portion 38a of the holding plate 38, and for the remaining part in the second portion 38b of the holding plate 38.

(25) In the first embodiment as shown in FIG. 4, the partial openings for each portion 38a, 38b are formed by projecting wall elements 42 in spaced arrangement, such that the partial openings are formed in between the wall elements 42. As visible in particular from FIG. 5, the first and second portion 38a, 38b of the holding plate 38 thus comprise a toothed arrangement.

(26) The exploded views of FIG. 5, FIG. 6 demonstrate how the separation of the first and second portions 14a, 14b of the holder 14 allows arrangement of the optical unit 16 within the holder 14:

(27) During assembly of a lighting unit 10, the first and second portions 14a, 14b of the holder 14 are in one manufacturing step arranged separately at a distance from each other. The optical unit 16 may than be easily arranged in between the first and second portions 14a, 14b of the holder 14. For example, the optical unit 16 may first be fitted into the lower, second portion 14b, such that the edges of the lens 20 are received within the lower portion 32b of the front frame 32 and that the collimator elements 18 may be arranged within the partial openings between the projecting wall portions 42 of the lower, second portion 38b of the holding plate 38.

(28) Then, the second portion 14b of the holder 14 may be joined to the first portion 14a, such that the front frame 32, back frame 34 and holding plate 38 are completed and fully enclose the lens 20 and collimator elements 18 of the optical unit 16.

(29) Finally, the holder 14 may be mounted to the carrier 12.

(30) In the resulting lighting arrangement 10, the collimator elements 18 are securely held and exactly positioned relative to the light sources 22 to maintain an exact distance d and minimize offset between the light sources 22 and receiving services 24. The collimator elements 18 are entirely surrounded in the holding plane B . . . B from all four sides by the bordering portions of the openings 36. The thickness of the holding plate 38 is relatively small compared to the length of the collimator elements 18, such that there is minimal disturbance of total internal reflection. The holder 14 contacts the optical unit 16 only in the region of the front frame 32 and holding plate 38, whereas the remaining portion of the optical unit 16 is not in contact with the holder 14 such that there is minimal light loss.

(31) The holding plate 38 is arranged closer to the receiving surface 24 than to the light emitting portion 26 of the collimator element 18, i.e. the collimator elements 18 are held within the openings 36 close to their back ends.

(32) It should be noted that the arrangement of the light sources 22 in a line and the division surface 40 between the first and second portions 14a, 14b of the holder 14 as shown in FIG. 4 are only examples of possible embodiments. In further embodiments, the light sources 22 may be arranged differently on the carrier 12, such as e.g. in a matrix configuration with rows and columns. Likewise, the collimator elements 18 may be provided not only in one line as in the first embodiment, but for example in two, three or more lines, or rows, corresponding to the arrangement of the light sources 22.

(33) FIG. 7a-7d illustrate the arrangement of collimator elements 18, openings 36 and the division surface 40 within the holding plate 38 for different embodiments.

(34) In a second embodiment according to FIG. 7a, a toothed arrangement of protruding wall elements 32 is formed only in the lower, second portion 38b of the holding plate 38, whereas the upper portion 38a of the holding plate 38 has a straight edge. Thus, partial openings with three bordering portions are formed in the second portion 38b, to be closed off by the edge of the first portion 38a once the first and second portions 38a, 38b are joined.

(35) In a third embodiment according to FIG. 7b, the collimator elements 18 are arranged in not only one row, but two rows in offset arrangement. Both the first and second portions 38a, 38b of the holding plate 38 are provided with toothed arrangements of projecting wall elements 42, albeit in alternating offset arrangement such that alternatingly openings 36 are bordered from three sides in one portion and closed off to the fourth side by the other portion of the holding plate 38. The light sources 22 on the carrier 12 (not shown for the second embodiments) are arranged in accordance with the arrangement of the collimator elements 18, i.e. in two rows in offset arrangement.

(36) In each of the fourth and fifth embodiments of FIG. 7c, 7d, a holder 14 is comprised of three portions, of which the first comprises a first, upper portion 38a of the holding plate 38, the second comprises a second, lower portion 38b of the holding plate 38, and the third comprises a third, center portion 38c of the holding plate 38.

(37) In the fourth embodiment (FIG. 7c), the collimator elements 18 are arranged in a matrix arrangement with rows and columns. A first group of openings 36a is formed between the first and third portions 38a, 38c of the holding plate 38 and a second group 36b of openings is formed between the second portion 38b and third portion 38c of the holding plate 38.

(38) In the fifth embodiment (FIG. 7d), four rows of collimator elements 18 are provided. A first group of openings 36a for the collimator elements 18 is provided between the first and third portions 38a, 38c of the holding plate 38 and a second group of openings 36b is provided between the second portion 38b and third portion 38c of the holding plate 38.

(39) It should be noted that the above-mentioned embodiments illustrate rather than limit the disclosure, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

(40) In the claims, any reference signs placed between parentheses shall not be construed as limiting the scope. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.

(41) In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.