FLEXIBLE LED LIGHTING STRIP WITH SLANTED LEDS

Abstract

The invention describes a flexible lighting strip for use in a vehicle signaling light. The flexible lighting strip comprises a multitude of light-emitting diodes. The flexible lighting strip is arranged to be bended around at least two, more preferably three linear independent axes. Light-emitting diodes of at least a first group of the light-emitting diodes are inclined with respect to a longitudinal extension of the flexible lighting strip such that surface normals of light exit surfaces of the first group of the light-emitting diodes enclose a first angle of more than 0 with corresponding surface normals of a light emission surface of the flexible lighting strip. The invention further relates to a light assembly comprising such a flexible lighting strip. The invention finally relates to a vehicle signaling light comprising such a vehicle light assembly.

Claims

1. A flexible lighting strip for use in a vehicle signaling light comprising: a multitude of light-emitting diodes, wherein the flexible lighting strip is arranged to be bended around at least two, more preferably three linear independent axes, wherein light-emitting diodes of at least a first group of the light-emitting diodes are inclined with respect to a longitudinal extension of the flexible lighting strip such that surface normals of light exit surfaces of the first group of the light-emitting diodes enclose a first angle of more than 0 with corresponding surface normals of a light emission surface of the flexible lighting strip, wherein the light-emitting diodes are mounted on a carrier structure, wherein the carrier structure is arranged to incline the light-emitting diodes with respect to the light emission surface of the flexible lighting strip, and wherein the carrier structure is arranged such that the angles between the surface normal of a light exit surface of a first light-emitting diode and the corresponding surface normal of a first part of the light emission surface associated with the first light-emitting diode increases with increasing curvature of the first part of the light emission surface.

2. The flexible lighting strip according to claim 1, wherein the flexible lighting strip comprises at least a second group of the light-emitting diodes, wherein the light-emitting diodes of the second group of the light-emitting diodes are inclined with respect to the longitudinal extension of the flexible lighting strip such that the surface normals of light exit surfaces of the second group of the light-emitting diodes enclose a second angle of more than 0 with the corresponding surface normals of the light emission surface of the flexible lighting strip, and wherein the second angle is different than the first angle.

3. The flexible lighting strip according claim 1, wherein the flexible lighting strip comprises at least three groups of the light-emitting diodes, wherein the light-emitting diodes of the at least three groups are inclined with respect to the longitudinal extension of the flexible lighting strip such that the surface normals of light exit surfaces of the at least three groups of the light-emitting diodes enclose different angles of more than 0 with the corresponding surface normals of the light emission surface of the flexible lighting strip, and wherein the angles change along a longitudinal extension of the flexible lighting strip.

4. The flexible lighting strip according to claim 1, wherein the carrier structure comprises carrier elements and connection elements in an alternating arrangement, and wherein the carrier elements are inclined with respect to the connection elements.

5. The flexible lighting strip according to claim 4, wherein the carrier elements and the connection elements are arranged in a saw tooth arrangement.

6. The flexible lighting strip according to claim 1, wherein the carrier structure comprises an anode track and a cathode track for supplying electrical power to the light-emitting diodes.

7. The flexible lighting strip according to claim 1, wherein the light-emitting diodes are embedded in a flexible translucent material.

8. The flexible lighting strip according to claim 7, wherein the translucent material is comprised by a light guiding structure, and wherein the light guiding structure is framed by a frame structure such that light emitted by the light-emitting diodes during operation of the flexible lighting strip leaves the light guiding structure via an opening of the frame structure.

9. The flexible lighting strip according to claim 1, wherein the flexible lighting strip further comprises a diffusor, wherein the diffusor is arranged to change a light distribution of light emitted by the light-emitting diodes during operation of the flexible lighting strip.

10. The flexible lighting strip according to claim 9, wherein the diffusor is arranged such that light outcoupling of light emitted by the light-emitting diodes is weighted in a direction perpendicular to the surface normals of the light emission surface of the flexible lighting strip.

11. A vehicle light assembly comprising: an electrical interface, wherein the electrical interface is arranged to couple the vehicle light assembly to an external power supply; and a flexible lighting strip including a multitude of light-emitting diodes, wherein the flexible lighting strip is arranged to be bended around at least two, more preferably three linear independent axes, wherein light-emitting diodes of at least a first group of the light-emitting diodes are inclined with respect to a longitudinal extension of the flexible lighting strip such that surface normals of light exit surfaces of the first group of the light-emitting diodes enclose a first angle of more than 0 with corresponding surface normals of a light emission surface of the flexible lighting strip, wherein the light-emitting diodes are mounted on a carrier structure, wherein the carrier structure is arranged to incline the light-emitting diodes with respect to the light emission surface of the flexible lighting strip, and wherein the carrier structure is arranged such that the angles between the surface normal of a light exit surface of a first light-emitting diode and the corresponding surface normal of a first part of the light emission surface associated with the first light-emitting diode increases with increasing curvature of the first part of the light emission surface.

12. A vehicle signaling light comprising: a vehicle light assembly including an electrical interface, wherein the electrical interface is arranged to couple the vehicle light assembly to an external power supply, a flexible lighting strip having a multitude of light-emitting diodes, and an electrical driver arranged to provide an electrical drive current to the light-emitting diodes, wherein the flexible lighting strip is arranged to be bended around at least two, more preferably three linear independent axes, wherein light-emitting diodes of at least a first group of the light-emitting diodes are inclined with respect to a longitudinal extension of the flexible lighting strip such that surface normals of light exit surfaces of the first group of the light-emitting diodes enclose a first angle of more than 0 with corresponding surface normals of a light emission surface of the flexible lighting strip, wherein the light-emitting diodes are mounted on a carrier structure, wherein the carrier structure is arranged to incline the light-emitting diodes with respect to the light emission surface of the flexible lighting strip, wherein the carrier structure is arranged such that the angles between the surface normal of a light exit surface of a first light-emitting diode and the corresponding surface normal of a first part of the light emission surface associated with the first light-emitting diode increases with increasing curvature of the first part of the light emission surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0027] The invention will now be described, by way of example, based on embodiments with reference to the accompanying drawings.

[0028] In the drawings:

[0029] FIG. 1 shows a perspective view of a first flexible lighting strip

[0030] FIG. 2 shows a first cross section of a second flexible lighting strip

[0031] FIG. 3 shows a second cross section of a third flexible lighting strip

[0032] FIG. 4 shows a cross section of a vehicle signaling light

[0033] FIG. 5 shows a third cross section of a fifth flexible lighting strip

[0034] In the Figures, like numbers refer to like objects throughout. Objects in the FIGS. are not necessarily drawn to scale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Various embodiments of the invention will now be described by means of the Figures.

[0036] FIG. 1 shows a perspective view of a first flexible lighting strip 100. The flexible lighting strip 100 comprises a frame structure with a flexible base 16 and flexible side walls 18. LEDs 20 are mounted on a carrier structure 30. The carrier structure 30 is characterized by a saw tooth arrangement. The LEDs 20 are mounted on one side of the saw tooth arrangement such that all light exit surfaces of the LEDs 20 are inclined with respect to a surface normal of a light emission surface of the flexible lighting strip 100. The light emission surface is at the same level as the upper surface of the flexible side walls 18 as shown in FIG. 3. The light exit surfaces of the LEDs 20 point in the same direction.

[0037] FIG. 2 shows a first cross section of a second flexible lighting strip 100 along the line A-A indicated in FIG. 1. Each LED 20 is mounted on a submount 25. The submounts 25 are mounted on a carrier structure 30. The carrier structure 30 comprises carrier elements 31 and connection elements 32. The LEDs 20 are mounted on the carrier elements 31 which are inclined with respect to a surface normal of a light emission surface 28 of the flexible lighting strip 100. The inclination of the carrier elements 31 and the corresponding inclination of light exit surfaces of the LEDs 20 do have the effect that an angle between a surface normal of the light exit surface 21 of one LED 20 enclose an angle of more than 0 with a corresponding surface normal of the light emission surface 28. Corresponding surface normal means the surface normal of the surface element of the light emission surface which is arranged directly above the LED 20. The surface normals of the light emission surface 28 point all in the same direction if the flexible lighting strip 100 is straight. The surface normals of the light emission surface 28 are directed in different directions if the flexible lighting strip 100 is bended. The carrier elements 31 are mechanically connected by connection elements 32. The carrier elements 31 and the connection elements 32 are arranged in saw tooth arrangement. The carrier structure 30 further comprises an anode track and a cathode track which are not shown in FIG. 2. The carrier structure 30, the submounts 25 and the LEDs 20 are embedded in a light guiding structure 22 which comprises a flexible translucent material (e.g. a silicone polymer).

[0038] FIG. 3 shows a second cross section of a third flexible lighting 100 strip along line B-B indicated in FIG. 1. The third flexible lighting strip 100 comprises a frame structure with a flexible base 16 and flexible side walls 18 (e.g. flexible plastic material or colored silicone) which enclose a flexible translucent material. The frame structure and the flexible translucent material built a light guiding structure 22. An opening of the frame structure which coincides with an upper surface of the flexible translucent material builds the light emission surface which is characterized by a surface normal of the light emission surface 28. FIG. 3 further shows a cross-section of a connection element of a carrier structure which consists in this embodiment of an anode track 34 and a cathode track 35 which are arranged to supply electrical power and electrical control signals to the LEDs 20.

[0039] FIG. 4 shows a cross section of a vehicle signaling light 200. The vehicle signaling light 200 comprises a flexible lighting strip 100 similar as discussed with respect to FIG. 2. The vehicle signaling light 200 further comprises a strip holder 140 for mounting the flexible lighting strip, an electrical interface 110 for receiving electrical power and control signals and an electrical driver 120 for electrically driving LEDs 20. The LEDs 20 are in this embodiment arranged in four groups of LEDs 20. The first group of LEDs 20 comprising one LED 20 is arranged on the right side of FIG. 4. A surface normal of the light exit surface 21 LED 20 comprised by the first group of LEDs 20 is collinear with a forward direction 50 of the vehicle signaling light 200 which coincides with a corresponding (local) surface normal of a light emission surface 28 of the flexible lighting strip 100. The second group of LEDs comprises one LED 20 which is arranged next to the first group of LEDs 20 going from the right side to the left side in FIG. 4. The surface normal of the light exit surface 21 of the LED 20 comprised by the second group of LEDs 20 encloses a small angle with the corresponding local surface normal of the light emission surface 28. The small angle is essentially the same like the angle enclosed between the (local) light emission direction 24 (direction of the intensity maximum) and the surface normal of the light emission surface 28. The third group of LEDs comprises one LED 20 which is arranged next to the second group of LEDs 20 going from the right side to the left side in FIG. 4. The surface normal of the light exit surface 21 of the LED 20 comprised by the third group encloses a different angle with the corresponding (local) surface normal of the light emission surface 28 than the LED 20 comprised by the second group. The fourth group of LEDs 20 comprises six LEDs 20 which are arranged next to the third group of LEDs 20 going from the right side to the left side in FIG. 4. The surface normals of the light exit surface 21 of the LEDs 20 comprised by the fourth group enclose the same angle with the corresponding (local) surface normal of the light emission surface 28. The angle corresponding to the fourth group of LEDs 20 is bigger than the angle associated with the LED 20 comprised by the third of LEDs 20 group. The angle enclosed between the surface normals of the light exit surfaces 21 and the (local) surface normals of the light emission surface 28 increases from the second group, to the third group and finally to the fourth group of LEDs 20. The LEDs 20 are mounted on a carrier structure 30 which comprises carrier elements 31 and connection elements 32 similar as discussed with respect to FIG. 2. The carrier elements 31 and the connection elements 32 are arranged in a saw tooth arrangement. The carrier structure 30 is arranged within a light guiding structure 22 comprising a frame structure (only the flexible base 16 is shown in FIG. 4) and a translucent flexible material. The flexible lighting strip 100 further comprises a diffusor 27 which builds the light emission surface. The diffusor 27 is arranged to support directionality of the light emitted by the inclined light exit surfaces 21 of the LEDs 20. FIG. 4 shows the angles of inclination in the final bended configuration of the flexible lighting strip 100 when the flexible lighting strip 100 is mounted in the strip holder 140. The angles of inclination between the surface normals of the light exit surface 21 and the surface normals of the light emission surface 28 may be different before the flexible lighting strip is mounted in the strip holder 140. The flexible lighting strip may, for example, comprise two groups of LEDs with different angles of inclination before mounting the flexible lighting strip 100. The first group of LEDs 20 may consist of the first and the second LED 20 on the right side in FIG. 4. The second group of LEDs 20 may consist of the remaining LEDs 20. Bending of the flexible lighting strip 100 during mounting in the strip holder 140 may in this alternative embodiment cause the different angles of inclination of the second group of LEDs and the third group of LEDs discussed above. The flexible lighting strip 100 may be straight before mounting in the strip holder 140. In an alternative embodiment it may be curved to simplify mounting.

[0040] FIG. 5 shows a third cross section of a fifth flexible lighting strip 100 strip along line C-C indicated in FIG. 1. The fifth flexible lighting strip 100 comprises a flexible frame structure similar as discussed with respect to FIG. 3 which enclose a flexible translucent material. The frame structure and the flexible translucent material built a light guiding structure 22. An opening of the frame structure which coincides with an upper surface of the flexible translucent material builds the light emission surface which is characterized by a surface normal of the light emission surface 28. The shape of the frame structure and the orientation of the flexible translucent material within the frame structure are inclined with respect to each other such that the light emission surface 28 is inclined with respect to the outer shape of the frame structure. The relative arrangement of the light emission surface 28 with respect to the frame structure therefore enables a tailored direction of light emission in the direction of line C-C. FIG. 5 further shows a cross-section of a carrier element of a carrier structure which consists in this embodiment of an anode track 34 and a cathode track 35 which are arranged to supply electrical power and electrical control signals to the LEDs 20 which is mounted on the carrier element. The frame structure may, for example, alternatively have a circular cross-section in order to adapt orientation of the light emission surface 28 depending on the application. The light emission surface 28 may be planar as shown in FIGS. 3 and 5 or may, for example, be curved.

[0041] While the invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive.

[0042] From reading the present disclosure, other modifications will be apparent to persons skilled in the art. Such modifications may involve other features which are already known in the art and which may be used instead of or in addition to features already described herein.

[0043] Variations to the disclosed embodiments can be understood and effected by those skilled in the art, from a study of the drawings, the disclosure and the appended claims. In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality of elements or steps. 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.

[0044] Any reference signs in the claims should not be construed as limiting the scope thereof.

REFERENCE SIGNS

[0045] 16 flexible base [0046] 18 flexible sidewalls [0047] 20 light-emitting diode (LED) [0048] 21 surface normal of light exit surface [0049] 22 light guiding structure [0050] 24 light emission direction [0051] 25 submount [0052] 27 diffusor [0053] 28 surface normal of light emission surface [0054] 30 carrier structure [0055] 31 carrier element [0056] 32 connection element [0057] 34 anode track [0058] 35 cathode track [0059] 50 forward direction [0060] 100 flexible lighting strip [0061] 110 electrical interface [0062] 120 electrical driver [0063] 140 strip holder [0064] 200 vehicle signaling light