Lighting unit with a light guide and method for mounting a lighting unit

Abstract

Lighting unit (1) for a vehicle headlight, comprising an elongated light guide (10) and a receiving means (11), wherein at least two light sources (12) are provided, which are spaced apart from each other on the receiving means (11) and each couple light into the light guide (10), wherein the receiving means (11) has a U-shaped support body (13) with a base section (13a) extending longitudinally along the elongated light guide (10) and with two leg sections (13b) on which the light sources (12) are arranged opposite each other, wherein a flexible conductor substrate (14) is provided, which is arranged on the support body (13) by holding the flexible conductor substrate (14) on the leg sections (13b) by retaining means (22), which are formed, for example, by clip-in features or by connecting elements.wherein the flexible conductor substrate (14) extends at least between the two light sources (12), wherein the light sources (12) are arranged on the flexible conductor substrate (14) such that they are received on the support body (13) via the flexible conductor substrate (14), characterized in that the flexible conductor substrate (14) is adapted to the U-shape of the support body (13) with the base section (13a) and the leg sections (13b) by flexible bending of the flexible conductor substrate (14) such that the flexible conductor substrate (14) lies in full contact with the support body (13).

Description

[0001] The present invention relates to a lighting unit for a headlight of a vehicle, comprising an elongate light guide body and a receiving means, wherein at least two lighting means are provided which are arranged at a distance from one another on the receiving means and each couple light into the light guide body. STATE OF THE ART

[0002] DE 10 2007 048 841 A1 shows a lighting unit for installation in a motor vehicle exterior mirror, wherein the lighting unit serves as a direction indicator. The lighting unit has a base housing, an inner housing, and a so-called lens. The base housing, the inner housing, and the lens in the form of a further housing part must be joined together to form the lighting unit. Several lighting devices, which are designed as LED light sources, are accommodated between the base housing and the inner housing. A light source unit, which is designed as a rigid substrate plate, serves to accommodate the LED light sources. Three LED light sources are shown as an example, which are arranged directly on the substrate plate. A further light source is arranged via a busbar at a distance from the substrate plate, and the base rail is laid with the individual LED light source in the base housing.

[0003] The base housing serves as a carrier body for accommodating the light source unit with the light sources, which are arranged directly on the substrate plate and serve to accommodate the light source, which is electrically contacted with the substrate plate via the busbar and held at a distance from the substrate plate by the base housing. Unfortunately, the arrangement of the LED light sources does not allow for any heat dissipation, as they are only held by their housing itself, and the housing is made of a plastic material that does not allow heat dissipation. The LED light sources can therefore only couple light with a lower power into the light guide, which is also housed in the base housing. The spaced-apart arrangement of the LED lamps allows light to be coupled into the light guide from different sides. The LED lamps are aligned accordingly by their holders.However, the alignment requires a correspondingly precise arrangement of the LED lamps on their holder and an alignment of the holder in the base housing, whereby the base housing cannot provide a lighting unit that is suitable for installation in a lighting device of a vehicle, for example in a headlight of the vehicle.

[0004] EP 2 277 741 B1 discloses a further lighting unit for a vehicle lighting device, which is also designed for installation in an exterior mirror of the vehicle to fulfill the function of a direction indicator in the exterior mirror. The lighting unit in turn comprises a housing in which a light guide is accommodated, and two LED lamps are accommodated at a distance from one another on respective electronic circuit boards. The formation of the lighting unit requires the arrangement of several electronic circuit boards for the LED lamps in the housing, so that several individual parts must be joined together to provide an individually handleable lighting unit. In particular, the alignment of the LED lamps with their electronic circuit boards, of which a total of three are described, must be carried out in a complex manner.

[0005] JP 2012-146584 A discloses a lighting unit for a vehicle lighting device comprising a light-emitting light guide body with light sources arranged on the end face, wherein the light guide body is held at each end by a metal-based flexible printed circuit board as a support body. The light guide body and the printed circuit board have corresponding, curved profiles, and the printed circuit board comprises two edge-side leg sections for accommodating the light sources and the light guide body.

[0006] DE 102 01 045 A1 discloses a light-emitting diode (LED) device, comprising: a light-emitting diode; a light-emitting diode drive circuit; a flexible circuit board having a contact tab region; wherein the light-emitting diode and the light-emitting diode drive circuit are mounted on a first side of the flexible circuit board, and wherein the contact tab region is folded such that the light-emitting diode emits light toward a central region of the flexible circuit board. DISCLOSURE OF THE INVENTION

[0007] The object of the invention is to create a simplified lighting unit for a vehicle headlight. The lighting unit should accommodate the light sources in a simple manner and position them relative to each other.

[0008] This object is achieved based on a lighting unit for a headlight of a vehicle according to the preamble of claim 1 and based on a method for assembling a lighting unit for a headlight of a vehicle according to claim 7 with the respective characterizing features. Advantageous developments of the invention are specified in the dependent claims.

[0009] The invention includes the technical teaching that the receiving means comprises a U-shaped carrier body, with a base section extending in the longitudinal direction of the elongated light guide body, and with two leg sections on which the illuminating means are arranged opposite one another, wherein a flexible conductor substrate is provided which is arranged on the carrier body in that the conductor substrate is held on the leg sections by holding means formed, for example, by clip-in formations or by connecting elements, wherein the conductor substrate extends at least between the two illuminating means, wherein the illuminating means are arranged on the flexible conductor substrate so that they are received on the carrier body via the flexible conductor substrate, and wherein the flexible conductor substrate is adapted to the U-shape of the carrier body with the base section and the leg sections by flexible bending of the conductor substrate,such that the flexible conductor substrate lies flat against the carrier body.

[0010] The invention advantageously uses a U-shaped carrier body to form a receiving means, and the carrier body according to the invention has a base section which extends approximately in the longitudinal direction of the elongated light guide body, wherein the base section has approximately the length of the light guide body in its longitudinal direction. At the end sides of the base section, leg sections are provided which protrude approximately perpendicularly from the base section. The light guide body can be arranged between the leg sections, wherein the light guide body does not preferably have to be held via the leg sections of the carrier body, and the light guide body can have a separate holding means with which it can be received, for example, on a base carrier body and which can also be a component of the lighting unit.

[0011] According to the invention, the illuminants are arranged on the inner sides of the leg sections, with the inner sides being approximately opposite one another due to the approximately parallel alignment of the leg sections. The light guide body can be arranged between the illuminants in such a way that light generated by the illuminants can be coupled into the light guide body.

[0012] According to the invention, a lighting unit is created that does not necessarily consist of a housing or a housing component, and the carrier body can be freely inserted into a vehicle headlight. The key advantage is that heat generated by the lamps and that must be dissipated from them can be dissipated from the lamps via the U-shaped carrier body. Consequently, the U-shaped carrier body also fulfills the function of cooling the lamps, which are preferably embodied as LED lamps.

[0013] To improve the cooling effect of the carrier body, it is made of a metallic material, particularly aluminum. For example, the carrier body can also have cooling fins on a free side, which enable further improved heat dissipation. Furthermore, the carrier body can be black anodized to further improve heat radiation.

[0014] According to the invention, a flexible conductor substrate is provided, which is arranged on the carrier body, wherein the conductor substrate extends at least between the two lighting devices and holds them in place. As an alternative to rigid circuit boards, thin, flexible circuit boards are known that form flexible conductor substrates, which are usually based on polyimide films and can be arranged on the carrier body according to the invention.

[0015] Flexible conductor substrates can be bent or folded and thus aligned three-dimensionally according to the required installation situation. According to the invention, a flexible conductor substrate is provided at least for receiving and electrically contacting the lighting means, wherein the flexible conductor substrate is arranged on the carrier body in a manner adapted to its contour. In particular, the flexible conductor substrate can be adapted to the U-shape of the carrier body with the base section and the leg sections by flexibly bending the conductor substrate. The bending of the flexible conductor substrate can occur in particular in bending regions formed by the transition of the base section into the leg sections of the U-shaped carrier body.It is also possible for the base section of the carrier body to have a curvature to which the flexible conductor substrate can be adapted, for example if the light guide body also has a curvature.

[0016] With further advantage, an electrical plug-in contact means can be provided, which is arranged on the conductor substrate and is designed, in particular, for electrically contacting the lighting means. The unit, which can be formed with the U-shaped carrier body and the flexible conductor substrate, can, in particular together with the light guide body, easily provide a lighting unit that serves for installation in a headlight of a vehicle. The electrical plug-in contact means can be designed such that it represents the only necessary electrical connection that must be established between the lighting unit and a peripheral electrical device in a vehicle, in particular in a headlight.

[0017] The present invention further relates to a method for assembling a lighting unit for a headlight of a vehicle, wherein at least two lighting means are provided which are received at a distance from one another on a receiving means, comprising at least the steps of providing a U-shaped carrier body with a base section and two leg sections to form the receiving means, and providing a flexible conductor substrate on which the lighting means are arranged and arranging the flexible conductor substrate adjacent to the base section and adjacent to the leg sections by performing a bending process in the conductor substrate such that the flexible conductor substrate is arranged in full contact with the carrier body, and establishing a holding connection between the conductor substrate and the carrier body at the leg sections by means of holding means,for example by clip-in moldings or connecting elements.

[0018] The method offers the advantage that the lamps can be easily positioned on a U-shaped carrier body without the lamps having to be handled individually during the assembly process. Thanks to the flexible conductor substrate, the lamps, together with their electrical contacts, can be arranged on the U-shaped carrier body in a single joining step. Furthermore, the lamps can be aligned so that they already assume the position on the U-shaped carrier body required for later operation. The bending process in the conductor substrate takes place in particular by adapting to the leg sections of the U-shaped carrier body, which can protrude approximately perpendicularly from the direction of extension of the base section of the carrier body.

[0019] According to the invention, the method further comprises the step of providing a light-guiding body arranged between the leg sections such that light generated by the illuminants can be coupled into the light-guiding body. The light-guiding body can be held in place by the U-shaped support body; however, a base support body can preferably be provided on which both the U-shaped support body and the light-guiding body are arranged in a holding manner independent of the support body. PREFERRED EMBODIMENT OF THE INVENTION

[0020] Further measures improving the invention are presented in more detail together with the description of a preferred embodiment of the invention with reference to the figures. It shows: Fig. 1 a view of a lighting unit for a lighting device of a vehicle with a receiving means designed according to the invention for receiving lighting means and a light guide body shown in perspective at a distance from the receiving means and Fig. 2 a perspective view of the lighting unit with a receiving means on which two lighting means are arranged and a light guide body arranged on the receiving means.

[0021] Fig. 1 shows a perspective view of an embodiment of a lighting unit 1 of the present invention, which is designed for installation in a headlight of a vehicle. The lighting unit 1 serves, for example, to provide a side position light that can be used to emit a yellow signal light. The lighting unit 1 is shown in an unassembled state and comprises a receiving means 11, which is designed according to the invention as a U-shaped carrier body 13. A light guide body 10 is shown above the carrier body 13, and the light guide body 10 has a light output structure 20, via which light that is coupled into the light guide body 10 via input surfaces 17 can be output again.A holding means 19 is used to hold the light guide body 10 in a holding position. This holding means is arranged, for example, approximately centrally on the light guide body 10, which light guide body 10 is elongated in a longitudinal direction 16. The coupling surfaces 17 are located on the end surfaces in the longitudinal direction 16 of the light guide body 10 and thus delimit it in its longitudinal direction, wherein the light output structure 20 extends along the length of the light guide body 10 on at least one side surface. The light coupled into the light guide body 10 via the coupling surfaces 17 can pass through the light guide body 10 based on the principle of total internal reflection, and the light can exit the structure surface through the light output structure 20. The light guide body 10 can be arranged on the carrier body 13 without the light guide body 10 being held in a holding manner by the carrier body 13.

[0022] The U-shaped support body 13 has a basic structure formed by an approximately straight base section 13a of the support body 13, which extends approximately parallel to the longitudinal direction 16 of the light guide body 10. At the end of the base section 13a, leg sections 13b protrude approximately perpendicularly from the direction of extension of the base section 13a, wherein the leg sections 13b are spaced from one another such that the light guide body 10 can be received between the leg sections 13b. The light guide body 10 does not have to be held on the support body 13, and by means of a base support body (not shown), the light guide body 10 can be received on the base support body by means of a holding means 19 formed thereon. The U-shaped support body 13 can be received on the base support body in a manner not shown in detail, so that the support body 13 and the light guide body 10 are held positioned relative to one another.

[0023] A flexible conductor substrate 14 is arranged on the U-shaped carrier body 13. This substrate essentially consists of a thin film, on which two illuminants 12 in the form of LEDs are attached at the ends. The flexible conductor substrate 14 rests against the base section 13a of the carrier body 13 and has two bending regions 18, so that the conductor substrate 14, with the coupled illuminants 12, continues to follow the course of the leg sections 13b at the ends. The flexible conductor substrate 14 is thus embedded inside the U-shaped carrier body 13.

[0024] In a molded-on side region of the carrier body 13, there is a section of the conductor substrate 14 on which an electrical plug-in contact means 15 is arranged, via which the conductor substrate 14 and consequently also the lighting means 12 can be electrically contacted. For further illustration, electronic components 21, particularly designed as SMD components, are arranged on the upper side of the flexible conductor substrate 14, which can, for example, perform additional electrical functions.

[0025] The illuminants 12 are arranged by the regions of the conductor substrate 14 introduced into the inside of the leg sections 13b of the carrier body 13 such that the illuminants 12 are approximately opposite one another when the illuminant 14 is arranged on the inside of the carrier body 13. If the light guide body 10 is inserted between the illuminants 12, light can be coupled into the coupling surfaces 17 provided at the ends of the light guide body 10 with each of the two illuminants 12. This arrangement is described in connection with the following Fig. 2 described in more detail.

[0026] Fig.Figure 2 shows the lighting unit 1 with a light guide 10 arranged between the leg sections 13b of the U-shaped support body 13. The lamps 12 are designed as SMD components on the flexible conductor substrate 14, so that the flexible conductor substrate 14 with both lamps 12 forms a joining unit that only needs to be attached to the U-shaped support body 13. Only a central section of the conductor substrate 14 needs to be laid over the base section 13a of the support body 13, and the respective end region of the conductor substrate 14, which areas carry the lamps 12, is attached to the leg sections 13b.

[0027] The conductor substrate 14 is inserted into the inner side of the U-shaped carrier body 13 by elastically bending the conductor substrate 14 in bending regions 18 formed by the transitions between the base section 13a and the leg sections 13b of the carrier body 13. The bending of the conductor substrate 14 is elastic. The conductor substrate 14 can be held on the leg sections 13b in a manner not shown in detail, for example by holding means 22, which can be formed, for example, by clip-in moldings or by connecting elements, and by which a holding connection can be established between the conductor substrate 14 and the carrier body 13.

[0028] The invention is not limited in its implementation to the preferred embodiment described above. Rather, a number of variants are conceivable, which also utilize the presented solution in other types of implementations. All features and / or advantages apparent from the claims, the description, or the drawings, including structural details, spatial arrangements, and method steps, may be essential to the invention both individually and in a wide variety of combinations. List of reference symbols 1 lighting unit 10 light guides 11 Recording equipment 12 bulbs 13 U-shaped support body 13a Basic section 13b Leg section 14 flexible conductor substrate 15 electrical plug-in contact means 16 Longitudinal direction 17 Coupling area 18 Bending area 19 Holding devices 20 Light decoupling structure 21 electronic component 22 holding devices

Claims

[1] Lighting unit (1) for a headlight of a vehicle, comprising an elongate light-guiding body (10) and a receiving means (11), wherein at least two illuminating means (12) are provided, which are arranged at a distance from one another on the receiving means (11) and each couple light into the light-guiding body (10), wherein the receiving means (11) has a U-shaped carrier body (13) with a base section (13a) which extends in the longitudinal direction of the elongate light-guiding body (10), and with two leg sections (13b) on which the illuminating means (12) are arranged opposite one another, wherein a flexible conductor substrate (14) is provided which is arranged on the carrier body (13), in that the flexible conductor substrate (14) is held on the leg sections (13b) by holding means (22), which are formed, for example, by clip-in formations or by connecting elements,wherein the flexible conductor substrate (14) extends at least between the two lighting means (12), wherein the lighting means (12) are arranged on the flexible conductor substrate (14) so that they are received on the carrier body (13) via the flexible conductor substrate (14), , characterized by that the flexible conductor substrate (14) is adapted to the U-shape of the carrier body (13) with the base section (13a) and the leg sections (13b) by flexible bending of the flexible conductor substrate (14) in such a way that the flexible conductor substrate (14) lies fully against the carrier body (13). [2] Lighting unit (1) according to claim 1, characterized by that the carrier body (13) is made of a metallic material, in particular of aluminum. [3] Lighting unit (1) according to one of the preceding claims, characterized bythat an electrical plug-in contact means (15) is provided which is arranged on the flexible conductor substrate (14) and is designed in particular for electrically contacting the lighting means (12). [4] Method for assembling a lighting unit (1) for a headlight of a vehicle, wherein at least two lighting means (12) are provided, which are received on a receiving means (11) at a distance from one another, comprising at least the following steps: - Providing a U-shaped carrier body (13) with a base section (13a) and with two leg sections (13b) for forming the receiving means (11), and - providing a flexible conductor substrate (14) on which the lighting means (12) are arranged, - arranging the flexible conductor substrate (14) adjacent to the base section (13a) and adjacent to the leg sections (13b) by performing a bending process in the flexible conductor substrate (14) such that the flexible conductor substrate (14) is arranged in full contact with the carrier body (13), and - Producing a holding connection between the flexible conductor substrate (14) and the carrier body (13) at the leg sections (13b) by means of holding means (22), for example by clip-in formations or by means of connecting elements. [5] Method according to claim 4, characterized by the step of providing a light guide body (10) which is arranged between the leg sections (13b) in such a way that light generated by the lighting means (12) can be coupled into the light guide body (10). [6] Method according to claim 5, characterized bythat the U-shaped carrier body (13) and the light guide body (10) are arranged together and preferably each on a base carrier body.

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