Lighting device with a housing with a G-shaped cross-section and formed from two profiles each open on one side for illuminating the interior of a motor vehicle

Abstract

A lighting device (2) for illuminating the interior of a motor vehicle (K), comprising an elongated housing (G) through which a strip-like carrier (25) with a plurality of illuminants (26) is held, wherein the housing (G) is designed as a reflector element having at least one reflector chamber (22), wherein light rays (L) emitted or emitted by the illuminants (26) are diffusely reflected or reflected in the reflector chamber (22) before reaching a light exit opening (23a), wherein the housing (G) is G-shaped in cross-section, characterized in that the housing (G) is formed in cross-section from two profiles (20, 21), each open on one side, which protrude into one another with their opening sides (Ö1, Ö2), whereby the reflector chamber (22) and a light exit chamber (22a) with the light exit opening (23a) are formed,wherein the light exit opening (23a) is formed by a leg (200) of one profile (20) and a leg (210) of the other profile (21) projecting into it, and the leg (210) of the other profile (21) projecting into one profile (20) leads to the formation of the light exit chamber (22a) separated from the reflector chamber (22).

Description

[0001] The invention relates to a lighting device for illuminating the interior of a motor vehicle with the features of the preamble of patent claim 1.

[0002] Such a lighting device is known from JP 2013 - 246 930 A. Specifically, this document describes an elongated lighting device which is arranged in an instrument panel above a glove compartment and extends along the width of the glove compartment. A light gap is formed between parts of the instrument panel. The lighting device consists of two profiles with an approximately L-shaped cross section, which are fastened to one another and form a housing for the lighting device. A strip-like light source unit with a plurality of light-emitting diodes (LEDs) is fastened in the housing. This emits light beams towards an opposite, vertical wall of the housing. The wall is provided with a reflective surface and is curved in such a way that the light beams are specifically reflected towards a light-permeable area of ​​the housing.The translucent area is located directly adjacent to the light gap, so that the light rays can emerge from the light gap towards the interior or towards the glove compartment, if open.

[0003] US 2014 / 0 362 574 A1 discloses a lighting device consisting of several strip-like LED elements, each housed in an elongated profile housing. Several profile housings can be electrically connected to one another via suitable connectors. The strip-like LED elements can be shortened as required.

[0004] US 2010 / 0 214 777 A1 describes a lighting device in which LEDs are arranged in a housing on a flexible substrate. The LEDs emit their light toward a reflector area on the housing, which in turn reflects the light toward a light disc. Additionally, the reflector area is coated with a white, heat-dissipating, diffusely reflective coating.

[0005] DE 20 2016 102 798 U1 discloses a surface lighting element for the interior of a vehicle. The light from LEDs is emitted toward a diffuser. The diffuser is held at a distance from the LEDs, and the LEDs have a beam cone such that the beam cones overlap in the plane of the diffuser.

[0006] Another lighting device is known from DE 20 2006 002 728 U1. In the luminaire disclosed therein, the elongated housing is formed by a U-shaped profile. An equally elongated support for LEDs (light-emitting diodes) is embedded in the base of the profile by means of a casting compound. The LEDs are arranged in groups next to one another in the longitudinal direction of the housing. Furthermore, the lighting device as a whole is designed to be flexible. For this purpose, it is made of synthetic rubber. The lighting device can be a few centimeters wide and several meters long. To enable cost-effective production, its manufacture as an extruded part is proposed.

[0007] DE 10 2015 107 047 A1 proposes a lighting device for indirect room lighting. Specifically, the lighting device consists of a light diffuser with an approximately rectangular cross-section and two adjacent hollow chambers. The light diffuser is strip-shaped and is attached to the underside of a sliding cabinet door by means of an anchor device. A light strip with a plurality of LEDs is arranged in the hollow chamber of the light diffuser facing away from the front of the cabinet. The light diffuser is made of a milky, translucent material and is intended to ensure essentially homogeneous light emission from the light emitted by a plurality of individual LEDs.

[0008] DE 20 2010 005 347 U1 relates to a shelf of a piece of furniture, wherein the shelf comprises a translucent material and an upper and a lower flat side, and a circumferential narrow side, and wherein a so-called edge lighting is provided, which has at least one illuminant arranged in a channel, which is arranged so as to radiate its light into the narrow side.

[0009] US 2011 / 0 199 767 A1 relates to a lighting unit for use in a refrigerated display case comprising an LED mounting portion with a plurality of light-emitting diodes mounted thereon, a reflector, and a lens. The LED mounting portion and the reflector are dimensioned and arranged to form a reflective cavity.

[0010] WO 2008 / 137 076 A1 relates to a lighting system comprising a holder for light-emitting diodes, which secures at least one light-emitting diode, and a modular unit with an arcuate section, wherein the arcuate section has at least one diffusely reflecting surface which is suitable for receiving and reflecting light from the at least one light-emitting diode.

[0011] WO 2006 / 126114 A1 relates to a lighting system for illuminating an object arranged in the vicinity of the lighting system. The lighting system comprises a plurality of light emitters arranged along a line to emit light substantially away from the object.

[0012] However, the above-mentioned lighting devices cannot meet the requirements regarding the required homogeneity in light emission that is desired in the automotive sector.

[0013] The present invention is therefore based on the object of providing a lighting device which meets high automotive requirements with regard to the homogeneity of the emitted light.

[0014] The present object is solved by the features of claim 1.

[0015] Advantageous embodiments or further developments of the invention can be found in the dependent claims.

[0016] The invention relates to a lighting device for illuminating the interior of a motor vehicle, comprising an elongated housing through which a strip-like carrier with a plurality of illuminants is held. Furthermore, the housing is designed as a reflector element having at least one reflector chamber.

[0017] As features of the invention, light rays emitted or emitted by the illuminants are diffusely reflectable or are diffusely reflected before they reach a light exit opening.

[0018] It has been shown that such a lighting device can achieve extremely homogeneous light emission, even when using point-type light sources such as LEDs. Furthermore, the light emission is sufficiently bright to allow lighting effects in the vehicle to be clearly perceived even during the day.

[0019] According to a further feature of the invention, the housing has a G-shaped cross-section. Such a cross-section allows the aforementioned reflector chamber and the light exit to be created easily. In particular, a G-shaped cross-section enables a large light path of the light emitted by the lamps relative to the installation space. This allows the lighting device to be constructed very compactly while maintaining high light efficiency and also offers a weight advantage over solutions with optical fibers. The large light path that can be created enhances the diffuse scattering of the generated light beams.

[0020] In order to be able to follow a given or desired contour of a light output or to adapt to variously curved housings, it is very useful to make the support for the light sources flexible in at least one plane. When using RGB LEDs, a flexible support also makes it much easier to calibrate the LEDs before the support is bent into a three-dimensional shape.

[0021] In order to contribute to the generation of a highly homogeneous light emission, it is proposed in another embodiment of the invention that the housing is made of a white, highly reflective material and / or is provided with a white, highly reflective coating.

[0022] The lighting device is simple in design and inexpensive to manufacture if the housing is formed in cross-section from two profiles, each open on one side. The profiles interlock with their openings. The individual profiles can then be manufactured very easily and secured together to create the overall profile.

[0023] Furthermore, there are the following preferred alternatives for the production of the housing: - Production by injection molding

[0024] This process is very well-tested and mature and can be implemented cost-effectively, especially for high quantities - Manufactured from foamed, microcellular films, preferably polyethylene terephthalate (PET) or polycarbonate (PC).

[0025] Such films have extremely good optical properties (especially reflective properties). - 3D printing production

[0026] With 3D printing, three-dimensional workpieces can be built layer by layer. This process can produce any desired contour.

[0027] It is very advantageous if the support, including the lamps, is designed as a cuttable element so that after cutting (shortening), the remaining part of the support remains fully functional. The support for the lamps, which may be designed as a circuit board, for example, can thus be shortened as needed from a uniform prefabricated length. In this way, the support can also be used for various geometric applications. Should the length of a prefabricated support be insufficient for a specific application, several supports can be connected in series.

[0028] By using a uniform carrier for different applications, electronics manufacturing costs can be significantly reduced. Calibration of light sources arranged on such a uniform carrier is also made considerably easier, as a calibration device does not have to be manufactured separately for each application. Calibration is necessary, for example, when RGB LED chips are used as light sources. In such LED chips, each LED chip has one red, one green, and one blue light-emitting LED. Through additive color mixing, which can be generated by a suitable control device, any color can be displayed.

[0029] It has been shown that the homogeneity of light emission can be further improved if each light source can generate or is generated a light segment perceptible to an observer. The light sources are arranged on the support at such a distance from one another that the generated or generated light segments overlap in an overlapping area. The light segments thus merge into one another along the longitudinal extent of the lighting device.

[0030] The illuminants can preferably be spaced at a distance of at least approximately 15 millimeters to approximately 35 millimeters, preferably at a distance of at least approximately 30 millimeters. This allows for optimal overlap of the illuminating segments.

[0031] It is also proposed that the housing be provided with a cross-sectional edge length of approximately 20 millimeters by 20 millimeters to approximately 30 millimeters by 30 millimeters, preferably with an edge length of approximately 25 millimeters by 25 millimeters. The housing does not necessarily have to be square in cross-section; it can also be rectangular. It is also conceivable for the sides of the housing cross-section to be slightly curved.

[0032] The length of the housing is preferably between 300 millimeters and 1500 millimeters.

[0033] It has been shown that such a housing design allows for sufficient coverage of a wide range of applications.

[0034] Finally, the invention also aims to protect a motor vehicle which is equipped with at least one lighting device according to the invention. A preferred exemplary embodiment of the invention is illustrated in the figures and is explained in more detail with reference to the figures in the following description. This also makes further advantages of the invention clear. The same reference symbols, even in different figures, refer to the same, comparable or functionally identical components. Corresponding or comparable properties and advantages are achieved, even if there is no repeated description or reference to them. The figures are not always to scale. In some figures, proportions may be exaggerated in order to emphasize features of an exemplary embodiment more clearly.

[0035] They show, schematically Fig. 1 a motor vehicle with a lighting device according to the invention, Fig. 2 a perspective view of the lighting device in isolation, Fig. 3 a cross-sectional view according to section III of Fig. 2, Fig. 4 a perspective view of the band-like support for the lamps, Fig. 5 a sectional view according to section view V of Fig. 4 and Fig. 6 the representation of a used profile of the housing of the lighting device in cross section, depending on preferred manufacturing variants.

[0036] The description first refers to the Fig. 1.

[0037] This figure shows a motor vehicle K which is provided with a lighting device 2 according to the invention in the area of ​​an instrument panel 1. The lighting device 2 is designed in the form of a light strip which extends almost over the entire length of the instrument panel 1. As the Fig. 2, the lighting device 2 has an elongated housing G with a longitudinal extension LE.

[0038] The housing G is formed from two profiles 20 and 21 which are open on one side and which are brought together in such a way that a slit-like light exit opening 23a is formed which extends along the entire length of the housing G.

[0039] The light exit opening 23a can be covered by a light disc 24.

[0040] From the Fig. Figure 3 shows the exact profile of the housing G. In cross-section, the housing G has a roughly G-shaped shape.

[0041] The profile 20 and the profile 21 have opening sides Ö1 and Ö2, i.e. sides with at least one opening, with which they are pushed into each other in such a way that the G-like profile of the housing G is produced.

[0042] Profile 20 has four legs 200, 201, 202, and 203, which are approximately perpendicular to each other. Legs 200, 201, and 202 are approximately the same length. Leg 203 is approximately one-quarter shorter. This creates a slot-like opening 23 between leg 200 and the end of leg 203.

[0043] The second profile 21 is approximately U-shaped, with legs 210, 211 and 212. The legs 210 to 212 are again aligned approximately perpendicular to each other.

[0044] The leg 212 runs approximately parallel to the leg 202, the leg 211 runs approximately parallel to the leg 203 and the leg 210 runs approximately parallel to the leg 200.

[0045] In the illustrated, collapsed state, the leg 210 protrudes into the opening 23 of the profile 20, just above the end of the leg 203 or even touching it. This occurs over approximately two-thirds of the length of the leg 200.

[0046] The lower leg 212 engages under the leg 202 at a close distance or even touching it by about half the length of the leg 202. This exact interlocking of the profiles 20 and 21 can prevent unwanted light scattering.

[0047] A band-like, i.e., elongated support 25 with a plurality of lighting devices 26 is attached to the vertical leg 211 of the profile 21 in the figure. The support 26 preferably extends along the entire longitudinal extent LE of the lighting device 2.

[0048] The illuminants 26 are spaced from each other at equal intervals. Each illuminant 26 is assigned an opening 27 in the leg 203 of the profile 20. In this way, light rays L generated by the illuminants 26 can enter a reflector chamber 22, which is formed at least partially by the inner sides of the legs 210, 203, 202, and 201.

[0049] As indicated by the light rays L', the light rays L radiated into the reflector chamber 22 by the illuminants 26 are diffusely reflected many times in the reflector chamber 22 before the reflected light rays L' reach a light exit chamber 22a and can exit from the housing G via the light exit opening 23a.

[0050] The light exit opening 23a is formed by the leg 200 of the profile 20 and the leg 210 of the profile 21 extending into it. The optional light disc 24 is indicated by dashed lines. The leg 210 also forms the light exit chamber 22a, which is separated from the reflector chamber 22.

[0051] It is clear that the G-shaped design of the housing G allows for a large traversable path of the light emitted by the lamps 26 relative to the required installation space. In this way, the lighting device 2 can be kept extremely compact.

[0052] To promote diffuse reflection in the reflector chamber 22 and to minimize light losses, the profiles 20 and 21 are preferably made of a highly reflective, particularly preferably white, material. Alternatively or additionally, the profiles 20 and 21 can be provided, at least in some areas, with a highly reflective, particularly preferably white, coating B (indicated by dashed lines).

[0053] To prevent bending of the lighting device 2 (see also Fig. 2), both the profiles 20, 21 and the band-like support 25 as well as the optional light disc 24 are made of a flexible material.

[0054] The profile of the housing G preferably has an edge length I1 by I2 of approximately 25 millimeters by 25 millimeters.

[0055] As already mentioned, the light rays L from the illuminants 26 entering the housing G are reflected diffusely, with only minimal reflection losses. The reflectance is preferably greater than 98 percent, so that the reflection behavior inside the housing G approximates the radiation characteristics of a Lambertian radiator. It should also be noted that, deviating from the exemplary embodiment, the legs of the housing G can also be curved or angled.

[0056] Based on the Fig. 4, the band-like carrier 25 will now be examined in more detail in isolation.

[0057] As already described, the carrier 25 is strip-like and flexible. It is designed, in particular, as a printed circuit board that supports the illuminants 26.

[0058] Preferably, the lighting means 26 are arranged at a mutual distance a along a longitudinal extension LE of the carrier 25 over the entire length of the carrier 25.

[0059] The lighting means 26 can preferably be designed as light-emitting diodes (LEDs), in particular as RGB light-emitting diodes for emitting light in a variety of colors.

[0060] The distance a between the illuminants 26 is preferably approximately thirty millimeters and approximately thirty illuminants 26 are preferably arranged on the carrier 25.

[0061] Furthermore, it can be seen that the carrier 25 is connected to a circuit board 28. The circuit board 28 is provided with a voltage converter, a bus interface and a microcontroller for suitable, fast and voltage-appropriate control of the lighting means 26 (see also Fig. 2).

[0062] Most preferably, the carrier 25 is designed as a uniform part. This means that the carrier 25 is always produced in the same way, i.e., with the same length and the same number of illuminants 26, even for different applications. To adapt to different geometric applications, the carrier 25 can be variably separated or shortened at a wide variety of separation points between the illuminants 26. This is conceivable at separation points T1, T2, or T3, which are shown only as examples. After such shortening (cutting to length) at a separation point, the remaining portion of the carrier 25, including the circuit board 28, is still fully functional. The carrier 25 can then be bent (at least in one plane) to the desired contour.

[0063] By implementing the carrier 25 as a flexible, identical part for various applications, the costs for manufacturing the carrier can be significantly reduced.

[0064] The same tool can always be used, and any necessary calibration of the illuminants 26 is also simplified. When the illuminants 26 are designed as RGB LEDs, calibration is necessary, at least according to the current state of the art. This calibration ensures that the RGB LEDs can emit light in defined, uniform colors, thus ultimately creating the basic prerequisite for a homogeneous light appearance. Calibration can always be performed in the same way using the same tool after the carrier 25 has been fitted with the illuminants 26, before the flexible carrier 25 is possibly bent into a desired shape that follows the shape of the housing G.

[0065] It is also conceivable that a single length of support 25 is insufficient. In this case, multiple supports 25 can be installed in a suitable housing. If necessary, one of the supports 25 can then be shortened as needed.

[0066] From the Fig. Figure 5 shows a partial sectional view of the carrier 25. It can be seen that rigid material components 25a are applied to the side of the carrier 26 facing away from the illuminants 25. The material components 25a consist of a heat-conducting material and serve to improve heat distribution on the carrier 25 and to improve heat dissipation.

[0067] Each illuminant 26 produces a specific, hemispherical luminous segment S due to its radiation characteristics.

[0068] It is very advantageous if the distance a between the illuminants 26 is selected such that the luminous segments S of the individual illuminants 26 overlap in an edge region, i.e., merge into one another. This is the case in the exemplary embodiment. Therefore, overlapping areas Ü are shown.

[0069] Due to the overlap, the light segments S visible to an observer can no longer be distinguished from one another or can no longer be counted, so that this contributes to a very homogeneous light appearance of the lighting device 2.

[0070] As a preferred embodiment, with the preferably selected distances a, with a preferred configuration of thirty illuminants 26, the preferably selected edge lengths I1, I2, a total length of the housing G of approximately 900 millimeters to approximately 1000 millimeters results.

[0071] Finally, the Fig. 6 illustrates the effect of various preferred manufacturing processes on the design of the profiles of the housing G.

[0072] This is according to Fig. 6a, for example, it is conceivable to produce a profile 20a of the lighting device using a 3D printer. With 3D printing, the construction of the profile 20a is computer-controlled according to specified dimensions and shapes to create the final workpiece. Legs 200a, 201a, 202a, and 203a are thus integrally connected to one another (by a material bond), with minimal geometric restrictions. Various materials are conceivable for the profile 20a, such as plastic, synthetic resin, or metal.

[0073] In the Fig. 6b shows a profile 20b made of foamed plastic films, for example, polyethylene terephthalate (PET) or polycarbonate (PC). Such films exhibit excellent diffuse reflection properties. However, they are only bendable in one plane. In this specific case, vertical legs 201b and 203b are therefore to be bent into the desired shape, and horizontal legs 200b and 202b are to be punched out accordingly and connected to the other legs. The legs are preferably connected by welding.

[0074] Finally, injection molding is also a preferred manufacturing process, for which plastic is particularly suitable. However, the geometry is also limited here. Only a U-shaped profile 20c with vertically positioned legs 200c, 201c, and 202c can be produced in a single operation. An undercut caused by a leg 203c is therefore unthinkable due to the impossibility of demolding. In this case, the leg 203c must also be added subsequently (see Fig. 6c). List of reference symbols 1 instrument panel 2 lighting device 20, 20a, 20b, 20c profile 21 Profile 22 Reflector chamber 22a Light exit chamber 23 Opening 23a Light exit opening 24 lens 25 ribbon-like carrier 25a rigid material components 26 bulbs 27 openings 28 circuit boards 200-203 thighs 200a-203a legs 200b-203b legs 200c-203c thighs 210-212 legs a distance B highly reflective coating G Housing K Motor vehicle I1, I2 edge length L light rays L' light rays LE Longitudinal extension Ö1, Ö2 opening pages S light segments T1-T3 separation points Ü Overlap

Claims

[1] Lighting device (2) for illuminating the interior of a motor vehicle (K), comprising an elongated housing (G) through which a band-like carrier (25) with a plurality of lighting means (26) is held, wherein the housing (G) is designed as a reflector element which has at least one reflector chamber (22), wherein light rays (L) emitted or emitted by the lighting means (26) are diffusely reflected or reflected in the reflector chamber (22) before they reach a light exit opening (23a), wherein the housing (G) is designed in a G-shaped cross-section, characterized byin that the housing (G) is formed in cross-section from two profiles (20, 21) which are each open on one side and which protrude into one another with their opening sides (Ö1, Ö2), whereby the reflector chamber (22) and a light exit chamber (22a) with the light exit opening (23a) are formed, wherein the light exit opening (23a) is formed by a leg (200) of the one profile (20) and a leg (210) of the other profile (21) projecting into this, and the leg (210) of the other profile (21) projecting into the one profile (20) leads to the formation of the light exit chamber (22a) separated from the reflector chamber (22). [2] Lighting device (2) according to claim 1, characterized by that the support (25) for the lighting means (26) is designed to be flexible. [3] Lighting device (2) according to one of the preceding claims, characterized bythat the housing (G) is made of a white, highly reflective material and / or is provided with a white, highly reflective coating (B). [4] Lighting device (2) according to one of the preceding claims, characterized by that the support (25) is designed as a variably cuttable element such that after cutting to length a remaining part of the support (25) remains fully functional. [5] Lighting device (2) according to one of the preceding claims, characterized by that a light segment (S) perceivable by an observer can be or is generated by each light source (26), wherein the light sources (26) are arranged at such a mutual distance (a) on the carrier (25) that the light segments (S) that can be or are generated overlap in an overlapping region (Ü). [6] Lighting device (2) according to claim 5, characterized bythat the distance (a) of the lighting means (26) is at least from about 15 mm to about 35 mm, preferably at least about 30 mm. [7] Lighting device (2) according to one of the preceding claims, characterized by that the housing (G) has an edge length of approximately 20 mm x 20 mm to approximately 30 mm x 30 mm, preferably approximately 25 mm x 25 mm, in cross section. [8] Motor vehicle (K), characterized by at least one lighting device according to one of the preceding claims.

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