DE102017213016A1 - MOTOR VEHICLE - Google Patents

Abstract

A vehicle interior lighting apparatus comprising a cavity formed by cavity walls; at least one LED light source disposed inside the cavity; a light guide having a light entrance surface and a light exit surface, the light entrance surface facing into the cavity and exposing the light exit surface to the interior of the vehicle; wherein the LED light source is disposed in the cavity such that all the luminous flux emanating from the LED light source is scattered by at least one scattering agent, and at least part of the scattered luminous flux enters the light guide via the light entrance surface and finally into the interior via the light exit surface the vehicle exits.

Description

Field of the invention

The invention relates to a lighting device for an interior of a vehicle.

Background of the invention

For the illumination of contour lines or trim strips (for example in door panels or instrument panels) in vehicles, so-called optical waveguides made of clear material are used, for example PMMA.

These are located behind a diffuser of diffuse material, such as polycarbonate with scattering pigments. The light of a single light source, for example an LED, is coupled in front of an optical waveguide. The optical waveguide scatters light over a defined length through a defined coupling-out structure. The diffuser helps to distribute the light more evenly.

The disadvantage of this application is, on the one hand, that the achievable brightness is limited to the luminous flux of a single LED (or a maximum of 2 LEDs, if coupled in on both sides of the optical waveguide); on the other hand, the whole diffuser shines in a uniform color and brightness; Effects such as color gradients or running light are not possible.

The solution to this problem is to use a board instead of the fiber optic cable, which is occupied by several LED light sources. These are so-called RGB LED illuminations (red, green, blue). That is, an LED light source in such an arrangement comprises three individual LED light sources with the three primary colors, whereby all colors can be visualized by different color combinations.

For cost reasons, it is advantageous to use as few such RGB LEDs as possible. The distances between the RGB LEDs are so chosen just large enough that on the diffuser still no drop in brightness between them can be seen in order to ensure a homogeneity of the lighting. This in turn results in a minimum distance between the LED light board and the lens, as at a too short distance otherwise the individual LEDs are recognizable as bright points of light.

Another factor that determines the distance between the RGB LED and the light exit surface is the necessary mix of light colors within the diffusing material. If the path of the differently colored light rays within the lens is too short, unwanted rainbow effects may show up.

In summary, the above boundary conditions result in a relatively large distance between LEDs and light exit surface or a minimum width for a lens: for a required LED distance of about 30 mm to the lens, for example, a lens width of about 30 mm is required. Such a dimension is extremely unfavorable for the design of a vehicle interior. A smaller structure would be advantageous.

• - Bekannte Lichtwellenleiter sind begrenzt auf den Lichtstrom einer (bzw. zwei) LED.
• - Farbkombinationen und -effekte sind nicht realisierbar.
• - Die Verwendung einer Platine mit mehreren LED-Lichtquellen kann zu inhomogener Beleuchtung (Lichtpunkten) sowie Regenbogeneffekten führen.
• - Erhöhen der LED Anzahl für bessere Homogenität erhöht den Preis.
• - Der Mindestabstand zwischen der Lichtquelle und der Lichtaustrittsfläche erhöht die Baugröße des Systems und schränkt die Gestaltungsfreiheit des Interieurs erheblich ein.

Thus, the prior art has the following disadvantages:

• Known optical waveguides are limited to the luminous flux of one (or two) LED.
• - Color combinations and effects are not feasible.
• - Using a board with multiple LED light sources may result in inhomogeneous lighting (spots of light) and rainbow effects.
• - Increasing the LED count for better homogeneity increases the price.
• - The minimum distance between the light source and the light exit surface increases the size of the system and considerably restricts the freedom of design of the interior.

Summary of the invention

According to the invention, these objects are achieved by a lighting device for an interior of a vehicle, comprising a cavity formed by cavity walls; at least one LED light source arranged inside the cavity; a light guide having a light entrance surface and a light exit surface, the light entry surface facing into the cavity and the light exit surface facing the interior of the vehicle; wherein the LED light source is disposed in the cavity such that all the luminous flux emanating from the LED light source is scattered by at least one scattering agent, and at least part of the scattered luminous flux enters the light guide via the light entrance surface and finally into the interior via the light exit surface the vehicle exits. The lighting device preferably comprises RGB / multicolored light sources.

• - die Vermeidung von Lichtpunkten und Regenbogeneffekten;
• - die Verwendung von klaren oder diffus streuenden Lichtleitern
• - die weitere Verringerung der Lichtleiterdicke (Streuscheibendicke) bei diffus streuenden Ausführungen; und
• - die Verringerung des Abstands Lichtquelle-Lichtaustrittsfläche. Dadurch wird eine Bauraumersparnis im Fahrzeug ermöglicht.
• - Die Anzeige von bewegten, besonders bevorzugt auch farbigen Lichteffekten entlang der linienförmigen Lichtaustrittsfläche.

According to the invention, the light of the LED light source is scattered in the cavity before it exits via the light guide into the interior of the vehicle. this makes possible

• - the avoidance of points of light and rainbow effects;
• - the use of clear or diffused light guides
• - The further reduction of the optical fiber thickness (lens thickness) in diffusely scattering designs; and
• - The reduction of the distance light source light exit surface. This allows a space savings in the vehicle.
• - The display of moving, particularly preferably colored light effects along the line-shaped light exit surface.

In summary, in the present invention, the light exit surface lights particularly evenly.

In one embodiment, the scattering agent is formed of a diffusely transparent medium, preferably of a scattering plastic, of a scattering film, and / or parchment paper, wherein at least a portion of the scattered luminous flux passed through the medium enters the light guide via the light entry surface and finally via the light exit surface in the interior of the vehicle exits. If the scattering-translucent medium (a single material and / or layers) is arranged between the light source and the light entry surface, the light can be scattered particularly advantageously before it enters the light guide. The diffusely translucent medium prevents light from hitting directly on the light entry surface of the light guide.

Particularly preferably, the scattering transparent medium can also lead to further color effects.

In a further embodiment, the scattering means is formed from at least one diffusely reflecting cavity wall, wherein at least a part of the light flux diffusely reflected by the cavity wall enters the light guide via the light entry surface and finally exits via the light exit surface into the interior of the vehicle. In this case, the light can be particularly advantageously reflected diffusely from the cavity wall and thus scattered before it exits via the light guide into the interior of the vehicle.

In one embodiment, the LED light source is arranged in the cavity such that at least part of the luminous flux is diffusely reflected several times by the cavity walls before it enters the light guide via the light entry surface and finally exits via the light exit surface into the interior of the vehicle. As a result, the light scattering can be increased, which leads, for example, to an even smaller installation space. With different colored LED light sources, the light mixture is also further increased.

In one embodiment, the at least one diffusely reflecting cavity wall is formed by a white and / or matt surface, wherein the at least one diffusely reflecting cavity wall is preferably formed by an adhesive tape or a film, more preferably by a white and matt adhesive tape. This ensures complete diffuse reflection and stray light foreclosure.

In a particularly preferred embodiment, the light entry surface and / or the light exit surface are formed diffusely scattering. This can be achieved, for example, by sandblasting these surfaces. As a result, the light is emitted particularly homogeneously in the interior of the vehicle. Furthermore, the necessary width of the light guide can be further reduced.

According to one embodiment, at least one of the cavity walls is designed to be reflective. After a first diffuse reflection on a cavity wall, light beams can be directed in the cavity in a targeted manner.

In a particularly preferred embodiment, the LED light source is arranged on one of the cavity walls, wherein a cover is preferably arranged between the LED light source and the light entry surface in such a way that light from the LED light source is prevented from striking the light entry surface directly. This ensures that no light hits the light entry surface of the light guide without first being diffusely reflected by a cavity wall.

According to one embodiment, the LED light source is arranged in the cavity such that the entire luminous flux emanating from the LED light source is radiated away from the light entry surface. This prevents light from hitting directly on the light entry surface of the light guide.

In a further preferred embodiment, a vehicle comprises a lighting device according to the invention.

In summary, according to the invention, the distance to the light exit surface is minimized by the previous breaking and targeted scattering of the LED light and unwanted rainbow effects or inhomogeneities (light spots) are completely avoided.

In this case, the LED light source radiates particularly preferably into the direction opposite to the diffusing screen (optical waveguide) into a completely white-matt-scattering or reflecting installation space. The positions / angles of the walls here are subject to an arrangement designed for reflection. By repeated diffuse reflection, scattering (eg with scattered paper as a diffusely scattering medium) and reflection (eg with mirror or chrome band), the individual rays are mixed to the exit point in the direction of the lens. Instead of direct irradiation, the light rays are particularly preferably redirected several times, divided and thereby scattered and mixed.

Further advantages include covering the diffuser (light guide) with a chrome band and / or white matte opaque tape to ensure complete reflection and stray light foreclosure.

The inventive arrangement a significantly reduced distance between the light source and light exit surface is possible. If the diffuser (light guide) made of a diffusely scattering material, this leads to a further reduction of the necessary width.

Also, an LED hue change is possible and the colors are miscible in a short space, i. RGB colors of the LED light sources mix homogeneously over a short distance.

In addition, it is possible to distribute a selective Lichtauskoppelung the LED light sources in a homogeneously bright strip. In this case, light is preferably conducted via a thin light-conducting element, the light guide, in the form of a narrow strip in the direction of the viewer.

list of figures

• 1 ein schematisches Ausführungsbeispiel der erfindungsgemäßen Beleuchtungsvorrichtung in einer Schnittansicht,
• 2 ein weiteres schematisches Ausführungsbeispiel der erfindungsgemäßen Beleuchtungsvorrichtung in einer Schnittansicht,
• 3 ein weiteres schematisches Ausführungsbeispiel der erfindungsgemäßen Beleuchtungsvorrichtung in einer Schnittansicht, und
• 4 ein weiteres schematisches Ausführungsbeispiel der erfindungsgemäßen Beleuchtungsvorrichtung in einer Schnittansicht.

Embodiments of the invention will be described below with reference to the figures. Showing:

• 1 a schematic embodiment of the lighting device according to the invention in a sectional view,
• 2 a further schematic embodiment of the lighting device according to the invention in a sectional view,
• 3 a further schematic embodiment of the lighting device according to the invention in a sectional view, and
• 4 a further schematic embodiment of the lighting device according to the invention in a sectional view.

Detailed description

1 shows an embodiment of a lighting device according to the invention 10 ,

The lighting device 10 has a cavity 20 up, through cavity walls 22 is formed. Preferably on a cavity wall 22 is an LED light source 30 arranged. Furthermore, the lighting device 10 a light guide 40 on. A light entry surface 42 of the light guide 40 points into the cavity 20 while a light exit surface 44 of the light guide 40 in the interior of the vehicle shows.

In addition, between the LED light source 30 and the light entry surface 44 a diffusely translucent medium 60 arranged. The whole of the LED light source 30 outgoing luminous flux according to the invention of the scattering translucent medium 60 scattered. At least part of the medium 60 Scattered luminous flux then passes over the light entry surface 42 in the light guide 40 and finally passes over the light exit surface 44 in the interior of the vehicle. In particular, by the scattering of the light in the cavity 20 before entering the light guide 40 the above-mentioned problems of the prior art are solved and the above advantages according to the invention are achieved.

In 1 is only an LED light source 30 shown. However, embodiments in which a plurality of LED light sources are also particularly preferred 30 essentially in Y Direction are arranged and the optical fiber 40 also essentially in Y Direction extends. This allows the light exit surface 44 be formed as a luminous band or as a luminous strip in the vehicle interior. That in the 1-4 shown coordinate system can be arbitrarily aligned in the vehicle. According to the invention in the present invention, the light exit surface lights 44 particularly uniform, which is then perceived as uniformly illuminating band / luminous strip in the interior of the vehicle.

2 shows a further embodiment of the lighting device according to the invention 10 , The whole of the LED light source 30 Outgoing luminous flux according to the invention of at least one cavity wall 22 diffusely reflected. At least part of the cavity wall 22 diffusely reflected luminous flux then passes over the light entry surface 42 in the light guide 40 and finally passes over the light exit surface 44 in the interior of the vehicle. In particular, by the diffuse reflection of the light in the cavity 20 before entering the light guide 40 the above-mentioned problems of the prior art are solved and the above advantages according to the invention are achieved.

Optional is in 2 also the scattering medium 60 shown that, for example, by scattering paper or scattering films, plastics, etc. may be formed. When light passes through the scattering medium 60 passes through, the scattering effect of the invention is in the cavity 20 additionally increased.

The 3 and 4 show alternative geometric shapes for the cavity 20 , In the cavity 20 is between the LED light source 30 and the light entry surface 42 a cover 50 arranged, which prevents light directly on the light entry surface 42 irradiates. Optional is in the 3 and 4 the diffusely scattering medium 60 between the cover 50 and a cavity wall 22 arranged.

In all embodiments, an upper cavity wall 22a optionally be formed for example by a white and matt shroud. As a result, for example, the installation of the LED light source 30 be made flexible. Of course, embodiments without shroud, but with other cavity walls 22 possible.

Furthermore, in all embodiments, in addition to the diffusely reflecting cavity wall 22 still reflecting cavity walls 22 be present (not shown). These can be formed for example by chrome bands. As a result, diffusely scattered light can be targeted to the light entry surface 42 be steered, which further improves the lighting effect in the interior of the vehicle.

LIST OF REFERENCE NUMBERS

10

lighting device

20

cavity

22

cavity wall

22a

upper cavity wall

30

LED light source

40

optical fiber

42

Light entry surface

44

Light-emitting surface

50

cover

60

scattering translucent medium

Claims (10)

An interior vehicle lighting device (10) comprising a cavity (20) formed by cavity walls (22); at least one LED light source (30) arranged inside the cavity (20); a light guide (40) having a light entrance surface (42) and a light exit surface (44), the light entry surface (42) facing into the cavity (20) and facing the light exit surface (44) into the interior of the vehicle; wherein the LED light source (30) is disposed in the cavity (20) such that all luminous flux from the LED light source (30) is scattered by at least one scattering means (22, 60) and at least a portion of the scattered luminous flux the light entry surface (42) enters the light guide (40) and finally exits via the light exit surface (44) into the interior of the vehicle. Lighting device (10) according to Claim 1 in which the scattering means is formed from a diffusely transparent medium (60), preferably from a scattering plastic, from a scattering film and / or parchment paper, wherein at least part of the scattered luminous flux passed through the medium (60) passes over the light entry surface (60). 42) enters the light guide (40) and finally exits via the light exit surface (44) into the interior of the vehicle. Lighting device (10) according to one of the preceding claims, wherein the scattering means is formed from at least one diffusely reflecting cavity wall (22), wherein at least a part of the luminous flux diffusely reflected by the cavity wall (22) is introduced into the light guide (40) via the light entry surface (42) ) and finally exits via the light exit surface (44) in the interior of the vehicle. Lighting device (10) according to Claim 3 wherein the LED light source (30) is disposed in the cavity (20) such that at least a portion of the luminous flux is diffusely reflected multiple times by the cavity walls (22) before entering the light guide (40) via the light entry surface (42) and finally exits via the light exit surface (44) in the interior of the vehicle. Lighting device (10) according to Claim 3 or 4 wherein the at least one diffusely reflecting cavity wall (22) is formed by a white and / or matt surface, wherein preferably the at least one diffusely reflecting cavity wall (22) is formed by an adhesive tape or a film, more preferably by a white and matt adhesive tape is. Lighting device (10) according to any one of the preceding claims, wherein the light entry surface (42) and / or the light exit surface (44) are formed diffusely scattering. Lighting device (10) according to one of the preceding claims, wherein at least one of the cavity walls (22) is formed reflective. Lighting device (10) according to one of the preceding claims, wherein the LED light source (30) is arranged on one of the cavity walls, wherein a cover (50) is preferably arranged between the LED light source (30) and the light entry surface (42). preventing light from the LED light source (30) from directly striking the light entry surface (42). Lighting device (10) according to one of the preceding claims, wherein the LED light source (30) is arranged in the cavity (20), that the entire outgoing light from the LED light source (30) is emitted away from the light entry surface (42). A vehicle comprising a lighting device (10) according to any one of the preceding claims.

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