Lighting apparatus for vehicles

A lighting device for vehicles, including a light source and including a two-dimensional luminous element, which has a light-coupling narrow side, a light-decoupling flat side and a deflector for deflecting the light coupled in at the light-coupling narrow side in the direction of the light-decoupling flat side, the two-dimensional luminous element including segmenter, with the aid of which the light-decoupling flat side is divided into luminous segments having different emission characteristics.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a lighting device for vehicles, including a light source and including a two-dimensional luminous element, which has a light-coupling narrow side, a light-decoupling flat side and a deflector for deflecting the light coupled in at the light-coupling narrow side in the direction of the light-decoupling flat side.

Description of the Background Art

A lighting device for vehicles is known from DE 10 2017 101 593 A1, in which a two-dimensional luminous element is assigned to a light source. The two-dimensional luminous element includes multiple luminous sections having different emission characteristics, which are effectuated by integrated dispersing elements of different designs. The know lighting device requires a relatively large installation space, since the light is coupled in through the spaced-apart light source on a flat side of the two-dimensional luminous element.

A lighting device for vehicles is known from EP 2 354 637 A2, which includes a light source and a two-dimensional luminous element, in which the light is coupled into the two-dimensional lighting element via a light-coupling narrow side thereof. The two-dimensional luminous element includes deflectors, so that the coupled light is deflected in the direction of a light-decoupling flat side. The disadvantage of the known lighting device is that an additional two-dimensional luminous element must be molded on to provide an additional emission characteristic or additional light function, which increases the manufacturing costs.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a lighting device for vehicles, which includes a two-dimensional luminous element, in such a way that light having different emission characteristics may be emitted in a space-saving and cost-effective manner.

To achieve this object, the invention is characterized in that the two-dimensional luminous element includes segmenters, with the aid of which the light-decoupling flat side is divided into luminous segments having different emission characteristics.

According to the invention, the two-dimensional luminous element itself includes segmenters, with the aid of which a light-emitting flat side of the two-dimensional luminous element may be divided into luminous sections having different emission characteristics. At least two luminous sections have different dispersing optical elements, so that light having different emission characteristics is emitted. The luminous sections each represent luminous surfaces, which have a different appearance. To an observer, the luminous sections appear as planar light sources (light emitters) of different sizes and/or having different contours and/or different luminosities and/or different directions of illumination. The luminous sections permit a homogeneous light emission over a wide area, since uniformly shaped dispersing optical elements are assigned to each of the luminous sections.

The segmenters is designed as a step between a first luminous section and a second luminous section. If a deflector is arranged on a rear side of the two-dimensional luminous element, the step runs on the rear side of the two-dimensional luminous element. The deflecting effect induced thereby is not detectable from the front side, so that a homogeneous light emission from different luminous sections is ensured.

The segmentor is designed as a separating web, which extends in a raised or recessed manner from a surface of the two-dimensional luminous element arranged on the rear side. The separating web acts as an optical partition line, since it already effectuates a refraction of the light, due to its shaping, so that a viewer perceives an optical separation hereby between adjacent luminous sections of the two-dimensional luminous element. The separating web itself is not perceived by the observer, since a front side of the two-dimensional luminous element is designed to be smooth or free of the separating web.

The separating web is arranged in a raised manner on a rear side of a front component of the two-dimensional luminous element and/or on a front side of a rear component of the two-dimensional luminous element. The separating web is covered by a rear component made from a diffused reflecting material, so that it is not detectable from either a front side or a rear side of the two-dimensional luminous element. Both the front side and the rear side of the two-dimensional luminous element may be provided with a smooth design. Due to the fact that the rear component is made from a diffusely luminous material or a material doped with nanoparticles, a homogeneous light emission of the luminous element over a wide area is achieved. An optional sputtering, mirroring, painting or printing of the rear side (rear flat side) of the luminous element prevents a rear-side light emergence and increases the efficiency due to a stronger front-side illumination.

According to a refinement of the invention, a light supplying element designed in the manner of a light guide abuts a light-coupling narrow side of the two-dimensional luminous element. The light supplying element is connected to form a single piece only with the front component of the two-dimensional luminous element, so that the entire luminous flux is coupled only into the front component. The rear component is used to receive the coupled light and to further homogenize the illumination in the particular luminous sections. Adjacent light guiding sections are separated from each other by separating slits, the separating slits each running on the separating webs of the luminous element. In this way, the light sources may be arranged independently of the location of the two-dimensional luminous element, the light assigned for the particular luminous sections being able to be coupled into the two-dimensional luminous element independently of each other via the corresponding light guiding elements. By selecting the light sources with respect to color and luminosity, the emission characteristic of the different luminous sections may thus be influenced.

According to one refinement of the invention, the light guiding elements run toward the light-coupling narrow side at an acute angle in a molded-on section. The molded-on section includes deflecting optics for deflecting the light guided in the light guiding elements in the direction of the light-coupling narrow side. A multichannel guiding of light on narrow sides of the two-dimensional luminous element may be advantageously provided hereby in a space-saving manner.

DETAILED DESCRIPTION

A lighting device for vehicles is preferably used as a signal lamp for generating a tail light, brake light, turn-signal and/or daytime running light function.

According to a first specific embodiment of the invention according toFIGS. 1 through 4, a lighting device includes a number of two-dimensional luminous elements1, which are arranged in a cup-shaped housing of the lighting device, which is not illustrated and is closed by a cover panel. Two-dimensional luminous elements1each have a number of light-coupling narrow sides2as well as oppositely situated flat sides3,4. A front flat side3is designed as a light-decoupling flat side, at which light L is decoupled. A rear flat side4forms a rear-side surface, on which deflectors5are provided for deflecting light L coupled in at light-coupling narrow side2.

As is apparent, in particular, fromFIG. 3, a number of first deflectors5and a number of second deflectors5′, separated via segmenter6, which differ in terms of their formation or design, are arranged on rear flat side4of two-dimensional luminous element1. Segmenter6is designed as a step, which, in a projection onto front flat side3of two-dimensional luminous element1, divides the latter into a first luminous section7and a second luminous section7′. Light L deflected at first deflectors5is deflected in the direction of a first segment of front flat side3, and the light deflected by second deflectors5′ is deflected into a second segment of front flat side3, so that light having different emission characteristics may be emitted by first luminous section7and second luminous section7′. First luminous section7is limited on the rear side by a first segment8of rear flat side4and a first segment9of front flat side3. Second luminous section7′ is limited by a second segment8′ of rear flat side4and a second segment9′ of front flat side3. A surface of flat sides3,4is multiple times larger than a surface of light-coupling narrow sides2or non-light-coupling narrow sides2′. First luminous section7and second luminous section7′ are thus essentially arranged side by side, whereby they undergo a separation with the aid of step6. Although front flat side3having the two segments9,9′ is provided with a smooth and differentially continuous design, rear step6would result in a different light emission characteristic, even if first luminous section7and second luminous section7′ were otherwise to have the same design.

According to an alternative specific embodiment of the invention, which is not illustrated, segmenter6may also be designed as a narrow lens-free strip on rear flat side4.

Front flat side3does not have a segmenter6.

Two-dimensional luminous element1is provided with a plate-shaped and rectangular design. A light guiding element10is molded over a molded-on section11on two light-coupling narrow sides2arranged at an angle to each other. Molded-on section11of light guiding elements10runs on light-coupling narrow side2at an acute angle φ to an extension direction ESthereof. In the present exemplary embodiment, two light guiding elements10are supplied in parallel to two-dimensional luminous element1, the molded-on sections11of the two light guiding elements10being spread apart in a corner area12of two-dimensional luminous element1. A light-decoupling surface of light guiding elements10essentially extends over the entire surface of light-coupling narrow side2.

Molded-on section11has this deflecting optics13on a side thereof facing away from light-coupling narrow side2, with the aid of which the light guided in light guiding element10is deflected in the direction of light-coupling narrow side2of two-dimensional luminous element1. Deflecting optics13may be designed, for example, as prism elements.

As is apparent fromFIG. 3, step6runs in the direction of corner area12of two-dimensional luminous element1, at which the two light-coupling narrow sides2of two-dimensional luminous element1converge. Step6preferably runs continuously between corner area12and a further corner area12′, a diagonal division of two-dimensional luminous element1into first luminous section7and second luminous section7′ taking place.

First deflectors5and second deflectors5′ may be formed, for example, by prism-shaped dispersing optical elements5,5′, which run with different orientations to each other (cf.FIG. 4).

According to an alternative specific embodiment of the invention, which is not illustrated, deflectors5,5′ may also be formed by diffractive optical elements in the μm or nm range, which are arranged within two-dimensional luminous element1. In this case, rear flat side4of two-dimensional luminous element1may also be provided with a smooth or differentially continuous design.

A light source, for example an LED light source or a laser light source, which couples light L into light guiding element10, may be arranged on a light-coupling surface of light guiding element10, which is not illustrated. Light guiding element10is preferably designed as a light guide. If necessary, the light-coupling surface of light guiding element10may be provided as a structured surface or with a coupling lens. The coupling lens may be formed, for example, by a plurality of prism elements.

Two-dimensional luminous element1and light guiding element10are both essentially made from a transparent plastic or glass material.

Alternatively, rear flat side4of two-dimensional luminous element1is provided with a sputtering, mirroring, painting or printing to emit coupled light only in the direction of light-decoupling flat side3.

According to a further specific embodiment of the invention according toFIGS. 5 through 8, a lighting device is provided, which includes a two-dimensional luminous element21, which has only a single light-coupling narrow side2. Three other narrow sides2′ are designed as non-light-coupling narrow sides.

Identical components or component functions of the exemplary embodiments are provided with the same reference numerals.

Two-dimensional luminous element21includes a rear component22, which is made from a diffusely luminous material or a material doped with nanoparticles, and a front component23, made from a transparent material. Nanoparticles are dispersing elements which are dimensioned in a nm range. Front component23has light-decoupling flat side3. Rear component22may be made from an opaque material, for example.

As segmenter. a separating web26, with the aid of which two-dimensional luminous element21is divided into three different luminous sections25,25′,25″, is raised from a front side24of rear component22facing front component23.

Alternatively, the separating web may also be recessed with respect to a rear flat side of luminous element1or21. For example, the separating web may run as a recess (groove) in rear flat side4of luminous element1. For example, the separating web may run as a recess (groove) in the rear side of front component23of luminous element21.

As is apparent fromFIG. 7, separating web26is provided with a rectangular design in cross section and is connected to rear component22only via a single edge side. The further edge sides of separating web26extend within front component23.

Separating web26has the same material as rear component22. Separating web26effectuates an optical separation between luminous sections25,25′,25″ of two-dimensional luminous element21, so that light having different emission characteristics is decoupled or emitted, depending on the light sources and/or on the deflectors integrated within front component23.

Alternatively, separating web26may be made from the same material as front component23or from a third opaque material, which differs from the material of front component23and rear component22.

As is apparent fromFIG. 6, light guiding elements27are connected only to front component23as a single piece on light-coupling narrow side2of two-dimensional luminous element21. Light guiding elements27are provided with a rectangular design in cross section and widen in a molded-on section28, so that the light-decoupling surface of light guiding elements27matches light-coupling narrow side2of front component23. Light guiding elements27are separated from each other only via separating slits29, so that light guiding elements27may run in light sources30arranged in a common plane. Due to separating slit29, adjacent light guiding elements27are arranged at a distance from each other. Separating slits29extend from the light-coupling surface of light guiding elements27up to the vicinity of the light-decoupling surface of light guiding elements27or the vicinity of light-coupling narrow side2of two-dimensional luminous element21. If light sources30emit lit of different light colors, different light functions may be generated via the same two-dimensional luminous element21, for example a turn-signal light function (yellow light) and a tail light function (red light). The variation with respect to the different light emission characteristics of different luminous sections25,25′,25″ is also determined by the dispersing optical elements of different designs within front component23.

According to an alternative specific embodiment of the invention, rear component22may also be made from a light gray, gray, black or red material or a material of another color instead of from a white, milky material.

According to an alternative specific embodiment of the invention, which is not illustrated, rear component22may also project over front component23in the extension direction of two-dimensional luminous element21, so that a frame of two-dimensional luminous element21is formed.

According to a further specific embodiment of the invention, which is not illustrated, rear component22may also be manufactured by a two-dimensional painting or by a printing or by a sputtering or by a mirroring. In this case, a two-component manufacturing of two-dimensional luminous element21is not necessary. In this design, front component23has recessed separating grooves on a rear side thereof as segmenter.

The illustrated exemplary embodiments represent preferred specific embodiments of the present invention. It should be noted that the illustrated features may be implemented not only in the feature combinations of the exemplary embodiments described, but also by combinations of features of the different exemplary embodiments.