EP3752766A1

EP3752766A1 - Lighting device for producing at least two light functions having a strip-shaped or line-shaped light appearance

Info

Publication number: EP3752766A1
Application number: EP19704739.2A
Authority: EP
Inventors: Alexander Thiel
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2018-02-15
Filing date: 2019-01-24
Publication date: 2020-12-23
Also published as: WO2019158338A1; DE102018202325A1

Abstract

The invention relates to a lighting device for a motor vehicle for producing at least two light functions having a strip-shaped or line-shaped light appearance. At least two light-emitting diodes (5, 6) are provided, by means of which light (L) of different color can be emitted. At least one optically active component (8) is provided, which redirects or deflects the light (L) of the light-emitting diodes (5, 6) toward a cover lens. According to the invention, a first optically active component (8) is arranged downstream of the light-emitting diodes (5, 6) in the light emission direction, which first optically active component concentrates incident, divergent light beams (L) exclusively in the direction of a first longitudinal center plane (H) of the lighting device (1). This occurs in such a way that the light beams (L) hit a second optically active component (4) arranged downstream of the first optically active component (8). The second optically active component (4) concentrates incident, divergent light beams (L) at a first boundary surface (4a) thereof exclusively in the direction of a second longitudinal center plane (V) of the lighting device, which is perpendicular to the first longitudinal center plane (H). The light beams (L) are scattered again at a second boundary surface (4b) of the component (4). By means of the invention, a lighting device can be provided which provides a plurality of signal light functions having a strip-shaped or line-shaped light appearance, with extreme homogeneity.

Description

description

Lighting device for generating at least two light functions with a streak or line-like light appearance

The invention relates to a lighting device for generating at least two light functions with a strip or line-like light appearance with the

Features of the preamble of claim 1.

Such lighting devices are already known from the general state of the art. Thus, there are lighting devices having a plurality of horizontally juxtaposed reflectors, each associated with two LEDs, one of which can emit a yellow and the other white light. In the light emission direction, an elongate, horizontally oriented intermediate light disk is arranged in front of the light emitting diodes, which is intended to lead to the homogenization of the light appearance. Depending on whether a direction indicator or a daytime running light is to be generated as a light function, either the yellow light or the white light emitting LEDs are activated. The disadvantage of this solution is that on the one hand several reflectors are needed and on the other hand, the homogeneity of the light emission is not satisfactory.

To avoid reflectors, it is also known to be arranged in pairs

Light emitting diodes, which can emit light of different colors, in

Lichtabstrahlrichtung a thick-walled optical component (so-called thick-wall optics) to be arranged, through which the emitted light of the light-emitting diodes can be diffused and then directed in the desired direction. However, there is also the disadvantage here that a plurality of light-emitting diodes is required in order to produce an elongated light appearance. In addition, the achievable homogeneity of the visible light appearance is not satisfactory here.

Finally, it is also known that the light of two LEDs different

Incorporate color radiation laterally in such a light guide, which extends in its length strip-like across the width of the lighting device. As a result, different light functions with a streak-like or line-like appearance can be generated with a minimum of light sources. US 6 340 239 B1 proposes a lighting device in which an incandescent lamp is used. The lighting device further comprises a lens and an intermediate lens. Between the incandescent lamp and the intermediate lens, a shield-like component is arranged which collects the light of the incandescent lamp both in the direction of a first longitudinal center plane of the illumination device and in the direction of a second longitudinal central plane of the illumination device perpendicular to the first longitudinal medial plane. As a result, all the light rays emitted by the incandescent lamp are directed towards the intermediate lens. In the assembled state of the lighting device, the first longitudinal center plane is horizontal and the second longitudinal central plane is vertical. The intermediate lens also has a sawtooth-like optical structure produced by vertically extending grooves, which faces the umbrella-like component. The incident on the intermediate lens light rays are finally aligned parallel to an optical axis of the bulb. The

Cover plate in turn has a the intermediate lens facing cushion optics, which serves for the final scattering of the light rays.

From US Pat. No. 6,264,347 B1, an illumination device is known in which a shield-like, optically active component is likewise arranged between an incandescent lamp and an intermediate lens. Through the optically active component, the light beams emitted by the incandescent lamp are in turn in the direction of a first longitudinal center plane of the illumination device and then in the direction of a second, perpendicular to the first

Longitudinal central plane standing longitudinal center plane of the lighting device collected so that they fall on the intermediate lens. However, the intermediate lens in turn has on its side facing the bulb or the umbrella-like component side only locally limited, sawtooth-like optics through which the light rays are aligned parallel to the optical axis of the bulb. In the areas of the intermediate lens without an optical structure, it is possible for a viewer, with the light bulb switched off, to look into the lighting device from the outside. This is to give the viewer a special optical depth impression.

The US 2007 0030 688 A1 discloses a lighting device, wherein in the light emission direction in front of a light emitting diode, an elongated, strip-like

Intermediate lens is arranged. The intermediate lens has a on the

LED convex convex curvature on. The light-emitting diode side facing away from the intermediate lens is equipped with a sawtooth-like optical structure. The

Light-emitting diode is in a transparent together with a conductive support part

Poured sealant. The sealant is elongated in the horizontal direction formed and has two hump-like projections which protrude from a block-shaped body of the sealant. In this way should be a very homogeneous

Light appearance can be achieved upon activation of the lighting device.

Finally, in DE 103 1 1 072 B4 a vehicle lamp with LEDs

which uses an indirect lighting method. Specifically, the light of a plurality of LEDs is first emitted to the rear in the direction of reflector segments and reflected by the reflector segments in the direction of a lens.

In view of the cited prior art, the present invention is the

Object on the basis of providing a lighting device with which with a few LEDs and without the use of reflectors or light guides at least two light functions with a streaky or linear light appearance can be generated and in which a very homogeneous light appearance is achievable.

This object is achieved with a lighting device having the features of claim 1. Advantageous embodiments or developments of the

The invention can be found in the dependent claims.

The invention is initially based on a lighting device for generating at least two light functions with a strip or line-like light appearance. In the lighting device there are at least two light-emitting diodes through which light of different color can be emitted. In this case, at least one optically active component is present, which converts the light of the LEDs in the direction of a lens or deflects.

Under lens is such a transparent or translucent component understood that shields the interior of the lighting device against environmental influences.

The invention now proposes that the light emitting diodes in the light emission direction is followed by a first, optically active component, which impinges, diverges

Light rays exclusively in the direction of a first longitudinal center plane of the

Lighting device collects. This takes place in such a way that the light rays fall on a second optically active component arranged downstream of the first optically active component. On the second optically active component impinging, divergent light beams are then at a first interface of the second optically active component exclusively in Direction of a second, perpendicular to the first longitudinal center plane standing longitudinal center plane of the lighting device collected. Finally, the light beams are scattered again at a second interface of the second optically active component.

By these features, a lighting device can be provided which provides an extremely homogeneous light appearance. Depending on the mounting position of

Lighting device is conceivable that the first longitudinal center plane is aligned horizontally and the second longitudinal center plane vertically. The reverse case is also conceivable.

According to a first development, it is proposed that the first, optically active component has a recess into which the light-emitting diodes project at least in part, their light being coupled in through areas of the recess, collected in the component in the direction of the first longitudinal center plane, and through at least one further surface is decoupled again.

By such an embodiment of the invention, the luminous efficacy can be increased and the alignment of the light beams can be effectively performed.

Another embodiment of the inventive concept proposes that incident light beams seen in said, first longitudinal center plane leave the first, optically active component at an angle of about 180 degrees. This contributes to the fact that the light functions, which are to be made optically visible as strip or line-like areas, have an extremely homogeneous light appearance.

According to a further development, the first boundary surface of the second, optically active component can have grooves running along its width, and the second boundary surface of the second optically active component can have a cushion optic. By creasing becomes one

formed sawtooth profile.

By such a development, the desired optical properties of the second component, namely first to collect the light in the direction of the second longitudinal center plane and then to scatter the light again, well feasible.

Thus, despite a strip or line-like light appearance of the

Light functions a high degree of homogeneity can be achieved, it is advantageous if the depth of the grooves decreases in lateral edge regions of the component towards its ends. In order to realize each of the light functions to be realized equally high quality, it is proposed that the optics of the first, optically active component is designed such that their focal point, seen in a plane of the light emitting diodes perpendicular to the optical axis, between the light emitting diodes.

In order that the lighting functions of a direction indicator and a daytime running light can be realized by the lighting device, it is proposed according to another development that at least one of the light-emitting diodes can emit yellow or orange light and at least one other of the light-emitting diodes white light. The

Lighting device according to the invention can then be part of a headlight, for example.

Another embodiment of the invention proposes that at least one of the light emitting diodes can emit yellow or orange light and at least one other of the light emitting diodes red light. In such a configuration, the lighting device may be part of a tail light, with the light functions of a

Direction indicator and a brake light can be generated.

With the invention, a motor vehicle to be placed under protection, which is equipped with at least one lighting device according to the invention.

Preferred embodiments of the invention are illustrated in the figures and will be explained in more detail with reference to the figures in the following description. As a result, even further advantages of the invention become apparent. The same reference numerals, even in different figures, refer to the same, comparable or functionally identical components. In this case, corresponding or comparable properties and advantages are achieved, even if a repeated description or reference does not occur. The figures are not always to scale. In some figures, proportions may be exaggerated to more clearly highlight features of an embodiment.

It show, each schematically

1 is a front view of a vehicle equipped with lighting devices according to the invention, Fig. 2 shows the representation of a portion of an inventive

Lighting device from the front,

3 is a Florenalschnitt according to sectional view III of Fig. 2,

4 shows a vertical section according to sectional view IV of FIGS. 2 and 3,

5 is a perspective view of the first, optically active component in

Unique position, in a first embodiment,

Fig. 6 is an illustration of the first, optically active component in one

Vertical section, according to section line VI of FIG. 3,

7 shows a detailed representation of the second optically active component according to the detail

VII of Fig. 3,

8a to 8c different views of the first, optically active component, in a second embodiment,

8d shows a vertical section through the second embodiment of the second optically active component, comparable to the sectional view from FIG. 6 and FIG

Figures 9a and 9b is a representation of the focal point of the first, optically effective

Component, when using two or three LEDs.

Fig. 1 shows schematically the front view of a motor vehicle K, which has two lighting devices 1 according to the invention. The lighting devices 1 are designed as headlights. Between them, a grille 2 is arranged. Each of the lighting devices 1 has a cover plate 3, which the

Lighting device 1 closes forward against environmental influences.

In the selected representation, the cover disk 3 has an upper region 3a and a lower, strip-like or line-like region 3b. The cover plate 3 is formed as a transparent cover plate, wherein behind the upper portion 3a

Light sources for generating a low beam and a high beam function are indicated by dashed lines. Behind the lower region 3b is an optically active component 4 in the form an intermediate lens visible. The function of the component 4 will be explained later in more detail.

In the exemplary embodiment, the lower region 3b of the lighting device 1 should be both the light functions of a strip-like daytime running light and a strip-like

Train direction indicator. The light functions should each appear as extremely homogeneous light stripes.

The basic structure of the lighting device 1 in a horizontal plane of the lower region 3b will now be described in greater detail with reference to FIGS. The

For clarity, the lens 3 is not shown.

Thus, Fig. 2 shows the optically active component 4, so the intermediate lens from the front. The intermediate lens 4 is formed as an elongate, strip-like component with a length I and a width b. H is a first, horizontal longitudinal center plane, with V a second, vertical longitudinal center plane of the lighting device 1 numbered.

As can be seen from FIG. 3, the optically active component 4 is made thin and slightly curved over its length I. It has a first, optically active interface 4a and a second, optically active interface 4b.

When viewed in the mounting position of the lighting device 1, the first interface 4a is formed by grooves R running vertically, ie perpendicular to the plane of the drawing. As a result, the first interface 4a has a sawtooth-like profile which extends substantially along the entire length I of the component 4.

It should be mentioned that the depth of the grooves R decreases continuously at the edge regions 40 towards the ends 41 of the component 4.

Behind the component 4, a circuit board 7 is arranged, which close together two

Light emitting diodes 5 and 6 carries. In the exemplary embodiment, the light-emitting diode 5 can emit yellow light, the light-emitting diode 6 white light.

Between the light emitting diodes 5, 6 and the second, optically active component 4, a first, optically active component 8 is arranged. The component 8 is formed umbrella-like and extends in the horizontal direction in a semicircle in front of the LEDs 5 and 6th As is clear from FIGS. 3 and 4, the first, optically active component 8 serves only or exclusively to emit light emitted from the light-emitting diodes 5 and 6

To collect light rays L in the direction of the horizontal longitudinal center plane H. The

Light beams L are collected in particular by the component 8 such that they are aligned parallel to the horizontal longitudinal center plane H and can thus fall on the second optically active component 4. With X, the direction of the optical axes of the LEDs 5, 6 numbered, which coincide with the longitudinal center plane H.

As shown in FIG. 3, no collection of the light rays L takes place in the direction of the vertical longitudinal center plane V through the component 8. These occur unchanged through the component 8 therethrough. Moreover, the light beams L, the component 8, in the horizontal

Longitudinal plane H considered leaving at an angle a of about 180 °. In this way, an extremely homogeneous illumination of the optically active component 4 is achieved.

Only through the optically active component 4 also takes place a collection of the light rays L in the direction of the vertical longitudinal center plane V. Specifically, a collection of

Light rays L in the direction of the vertical longitudinal center plane V through the first interface 4a. Subsequently, a scattering of the light beams L by the second takes place again

Boundary surface 4b in both the horizontal and in the vertical direction, wherein the second interface 4b is formed by a cushion optics KO.

Due to the separate vertical and horizontal collection of the light beams L through the component 8 on the one hand and the component 4 on the other hand, a maximum of light of the LEDs 5 and 6 can be utilized without it to the viewer to a point-like

Light phenomenon (so-called hot spots) or other inhomogeneities on the component 4 comes. Rather, a long, extremely homogeneous illumination is achieved.

With reference to FIG. 5, the first, optically active component 8 is shown in isolation.

Thus it can be seen that it has on its the light-emitting diodes 5 and 6 facing inside horizontally aligned grooves. On its, the light-emitting diodes 5 and 6 facing away from surface 8 b, the component 8 is formed smooth. It is characterized by the semicircular

Forming the component 8 is formed in an approximately semi-cylindrical receiving area 8a.

As is clear from FIG. 6, the light-emitting diodes 5 and 6 are positioned relative to the component 8 in such a way that they protrude somewhat into the receiving region 8a. Furthermore, the optical axes X of the light-emitting diodes 5, 6 pass through the most pronounced point of a concave elevation 8c. From the light-emitting diodes 5, 6 emitted light beams L are in (vertical) outer edge regions of the component 8 is first broken and then over a

Total reflection in the direction of the outer surface 8b forwarded. By contrast, only a refraction of the incident light beams L occurs between the outer regions.

It will now be shown once more in detail how an alignment of the light beams L is accomplished by the second, optically active component 4 with reference to FIG.

Thus, the light rays L incident on the first boundary surface 4a are first collected in the direction of the vertical longitudinal center plane V and are preferably aligned parallel to one another. This is preferably done so that the light rays point in the usual direction of travel.

When the light beams L fall on the second interface 4b, they are scattered in both a vertical and a horizontal direction. The interface 4b is formed in the form of a cushion optic KO.

In the figures 8, an alternative embodiment for a first, optically effective component 9 is now shown.

Thus, it can be seen with reference to FIGS. 8a to 8c that the component 9 is formed in plan view by a semi-cylindrical body of revolution. The component 9 has, from a view according to FIG. 8c, a surface 9a facing the light-emitting diodes 5, 6 and a surface 9f facing away from the light-emitting diodes 5, 6. The surface 9a is flat, while the surface 9f is bent semicircular. Furthermore, an upper surface 9e and a lower surface 9g are provided. Both the surface 9e and the surface 9g deepen in the direction of an imaginary axis of rotation M and take there the smallest distance from each other (see Fig. 8b).

In the surface 9a, a recess A is mounted, which is also formed in a view of FIG. 8c in the outline of a semicircle.

The recess A has upper and lower surfaces 9b and a circumferential surface 9c. The surface 9 c is convex and has approximately at mid-height of

Recess A on her unloading point. As can be seen with reference to FIG. 8d, the light emitting diodes 5, 6 and the component 9 are aligned in the assembled state of the lighting device 1 such that the light emitting diodes 5, 6 protrude into the recess A and optical axes X of the light emitting diodes 5, 6 at height the unloaded point of the surface 9c lie. Of the LEDs 5, 6

emitted light beams are thus coupled through the surfaces 9b and 9c in the component 9, wherein the light beams L coupled via the surfaces 9b arrive at the surfaces 9e and 9g under total reflection to the surface 9f and there emerge from the component 9. The light beams L coupled in via the surface 9c, on the other hand, are refracted at the surface 9c and from there pass directly to the surface 9f, where they emerge from the component 9. The light beams L emerging from the component 9 via the surface 9f are aligned in the direction of the horizontal longitudinal center plane H, preferably parallel to it. An alignment of the light beams L in the direction of the vertical longitudinal center plane V (identical to drawing plane) does not take place here either.

Finally, it will be discussed shortly with reference to FIGS. 9a and 9b, as when using a plurality of light emitting diodes, the optics of the first, optically active component 8 or 9 can be suitably adapted to the light emitting diodes.

Thus, in the exemplary embodiment according to FIG. 9a, only two light-emitting diodes 5, 6 are used, of which one can emit a yellow or orange light and the other white light. The optics of the first, optically active component 8 or 9 is now designed such that their focal point B is located on an imaginary connecting line 10 of the light-emitting diodes 5 and 6 between the light-emitting diodes 5 and 6. The connecting line 10 lies in a plane which is perpendicular to the optical axes of the LEDs 5, 6.

More specifically, the focal point B is on the connecting line 10 where it has the same distance to both light-emitting diodes 5 and 6.

In Fig. 9b an embodiment is shown, in which on the board 7 three

Light emitting diodes are arranged. Thus, a light-emitting diode for emitting light in a first color (for example yellow) and two light-emitting diodes 6 for emitting light in a second color (for example white) are present. The optical axes of the LEDs are at regular angular intervals on an imaginary circle 1 1 perpendicular to the optical axes. In this embodiment, the optics of the first optically active component 8 or 9 is now designed such that their focal point B falls into an imaginary center of the circle 1 1. LIST OF REFERENCE NUMBERS

1 lighting devices

2 grille

3 lens

3a upper portion of the lens

3b lower portion of the lens

4 second optically active component; Between Lens

4a first interface

4b second interface

5 LED

6 LED

7 board

8 first, optically effective component

8a recording area

8b area

8c convex elevation

9 first, optically effective component

9a-9g surfaces

10 connecting line

1 1 circle

40 border areas

41 ends a angle

A recess

b width

B focal point

H horizontal longitudinal center plane

K motor vehicle

KO cushion optics

I length

L beams of light

M imaginary axis of rotation

R grooves

V vertical longitudinal center plane

X optical axis

Claims

claims

1. Lighting device (1)) for a motor vehicle (K) for generating at least two light functions with a streak-like or line-like light appearance, wherein at least two light-emitting diodes (5,6) are present through which light (L) of different color can be emitted, wherein at least one optically active component (8, 9) is present, which deflects or deflects the light (L) of the light-emitting diodes (5, 6) in the direction of a lens (3), characterized in that the light-emitting diodes (5, 6) a first optically active component (8, 9) is arranged downstream of the light emission direction, which impinges, diverging, light rays (L)

exclusively in the direction of a first longitudinal center plane (H) of the

Lighting device (1) collects, such that the light beams (L) on a the first optically active component (8, 9) downstream, second optically active component (4), which divergent light beams (L) at a first, own interface ( 4a) exclusively in the direction of a second, perpendicular to the first longitudinal center plane (H) standing longitudinal center plane (V) of the lighting device (1) collects and at a second, own interface (4b) scatters again.

2. Lighting device (1) according to claim 1, characterized in that the first, optically active component (9) has a recess (A), in which the

Light-emitting diodes (5, 6) protrude at least partially, wherein the light (L) by surfaces (9b, 9c) of the recess (A) coupled in the component (9) in the direction of the first longitudinal center plane (H) and collected by at least one further Surface (9f) is decoupled again.

3. Lighting device (1) according to claim 1 or 2, characterized in that incident light beams (L), seen in the first longitudinal center plane (H), the first optically active component (8, 9) at an angle (a) of approximately Leave 180 °.

4. Lighting device (1) according to one of the preceding claims, characterized in that the first boundary surface (4a) of the second, optically active component (4) in the direction of its width (b) extending grooves (R) and the second interface (4b ) of the second optically active component (4) has a cushion optic (KO).

5. Lighting device (1) according to claim 4, characterized in that the depth of the grooves (R) in lateral edge regions (40) of the component (4) to its ends (41) decreases towards.

6. Lighting device (1) according to one of the preceding claims, characterized in that the optics of the first, optically active component (8, 9) is designed such that the focal point (B) in a plane of the light-emitting diodes (5, 6), Seen perpendicular to the optical axes (X), between the light emitting diodes (5, 6).

7. Lighting device (1) according to one of the preceding claims, characterized in that at least one of the light emitting diodes (5, 6) yellow or orange light and at least one other of the light emitting diodes (5, 6) can emit white light.

8. Lighting device (1) according to one of the preceding claims 1 to 6, characterized in that at least one of the light emitting diodes (5, 6) yellow or orange light and at least one other of the light emitting diodes (5, 6) can emit red light.

9. Motor vehicle (K), characterized by at least one lighting device (1) according to one of the preceding claims.