DE102012015057A1 - Lighting apparatus for use in decorative element in interior of vehicle, has light source and optical element which has light output surface and two components - Google Patents

Abstract

The lighting apparatus (10) has a light source (1) and an optical element (5) which has a light output surface (7) and two components (5-1,5-2), where the former component of the optical element is made from a light-permeable material. The latter component of the optical element is impermeable for the light entering in the latter component and emitted from the light source, if the light path in the latter component exceeds a border light path.

Description

The present invention relates to a lighting device for a vehicle having a light source and an optical element which has a light output surface and which comprises at least two components, wherein the first component of the optical element consists of a light-transmissive material. Furthermore, the invention relates to a decorative element in the interior of a vehicle, which comprises such a lighting device.

From the DE 10 2006 011 849 A1 is a vehicle with a arranged in the field of the dashboard decorative element known. A part of the decorative element is formed by a ceramic layer, wherein the ceramic layer is permanently connected to a plastic carrier part of the decorative element. The plastic carrier part may be made of a translucent material. The light of a light source can be fed into the plastic carrier part, whereby the ceramic layer can be backlit.

In the DE 10 2009 017 363 A1 a decorative element for a motor vehicle is described, which comprises an at least partially transparent decorative film, which is applied to a flat carrier element and back-injected with two plastic layers. At least the first plastic layer is at least partially transparent, so that it can be used as a light guide.

From the DE 10 2008 064 233 A1 is known as a door sill for motor vehicles. It consists of several interconnected plastic components. A surface portion of the door sill is formed by a printed translucent film whose back is at least partially fixedly connected to a made of a translucent plastic material plastic component, which can be used as a light guide for a lighting source. This plastic component is in turn used or embedded in a plastic component of an opaque plastic material, the latter plastic component is connected by injection or by gluing firmly to the translucent plastic component.

Finally, out of the DE 10 2010 018 591 A1 a foil-decorated plastic part known. In the manufacturing process for this plastic part, in a first injection molding step, a first section of the surface of the plastic part to be decorated is produced using a first decorative film. In a second injection molding step, a second section of the surface to be decorated is produced using a second decorative film.

The present invention has for its object to provide a lighting device of the type mentioned above, which allows an attractive design and lighting in particular of the vehicle interior and which is perceived by the eye of the beholder as a little exhausting.

According to the invention, this object is achieved by a lighting device having the features of claim 1. Advantageous embodiments and further developments emerge from the dependent claims.

The optical element of the lighting device according to the invention contains two material components. The first component is made of translucent material. According to the invention, the second component is impermeable to the light emitted by the light source and entering the second component when the light path in the second component exceeds a limiting light path. By contrast, the second component is partially transparent to the light emitted by the light source and entering the second component if the light path in the second component is shorter than the limiting light path. Furthermore, the optical element has a first region, in which the thickness of the second component exceeds the limiting light path, a second transition region, in which the thickness of the second component of the optical element is smaller, in particular monotonically smaller, and a third region, in the direction the thickness of the optical element, the second component is not or is arranged with a minimum thickness, so that the light of the light source is emitted at the light output surface of the third region with maximum light intensity and at the light outcoupling surface in the second transition region towards the light outcoupling surface of the first region is emitted with decreasing light intensity, in particular with monotonically decreasing light intensity. In the first area then no more light exits at the light output surface.

The thickness of the optical element is understood to mean the material thickness of the optical element in the light outcoupling direction, that is to say perpendicular to the light outcoupling surface. The optical element is therefore in particular a planar element which has a constant or varying thickness. The thickness of a component of the optical element is understood to mean the material thickness of this component in the light outcoupling direction, that is to say perpendicular to the light outcoupling surface.

The two material components of the optical element have different optical properties. The first component is translucent, so that light can pass substantially unhindered to the light output surface. In the case of the second material component of the optical element, the light emission depends on the path of the light through this second component. When this light path through the second component exceeds a certain limiting light path, no light emerges from the light outcoupling surface. If, however, the light path through the second component is less than the limiting light path, at least a certain proportion of the maximum intensity occurs at the corresponding light outcoupling surface. The light intensity is higher, the lower the light path through the second component of the optical element. Since now the thickness of the second component of the optical element in the second transition region from the first region to the third region is smaller, especially monotonically lower, and the light path is shorter by the second component in the transition region, in particular monotonically shorter. In the third area, the light no longer passes through the second component, but only through the translucent first component. As a result, the light intensity in the third region emerges with maximum light intensity and continuously decreases in the direction of the third region.

In this way, the illumination device according to the invention avoids a hard transition between the luminous surface and the dark surface of a diaphragm which is formed by the first region of the optical element. The light emitted by the lighting device is therefore advantageously perceived by the eye of a viewer in the interior of a vehicle as not so exhausting. It can be advantageously realize a soft light pattern on the surface of the light output surface.

If the thickness of the second component of the optical element is monotonically lower, in particular strictly monotonically lower, so that the light of the light source at the light outcoupling surface in the second transition region in the direction of the light outcoupling surface of the third region with monotonically decreasing light intensity, in particular with strictly monotonically decreasing light intensity , is emitted, it is advantageously possible to generate a particularly soft course of brightness on the light outcoupling surface of the optical element which disengages from the third region in the direction of the first region on the light outcoupling surface.

According to a further embodiment of the illumination device according to the invention, the thickness of the second component is continuous as a function of a position in a direction perpendicular to the thickness of the optical element, at least during the transition from the first region to the second transition region of the optical element. Preferably, the function is also differentiable in the transition from the first region to the second transition region. In particular, the thickness of the second component has a maximum value in the first region and then drops in the second transition region until the thickness of the second component is zero at the transition to the first region, since the third region in the direction of the thickness of the optical element is only the first component having. The function of the thickness of the second component in this case has no jumps in the transition from the first region to the second transition region and in particular also no kink. It is a continuous differentiable transition.

In accordance with a further embodiment of the illumination device according to the invention, the thickness of the second component as a function of a position in a direction perpendicular to the thickness of the optical element is also continuous and in particular also differentiable during the transition from the second transition region into the third region of the optical element. Even with this transition to the third area, there is thus no jump and optionally no kink. According to another embodiment, although there is no jump in the transition to the third region, but a kink, so that the function of the thickness of the second component is continuous but not differentiable. In this way, it is advantageously achieved that a particularly smooth course of brightness is achieved during the transition into the first region, which is perceived by the viewer's eye as less strenuous.

According to a further development of the illumination device according to the invention, the regions of the optical element are arranged such that a light line is produced whose light intensity becomes monotonically lower toward the edge of the light line. The light intensity thus decreases monotonically in a direction perpendicular to the longitudinal extent of the light line. It is thus avoided a sharply delimited line of light, which is perceived by the eye of the observer as exhausting, but it is a soft end of the light line generated towards the edge.

Further, this light line may end in an end portion in which the thickness of the second component of the optical element increases toward the end of the light line to the thickness in the first region, so that the light intensity monotonically decreases toward the end of the light line. The light intensity thus not only sounds to the edge, but also in the end section. This, too, is perceived by the eye of the beholder as pleasant and less strenuous.

According to a further embodiment of the lighting device according to the invention, the optical element is produced by multi-component injection molding. The two components may consist of a plastic, wherein the plastic material of the first component is translucent, the plastic material of the second component, however, is colored so that the incident light is completely absorbed by a Grenzlichtweg by the second component. If, however, this limit light path is exceeded, only a part of the incoming light is absorbed. In this way, the optical element can be produced very inexpensively. In addition, the transition from the first component to the second component of the optical element can be set very precisely, whereby a desired light emission characteristic can be generated very accurately.

According to a development of the illumination device according to the invention, this comprises a surface light guide which distributes the light emitted by the light source and couples it in a planar manner into a light coupling surface of the optical element. The light input surface of the optical element is arranged in particular opposite of the light output surface. The light enters from the surface light guide vertically into the light-incoupling surface of the planar optical element and emerges vertically again at the light outcoupling surface, provided that it has not been absorbed by the second component of the optical element. In this way, a very homogeneous, uniform light distribution can be generated, in particular in the third region of the optical element. In addition, in the depth direction results in a very compact construction of the lighting device, since the light of the light source can be laterally coupled into an end face of the surface light guide.

According to a development of the illumination device according to the invention, the light output surface of the optical element is coated so that no light emission is perceptible during the day even in the light output surface of the second transition region. During the day, this ensures that the light output surface provides a hard transition between light and dark areas. At night, on the other hand, a soft brightness progression is still provided.

The invention further relates to a decorative element in the interior of a vehicle, which comprises the lighting device described above.

The invention will now be explained with reference to an embodiment with reference to the drawings.

1 shows a partial sectional view of the embodiment of the lighting device according to the invention,

2 shows a further sectional view of the embodiment of the lighting device according to the invention, and

3 shows the brightness curve, which is generated by the embodiment of the lighting device according to the invention.

The lighting device 10 is in the embodiment, which will be described below, integrated into a decorative element, which is arranged in the interior of the vehicle. The lighting device 10 includes one or more light sources 1 , which are formed for example as light-emitting diodes. The light emission of the light sources 1 is via a light input surface 3 trained face of a surface light guide 2 in the surface light guide 2 coupled. The surface light guide 2 is designed so that via the light coupling surface 3 coupled light evenly in the light guide 2 is distributed and homogeneous at the light output surface 4 in the direction of a light input surface 6 an optical element 5 is decoupled.

The optical element 5 includes two components 5-1 and 5-2 and has been produced in two-component injection molding. At the first component 5-1 It is an opaque, translucent material made of plastic, which via the light incidence surface 6 of the optical element 5 Coupled light evenly to the opposite light output surface 7 passes. The light, which is perpendicular in the z-direction (see 1 ) at the light input surface 6 of the optical element 5 occurs, thus occurs in the direction of the thickness of the optical element 5 that is, in the z-direction, through the optical element 5 through and occurs at the light output surface 7 back out and get there by the opticsement 5 emitted.

The second component 5-2 of the optical element 5 On the other hand, it has special optical properties in terms of transmission. When the light path in the second component exceeds a boundary light path, the light entering the second component is completely absorbed, that is, the second component 5-2 is opaque in this case. If, however, the light path in the second component 5-2 is shorter than the Grenzlichtweg is a part of the second component 5-2 incoming light absorbs, while the other part is transmitted. In this case, the second component is 5-2 thus partially permeable to the incoming light. In particular, there is a linear relationship between the absorbed portion of the incoming light and the length of the light path through the second component 5-2 , However, another functional relationship is also possible depending on the desired radiation characteristic.

In the embodiment described here, the length of the limit light path corresponds to the second component 5-2 the thickness of the optical element 5 , Thus, light, which is in an area of the optical element 5 occurs at which the thickness of the optical element 5 completely from the second component 5-2 is formed, completely absorbed. In this area, the optical element shadows 5 the light of the surface light guide 2 thus completely off. In an area where only a section in the direction of the thickness of the optical element 5 from the second component 5-2 is formed and the remaining portion of the first component 5-1 , is determined according to the thickness of the second component 5-2 only part of the light intensity at the light output surface 7 radiated. In this case, the optic element works 5 thus as a light distribution element. Under the thickness of the second component 5-2 of the optical element 5 is the material thickness of the second component 5-2 of the optical element 5 understood in z-direction.

In the optical element 5 now three areas are formed: In a first area A, the thickness of the second component corresponds 5-2 the boundary light path defined above or exceeds this, so that light, which in the area A of the light output surface 4 of the surface light guide 2 over the light coupling surface 6 in the optical element 5 is coupled substantially vertically, is completely absorbed and thus not in the light output surface 7 in area A exits. Even with the light source switched on 1 the light output surface remains 7 in this area A thus dark. In the present embodiment, in the region A, the optical element 5 completely made of the material of the second component 5-2 ,

At a point P1 (see 1 ) goes the first area A of the optical element 5 in the direction of the xy plane in the second transition region B over. Considering the thickness of the second component 5-2 that is, the extension of the second component 5-2 in the z-direction, as a function of a direction perpendicular to the thickness of the optical element 5 that is, for example in the x-direction, this function is constant in the area A and passes continuously and differentially at the point P1 into the second transition area B, in which the thickness of the second component 5-2 of the optical element 5 strictly monotonically lower. The second transition region B extends in the xy direction until the thickness of the second component 5-2 at point P2 (see 1 ) Is zero. This is followed by the third region C, in which the optical element 5 only from the first component 5-1 is formed. In the present embodiment, the transition at point P2 from the second transition region B to the third region C is continuous, but not differentiable. In the function of thickness, this results in a kink.

In the second transition region B further decreases with the reduction of the thickness of the second component 5-2 the thickness of the first component 5-1 correspondingly strictly monotone, so that the second transition region B of the two components 5-1 and 5-2 is formed in varying thickness ratios.

In the light emission direction L of the lighting device 10 thus results in the third area C on the light output surface 7 of the optical element 5 a range of maximum light intensity, which decreases in the transition region B until in the first region A no more light both Lichtauskoppelfläche 7 exit.

Optionally, on the light output surface 7 Finally, a coating 14 be applied, which ensures that by day no light emission at the light output surface 7 of the second transition region B is perceptible. By day in this case, therefore, the fading out of the light intensity to the edge is imperceptible, at night, this decreasing brightness curve towards the edge for the viewer in the interior of the vehicle, however, clearly visible.

In the 2 are again different ways of training the optical element 5 shown to produce different light output characteristics:
In the section 8th is the related to 1 explained emission characteristic shown in which emerges in the middle of light with maximum light intensity and towards the edge, the light intensity decreases strictly monotonous until it completely disappears.

In the section 9 is a known per se embodiment of the first component 5-1 of the optical element 5 shown, by which a light characteristic is generated, which results in a hard transition between maximum light intensity and a mask, in which no light is emitted.

In the section 11 is an arrangement of the first component 5-1 shown, which produces a leaking tip of a light line. Such a light line will be related to 3 explains:
From the visual element 5 In this case, this is due to the distribution of the two components 5-1 and 5-2 in the optical element 5 a line of light 12 generated, which in a direction perpendicular to the light line 12 that is to the edge of the light line 12 , dies out. This decay is generated by the transition region B described above, in which the thickness of the second component 5-2 for the third Area C is towards less. Furthermore, a light line 13 generated, which has a hard transition to the edge, that is, the edge does not end. In the end sections 15 the light lines 12 and 13 However, it takes the thickness of the second component 5-2 towards the end of the light lines 12 and 13 to the thickness in the first area A, so that the light intensity toward the end of the light lines 12 and 13 becomes monotonically smaller.

LIST OF REFERENCE NUMBERS

1

light source

2

Light guides

3

light injection

4

light coupling

5

optical element

5-1

first component of the optical element

5-2

second component of the optical element

6

light injection

7

light coupling

8th

Section of the visual element 5

9

Section of the visual element 5

10

lighting device

11

Section of the visual element 5

12

light line

13

light line

14

coating

15

End portion of the light line 12 respectively. 13

16

decorative element

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006011849 A1 [0002]
• DE 102009017363 A1 [0003]
• DE 102008064233 A1 [0004]
• DE 102010018591 A1 [0005]

Claims (10)

Lighting device ( 10 ) for a vehicle with - a light source and - an optical element ( 5 ), which has a light output surface ( 7 ) and which at least two components ( 5-1 . 5-2 ), wherein the first component ( 5-1 ) of the optical element ( 5 ) consists of a translucent material, characterized in that - the second component ( 5-2 ) of the optical element ( 5 ) for that of the light source ( 1 ) and into the second component ( 5-2 ) light is impermeable when the light path in the second component ( 5-2 ) exceeds a limiting light path, and for that of the light source ( 1 ) and into the second component ( 5-2 ) light is partially transmissive, when the light path in the second component ( 5-2 ) is shorter than the limiting light path, and - the optical element ( 5 ) has a first region (A) in which the thickness of the second component ( 5-2 ) exceeds the limiting light path, a second transition region (B), in which the thickness of the second component ( 5-2 ) of the optical element ( 5 ), and a third region (C), in which in the direction of the thickness of the optical element ( 5 ) the second component ( 5-2 ) is not arranged or with a minimum thickness, so that the light of the light source ( 1 ) at the light output surface ( 7 ) of the third region (C) with maximum light intensity is emitted and at the light output surface ( 7 ) in the second transition region (B) in the direction of the light output surface ( 7 ) of the first region (A) is emitted with decreasing light intensity. Lighting device ( 10 ) according to claim 1, characterized in that in the second transition region (B) the thickness of the second component ( 5-2 ) of the optical element monotonically decreases, so that the light of the light source ( 1 ) at the light output surface ( 7 ) in the second transition region (B) in the direction of the light output surface ( 7 ) of the first region is emitted with monotonically decreasing light intensity. Lighting device ( 10 ) according to claim 1 or 2, characterized in that the thickness of the second component ( 5-2 ) as a function of a position in a direction (x, y) perpendicular to the thickness of the optical element ( 5 ) at least at the transition (P1) from the first region (A) into the second transition region (B) of the optical element ( 5 ) is steady. Lighting device ( 10 ) according to one of the preceding claims, characterized in that the thickness of the second component ( 5-2 ) as a function of a position in a direction (x, y) perpendicular to the thickness of the optical element ( 5 ) at least at the transition (P1) from the first region (A) into the second transition region (B) of the optical element ( 5 ) is differentiable. Lighting device ( 10 ) according to one of the preceding claims, characterized in that the regions (A, B, C) of the optical element ( 5 ) are arranged so that a light line ( 12 ) whose light intensity is at the edge of the light line ( 12 ) becomes monotonically smaller. Lighting device ( 10 ) according to claim 5, characterized in that the light line ( 12 ) in an end section ( 15 ), in which the thickness of the second component ( 5-2 ) of the optical element ( 5 ) towards the end of the light line ( 12 ) increases to the thickness in the first region (A), so that the light intensity in the direction of the end of the light line ( 12 ) becomes monotonically smaller. Lighting device ( 10 ) according to one of the preceding claims, characterized in that the optical element ( 5 ) is produced by multi-component injection molding. Lighting device ( 10 ) according to one of the preceding claims, characterized in that the lighting device ( 10 ) a surface light guide ( 2 ) comprising the light source ( 1 ) emitted light and surface in a Lichteinkoppelfläche ( 6 ) of the optical element ( 5 ). Lighting device ( 10 ) according to one of the preceding claims, characterized in that the light output surface ( 7 ) of the optical element ( 5 ) is coated so that by day at the light output surface ( 7 ) of the second transition region (B) no light emission is perceptible. Decorative element ( 16 ) in the interior of a vehicle, which the lighting device ( 10 ) according to any one of the preceding claims.

Images