DE102009035741A1 - Light i.e. rear light, for e.g. passenger car, has active body with boundary surface formed such that it reflects light sent by light source and coupled into optically active body and retroreflects light into active body - Google Patents

Abstract

The light (10) has a light radiation element radiating light sent by a light source (24) i.e. LED such as red color LED, attached to the radiation element in a light emission direction (14). The radiation element and a retro-reflecting element are integrated into a common optically active body (18). The active body has three-dimensional structured boundary surfaces (20), where one of the boundary surfaces is formed such that it reflects the light sent by the light source and coupled into the optically active body and retroreflects the light into the active body. The LED comprises yellow or orange color LEDs.

Description

The The invention relates to a lamp for a motor vehicle with at least one active light emitting element and at least one passive retroreflective retroreflective element. The light-emitting element radiates from at least one of the Lichtabstrahlelement associated Light source of the light emitted light in a light exit direction from. The retroreflective retroreflective element reflects from outside the luminaire at a certain angle of incidence on the retroreflective element incident light rays in essentially parallel to the incident light rays back again. The light-emitting element and the retroreflective retroreflective element are in a common optically effective body with integrated totally reflective properties.

Out The prior art is a variety of lighting devices known for vehicles. That's how you differentiate first between headlights and lights. Headlamps are exclusive arranged in the front area of a vehicle. They serve beside the Traffic safety by visualization of the vehicle for other road users in particular the illumination of the road in front of the vehicle to improve the visibility for the driver. Headlamps can use as light source at least one incandescent lamp, gas discharge lamp or LED. They work according to a reflection principle, So with a reflector mirrored to the light source, or according to a projection principle with an additional, im Beam path arranged projection lens.

to shine Mainly serve the traffic safety by visualization of the vehicle for other road users and become preferably as rear lighting, flashing light or position light in the rear, Side and / or front of the vehicle used. As light sources Luminaires are usually incandescent or Light-emitting diodes (LEDs) and work preferably according to the reflection principle. The lights usually have one reflective area, the light rays emitted from the light source reflected so that the light rays emerging from the luminaire in the light exit direction a desired light distribution exhibit. A light distribution is both by the extent of the emerging light beam in horizontal and vertical Direction as well as by the local illuminance values characterized.

Next The described active headlights and lights have vehicles further passive retroreflective reflectors. Retroreflective means that light rays in a given Angle of incidence against the light exit direction in the reflector incident, by one of the light entrance surface of the reflector opposite Reflecting section in Lichtaustrittrichtung substantially parallel be reflected to the incident light rays. Retroreflective Reflectors are predominantly in the rear area and / or arranged on the sides of a motor vehicle. The reflectors Thus, from the outside incident light essentially reflect in the direction of incidence and thus provide inactive Light sources of the vehicle for visualization of the Vehicle. The retroreflective reflectors are either integrated into the lighting device or as a separate reflector arranged on the vehicle. Reflectors are also not at motorized vehicles, such as. Bicycles used. They are subject to legal requirements, eg. B. Specifications of the Economic Commission for Europe (ECE).

From the DE 200 22 581 U1 a luminaire for a vehicle is known, comprising light emitting elements and retroreflective elements, which in the example of 9 the document are integrated in a common optically effective body with total reflective properties. The optically effective body has a T-shape with two substantially mutually perpendicular legs. Before a front side of the one leg, a light source in the form of an LED is arranged and couples light into the optically active element. The coupled-in light is propagated by means of total reflection at boundary surfaces of the first leg along the leg and is coupled out in a light exit direction on an end face opposite light exit surface, which extends substantially transversely to the longitudinal extent of the first leg and along the longitudinal extent of the second leg. Reflective elements are formed in the light exit surface of the second leg which reflect light beams striking the light exit surface from outside the luminaire substantially parallel to the incident light beams. In the known luminaire, therefore, the light-emitting elements and the retroreflective elements are formed as functionally separate parts.

The retroreflective elements of the known luminaire are designed as so-called. In a triple mirror are arranged at right angles to each other mirrors, which have a common corner point and thus together form a cube corner (see. 8th the publication).

The known lamp has the disadvantage that for the manufacture of the retroreflective elements in an injection molding an injection mold, with the pointed cube corners can be produced with a sufficiently high precision, relatively expensive to produce, resulting in the production of the retroreflective elements to a high cost and correspondingly high production costs.

Furthermore In the known luminaire, the light-emitting element of the retroreflective elements is functional separated, so that the lamp is relatively large building. In a view from the outside on the lamp arise separate areas that either only actively emit light or only passively reflect light.

task The invention is a luminaire of the type mentioned in such a way To further develop that the lamp easier and therefore more cost-effective is to produce. In addition, the lamp should be as compact as possible be constructed.

to Solution to the problem is proposed that the optical having effective body interfaces, at least one of the interfaces is arranged and formed in this way is that they are emitted both by the at least one light source and in the optically active body coupled light a light output surface of the optically active body reflected as well as from outside the luminaire through the Light output surface in the optically active body coupled-in light retroreflected. So it is suggested a component which acts as a retroreflector and also as a light guide to use as two previously separate functions, the passive Reflector function and the active luminaire function, with each other to combine and integrate into a component. The invention is particularly suitable for a realization of a combination of passive and active reflectors in a single Component.

Of the optically effective body is made of a transparent material (Glass or plastic) and according to the invention has a in a special way arranged or trained interface. The interface may, for example, as a reflection surface be educated. It can simultaneously as a reflection surface for the light beams actively emitted by the light source and as a retroreflective reflective surface for the passive Reverse reflector function can be used. The reflection can thereby - depending on an embodiment of the reflection surface - after the rules of specular reflection or the rules of total reflection respectively. The in the optically active body according to Art an optical fiber propagated light rays are on impact the reflection surface is reflected so that they under an angle to the light exit surface of the optically effective Meet a body in which it no longer totally reflects, but be decoupled from the optically effective body. On an additional reflection surface can at the lamp according to the invention are dispensed with. In addition, the outside of the light through the exit surface in the optically active body incident light rays through the reflection surface substantially retroreflected parallel to the incident light rays.

One important aspect of the present invention is that the retroreflective reflective surface of the optically effective Body on one of the light input and light output surface the optically active body opposite interface is trained. From the outside at a certain angle of incidence on the optically active body incident light rays are not immediately at the light input or light output surface retroreflected, but only pass through the light entry surface into the optical body and are thereby broken. Only then does the light hit the reflection surface and is there in the direction Lichtaus- or Lichteinkoppelfläche retroreflected. The retroreflected light then passes through the Light exit surface substantially parallel to the incident Light rays again from the optically effective body.

Furthermore becomes the light emitted by the at least one light source on a narrow side of the optically active body in this coupled and propagated therein along a longitudinal extent of the body. At least over a subarea the longitudinal extent of the optically active body the reflection surface is formed, which corresponds to that of the Light source emitted and coupled into the body Reflected light rays towards the light output surface. Thus, the light emitted by the light source can evenly over a relatively large area distributed and out of the optically effective body to be decoupled. This will prevents the light spot areas with particularly high Luminance (so-called hot spots), which is undesirable by customers and other road users as subjectively disturbing become.

Preferably, the optically active body is made up of two concentric cylinders with different radii, each cylinder comprising a certain circumferential angle. Thus, the circumferential surface extends, for example. Of the one cylinder in cross-section viewed from 0 ° to 180 ° and that of the other cylinder from 180 ° to 360 °. The radii ratios of the two cylinders are dependent on the refractive index of the material used of the optically active body. In this case, the optically active body can be constructed such that, for example, the reflection surface of the larger cylinder and the light output surface of the smaller cylinder is formed. The optically effective body thus represents a simple structure that is light and easy so that it can be inexpensively manufactured and easily installed in a lamp or a headlight.

For the invention it is advantageous that the light output surface the reflective and retroreflective interface is arranged opposite. Light rays from the arranged in the light source occur over a other light input surface (the narrow side) in the optically effective Body, as rays of light coming from an external light source (For example, a headlight of a foreign vehicle) were sent out and retroreflected to enter over a long side. However, both light beam paths lead to the common Reflection surface of the optically active body and from there towards the opposite reflected common light exit surface and over this decoupled. Through the shared reflection surface as well as the shared light output surface the optically effective body is a very compact unit It can be in a light several such optically effective body in almost any way, preferably next to each other or on top of each other, where several juxtaposed or superimposed optically effective body preferably contiguous by a surface are formed. Also a combination with other lighting modules inside the lamp is conceivable. The entire lamp forms with it a very compact and effective unit.

Farther is advantageous that the reflective and retroreflective Interface at least partially a three-dimensional Structure having the three-dimensional structure of the interface for example, several prismatic or pyramidal may have configured reflection elements. Here are the Areas of the prisms or pyramids aligned such that on the one hand emitted by the light source arranged in the light and light beams coupled into the optically active body in a predetermined angular range on the surfaces of the Prisms or pyramids impinge that the light rays in Direction of the light output surface are reflected and can escape there. On the other hand, from outside the light striking the optically active body Light rays through the reflection surface parallel to the incident light rays back from the optically active body decoupled.

Further It is advantageous that the three-dimensional structure of the interface is arranged and designed such that the at least a light source and emitted from the optically active body decoupled light beams a desired light distribution outside the lamp. This ensures that that the lamp without further means for varying the light distribution the legal requirements of the Economic Commission for Europe (ECE).

to Achieving a desired light distribution may be desirable be that the three-dimensional structure of the interface partially formed differently. That way you can differently inclined reflective surfaces of the prisms or pyramids can be realized. In addition, the reflection surface in areas either more for the Lichtleitereflexion or rather be optimized for retroreflection. Conceivable is also that individual arranged in the luminaire optically effective bodies are designed such that they are substantially only as a light guide and other optically arranged in the luminaire effective body essentially only as a retroreflector Act.

To the legal requirements belong beside the required ones Light distribution also requirements regarding the color the emitted light of the light. This is, for example, in Germany prescribed that brake lights must emit red light, On the other hand, flashing lights can emit red or yellow light. Reverse lights must have white light send out. Therefore, it is advantageous that the light emitting element associated light source comprises at least one light emitting diode and that the at least one light-emitting diode emits light of a color, which corresponds to the color of the light emitted by the lamp. This can be dispensed with additional color filter, by absorption losses to a reduction in light intensity would lead. Overall, this results Way a particularly good efficiency of the lamp.

Reflectors predominantly turn red in Germany; in the US, on the other hand, so-called passive sidemarkers on the sides of vehicles have to emit yellow light and so-called active sidemarkers have to emit yellow light. To achieve a desired color of the retroreflected light, a suitable color filter element is advantageously arranged in the beam path of the retroreflected light striking the optically effective body or coupled out of it. Since, for the most part, the light color of the light-emitting element is identical to the light color of the reflector (eg red), in this case virtually no absorption losses take place for the luminous intensity of the luminaire function, since the light-emitting element already emits light rays in the color of the color filter element. It is therefore particularly advantageous to build luminaires in which the color of the light emitting element and the color of the retroreflector match as much as possible. Of course, the color filter element may also be an integral part of a cover be the disc of the light. In this way, active and passive sidemarkers can be realized.

Possible is also that between the at least one light emitting diode and a light coupling surface of the optically active body a color filter element in the beam path of the at least one Light source emitted light is arranged. This arrangement makes sense if the light source emits only white light, the light actively emitted by the lamp but a different color should have.

following is a preferred embodiment with reference to FIGS the invention explained in more detail. Show it:

1 a schematic representation of a lamp according to the invention in a longitudinal section;

2 a side view of an optically active body of the lamp 1 ;

3 a perspective view of a first possible embodiment of a reflection surface of the optically active body 2 ; and

4 a possible perspective view of the optically active body of 2 ,

Detailed description of the figures

1 shows a lamp according to the invention 10 , In particular, a tail lamp, for a motor vehicle, which may be designed in particular as a passenger car, a truck or a motorcycle. The lighting device 10 has a housing 12 on, in the light exit direction 14 one with a translucent cover 16 having closed light exit opening. The housing 12 is preferably made of plastic. The cover 16 can be made of plastic or glass and has no optical elements, for example. To a scattering of light.

Inside the case 12 points the light 10 a light source 24 on. That from the light source 24 emitted light does not leave the light directly 10 but indirectly via one in the beam path of the light source 24 arranged optically active body 18 , The body 18 is made of a transparent material (eg glass or plastic). The optically effective body 18 is preferably composed of two concentric cylinders (see. 4 ).

A subregion of the optically active body 18 includes a three-dimensionally structured interface 20 , which is described in more detail later. The remaining interfaces of the optically active body 18 are smooth in the illustrated embodiment. One of the three-dimensionally structured interface 20 opposite surface of the optically active body 18 serves as a light output surface 22 , In this case, in the optically active body 18 the three-dimensionally structured interface 20 from the larger cylinder and the light output surface 22 are formed by the smaller cylinder of the concentrically arranged cylinder (see. 4 ).

In 1 is below a lower narrow side of the optically active body 18 the light source 24 in the form of a on a heat sink or socket 26 attached light emitting diode 24 arranged. The base 26 serves for mechanical fastening and electrical contacting of the light-emitting diode 24 (in 1 not shown). Of course, it is conceivable, even more than a light emitting diode 24 to use as a light source. In addition, for example, an incandescent lamp could be provided as a light source.

The light-emitting diode 24 steals light in the direction of the lower narrow side of the optically active body 18 off, something by a below the light emitting diode 24 arranged reflector element or an attachment optics for the light emitting diode 24 (both not shown) could be supported. The light-emitting diode 24 can emit white light, but it can also emit colored light (eg yellow or red). In the light 10 can also have several optically effective bodies 18 in any manner, preferably side by side or in the plane of the drawing, one behind the other, be arranged, each having at least one light emitting diode 24 assigned.

2 shows the optically effective body 18 out 1 in a longitudinal section in detail. The three-dimensionally structured interface 20 includes juxtaposed prisms 28 , For the sake of clarity, only a prism with the reference numeral 28 is designated. For a better illustration, see 3 the three-dimensionally structured interface 20 with several prisms 28 shown in perspective. This shows the prisms 28 for better illustration a linear extension. In a real optically active body, the prisms would 28 and the light output surface 22 Of course, viewed in cross-section, they have a circular segment-shaped extent. Each of the prisms 28 has two sloping prism faces 29 so that light can be reflected on them by total reflection (cf. 2 ). Alternatively or additionally, it would be conceivable to use the surfaces 29 to be provided with a reflective layer.

The optically effective body 18 includes in addition to the function of a light emitting element with egg ner light guide function for the light beams of the active radiating LED 24 for any luminaire function (eg brake light, flashing light, position light, active sidemarkers, etc.) also a retroreflective element for a passive (retroreflective) retroreflective function for visualizing the vehicle in the case of inactive light sources of the vehicle.

Based on 2 the luminaire function and the reflection function will be explained in more detail on the basis of an exemplified beam path. To realize the luminaire function, the LED emits 24 light rays 30 in the direction of the narrow side 32 of the optically active body 18 , The narrow side 32 serves as a light input surface. The rays of light 30 meet at a relatively steep angle on the light coupling surface 32 and become there in the body 18 coupled. In the transition from an optically thinner medium (eg air) into a more dense medium (material of the optical element 18 ; z. As glass or plastic) are the light rays 30 to the surface normal of the coupling surface 32 broken down. The optically effective body 18 is designed to have totally reflective properties. In the process, the coupled light beams become 30 at the interfaces at the transition between the optically denser medium and the optically less dense medium totally reflected, provided that they impinge on the interfaces in a relatively flat, suitable for total reflection angle. In the example shown, the light beam 30 at the light output surface 22 at the point 34 totally reflected.

Then the light beam hits 30 on the three-dimensionally structured interface 20 more precisely on the prism surface 29 eg in the point 36 , The prism surfaces 29 are aligned so that the light rays 30 on the surfaces 29 to the light exit surface 22 are totally reflected, in such a way that the on the light exit surface 22 meeting light rays 30 at such an acute angle to the surface 22 that they are not totally reflected, but from the optical element 18 be decoupled (eg in the point 38 ). At the transition from the optically denser to the optically thinner medium, the light rays 30 broken away from the surface normal. The direction of the optically effective body 18 decoupled light beams 30 in the light exit direction 14 depends on the angle of incidence of the light rays 30 in the light coupling surface 32 as well as the inclination of the prism surfaces 29 or their angle relative to each other. The angles are coordinated so that the decoupled light beams 30 preferably without further optically effective means (eg prisms) a desired or legally prescribed light distribution outside the luminaire 10 produce. Also the longitudinal extension (eg straight or curved) or the shape of the optical body 18 has influence on the light exit direction 14 the rays 30 ,

In addition to the light distribution is also the color of the emitted light of the lamp 10 legally required. This can be done by choosing a specific variant of the light emitting diode 24 be realized, which can be made so that it emits light of a particular color. At the refractions and reflections in the optically active body 18 remains that of the LED 24 received emitted light color. Between the light emitting diode 24 and the light coupling surface 32 of the optically active body 18 can a color filter element (not shown) in the beam path of the light emitting diode 24 be emitted light emitted. In this case, with a light source that emits white light, any colored light of the lamp 10 be generated.

Will the light 10 eg of light rays 40 a headlight of an oncoming traffic participant headlighted acts in this case, the reflection function of the optically active body 18 , The beam path for the reflection function is in 2 dotted marked. The rays of light 40 meet at a relatively steep angle to the actual light output surface 22 of the optically active body 18 on. The rays of light 40 occur at the light output surface 22 in the optically active body 18 one. In this respect, the light output surface 22 be referred to in this case as a light entry surface. The rays of light 40 when coupling into the optically active body 18 broken and arrive directly, ie without a total reflection at one of the interfaces of the body 18 , on one of the prismatic surfaces 29 the three-dimensionally structured interface 20 , Due to the right angle of the prism surfaces 29 the light rays become one another 40 first to an opposite prism surface 29 at the three-dimensionally structured interface 20 reflected and from there again in the direction of the light output surface 22 reflected back. The reflected light rays are substantially parallel to the incident light rays 40 , So there is a reversal of the incident light rays 40 (Retroreflexion), which is substantially parallel to the direction of light back at the light output surface 22 from the optically effective body 18 be disconnected and exit.

The color is also required by law for the reflected light. The color can be realized by a color filter element (not shown), in front of the light output surface 22 is arranged. The color filter element can be an integral part of the optically active body 18 be. But it can also be in the cover 16 the light 10 be integrated.

To meet all legal requirements of the Light distribution of the luminaire 10 To fulfill, it may be necessary that the three-dimensional structure 28 . 42 the interface 20 partially formed differently (not shown). This can make the interface 20 In some areas, they are either optimized for the luminaire function or rather for the retro-reflective function.

4 shows a possible perspective view of the optically active body 18 from 2 , The light-emitting diode 24 is not visible but is below the optical element 18 opposite the also not visible coupling surface 32 arranged. In 4 is particularly the cross-sectionally circular segmental configuration of the light output surface 22 as well as the light output surface 22 opposite three-dimensionally structured interface 20 with the prisms 28 clear. For the sake of clarity, only three prisms 28 marked with the reference number. The coupling surface 32 opposite end face of the optical element 18 may be mirrored to prevent uncontrolled leakage of light.

Of course it would be conceivable, the principle described here except for lights also with headlights or any other lighting equipment to use for vehicle with and without internal combustion engine.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 20022581 U1 [0005]

Claims (13)

Lamp ( 10 ) for a motor vehicle with at least one light emitting element which is illuminated by at least one light source ( 24 ) of the luminaire ( 10 ) emitted light in a light exit direction ( 14 ), and having at least one retroreflective retroreflective element, wherein the light-emitting element and the retroreflective retroreflective element in a common optically active body ( 18 ) are integrated with totally reflecting properties, characterized in that the optically active body ( 18 ) Has interfaces, at least one of the interfaces ( 20 ) is arranged and configured in such a way that it can be detected both by the at least one light source ( 24 ) and in the optically active body ( 18 ) coupled light on a light output surface ( 22 ) of the optically active body ( 18 ) as well as from outside the luminaire ( 10 ) through the light output surface ( 22 ) in the optically active body ( 18 ) coupled-in light retroreflected. Lamp ( 10 ) according to claim 1, characterized in that the light output surface ( 22 ) of the at least one interface ( 20 ) is arranged opposite one another. Lamp ( 10 ) according to claim 1 or 2, characterized in that the at least one interface ( 20 ) at least partially a three-dimensional structure ( 28 ; 42 ) having. Lamp ( 10 ) according to claim 3, characterized in that the three-dimensional structure of the interface ( 20 ) several prism-shaped elements ( 28 ) having. Lamp ( 10 ) according to one of claims 3 or 4, characterized in that the three-dimensional structure ( 28 ; 42 ) of the at least one interface ( 20 ) is arranged and configured in such a way that the light emitted by the at least one light source ( 24 ) originating from the optically active body ( 18 ) coupled out light beams ( 30 ) a desired light distribution outside the luminaire ( 10 ) produce. Lamp ( 10 ) according to one of claims 3 to 5, characterized in that the three-dimensional structure ( 28 ; 42 ) of the at least one interface ( 20 ) is formed differently in regions. Lamp ( 10 ) according to one of claims 3 to 6, characterized in that the three-dimensional structure ( 28 ; 42 ) of the at least one interface ( 20 ) has at least partially totally reflecting properties. Lamp ( 10 ) according to one of the preceding claims, characterized in that the light emitting element associated light source at least one light emitting diode ( 24 ). Lamp ( 10 ) according to claim 8, characterized in that the at least one light-emitting diode ( 24 ) of white deviating colored light, in particular red, yellow or orange light emits. Lamp ( 10 ) according to one of the preceding claims, characterized in that the at least one light-emitting diode ( 24 ) emits white light and that in the light exit direction ( 14 ) after the light output surface ( 22 ) of the optically active body ( 18 ) a color filter element, the colored light, in particular red, yellow or orange light passes, in the beam path of the coupled-out light ( 30 ; 40 ) is arranged. Lamp ( 10 ) according to claim 10, characterized in that the color filter element integral part of a cover ( 16 ) of the luminaire ( 10 ). Lamp ( 10 ) according to one of the preceding claims, characterized in that between the at least one light source ( 24 ) and a light input surface ( 32 ) of the optically active body ( 18 ) a color filter element in the beam path of the at least one light source ( 24 ) emitted light is arranged. Luminaire arrangement for a motor vehicle, characterized in that the luminaire arrangement comprises a plurality of luminaires ( 10 ), of which at least one is designed according to one of claims 1 to 12.

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