DE102015202595A1 - Lighting device of a vehicle - Google Patents

Abstract

The invention relates to a lighting device (20) of a vehicle for generating a predetermined lighting function, comprising a light source (22), a light guide (24) having a light entry surface (23), totally reflecting side surfaces and a light exit surface (27), wherein at least a portion of the the light (22) emitted light into the light guide (24) coupled in this on the side surfaces along a preferred direction (25) forwarded by total reflection and coupled via the exit surface (27), and a reflector (28) with at least one mirrored Reflection surface (29) which directs at least a portion of the coupled-out light in a Hauptabstrahlrichtung (35) from the illumination device (20). In order to achieve a high efficiency and a homogeneously luminous surface, it is proposed that the light guide (24) at a distal end has a slanted total reflecting deflection surface (26; 26a, 26b; 26c, 26d) which directs the light from the preferred direction (25) deflects in the direction of the exit surface (27), so that the light in a main exit direction (39) decouples from the light guide (24) which is approximately perpendicular or opposite to the preferred direction (25).

Description

The present invention relates to a lighting device of a vehicle for generating a predetermined lighting function. The illumination device comprises a luminous means for emitting light and a light guide having a light entry surface, totally reflecting side surfaces and at least one light exit surface. At least part of the light emitted by the light source is coupled via the entry surface into the light guide, forwarded in the latter at the side surfaces along a preferred direction by means of total reflection and coupled out via the at least one exit surface. Furthermore, the illumination device comprises a reflector with at least one mirrored reflection surface, which directs at least a portion of the coupled-out light in a main emission direction from the illumination device.

An illumination device of the type mentioned can, for example. The US 8,727,574 B2 be removed. The known illumination device has a rotationally symmetrical reflector with a mirrored reflection surface, a light source in the form of a light-emitting diode, and a rod-shaped light guide whose longitudinal extent extends along an axis of rotation of the reflector. Light of the light emitting diode is coupled via a light entry surface into the light guide, forwarded along the longitudinal extent of the light guide by total reflection and reflected at a arranged opposite the entrance surface concave mirrored deflecting surface and coupled out via a convex curved light exit surface of the light guide. The decoupled light beams have a common virtual focus and hit the reflective surface of the reflector. The reflection surface is shaped such that the incident light rays are reflected parallel to each other and parallel to a preferred direction in which the light rays in the light guide are propagated by total reflection. The light-emitting diode and the light guide with the deflection surface and the exit surface together form a virtual light source, which is to be installed as a replacement for conventional light bulbs in a lighting device.

Lighting devices for motor vehicles with light-emitting diodes as bulbs, light guides and reflectors can, for example, the DE 10 2010 048 660 A1 and the DE 10 2013 205 303 A1 be removed.

• A) soll das Verhältnis einer leuchtenden Fläche, die ein Betrachter sieht, der entgegen der Hauptabstrahlrichtung der Beleuchtungseinrichtung in diese blickt, zu dem benötigten Bauvolumen (oder der benötigten Bautiefe) möglichst groß sein,
• B) sollen dem Betrachter alle Flächenelemente der leuchtenden Fläche der Beleuchtungseinrichtung aus einem möglichst großen Betrachtungswinkelbereich möglichst hell und homogen (das Verhältnis des hellsten zu dem dunkelsten Punkt sollte nicht größer als 2:1 sein) erscheinen,
• C) sollen gesetzliche Vorgaben und Vorgaben des Fahrzeugherstellers (die über die gesetzlichen Vorgaben hinaus gehen können) hinsichtlich der abgestrahlten Lichtverteilung erfüllt werden, und
• D) sollen für die optisch wirksamen Flächen keine Einschränkungen hinsichtlich Symmetrie vorliegen, wodurch es möglich wird, auch außergewöhnliche Designvorgaben der Fahrzeughersteller zu realisieren.

The present invention has for its object, a low-cost light for a vehicle (motor vehicle, bicycle, ship, aircraft, etc.) vorzugschlagen. there

• A) should the ratio of a luminous surface, which sees a viewer, who looks against the main radiation direction of the illumination device in this, be as large as possible to the required volume of construction (or the required depth),
• B) the observer should see as bright as possible and homogenous all surface elements of the illuminating surface of the illuminating device from the widest possible viewing angle range (the ratio of the brightest to the darkest point should not be greater than 2: 1),
• C) should comply with legal requirements and specifications of the vehicle manufacturer (which can go beyond the statutory requirements) with regard to the radiated light distribution, and
• D) should be present for the optically effective surfaces no restrictions on symmetry, making it possible to realize even unusual design specifications of vehicle manufacturers.

To solve this problem, it is proposed, starting from the illumination device of the type mentioned above, that the light guide at a distal end at least one with respect to the total reflecting side surfaces of the light guide obliquely total reflecting deflection, which redirects the light from the preferred direction in the direction of the exit surface, so in that the light decouples in a main exit direction from the light guide which runs approximately perpendicular or opposite to the preferred direction, wherein the light guide in the preferred direction in at least one plane from the entry surface to the at least one deflection surface has a widening cross-sectional area, such that that in the preferred direction passed through the light guide light is focused at least in one plane.

According to the invention, the illumination device comprises two optically active parts, namely a light guide and a mirrored reflector. If none of these parts is used to produce the light distribution of the resulting lighting function, can be arranged as a third component in the beam path of the reflected light transparent cover with optically active elements (concave and / or convex facets on the inside and / or outside of the cover , For example, cylindrical lenses or prisms added) (so-called diffusion disc). An important aspect of the invention consists in the total reflecting deflection surface of the light guide, which, together with the reflector, ensures that the main emission direction of the illumination device is different from the preferred direction in which the light rays in the light guide are forwarded by total reflection. The deflection of the light rays in the light guide can be used to broaden and homogenize the on the Reflector incident light can be used. With the present invention, particularly compact lighting devices, in particular with a low overall height, can be realized. Furthermore, a rotational symmetry of the illumination device according to the invention is not required. On the contrary, the illumination device can be used to particular advantage to realize relatively wide, but flat or relatively high, but narrow motor vehicle lights. By dispensing with mirrored areas in or on the light guide, the lighting device according to the invention has special advantages in the production of the light guide.

Advantageous developments of the present invention are the subject of the dependent claims.

Particularly preferred embodiments of the present invention and associated advantages will become apparent from the following description of the figures. Show it:

1 a front view of a motor vehicle headlamp comprising a lighting device according to the invention;

2 a perspective view of the headlight 1 ;

3 a central section through a lighting device according to the invention according to a first embodiment;

4 a perspective view of the lighting device 3 ;

5a to 5d in each case a plan view of a possible form of a light guide of a lighting device according to the invention;

6 a section through a part of a light guide of a lighting device according to the invention;

7 a section through a portion of another optical fiber of a lighting device according to the invention;

8th a section through a portion of another optical fiber of a lighting device according to the invention;

9 a section through a portion of another optical fiber of a lighting device according to the invention;

10 a section through a portion of another optical fiber of a lighting device according to the invention;

11 a section through a portion of another optical fiber of a lighting device according to the invention;

12 a section through a portion of another optical fiber of a lighting device according to the invention;

13 a section through a portion of another optical fiber of a lighting device according to the invention;

14a a luminance gradient over the height of a lens of a lighting device according to the invention, for example. According to 1 and 2 ;

14b a view from the front of the lens of a lighting device according to the invention, for the in 14a the luminance curve is shown;

15 a plan view of a light guide of a lighting device according to the invention;

16 a perspective view of a lighting device according to the invention;

17 a sectional view through the illumination device 16 ;

18 a perspective view of another lighting device according to the invention;

19 a sectional view through the illumination device 18 ;

20 a further embodiment of a lighting device according to the invention in a front view;

21 the lighting device off 20 in a side view;

22 the lighting device off 20 in a plan view;

23 a perspective view of the illumination device 20 ;

24 a horizontal section through the illumination device according to 20 ;

25 a with the lighting device according to the 20 to 24 viable appearance of the illumination device; and

26 a plan view of a further embodiment possibility of a light guide of a lighting device according to the invention.

1 shows the front view of a motor vehicle headlight, in its entirety by the reference numeral 1 is designated. The headlight 1 is in a front portion of a motor vehicle in a designated mounting hole in the vehicle body 2 built-in. At the bottom of the headlamp 1 is a cover frame 3 arranged, of a lower contour of the installation opening of the body 2 follows, in which the headlight 1 is used (see 2 ). The headlight 1 is divided into an upper section and a lower section. In the upper section of the headlight 1 are two light modules 4 . 5 arranged, which are designed to realize a headlight function. The headlamp function may be, for example, a dipped beam, a high beam, a fog light or any adaptive front lighting (AFL). The headlight function can be from one of the light modules 4 . 5 alone or through both light modules 4 . 5 be generated in combination with each other. The light modules 4 . 5 can be designed either as a reflection module or as a projection module. In the example shown, the light module 4 formed as a reflection module, which is a reflector 6 with a central opening 7 for receiving a light source. The light module 5 may also be formed as a reflection system, in which case only one reflector 8th (without an opening for the light source) is shown. The light source can be below the reflector 8th so that they are in 1 are not visible, and light up in the reflector 8th shine through the reflector 8th in a main emission direction of the headlamp 1 is deflected essentially in the direction of travel.

In the lower section of the headlight 1 are two apertures 9 arranged, each one chamber 10 define. The insides of the panels 9 are preferably mirrored. In the chambers 10 in each case a lighting device according to the invention is arranged. The lighting devices can either individually or in combination with each other for the realization of any lighting function. The lighting function is, for example, a daytime running light, a flashing light, a position or parking light. In the example shown, those in the chambers are used 10 arranged lighting devices for the realization of a daytime running light function. The chambers 10 or their openings in the direction of travel define the size and shape of a luminous surface of the lighting devices. The luminous surfaces have in relation to the width of a very small height, the vehicle outside (in 1 to the right) increases slightly.

In each case an upper wall 11 of the chambers 10 and / or a bottom wall of the reflectors 6 . 8th the light modules 4 . 5 forms a separating element between the upper portion and the lower portion of the headlamp 1 , The separating elements 11 Can also be used as a separate component between the top and the bottom section of the headlamp 1 and / or be formed as a single component. The separating element 11 has a substantially horizontal surface extent.

2 shows a perspective view of the headlamp 1 out 1 , The body parts 2 , which define the installation opening of the body and the built-in body lights 1 surrounded, are in 2 not shown. It stands out that the chambers 10 have a relatively large width, but only a relatively small amount. Would you in the two lower chambers 10 Using central bulbs and two paraboloidal reflectors, over 80% of the paraboloids would have to be removed due to the given very flat design and due to the openings for the central bulbs in the reflectors, resulting in a reduction in the efficiency of the chambers 10 realizable lights would result in the same magnitude. Furthermore, significantly less luminous flux would strike the outer regions of the reflectors than the central regions. A viewer would perceive a very bright center and a very strong decrease in brightness to the outside. The appearance of the lights would be extremely inhomogeneous. In addition, a viewer would perceive the openings in the reflectors as dark rings, in the center of the bulbs are perceived as a particularly bright point (so-called "hot spot").

With the present invention, a lighting device for motor vehicles to be proposed, for example, in the very shallow chambers 10 can be integrated and at the same time has a high efficiency and ensures homogeneous illumination of the entire luminous surface.

3 shows a vertical longitudinal section through a first embodiment of a lighting device according to the invention, in its entirety by the reference numeral 20 is designated. On a circuit board 21 is a light source 22 attached to the emission of light and electrically contacted. The light source 22 includes, for example, one or more semiconductor light sources, in particular in the form of one or more light-emitting diodes. Several light-emitting diodes are preferably arranged like a matrix and / or next to one another. The light emitting diodes can produce different light colors, so that different lighting functions can be realized. That of the bulb 22 emitted light penetrates under refraction through a light entry surface facing her 23 a light guide 24 in the light guide 24 and there is there by total reflection in a preferred direction 25 up to an angled deflection surface 26 transported. The deflection surface 26 includes in the in 3 shown section two straight line 26a . 26b which adjoin one another at an obtuse angle. After a deflection of the light, it passes through a light exit surface 27 under refraction in a main exit direction 39 from the light guide 24 out. The illustrated section through the exit surface 27 is a straight line. The exit surface can of course be curved perpendicular to the plane of the drawing (cf. 4 ). One of the exit surface 27 associated reflector 28 with a mirrored reflection surface 29 generates a law-compliant light distribution of the resulting lighting function through an outlet opening 30 the lighting device 20 is emitted. The outlet opening 30 corresponds essentially to an opening of one of the chambers 10 of the headlight 1 in which the lighting device 20 is arranged.

In 3 are two examples from the light guide 24 decoupled light beams 31 . 32 shown. A privacy screen 33 is schematically drawn and corresponds for example to the aperture 9 the chamber 10 in which the lighting device 20 is arranged, and / or the cover frame 3 of the headlight 1 , So the board 21 does not project into the beam path of the reflected light rays is the light guide 24 at the one with the coupling surface 23 provided inclined end down or moved in its entirety downwards (not shown). The light guide 24 widens in the in 3 shown cross section of the coupling surface 23 up to the deflection 26 on, whereby the opening angle of the transported light cone is reduced, that is through the light guide 24 in that direction 25 bundled by total reflection transported light is bundled. This allows increased efficiency in the deflection of the deflecting element 26 ,

The light guide 24 preferably has a plate-like configuration with a flat extension (see. 4 ). In the preferred direction 25 considered decreases the thickness of the light guide 24 from the entrance area 23 up to the deflection 26 to (cf. 3 ). This allows the light rays in the plane of the 3 or a parallel plane to be bundled. In an extension plane perpendicular to this plane, the light guide has 24 the shape of a cake piece, wherein also in the plane of extension of the cross section of the light guide 24 from the entrance area 23 up to the deflection 26 increases (cf. 4 ).

In 4 is a perspective view of the lighting device 20 out 3 shown. The used light guide 24 has in a plan view the shape of a circle segment with a blunt tip, which is the entrance surface 23 forms. Both in plan view and in a vertical section (see. 3 ) takes the cross section of the light guide 24 starting from the entrance surface 23 to the deflection 26 or the exit surface 27 towards. Total reflecting side surfaces form both an upper side 24a as well as a base 24b of the light guide 24 , To the side is the circular arc segment-shaped light guide 24 through lateral boundary surfaces 24c completed, the rays of light, which meet the condition for total reflection, also back into the light guide 24 can reflect. The light guide 24 has as a special feature over known light guides, which are intended for use in lighting devices for motor vehicles, at least one with respect to the top and bottom 24a . 24b oblique deflection surface 26 at the distal, ie the entrance surface 23 opposite end of the light guide 24 , Preferably, the angle of the circular arc segment of the light guide corresponds 24 the double critical angle of total internal reflection. In this case, meet the interfaces 24c no light rays anymore and you get inside the light guide 24 an ordered bundle of light, with only reflections on the surfaces 24a and 24b occur.

The pages 24a . 24b of the light guide 24 do not run exactly parallel to each other and bundle incoming light rays in the plane perpendicular to the plane of extension. In the plane of extension, a bundling only by the refraction at the light entrance surface 23 reached. 'Ordered' in this context means that when two light rays are side by side at the same angle in the light guide 24 enter, then again close to each other and at the same or similar angle from the light guide 24 escape. In the example shown, the two incoming light beams only become at a similar (not exactly the same) angle to each other from the light pipe 24 escape. In these conditions, a reflector 28 be designed very efficiently. A resulting light beam allows a particularly efficient design of the reflector 28 , The width of the light exit surface can then only over the depth of the light guide 24 be varied.

In addition, the shape of the light guide 24 not necessarily by a semicircle around the bulb 22 given around. The reflector 28 indicates as a possible feature a reflection surface 29 with optically active elements arranged thereon 34 on. The optically active elements 34 For example, are formed as convex or concave curved cylindrical reflection sections, wherein cylinder axes of the cylindrical reflection sections 34 preferably parallel to the cutting plane 3 and every other vertical cutting plane. Due to the optically effective elements 34 For example, a desired scattering of the reflected light in the horizontal direction can be achieved, so that the entire light exit opening 30 or a transparent cover that closes this is illuminated as homogeneously and evenly as possible. Alternatively or additionally, it would also be conceivable to use the light exit surface 27 of the light guide 24 to be provided with optically active elements (not shown) or the light exit opening 30 closing transparent cover of the lighting device 20 , for example, the chamber 10 of the headlight 1 from the 1 and 2 or the entire housing of the headlamp 1 could close to provide with optically active elements. Overall, that's from the reflector 28 reflected light in a main emission direction 35 through the light exit opening 30 directed. The reflector 28 So steers that in the main exit direction 39 from the light guide 24 emerging light by about 90 ° in the main emission direction 35 the lighting device 20 around.

In the 5a to 5d are various possible embodiments of the light guide 24 for the lighting device according to the invention 20 shown. In contrast to the known from the prior art, in plan view semicircular light guides (see FIG. DE 10 2010 048 660 A1 respectively. DE 10 2013 205 303 A1 ) have the light guides shown here 24 a deflection surface 26 Regarding the totally reflecting top and bottom of the light guide 24 stands diagonally. In addition, the light guides known from the prior art have 24 no light exit surface 27 placed on the top or bottom of the light guide 24 is arranged. In the top view 5a is the deflection 26 below the exit surface 27 and is therefore only shown in dashed lines. Also drawn by way of example are two light beams 36 and 37 (Grenzstrahlen), the almost grazing on the entrance surface 23 meet and just in breaking into the light guide 24 enter. Outwardly, therefore, are none of the light rays 36 . 37 outgoing further rays in the light guide 24 possible, provided the light entry surface 23 just trained. Of course, resulting in a curved light entrance surface 23 Boundary rays at a different angle. Because the light rays 36 . 37 in the plane shown here almost perpendicular to the exit surface 27 They will meet when leaving the light guide 24 in the plane shown not or only slightly broken. The area of the light guide 24 which is outside the range through which the boundary rays 36 . 37 can be transported, for example, to attach the light guide 24 be used or simply completely omitted.

5b shows with a thin line the light guide 24 out 5a , In the light guide shown here 24 ' become the deflection surface 26 as well as the light exit surface 27 however by a circle section 38 formed with a radius R, which is greater than the radius of the circular section of the light guide 24 out 5a is. The circle section 38 is preferably in the region of the deflection and exit surfaces 26 . 27 between the boundary rays 36 . 37 , The special design of the light guide 24 ' out 5b As a result, the exiting light beam (between the boundary rays 36 ' and 37 ' ) has a larger opening angle than in the example 5a , The reason is that the light rays 36 . 37 in the light guide 24 ' not perpendicular to the deflection surface 26 or the exit surface 27 meet and the light guide 24 ' leave under break. The refraction causes the exit angle of the light rays 36 . 37 increased in accordance with the law of refraction. For comparison with the further-opening light beam (between the light beams 36 ' and 37 ' ) is in 5b that with the light guide 24 out 5a achievable narrower light beams dotted marked.

5c shows another example of a light guide 24 " in which the deflection and the exit surface 26 . 27 through a circle section 38 ' also with one opposite the light guide 24 out 5a enlarged radius R is formed. However, the center F 'of the circle section 38 ' moved to the side, wherein the deflection and exit surfaces 26 . 27 and thus also the emerging light beam (between the light beams 36 ' and 37 ' ) are asymmetrical. The previously shown circular Lichtumlenk- and light exit surfaces 26 . 27 are to be understood as examples only. It is also possible straight, elliptical or free-form surfaces.

5d shows another possibility, such as the light guide 24 '' the lighting device 20 theoretically could be designed. However, this example is not particularly advantageous because the light rays in the center of the exiting light beam (between the light beams 36 ' and 37 ' ) overlap (see the example drawn by way of example) 36 " ), which causes no clear reflection surface 29 for the reflector 28 that exists from the light guide 24 '' according to 5d decoupled light for the realization of a given lighting function with a defined light distribution reflected or the reflector 28 must be placed in an area where no overlap (as in the place 36 " ) takes place, so closer to the light guide 24 '' or farther away than the spot 36 " ,

6 shows in section a first embodiment of the deflection and exit surfaces 26 . 27 a light guide 24 in the lighting device according to the invention 20 can be used. A beveled deflection surface 26 at the distal end of the light guide 24 (opposite the Light entry surface 23 ) directs it by means of total reflection in the direction 25 Forwarded light by total reflection, so that it is refracted by the exit surface 27 in a main exit direction 39 couples out. The exit surface 27 is through an end portion of the top of the light guide 24 educated. A central jet of a on the deflection 26 the light beam is in 6 shown by dashed lines and with the reference numeral 40 designated.

Those rays of light that dotted between the two marked rays 41 on the deflection 26 meet, do not meet the condition for total reflection and therefore occur under refraction by the deflection 26 from (compare the beaten light rays 41 ' ). This leads to a loss of usable light for the lighting function and a deterioration of the efficiency. The dotted light beam 42 next to a wish light beam 43 indicates which directions are affected by the undesired effect (decoupling of the light rays 41 ' ) get lost. The light exit surface 27 is a part of a side surface of the light guide 24 that actually the light by total reflection in the light guide 24 forwards. Due to the deflection of the light rays at the deflection 26 However, the light rays hit the exit surface so steeply 27 that the conditions for total reflection are no longer met, and therefore uncouple.

The comments on the light guide 24 out 6 and the following ones 7 to 13 are greatly simplified, since it is only the in 5a shown simplified case (optical fiber 24 as a semicircle around the bulbs 22 ) and is thus a two-dimensional problem. In all other cases, the light rays leave after deflecting at the deflection 26 the drawing plane of the 6 to 13 , However, to clarify the principle of the present invention and the associated advantages, this simplified illustration is sufficient. Basically, here and in the following 7 to 13 shown embodiments for the deflection and exit surfaces 26 . 27 in any light guides, eg. The light guides 24 . 24 ' . 24 " from the 5a to 5c be provided. In an implementation of the illumination device according to the invention 20 However, in particular with regard to the configuration of the light guide 24 Also the added 3D effects are considered. The deflection of the light rays at the deflection 26 of the light guide 24 out 6 The more effective it is, the larger the deflection angle, the narrower the deflection surface 26 falling light bundles 44 is. It should therefore, if possible, in the 3 and 4 illustrated and explained in the associated description of the figure constriction of the light beam by reducing the cross section of the light guide 24 be performed.

7 shows a second embodiment of a light guide 24 as in the lighting device according to the invention 20 can be used. The deflection area is still at the distal end of the light guide 24 arranged. The deflection surface 26 of the light guide 24 is about the thickness of the light guide 24 out to the top (cf. 4 ) or extended in the view shown here down. From a lower end of the deflection 26 becomes (in the example shown) parallel to a light-guiding side surface of the light guide 24 the light exit surface 27 educated. The light exit surface 27 will end up over a step 45 again with the light-guiding side surface of the light guide 24 connected. This level 45 serves as a diaphragm and prevents light rays directly, that is, without deflection at the deflection 26 , on the lower exit surface 27 can fall.

Dashed lines drawn and with the reference numeral 46 are the steepest light rays present in the incoming light beam. The extension of the deflection 26 is just chosen so that the steepest ray 46 ' that is not of the level 45 dimmed to the (lower) end of the deflection 26 meets. The effect of the downturned deflection surface 26 and the downwardly shifted light exit surface 27 is that light is not on the in 6 existing and dotted here drawn surface piece 47 can be reflected (as long as the condition for total reflection is fulfilled), since this surface piece 47 in the light guide 24 out 7 not available. Would that be the area piece 47 in the light guide 24 of the 7 present, the rays of light would 46 in the dotted way (beams of light 46 " ) at such a steep angle to the deflection 26 that the condition for total reflection would not be fulfilled there. The rays of light 46 " would be breaking over the deflection surface 26 from the light guide 24 be decoupled. About the size of the extension of the deflection 26 down and the corresponding displacement of the light exit surface 27 downwards, it is possible to control which proportion of light should be "saved", since it does not, for example, like the light rays 46 " undesirably over the deflection surface 26 from the light guide 24 is decoupled.

8th shows the light guide 24 with extended deflection surface (as in 7 ), but with a shorter "attached square", that is, the width of the light exit surface 27 is shorter. Here is the light-guiding side surface of the light guide 24 in front of the stage 45 so far inclined that the steepest light beams present in the incoming light beam 48 , which are shown in dashed lines, after a reflection on this inclined surface 49 at the deflection surface 26 meet the conditions for total reflection. The length of the deflection surface 26 (down) is again the steepest ray 48 ' defined that just at the stage 45 passed. The deflection surface 26 is pulled down so far that the boundary ray 48 ' just on the lowest end of the deflection 26 meets.

9 shows another possibility, the efficiency of the deflection and thus the light guide 24 continue to increase. Again, the deflection surface 26 lengthened and turn the length of the deflection 26 through the steepest ray of light 50 (dotted) defined, just at the stage 45 passes and on the lower end of the deflection 26 meets. In contrast to the previous examples here is the inclination of the exit surface 27 chosen so that a deflected light beam meeting them 51 is deflected by a few degrees further in the same direction (by refraction at the light exit surface 27 ). This additional deflection can be used to the first deflection at the deflection 26 less strong, resulting in a greater proportion of light rays 51 in the incoming light beam, the condition for total reflection at the deflection surface 26 can fulfill.

10 shows an embodiment of the light guide 24 for use in a lighting device according to the invention 20 as an advancement of the light guide 24 out 7 can be viewed. In this case, the deflection by two adjacent deflecting surfaces 26a . 26b realized, which are formed in the illustrated vertical section both flat, but curved perpendicular to the plane of the drawing. Of course, the deflection surfaces 26a . 26b in the illustrated section also different, for example. Concave or convex curved, be configured. While the upper deflection 26a the non-extended deflection 26 from the example of 6 corresponds corresponds to the lower deflection surface 26b the extension of the deflection 26 , such as in the 7 and 8th shown.

Looking at a point on the lower extended deflection 26b , you can see that there is a light beam arriving there 52 is considerably narrower than the light beam 44 that points to points of the upper deflection 26a meets. This is due to the fact that only downgoing light rays on the lower deflection 26b can meet. For another, this is because the level 45 flat downwards running beams dimming. The light beam 52 at one point on the extended deflection surface 26b So is the steepest in the incoming light beam 52 existing and the flattest, just not through the stage 45 limited dimmed beam. The width of the light beam 52 decreases the more, the further down the considered point on the extended deflection 26b lies. At the lowest point, in turn, through the (dotted) steepest ray 53 is limited, only the steepest beam comes 53 at. In the example of 10 For a given point, the slope of the extended deflection surface became 26b changed so that the central beam 54 of the narrow beam of light 52 is deflected in the same direction as the central beam 40 of the broad beam of light 44 on the undiluted deflection surface 26a , That means that in the middle of the wide emitted light beam 43 additional light rays arrive. Without tilting the extension 26b That would be the extension 26b reflected light to the edge of the broad beam emitted 43 radiate. All in all, this method can be used to influence the distribution of the total emitted light in the realized lighting function.

Based on 6 to 10 described methods for varying the optical fibers used 24 can be used individually or in combination with each other. In these figures, only straight lines have been used for ease of description. Of course, also (usually) slightly curved surface may be advantageous instead, especially in the example of 10 , as the bundle width with the reflection on deflecting surface 26a . 26b varied.

11 shows a deflection area with two deflection surfaces 26c . 26d which are at a right angle to each other. Unlike the previous embodiments of a light guide 24 for the lighting device according to the invention 20 where deflection angles of about 90 degrees could be realized, can at the light guide 24 out 11 with the two deflection surfaces 26c . 26d , which are at a right angle to each other, deflection can be realized up to 180 degrees. A central beam 40 , which is deflected by 180 degrees, is shown as an example. The exit surface 27 In this case, it has been rotated by 90 ° with respect to the previous embodiments, so that they are directed backwards against the direction 25 is directed, and forms a connecting surface between the lowest point of the deflection 26d and the stage 45 , If the two deflection surfaces 26c . 26d are at a greater angle than 90 degrees to each other, deflection angle of less than 180 degrees can be realized. The efficiency of such a diversion can be determined by means of the above with regard to 6 to 10 optimized methods are described.

In 12 is an embodiment of a light guide 24 for use in a lighting device according to the invention 20 represented, in which the deflection also two deflection surfaces 26c . 26d having. However, these are at an angle of about 270 degrees to each other, so that the light in two directions from the light guide 24 is decoupled. In the illustrated example, the two directions are opposite to each other. In 12 are two light beams by way of example 55 drawn, which are deflected in opposite directions. By a variation of the angle in which the two deflection surfaces 26c . 26d can stand each other, the two directions in which the light from the light guide 24 is decoupled, be varied. The delivery of the light in two directions can be symmetrical or unbalanced (not shown), as shown. The efficiency of such a redirection can be determined by means of the above with reference to the 6 to 10 optimized methods are described. One or both diversions can also, as in 11 are shown executed, so that deflections in an angular range of 90 ° to 180 ° can be realized.

13 shows an embodiment of a light guide 24 for use in a lighting device according to the invention 20 in which an inclined deflection surface 26e not at the distal end of the light guide 24 But in a light-guiding side surface (eg., The top) of the light guide 24 , is arranged. The deflection surface 26e Reflects incident light rays, which meet the condition for total reflection, in the direction of one in the region of the opposite light-guiding side surface of the light guide 24 arranged light exit surface 27e , The light exit surface 27e differs from the rest of the light-conducting surface of the light guide 24 merely by putting on it from the deflection surface 26e deflected light rays impinge, which is the condition for total reflection at the exit surface 27e do not meet and thus out of the light guide 24 be decoupled. Other rays of light in the light guide 24 in the direction 25 be forwarded by total reflection and on the light-guiding side surface of the light guide 24 in the area of the exit surface 27e meet, but not before at the deflection 26e Been deflected, usually meet the condition for total reflection and will be back in the light guide 24 reflected.

In addition to the deflection and exit surfaces 26e . 27e can be at the distal end of the light guide 24 as in the 6 to 12 shown, also deflection and exit surfaces 26 . 27 be provided. In the example of 13 can change the shapes of the two deflection surfaces 26 . 26e differ from each other. Further deflection surfaces, for example along the further extent of the light-guiding side surface, can also be provided. Because of the deflection 26 at the end of the light guide 24 the entire "rest" of the still in the light guide 24 deflected existing light and the light exit surface 27 from the light guide 24 is decoupled, the non-arranged at the end deflection, for example, the deflection 26e , also be performed pieced along a shape curve. In 13 are two light beams by way of example 56 . 57 drawn, the light beam 56 on the deflection 26e meets and over the exit surface 27e from the light guide 24 is decoupled and the light beam 57 on the deflection 26 meets and over the light exit surface 27 from the light guide 24 is decoupled.

The shape of the reflection surface 29 of the reflector 28 the lighting device according to the invention 20 is preferably determined by a mathematical method. This is done at a variety of discrete points on the reflection surface 29 on the basis of the decoupled light beam occurring from a certain direction on this point, the point of the reflection surface 29 calculated such that the incident light beam is reflected in a certain predetermined, well-defined direction. In this way, the reflection surface 29 be calculated at the discrete points. Finally, it is then possible to interpolate between the individual calculated discrete points in order to determine the surface course of the reflection surface 29 to obtain.

Because at every point of the light exit surface 27 of the light guide 24 It is known in which direction the light rays emerge, one can, after the selection of a desired wavefront by means of a known from exploratory geology wavefront method, a reflector 28 or its reflection surface 29 construct, so that the predetermined light distribution of the resulting lighting functions of the lighting device 20 is realized. When using the wavefront method to calculate the shape of the reflection surface 29 The wavefront method can be significantly simplified compared to the applications in exploratory geology, since rays are always in the same medium (air) on the road and thus it is known that no refractive surfaces between the light guide 24 and the reflection surface 29 to take into account. Furthermore, it is known that only one reflective surface 29 is present. For lighting equipment 20 For motor vehicles, one usually uses flat desired waves, which propagate in the 0 ° / 0 ° direction (horizontal = 0 °, vertical = 0 °).

In a final step in the development of the lighting device 20 can by means of optically active scattering elements either on the photoconductive side surfaces of the light guide 24 , the deflection surface 26 or the exit surface 27 the light guide and / or on the reflection surface 29 of the reflector 28 and / or on an additional component (for example, a scattering disk arranged in the beam path) which is generated by law (and possibly by the customer even more sharply defined) light distribution. In the in the 3 and 4 shown illumination device 20 The scattering was by means of cylindrical, vertically extending scattering elements 34 on the reflector 28 or its reflection surface 29 generated. In this case, the cover can be designed as a so-called. Clear disc without optically active elements.

14 shows by means of in the 1 and 2 presented example, which high degree of homogeneity with the illumination device according to the invention 20 in a chamber 10 of the headlight 1 is arranged, can be generated. This is due to the fact that the exit surface 27 of the light guide 24 as elongated in approximately the shape of the reflector 28 the following light source acts (cf. 4 ). The light guide 24 thus generates from the substantially point-shaped light source 22 an elongated virtual light source on the light exit surface 27 of the light guide 24 , wherein a longitudinal extent of the virtual light source of a longitudinal extent of the reflector 28 the lighting device 20 equivalent.

In 14a is a curve of the luminance of the entire light exit surface 30 the lighting device 20 shown. It can be seen clearly that the ratio of maximum luminance to minimum luminance is less than 2: 1. This results in a very homogeneous appearance of the illumination device according to the invention for the inexperienced viewer 20 , This is also due to the in 14b shown appearance of the lamp 20 approved. 14b shows a view from the front of the lens of the illumination device according to the invention 20 , It clearly shows the effect of vertically arranged scattering elements 34 on the reflection surface 29 of the reflector 28 (see. 4 ).

In 15 is a schematic plan view of a light guide 24 for use in the lighting device according to the invention 20 shown (similar to the light guide 24 out 4 ), in front of its entrance surface 23 three LEDs 22a . 22b . 22c are positioned so that all three light emitting diodes 22a . 22b . 22c Light over the entrance area 23 in the light guide 24 inject. The bulbs 22a to 22c can emit light of an identical color or in different colors. Furthermore, in 15 one light beam each 58 . 59 from a lateral LED 22a and the middle LED 22b located. For the currently smallest feasible distance between two adjacent LEDs 22a to 22c of about 2.2 mm results in the in 15 drawn length of the rays 58 . 59 of about 80 mm an angle between the light rays 58 . 59 of about 1.5 degrees. This allows a lighting device 20 as daytime running lights and flashing lights (with white or yellow light emitting diodes) or in the case of a taillight as tail light and / or as a brake light (all LEDs red) or to realize similar lighting functions without loss of efficiency. In an approximation that is sufficiently accurate for the present case of application, the angle deviation results for: arctan (LED distance / distance from entrance surface 23 to deflection 26 ) = arctane (2.2 mm / 80 mm) = arctane (0.0275) = 1.575 degrees.

In the 16 (perspective view) and 17 (Vertical section) is part of another embodiment of a lighting device according to the invention 20 shown. Here is the light guide 24 similar to the one in 11 illustrated light guide 24 educated. The 16 and 17 show the light guide 24 and the reflector 28 , Board, lamps, diffusers and panels are not shown. The beam path in the lighting device 20 illustrates a dashed line example light beam 60 in 17 , As in this embodiment, the distance between the exit surface 27 and the reflector 28 or the reflection surface 29 is relatively large, the exit surface 27 executed here convexly curved. This can be realized by a plurality of superimposed planar surfaces or by one or more curved surfaces. This makes it possible on the reflector 28 or the reflection surface 29 to "aim", as a reduction in the opening angle of the light guide 24 decoupled light beam and thus a higher efficiency can be achieved.

The 18 (perspective view) and 19 (Vertical section) show a further embodiment of a lighting device according to the invention 20 , Again, the board, the light emitting diode, diffusers and panels are not shown. The deflection surface 26 of the light guide 24 is similar to the one in 7 shown light guide 24 extended (here: over the thickness of the light guide 24 extended upwards). However, the light guide has 24 from the 18 and 19 above no level 45 , Rather, the light exit surface 27 by a bent along a bend distal end portion of the upper light-guiding side surface of the light guide 24 educated. The deflection surface 26 and the exit surface 27 run at a small angle relative to each other (smaller than the 6 to 10 ). The deflection area can (as in the 6 to 9 ) a deflection surface 26 or (as in 10 ) Several, for example. Two deflection surfaces 26a . 26b , exhibit.

The light exit surface 27 does not run as in 7 shown, parallel to the light-conducting side surfaces of the light guide 24 but parallel to the steepest in the light guide 24 extending light beam, so that they can only be hit by light rays, previously at the deflection 26 have been reflected. This causes the light over the light exit surface 27 under a small one Angle from the light guide 24 exit. This allows the reflector 28 at a relatively great distance from the light pipe 24 or from the light exit surface 27 to place without affecting the overall height of the lighting arrangement 20 would increase decisively. Due to the increased distance between the light exit surface 27 and the reflector 28 the reflector width can be increased. In 19 is an example of a ray of light 61 located on the deflection 26 is deflected over the light exit surface 27 at a shallow angle out of the light pipe 24 exit, at the reflection surface 29 of the reflector 28 reflected and in the main emission direction 35 is diverted.

The 20 to 24 show different views of a further embodiment of a lighting device according to the invention 20 , In 20 is a front view (opposite to the main radiation direction 35 ), 21 shows a side view of the lighting device 20 . 22 a plan view of the lighting device 20 . 23 a perspective view of the lighting device 20 and 24 a horizontal section through the illumination device 20 , The light guide used here 24 has a two-sided extraction similar to that in FIG 12 shown light guide 24 , In contrast to the embodiment of the 12 are the exit surfaces 27a . 27b inclined, as in principle 9 shown. In addition, the exit surfaces 27a . 27b with a diffusing optic of horizontal cylinders 34a provided, which accomplish the vertical dispersion for the legally prescribed light distribution of the lighting function. The on both sides of the light guide 24 arranged, in this example integrally formed reflector 28 with two separate reflection surfaces 29a . 29b has vertically standing curved cylindrical scattering elements 34b on, which cause the horizontal distribution for the legally prescribed light distribution.

In contrast to the previously discussed embodiments, the embodiment of the 20 to 24 a screen 33 as an additional component. On the one hand, it serves to put one in front of the luminaire 20 standing observer no insight on power supplies, the board 21 , Heatsink and other innards of the lighting device 20 Has. On the other hand, the screen 33 for fixing the light guide 24 and / or the reflector 28 be used. The aperture 33 is in 21 integral with a bottom plate 62 connected (so-called stand pattern). Of course, the screen can 33 also with a housing of the lighting device 20 and / or the headlight 1 be connected. Advantageously, in a vehicle instead of an additional component, such as the screen 33 , use a Bezel (screen / design element) that exists anyway.

23 shows a perspective view without aperture 33 and bottom plate 62 , Here are the cylindrical scattering elements 34a on the light exit surfaces 27a . 27b of the light guide 24 and the scattering elements 34b on the reflection surfaces 29a . 29b of the reflector 28 to recognize. 24 shows a horizontal section through the illumination device 20 from the 20 to 23 , The illustrated example light beam 63 is shown in dashed lines, the scattering elements 34b on the reflection surfaces 29a . 29b are just to recognize. 25 shows the great homogeneity, with the illumination device according to the invention 20 according to the embodiment of the 20 to 24 over the entire reflection surface 29a . 29b can be achieved.

26 shows a further possible embodiment of a light guide 24 for use in the lighting device according to the invention 20 , Instead of a reflector as previously described 28 with one or a maximum of two reflecting surfaces 29 with out of the light guide 24 to irradiate decoupled light, is made by suitable choice of the shape of the light guide 24 and the deflection and exit surfaces 26 . 27 the possibility of separated light beams 64 . 65 . 66 in larger numbers and for these individual bundles 64 . 65 . 66 suitable reflection surfaces 29 to develop. In the example of 26 become three light bundles 64 . 65 . 66 generated in the case of unilateral decoupling or six light bundles in the case of two-sided decoupling.

In this case, all the light bundles could 64 . 65 . 66 through a separate reflector 28 be redirected, or there is a possibility for groups of light bundles 64 . 65 . 66 separate reflectors 28 or all the light bundles can develop 64 . 65 . 66 with a single integral, several separate reflecting surfaces 29 having reflector 28 are processed. Of course, the reverse case is also conceivable, namely that the light bundles 64 . 65 . 66 from several separate light guides 24 from a one-piece reflector 28 or a single reflection surface 29 are processed.

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

• US 8727574 B2 [0002]
• DE 102010048660 A1 [0003, 0047]
• DE 102013205303 A1 [0003, 0047]

Claims (19)

Lighting device ( 20 ) of a vehicle for generating a predetermined lighting function, comprising a light source ( 22 ) for emitting light, a light guide ( 24 ) with a light entry surface ( 23 ), totally reflecting side surfaces and at least one light exit surface ( 27 ), wherein at least a part of the light source ( 22 ) emitted light over the entrance surface ( 23 ) in the light guide ( 24 ), in this at the side surfaces along a preferred direction ( 25 ) forwarded by total reflection and on the at least one exit surface ( 27 ) and a reflector ( 28 ) with at least one mirrored reflecting surface ( 29 ), which at least a part of the coupled-out light in a main emission direction ( 35 ) from the lighting device ( 20 ), characterized in that the light guide ( 24 ) at a distal end at least one with respect to the total reflecting side surfaces ( 24a . 24b ) of the light guide ( 24 ) obliquely totally reflecting deflecting surface ( 26 ; 26a . 26b ; 26c . 26d ), the light from the preferred direction ( 25 ) in the direction of the exit surface ( 27 ), so that the light in a main exit direction ( 39 ) from the light guide ( 24 ) which is approximately perpendicular or opposite to the preferred direction (FIG. 25 ), wherein the optical fiber ( 24 ) in the preferred direction in at least one plane from the entrance surface ( 23 ) to the at least one deflection surface ( 26 ; 26a . 26b ; 26c . 26d ) has a widening cross-sectional area, so that in the preferred direction ( 25 ) through the light guide ( 24 ) passed light is focused at least in one plane. Lighting device ( 20 ) according to claim 1, characterized in that the light guide ( 24 ) in the preferred direction in two planes that are perpendicular to each other, from the entrance surface ( 23 ) to the at least one deflection surface ( 26 ; 26a . 26b ; 26c . 26d ) has a widening cross-sectional area, so that in the preferred direction ( 25 ) through the light guide ( 24 ) passed light is bundled in two levels. Lighting device ( 20 ) according to claim 1 or 2, characterized in that the light exit surface ( 27 ) of the light guide ( 24 ) is provided with optically active elements for beam shaping. Lighting device ( 20 ) according to one of claims 1 to 3, characterized in that a reflection surface ( 29 ) of the reflector ( 28 ) with optically active elements ( 34 ) is provided for beam shaping. Lighting device ( 20 ) according to one of claims 1 to 4, characterized in that in the beam path of the reflector ( 28 ) reflected light is arranged a lens with optically active elements for beam shaping. Lighting device ( 20 ) according to one of claims 1 to 5, characterized in that the main emission direction ( 35 ) into which the reflector ( 28 ) that from the exit surface ( 27 ) of the light guide ( 24 ) decoupled light, approximately perpendicular to the main exit direction ( 39 ) of the light from the light guide ( 24 ) runs. Lighting device ( 20 ) according to one of claims 1 to 6, characterized in that the light guide ( 24 ) next to a beam path of the reflector ( 28 ) in the main emission direction ( 35 ) reflected light is arranged. Lighting device ( 20 ) according to one of claims 1 to 7, characterized in that the light guide ( 24 ) has an areal extent in a sectional plane, wherein the sectional plane next to the beam path and substantially parallel to the main radiation direction ( 35 ) of the reflected light is arranged. Lighting device ( 20 ) according to claim 8, characterized in that the light guide ( 24 ) in the sectional plane of the entrance surface ( 23 ) to the at least one deflection surface ( 26 ; 26a . 26b ; 26c . 26d ) has a widening shape. Lighting device ( 20 ) according to one of claims 1 to 9, characterized in that the light guide ( 24 ) is configured such that all in the light guide ( 24 ) in the preferred direction ( 25 ) by means of total reflection forwarded light rays at least once at the at least one deflection surface ( 26 ; 26a . 26b ; 26c . 26d ) are totally reflected before being applied to the at least one exit surface ( 27 ) to meet. Lighting device ( 20 ) according to claim 10, characterized in that the at least one totally reflecting deflecting surface ( 26 ; 26a . 26b ; 26c . 26d ) over a thickness of the light guide ( 24 ) out in the direction of the main exit direction ( 39 ), so that the light guide ( 24 ) a step ( 45 ) of one of the totally reflecting side surfaces ( 24a . 24b ) of the light guide ( 24 ) reflected light rays from the at least one exit surface ( 27 ) shaded. Lighting device ( 20 ) according to claim 11, characterized in that a height of the step ( 45 ) is dimensioned such that the steepest of the in forwarding the light beams in the preferred direction ( 25 ) through the light guide ( 24 ) of one of the totally reflecting side surfaces ( 24a . 24b ) of the light guide ( 24 ) reflected light rays ( 46 ' . 48 ' . 50 . 53 ) the exit surface ( 27 ) is no longer reached, but on the at least one deflection surface ( 26 ; 26b ; 26d ) and from this to the exit surface ( 27 ) is reflected. Lighting device ( 20 ) according to claim 11 or 12, characterized in that the at least one exit surface ( 27 ) is inclined such that of the at least one deflection surface ( 26 ; 26a . 26b ; 26c . 26d ) on the exit surface ( 27 ) obliquely incident light beams ( 51 ) when decoupling from the light guide ( 24 ) are further refracted in the direction from which they reach the at least one exit surface ( 27 ). Lighting device ( 20 ) according to one of claims 1 to 13, characterized in that the or each deflection surface ( 26 ; 26a . 26b ; 26c . 26d ) each comprise at least one planar partial surface. Lighting device ( 20 ) according to claim 14, characterized in that the or each deflection surface ( 26 ) a first planar partial surface ( 26a ) further away from the at least one exit surface ( 27 ) and an adjoining second planar partial surface ( 26b ) closer to the at least one exit surface ( 27 ), wherein the two planar partial surfaces ( 26a . 26b ) adjoin one another at an obtuse angle. Lighting device ( 20 ) according to claim 14, characterized in that the or each deflection surface ( 26 ) a first planar partial surface ( 26c ) and an adjoining second planar partial surface ( 26d ), wherein the two planar partial surfaces ( 26c . 26d ) at an angle of about 90 ° to each other, so that the light in a main exit direction ( 39 ) from the light guide ( 24 ) which is approximately opposite to the preferred direction (FIG. 25 ) in the optical fiber ( 24 ) passed light passes. Lighting device ( 20 ) according to claim 14, characterized in that the or each deflection surface ( 26 ) a first planar partial surface ( 26c ) and an adjoining second planar partial surface ( 26d ), wherein the two planar partial surfaces ( 26c . 26d ) at an angle of about 270 ° to each other, so that the light in two oppositely directed main exit directions ( 39 ) from the light guide ( 24 ), each approximately perpendicular to the preferred direction (FIG. 25 ) in the optical fiber ( 24 ) passed on light. Lighting device ( 20 ) according to claim 17, characterized in that the reflector ( 28 ) of the lighting device ( 20 ) two each in the beam path of the in the opposite main exit directions ( 39 ) from the light guide ( 24 ) of decoupled light ( 29a . 29b ) having. Lighting device ( 20 ) according to one of claims 1 to 18, characterized in that the at least one reflection surface ( 29 ) of the reflector ( 28 ) is formed as a free-form surface, wherein the at least one reflection surface ( 29 ) is calculated at a plurality of discrete points in each case in such a way that the light emitted from the light guide ( 24 ) and to the respective point of the reflection surface ( 29 ) falling light is reflected in a predetermined range of the light distribution, and the at least one reflection surface ( 29 ) is interpolated between the calculated discrete points.

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