DE202017104776U1 - Optical fiber for use in a vehicle light emitting device, light emitting device and vehicle - Google Patents

Abstract

A light guide (1, 1 ') for use in a light emitting device of a vehicle, comprising: - a coupling surface (10, 10') for coupling light into the light guide, - a first reflection surface (12, 12 ') comprising at least at least one light and at least partially reflected light impinging on it, a second reflection surface (14, 14 ') which reflects light striking it at least once and at least partially from a second predetermined solid angle range, - a decoupling surface (16, 16 ') for decoupling of light, wherein the coupling surface (10, 10'), the first reflection surface (12, 12 '), the second reflection surface (14, 14') and the decoupling surface (16, 16 ') are formed and mutually are arranged so that at least when coupling light beams in a predetermined direction of irradiation (20a, 20a ') via the coupling surface (10, 10') in the Lichtl At least a first portion of the light beams from the first predetermined solid angle range reaches the first reflection surface (12), is reflected thereby at least simply and at least partially, so that light beams (20c, 20c ') from the second predetermined Spacing space forth on the second reflection surface (14, 14 ') and are at least easily and at least partially reflected by this such that light beams (20d1, 20d2, 20d3, 20d1', 20d2 ', 20d3') to the decoupling surface (16, 16 ' ) and exit therefrom in an exit direction from the light guide (1, 1 '), which with the irradiation direction (20a, 20a') includes an obtuse angle (α).

Description

The invention relates to a light guide for use in a light emitting device of a vehicle and a light emitting device with the light guide and a vehicle with a turn signal or a warning light, which comprises the light guide.

From the DE 10 2004 015 544 A1 the use of a light guide is known, which is integrated in an exterior mirror and is part of a luminous display device in the outside mirror. A light emitting diode is embedded in the light guide, and the light emanating from this is partially reflected one to several times at interfaces of the light guide. A rear of the interfaces is structured in small pieces, for example, by gradations, to direct the light of the LED in different directions. The light exits the unstructured front interface.

A disadvantage of this arrangement is that the light-emitting diode must be arranged in a recess in the middle of the light guide, so that the assembly and maintenance are difficult. Despite the small-scale structuring, the entire angular range over which the light emerges is relatively small.

It is therefore the object of the present invention to provide a light guide for use in a light emitting device of a vehicle, which is more flexible. Preferably, he should also allow another and more preferably even variable arrangement of the light source.

This object is achieved by a light guide having the features of patent claim 1, a light-emitting device having the features of patent claim 13 and by a motor vehicle having the features of patent claim 14 or 15.

The light guide according to the invention for use in a light emitting device of a vehicle thus comprises a coupling-in surface for coupling light into the light guide. It comprises a first reflection surface, which reflects light striking it at least once (at least once) from a first predetermined solid angle range, and this at least partially, ie with an intensity that possibly reduces with respect to the intensity of the light rays incident from the first predetermined solid angle range is. The reflection can take place for different frequencies of the light in different ways, and all subsequent statements about the light and its reflection apply to at least individual wavelengths or wavelength ranges. Preferably, they apply to the entire wavelength range of visible light, ie from about 380 nm and 750 nm.

The optical waveguide further comprises a second reflection surface which, at least from a second predetermined solid angle range, at least simply and at least partially reflects light incident thereon, given the same definitions as for the first reflection surface above. Finally, the light guide comprises a coupling-out surface for coupling out light. The coupling surface, the first reflection surface, the second reflection surface and the decoupling surface are configured and arranged relative to one another such that at least a first (directional or intensity) component of the light rays emerges, at least when coupling in light beams in a predetermined irradiation direction via the coupling surface into the light guide The first predetermined solid angle range arrives at the first reflection surface, is at least simply and at least partially reflected by it, so that all of these light rays or a part thereof (for example with lower intensity) reach the second reflection surface from the second predetermined spatial region and at least thereof are simply and at least partially reflected such that in turn all these light rays or a part thereof (for example, with lower intensity) reach the decoupling surface and exit via this in an exit direction of the light guide, which e includes an obtuse angle with the direction of irradiation. An obtuse angle is an angle of between 90 ° and 180 °. In connection with the reflection, this means that the exiting light beams have a directional component which is opposite to the direction of irradiation. Due to the property of the light guide to reflect light almost back to the starting point, the light source in conjunction with the light guide can to some extent "radiate around the corner". This is of great advantage, especially if the coupling surface is provided as an outer surface of the light guide: then the light source may be spaced apart, for example in a rearview device as in an exterior mirror, hidden in a housing. This results in larger and new design options for the design of the review device.

In a preferred embodiment, the coupling-in surface, the second reflection surface and the decoupling surface are formed and arranged relative to one another such that at least when light rays are coupled in a predetermined direction of irradiation, a second fraction of the light rays (that into another Direction is radiated, or even a proportion of the original total intensity) from the second predetermined space area forth on the second reflection surface and is at least easily and at least partially reflected from this such that light rays reach the outcoupling surface and exit through this in an exit direction of the light guide , which encloses an acute angle with the direction of irradiation. An acute angle is less than 90 °. With the second portion of the light beams, therefore, the range of directions for light radiation is particularly wide, allowing for use in light emitting devices that need to be visible from many directions, such as in a turn signal of a vehicle.

The material of choice for optical fibers is plastic, because it can be easily and inexpensively manufactured by (injection) casting techniques or other plastic processing methods. Preferably, the light guide is completely made of plastic. Further, preferably the plastic material is homogeneous in its composition, density and transparency.

The possibilities for designing the reflections and the light emission are particularly high if the first reflection surface and / or the second reflection surface is or are not flat, ie if they contain curved sections or are curved completely in one.

It is advantageous if the first reflection surface and / or the second reflection surface have a structuring such that upon impact of first and second light beams on different areas of the respective reflection surface, by at most 10% and preferably at most 3% of a longest extent of Diffused light guide, the first and second light beams are reflected in up to 15 ° from each other different directions. In other words, the small-scale structuring ensures that a whole fan is emitted to light rays.

With regard to typical dimensions of, for example, rearview devices, it can similarly be defined that the first reflection surface and / or the second reflection surface have a structuring such that when first and second light rays impinge on different regions of the respective reflection surface which do not exceed 2 mm, preferably spaced apart by at most 1 mm, and more preferably by at most 0.5 mm, the first and second light beams are reflected in directions different by up to 15 ° from each other.

A structuring can generally be designed so that the first reflection surface and / or the second reflection surface have a plurality of (preferably similar and particularly preferably identical) structures, which are formed as optical elements, preferably in the form of prisms or cushions. For example, in the case of such prisms and also not so perfect structures, these each have at least two partial surfaces which are at an angle of between 80 ° and 100 ° to each other (ie substantially perpendicular to each other). (The prisms even have three partial surfaces, which are preferably exactly perpendicular to each other.) In the case of modifications, the optical structures have rounded corners and edges in comparison to such angular shapes.

Typically, the first reflection surface is formed on or as an end face of the light guide, which faces the coupling surface. In particular, it makes sense if the first reflection surface has two partial surfaces which are at an angle of 90 ° to one another, wherein a first partial surface is at an angle of 135 ° to the direction of irradiation, so that a total reflection occurs at the first reflection surface. In the case of a total reflection in the region of the first reflection surface, naturally the loss of intensity of the light guide as a whole is generally low. In the case of such an end face may also be desired that there (approximately adjacent to the first outcoupling surface) a second outcoupling surface is arranged on the at least when coupling light beams in a predetermined direction of incidence on the coupling surface in the light guide at least a portion of the unreflected light beams exits the light guide. This also makes the range of radiation angles can be made particularly wide.

Overall, in an advantageous embodiment, by suitable choice of the outer surfaces and (usually so anyway) of the reflection surfaces, as regards their position to each other, and be ensured by a suitable choice of the material used for the light guide and optionally the small-scale structures on a reflective surface that the intensity of the light beams which reach the outcoupling surface and emerge from the light guide via the latter in an exit direction which includes an obtuse angle with the direction of irradiation is at least 25% of the intensity of the light coupled in via the coupling surface. In other words, at least a quarter of the intensity should be reflected back almost ("around the corner") to allow broad application of the light pipe

The reflectivity can be aided by the fact that the first reflection surface and / or the second reflection surface has or have a reflective coating.

The light-emitting device according to the invention for a vehicle comprises the light guide according to the invention.

A vehicle according to the invention, in particular a motor vehicle, has a turn signal as a light-emitting device, which has the light guide according to the invention.

Another vehicle according to the invention, in particular a motor vehicle, has a warning light as a light-emitting device which has the light guide according to the invention. This is especially helpful in lane departure warning systems, which are supposed to radiate light inwards as a warning from the exterior mirror to the driver, because then the light source (lamp) can be arranged further inwards (closer to the vehicle body) than usual.

Overall, the light-emitting device is advantageously arranged in an exterior rear view device, preferably an exterior mirror.

In the following the invention and its embodiments will be explained in more detail with reference to the drawing. This shows

1 a section through an optical fiber according to a first embodiment of the invention, and

2 a section through an optical fiber according to a second embodiment of the invention.

The in 1 in the whole with 1 designated light guide has a coupling surface 10 on a first end face, and on the opposite end face a first reflection surface 12 consisting of two subareas 12a . 12b consists. On a back of the light guide 1 is a second reflection surface 14 provided, and on a front side of the light guide 1 a decoupling surface 16 , All surfaces 10 . 12 . 14 and 16 together form the outer contour of the light guide, which is injection molded entirely from a transparent plastic. The optical behavior of light at these surfaces is thus defined by the optical transition from the transparent plastic to air. The decoupling surface 16 is perpendicular to the coupling surface 10 and they are both. The first part surface 12a is flat and is at an angle of 135 ° to the decoupling surface. The second subarea 12b is equally flat, and the two faces 12a and 12b are at right angles to each other. The second reflection surface 14 is not parallel to the decoupling surface, but deviates from such an arrangement by an angle ε, it stands at an angle of 135 ° - ε on the second subarea 12b , so that between the coupling surface 10 and the second reflecting surface gives an angle of 90 ° + ε. The second reflection surface has small-scale structures 18 on, such as small prisms (conventional retroreflectors), a sawtooth profile with sharp teeth, such with rounded teeth, pillows, and the like.

Is by means of a light source (for example, a light emitting diode) light (see light rays 20a ) via the coupling surface 10 coupled into the light guide, in the example by vertical incidence of light on the coupling surface 10 , so gets a beam of light 20a to the first partial area 12a the first reflection surface, where it meets at an angle of incidence of 45 ° and is correspondingly reflected in the angle of 45 °, hitting the second surface 12a The first reflection surface at the angle of incidence of 45 ° and is reflected accordingly in the angle of 45 °, that is in the exact opposite direction to the incident light beam 20a reflected. Because the second reflection surface 14 obliquely, enters the current in the opposite direction light beam 20c to this. There the structures effect 18 the second reflection surface 14 another reflection, which depends on the impact on the structures according to the light rays 20d1 . 20d2 . 20D3 can take place, which radiate in at least 15 ° from each other different angles through the decoupling surface 16 therethrough. The different angles already arise when the points of impact are spaced apart by a few millimeters, for instance by 2 mm.

The most reflected light beam 20d1 also has a component in the opposite direction to the injected light beam 20a , So is not perpendicular to this, but at an angle α of between 90 ° and 180 °, ie an obtuse angle. The light guide 1 is so used in rearview devices with integrated turn signal or warning light, where the light source should be located as close to the vehicle body.

The in 2 in the whole with 1' designated optical fiber has comparable features, and corresponding elements and light beams are the same reference numerals as in 1 which is followed by an apostrophe ("'"). Below are the differences to the light guide 1 described: The effect should in particular be that also light is emitted in angular ranges, the light guide 1 not be irradiated.

On the one hand, this is the coupling surface 10 ' graded and made of three partial surfaces 10a ' . 10b ' . 10c ' educated. The second reflection surface 14 ' and the decoupling surface 16 ' Both are curved in the same direction, preferably with concentric or at least approximately parallel contours. At the second end face is a second outcoupling surface 16b ' provided, and the first reflection surface 12 ' includes rounded faces 12a ' . 12b ' ,

The beam path here also includes the light rays 20a ' . 20b ' . 20c ' , which leads to light emission with component in the return direction to the coupling direction, see light beams 20d1 ' . 20d2 ' . 20D3 ' , Other rays of light 20a '' but are reflected so that light rays 20b1 '' . 20b2 '' . 20b3 '' result, which at an acute angle β, that is smaller than 90 °, to the Einkoppelrichtung according to light rays 20a stand. Other light beam components 20a ''' arrive without reflection through the second decoupling surface 16b ' outward.

The light guide 1' is used because of its radiation in different directions, especially in a turn signal, which is integrated in a rear view device. 1 . 1' optical fiber 10 . 10 ' coupling surface 10a ' . 10b ' . 10c ' Partial surfaces of the coupling surface 10 ' 12 . 12 ' First reflection surface 12a . 12b . 12a ' . 12b ' Partial surfaces of the first reflection surface 12 respectively. 12 ' 14 . 14 ' Second reflection surface 16 . 16 ' outcoupling 16b ' Second decoupling surface 18 . 18 ' Structures in the second reflection surface 14 . 14 ' 20a . 20b . 20c . 20d1 . 20d2 . 20D3 . 20a ' . 20b ' . 20c ' . 20d1 ' . 20d2 ' . 20D3 ' . 20a '' . 20b1 '' . 20b2 '' . 20b3 '' . 20a ''' light rays α, β angle

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 102004015544 A1 [0002]

Claims (16)

Optical fiber ( 1 . 1' ) for use in a light emitting device of a vehicle, comprising: - a coupling surface ( 10 . 10 ' ) for coupling light into the light guide, - a first reflection surface ( 12 . 12 ' ), the at least from a first predetermined solid angle range incident light at least simple and at least partially reflected, - a second reflection surface ( 14 . 14 ' ), the at least from a second predetermined solid angle range incident light at least simply and at least partially reflected, - a decoupling surface ( 16 . 16 ' ) for coupling out light, wherein the coupling surface ( 10 . 10 ' ), the first reflection surface ( 12 . 12 ' ), the second reflection surface ( 14 . 14 ' ) and the decoupling surface ( 16 . 16 ' ) are formed and arranged to each other such that at least when coupling light beams in a predetermined direction of irradiation ( 20a . 20a ' ) via the coupling surface ( 10 . 10 ' ) in the light guide ( 1 . 1' ) at least a first portion of the light beams from the first predetermined solid angle range forth on the first reflection surface ( 12 ) is at least easily and at least partially reflected by this, so that light rays ( 20c . 20c ' ) from the second predetermined space area forth on the second reflection surface ( 14 . 14 ' ) and at least be reflected by this at least partially and in such a way that light rays ( 20d1 . 20d2 . 20D3 . 20d1 ' . 20d2 ' . 20D3 ' ) to the decoupling surface ( 16 . 16 ' ) and via this in an exit direction from the light guide ( 1 . 1' ) emerge, which with the Einstrahlrichtung ( 20a . 20a ' ) includes an obtuse angle (α). Optical fiber ( 1' ) according to claim 1, wherein the coupling surface ( 10 ' ), the second reflection surface ( 14 ' ) and the decoupling surface ( 16 ' ) are formed and arranged relative to one another such that at least when light beams are coupled in a predetermined direction of irradiation, a second portion of the light beams ( 20a '' ) from the second predetermined space area forth on the second reflection surface ( 14 ' ) and is reflected by this at least simply and at least partially so that light rays ( 20b1 '' . 20b2 '' . 20b3 '' ) to the decoupling surface ( 16 ' ) and via this in an exit direction from the light guide ( 1' ) emerge, which with the Einstrahlrichtung ( 20a ' ) includes an acute angle (β). Optical fiber ( 1 . 1' ) according to claim 1 or 2, which is formed of plastic and is preferably formed entirely of plastic. Optical fiber ( 1 . 1' ) according to one of claims 1 to 3, in which the first reflection surface ( 12 ' ) and / or the second reflection surface ( 14 . 14 ' ) is not-or is. Optical fiber ( 1 . 1' ) according to claim 4, wherein the first reflection surface and / or the second reflection surface ( 14 . 14 ' ) have a structuring such that upon impact of first and second light beams on different areas of the respective reflection surface ( 14 . 14 ' ) not exceeding 10% and preferably not exceeding 3% of the longest extent of the optical fiber ( 1 . 1' ) are spaced from each other, the first and second light beams are reflected in up to 15 ° from each other different directions. Optical fiber ( 1 . 1' ) according to claim 4, wherein the first reflection surface and / or the second reflection surface ( 14 . 14 ' ) have a structuring such that upon impact of first and second light beams on different areas of the respective reflection surface ( 14 . 14 ' ) which are spaced apart by at most 2 mm, preferably at most 1 mm and more preferably at most 0.5 mm apart, the first and second light beams are reflected in directions different by up to 15 ° from each other. Optical fiber ( 1 . 1' ) according to one of claims 1 to 6, wherein the first reflection surface and / or the second reflection surface ( 14 . 14 ' ) a plurality of preferably similar structures ( 18 . 18 ' ), which are formed as optical elements, preferably in the form of prisms or cushions. Optical fiber ( 1 . 1' ) according to claim 7, wherein the structures ( 18 . 18 ' ) each have at least two partial surfaces which are at an angle of between 80 ° and 100 ° to each other. Optical fiber ( 1 ) according to one of claims 1 to 7, in which the first reflection surface ( 12 ) two partial surfaces ( 12a . 12b ), which are at an angle of 90 ° to each other, wherein a first partial surface is at an angle of 135 ° to the direction of irradiation, so that at the first reflection surface ( 12 ) a total reflection takes place. Optical fiber ( 1' ) according to one of claims 1 to 8, in which adjacent to the first reflection surface ( 12 ' ) a second decoupling surface ( 16b ' ) is arranged on the at least when coupling light beams in a predetermined direction of irradiation via the coupling surface ( 10 ' ) in the light guide ( 1' ) at least one share ( 20a ''' ) of the non-reflected light rays from the light guide ( 1' ) exit. Optical fiber ( 1 . 1' ) according to one of claims 1 to 9, which is designed such that the intensity of the light beams ( 20b1 '' . 20b2 '' . 20b3 '' ) leading to the decoupling surface ( 16 ' ) and via this in an exit direction from the light guide ( 1' ) emerge, which with the Einstrahlrichtung ( 20a ' ) includes an obtuse angle (α), at least 25% of the intensity of the over the coupling surface ( 10 . 10 ' ) coupled light amounts. A light guide according to any one of claims 1 to 11, wherein the first reflection surface and / or the second reflection surface comprises or have a reflective coating. Light-emitting device for a vehicle, with the light guide ( 1 . 1' ) according to any one of claims 1 to 12. Vehicle, in particular a motor vehicle, with a turn signal as a light-emitting device, the light guide ( 1 . 1' ) according to one of claims 1 to 12. Vehicle, in particular a motor vehicle, with a warning light as a light-emitting device, the light guide ( 1 . 1' ) according to one of claims 1 to 12. Vehicle according to claim 14 or 15, in which the light-emitting device is arranged in an exterior rear view device, preferably an exterior mirror.

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