[0001] The present invention relates to a Lighting device for a vehicle, in particular a
motor vehicle, wherein the lighting device comprises at least one lighting unit which
is configured to emit a light beam in a first light emission direction, wherein the
light rays of said light beam are parallel or essentially parallel to the first light
emission direction
- in cutting planes parallel to a vertical plane containing the first light emission
direction, or
- in cutting planes parallel to a horizontal plane containing the first light emission
direction, or
- in cutting planes parallel to the vertical plane containing the first light emission
direction and in cutting planes parallel to a horizontal plane containing the first
light emission direction, wherein
the at least one lighting unit is configured to produce for itself alone a light distribution
with said light beam emitted by it in an area in front of the lighting unit, in particular
in a traffic area, e.g. on a road.
[0002] The wording "light rays are parallel to each other in a plane" means that the projections
of said light rays in this plane are parallel to each other.
[0003] The invention also relates to a vehicle headlight comprising at least one lighting
device.
[0004] Finally, the invention relates to a vehicle, in particular a motor vehicle comprising
at least one lighting device or at least one vehicle headlight according.
[0005] Lighting devices for vehicles, in particular motor vehicles, for producing a light
distribution in front of the vehicle, for example on a road in front of the vehicle,
have been sufficiently known from the state of the art for many years. In most cases,
these light distributions are so-called main beam distributions, for example, low
beam distributions, high beam distributions, and so on.
[0006] The present invention relates to lighting devices for vehicles which have one or
more light units, whereby these light units jointly produce a desired light distribution.
Each light unit emits a light beam of parallel or essentially parallel light rays,
said light beam of parallel or essentially parallel light rays produces or contributes
(in the case of two or more light units) to the light distribution. In the case of
a lighting device with two or more light units, the emitted light beams of parallel
or essentially parallel light beams are preferably parallel to each other, i.e. the
propagation directions of the light beams are preferably parallel to each other.
[0007] It is clear to the person skilled in the art that such a light unit not only generates
parallel or essentially parallel light rays, but that a light unit also emits light
rays to a certain extent that are not parallel to the light beam of parallel or essentially
parallel light rays. However, the invention relates to lighting devices with lighting
units in which the light beam of parallel or essentially parallel light rays forms
the light distribution; in other words, the lighting unit(s) project(s) the light
distribution to infinity.
[0008] The one or more lighting units are arranged in a headlamp housing, for example, whereby
such headlamp housings are often sealed with a transparent cover disc. This usually
allows a view of the at least one lighting unit from outside the headlamp housing
or from outside the vehicle.
[0009] For design reasons, however, it is often undesirable for the lighting unit(s) to
be visible from the outside.
[0010] It is an object of the invention to prevent the lighting unit(s) from being seen
when looking at or into the lighting device from the outside.
[0011] This object is solved with a lighting device mentioned at the beginning, wherein
according to the invention an optical device is provided after the at least one lighting
unit seen in the direction of light propagation, wherein the optical device comprises
- a number of first optically effective surfaces, wherein each first optically effective
surface has a first optical axis, wherein light rays of the light bundle coming from
the at least one lighting unit are focused by each first optically effective surface
into a focus point or a focal line of the respective first optically effective surface,
and
- a number of second optically effective surfaces, each second optically effective surface
having an optical axis and a respective focal point or focal line, wherein each second
optically effective surfaces is configured to form light rays, which emanate from
their respective focal point or their respective focal line, into a bundle of parallel
or essentially parallel light rays,
wherein each first optically effective surface is assigned in a one-to-one manner
to precisely one second optically effective surface,
and wherein the first optically effective surfaces and second optically effective
surfaces assigned to each other are arranged relative to one another such that their
focal points or focal lines coincide and wherein each focal point or focal line is
arranged between its first optically effective surface and its second optically effective
surface,
and wherein the optical axes of first optically effective surfaces and second optically
effective surfaces assigned to each other run parallel to one another,
and wherein all optical axes of the first and second optically surfaces are parallel
to each other,
and wherein the first light emission direction is parallel to the direction to the
optical axes of the first and second optically surfaces,
so that the light rays of the light beam emitted by the at least one lighting unit
and propagating in the first light emission direction emerge, after passing through
the associated first optically effective surfaces and the second, optically effective
surfaces as a modified light beam propagating in a second light emission direction,
wherein the light rays of said modified light beam are parallel or essentially parallel
to the second light emission direction,
- in cutting planes parallel to a vertical plane containing the second light emission
direction, or
- in cutting planes parallel to a horizontal plane containing the second light emission
direction, or
- in cutting planes parallel to the vertical plane containing the second light emission
direction and in cutting planes parallel to a horizontal plane containing the second
light emission direction, wherein
wherein the second light emission direction is identical to the first light emission
direction.
[0012] In particular, if the light rays of the light beam emitted by the at least one lighting
unit are parallel or essentially parallel to the first light emission direction in
cutting planes parallel to a vertical plane containing the first light emission direction,
the light rays of the modified light beam are parallel or essentially parallel to
the second light emission direction in cutting planes parallel to a vertical plane
containing the second light emission direction.
[0013] In particular, if the light rays of the light beam emitted by the at least one lighting
unit are parallel or essentially parallel to the first light emission direction in
cutting planes parallel to a horizontal plane containing the first light emission
direction, the light rays of the modified light beam are parallel or essentially parallel
to the second light emission direction in cutting planes parallel to a horizontal
plane containing the second light emission direction.
[0014] In particular, if the light rays of the light beam emitted by the at least one lighting
unit are parallel or essentially parallel to the first light emission direction in
cutting planes parallel to a vertical plane containing the first light emission direction
and in cutting planes parallel to a horizontal plane containing the first light emission
direction, the light rays of the modified light beam are parallel or essentially parallel
to the second light emission direction in cutting planes parallel to the vertical
plane containing the second light emission direction and in cutting planes parallel
to a horizontal plane containing the second light emission direction.
[0015] This has the effect that the light distribution produced by the modified light beam
is identical or essentially identical to the light distribution produced by the at
least one light unit for itself alone.
[0016] The optical device does not change the direction of propagation of the parallel or
essentially parallel light rays emitted by the at least one lighting unit, so that
the light distribution is not or only slightly changed.
[0017] The lighting unit(s) do not emit light rays that are not essentially parallel to
the first emission direction, thus the light distribution is not or only slightly
influenced by the optical device. However, when viewed at daylight from outside, ambient
light, which is illuminating the light module from outside enters and exits the module
in various different directions. This light, which exits the module and can be viewed
from outside, is generally not parallel to the first emission direction and is thus
diffused or smeared out by the optical device. Thus, the light module cannot be viewed
from an external observer from a direction different to the main emission direction.
[0018] The modifications of the lighting device according to the invention therefore do
not or only insignificantly change the generated light distribution, so that identical
light distributions or light distributions that are essentially identical with respect
to a light distribution, that is generated by the at least one lighting unit alone
(i.e., without an optical device according to the invention), are generated.
[0019] A light distribution is defined by its shape, for example the position of a cut-off
line, and/or by illuminance values that are to be fulfilled at certain measuring points.
These illuminance values are usually specified by standards or laws.
[0020] Light distributions are considered identical or essentially identical, for example,
if either all illuminance values are identical at all relevant measuring points or
only deviate within certain specified limit values, whereby the deviations must be
within the deviations permitted by law or standard.
[0021] Advantageous embodiments of the invention are described in the dependent claims.
[0022] It may be provided that the optical axes of first optically effective surfaces and
second optically effective surfaces assigned to each other coincide.
[0023] It may be provided that each first optically effective surface and its associated
second optically effective surface define an optically transparent optical body.
[0024] Accordingly, it may be provided that, as will be described later, a first optically
effective surface and a second optically effective surface assigned to each other
form a (small), optically transparent body, e.g. in the form of a micro lens or on
the form of a cylindrical lens. The first optically effective surface forms a light
inlet surface of this body, the second optically effective surface forms the light
outlet surface of this optical body. Each individual optical body is made of an optically
transparent material, preferably all optical bodies are made of the same material.
The focal points or focal lines are thus located within the respective optically transparent
optical body. The micro lenses have no beam diaphragm or similar between their first
optically effective surface and their second optically effective surface.
[0025] Further, it may be provided that the optical bodies are directly adjacent to one
another, wherein, for example,
- the individual optical bodies are extending transversely, in particular horizontally,
and are arranged one above the other, or
- the individual optical bodies are arranged in an m x n array of columns and rows,
where m ≥ 2 and n ≥ 2.
[0026] It may be provided that the first optically effective surfaces are directly adjacent
to one another and form a continuous light-inlet surface, and wherein the second optically
effective surfaces are directly adjacent to one another and form a continuous light-emitting
surface.
[0027] Preferably, it is provided that the optical bodies are connected to one another in
one piece and form the optical device.
[0028] It may be provided that the first optically effective surfaces and/or the second
optically effective surfaces are curved, in particular convexly curved.
[0029] For example, the first and/or second, preferably the first and second optically effective
surfaces are curved both vertically and horizontally. In this case, first and second
optically effective surfaces assigned to each other each form a so-called microlens
and the optical device is a microlens array. A projection of the optically effective
surfaces in a plane normal to the optical axis of the respective optically effective
surface forms, for example, a square or a rectangle or a polygon. Associated first
and second optically effective surfaces preferably have an identical shape of projection
and identical size and preferably coincide identically when projected into the same
plane.
[0030] In the case where the first and second optically effective surfaces form micro lenses,
a focal point (one focal point for each optically effective first/Second surface,
both focal points coincide) is located within the optical body bounded by two optically
effective surfaces, as already described in detail. In this case, the deflection occurs
at both optically effective surfaces in both horizontal and vertical directions, whereby
the direction of the light rays after passing through the optical device is unchanged
from the direction before the optical device.
[0031] It may be provided that the focal points or focal lines of the first optically effective
surfaces and the second optically effective surfaces lie in a common plane, wherein
preferably a normal vector to the common plane is parallel to the first light emission
direction of the light beam emitted from the at least one lighting unit.
[0032] These features ensure that first light emission direction and the second light emission
directions are parallel to each other.
[0033] Furthermore, it may be provided that the focal lines run horizontally and transversely
to the first light emission direction of the light beam emitted by the at least one
lighting unit, in particular perpendicular to said first light emission direction.
[0034] In this case of cylindrical lenses formed by first and second optically effective
surfaces the first and/or second, preferably the first and second optically effective
surfaces are curved in vertical direction, so that the light rays propagating parallel
or essentially parallel to the first light emission direction, which is parallel to
the optical axis of the two optically effective surfaces, are deflected twice in vertical
direction when passing through the optical device in order to propagate in the second
light emission direction after the optical device, wherein the second light emission
direction is identical to the first light emission direction.
[0035] It may be provided that a cylindrical lens is provided in the beam path after the
at least one lighting unit, the cylinder axes of which cylindrical lens runs vertically
and in particular perpendicular to the first light emission direction of the light
beam emitted by the at least one lighting unit.
[0036] This embodiment can be useful if the optical device is made up of individual transverse
cylindrical lenses as described above. The light entry and exit surface of this cylindrical
lens ("macro cylindrical lens", in contrast to cylindrical lenes formed by a first
and a second optically effective surface, which may also be denoted as "micro cylindrical
lens") are curved in a horizontal direction. Accordingly, said "macro" cylindrical
lens generates horizontal deflection of the light rays of the light beam emitted by
the at least one lighting unit on both its light entry and its light exit surface,
so that after passing through the macro cylindrical lens, the light beam propagates
in the same direction as the light beam before the macro cylindrical lens, and the
light rays of the light beam after the macro cylindrical lens are parallel or essentially
parallel to the direction of the light beam.
[0037] Such a macro cylindrical lens can alternatively or in addition be used to parallelize
light that is not emitted in parallel from the lighting unit.
[0038] Light rays (entering the lighting device from outside and reflected back to the outside)
are not parallel or not essentially parallel to the first emission direction of the
light beam and thus are horizontally scattered to make it difficult or impossible
to see the lighting unit(s) from outside from the side.
[0039] Preferably, it is provided that the (macro) cylindrical lens is arranged between
the at least one lighting unit and the optical device.
[0040] This ensures that both the lighting unit and the macro cylindrical lens cannot be
recognized from the outside.
[0041] Another advantage of the macro cylindrical lens may be that it focuses vertical structures,
which is why vertical lines are imaged sharply, and horizontal structures (top and
bottom edges) are not, so that a (smooth) transition of the bottom and top edges can
be realized.
[0042] It may be provided that the lighting unit is configured to generate the lighting
unit is configured to generate at least one of the following light functions and its
corresponding light distribution:
- a light function producing a light distribution with a cut-off line, in particular
an essentially horizontally cut-off line;
- a low-beam (light distribution);
- a high beam (light distribution) or a light function producing a part of a high beam
light distribution;
- a cornering light (light distribution);
- an adaptive driving beam (ADB) (light distribution);
- a part of a driving beam light (a light function producing a part of a driving beam
light distribution);
- a daytime running light (light distribution),
- a turn-indicator (light distribution).
[0043] The invention is explained in more detail below with reference to the drawing:
Fig. 1 shows a lighting device according to the state of the art,
Fig. 1a shows a light distribution produced with a lighting device of Figure 1,
Fig. 2 shows a lighting device according to a first embodiment according to the invention,
Fig. 2a shows a detail D2 of Figure 2 in enlarged view,
Fig. 2b shows a vertical section through a lighting unit and the optical device of
Figure 2,
Fig. 2c shows a horizontal section through a lighting unit and the optical device
of Figure 2,
Fig. 3 shows a lighting device according to a second embodiment according to the invention,
Fig. 3 a shows a detail D3 of Figure 3 in enlarged view,
Fig. 3b shows a vertical section through a lighting unit and the optical device of
Figure 3,
Fig. 3c shows a horizontal section through a lighting unit and the optical device
of Figure 3,
Fig. 4 shows a sub-variant of the second embodiment shown in Figure 3,
Fig. 4a shows the behavior of light rays passing through a (macro) cylindrical lens
before passing through the optical device in a horizontal section through the lighting
device, and
Fig. 5 & 6 show, in purely schematic form, the influence of the invention on non-parallel
light beams.
[0044] Figure 1 shows a lighting device 1 for a vehicle, in particular a motor vehicle, wherein the
lighting device 1 comprises at least one, in the example shown four lighting units
100a, 100b, 100c, 100d. Each lighting unit 100a, 100b, 100c, 100d comprises a light
source 101a, 101b, 101c, 101d, wherein each light source for example comprises one
or more LEDs. Furthermore, each lighting unit 100a, 100b, 100c, 100d comprises optical
means 102a, 102b, 102c, 102d, for example a reflector, an optically transparent body,
etc. wherein said optical means 102a, 102b, 102c, 102d of a lighting unit are configured
to bring the light emitted by the light source of the respective lighting unit into
a desired shape. In the present case each lighting unit is configured to emit a light
beam B1 which propagates in a first light emission direction X1. The light rays S1
of said light beam are parallel or essentially parallel to the first light emission
direction X1. In other words, the lighting unit(s) project(s) the light distribution
to infinity. For the sake of simplicity, in the following, when it is said that light
rays are parallel to a direction, this also means that they can be essentially parallel
to said direction.
[0045] In the example shown, the four light units each generate a light beam B1 with a first
light emission direction X1, wherein all first light emission directions X1 preferably
are identical.
[0046] The at least one lighting unit, in the example shown the four lighting units 100a,
100b, 100c, 100d together, are configured to produce for itself alone, this means
without further optical means, a light distribution LV (see
Figure 1a) with the light beam(s) B1 of parallel light rays S1 emitted by it/them in an area
in front of the lighting unit 100a, 100b, 100c, 100d, in particular in a traffic area,
e.g. on a road.
[0047] For example, a lighting device 1 as shown in
Figure 1 with lighting units 100a - 100d is configured to generate at least one of the following
light functions and its corresponding light distribution:
- a light function producing a light distribution with a cut-off line, in particular
an essentially horizontally cut-off line;
- a low-beam (light distribution);
- a high beam (light distribution) or a light function producing a part of a high beam
light distribution;
- a cornering light (light distribution);
- an adaptive driving beam (ADB) (light distribution);
- a part of a driving beam light (a light function producing a part of a driving beam
light distribution);
- a daytime running light (light distribution),
- a turn-indicator (light distribution).
[0048] Figure 1a, as an example, shows an ADB light distribution with five ADB segments arranged next
to each other, which are generated with the light modules 100a - 100d of the lighting
device 1 according to
Figure 1, whereby the second and fourth segments are switched off.
[0049] Figures 2, 2a, 2b, and
2c show a first embodiment of a lighting device 1 according to the invention.
[0050] Figure 2a shows a detail D2 of
Figure 2 in an enlarged view.
[0051] Figures 2b and 2c show a vertical section and a horizontal section respectively (the sections being
parallel to the optical axes of the first/second optically effective surfaces) through
one of the four lighting units 100a and a corresponding section of an optical device
200. It is emphasized that
Figure 2a and
Figure 2b are not to scale with respect to
Figure 2 (i.e. the section of the optical device 200 is clearly drawn too large), in order
to be able to illustrate the relationships more clearly.
[0052] The lighting device 1 of
Figure 2 comprises the four lighting units 100a - 100d of
Figure 1 (just for the sake of completeness, it should be mentioned once again that the four
lighting units are merely a concrete example, but are in no way restrictive; fewer,
e.g. only one lighting unit, but also more than four lighting units can be provided),
which emit light beams B1 of light rays S1. Now, according to the invention the optical
device 200 as already mentioned is provided after the lighting units 100a, 100b, 100c,
100d seen in the direction of light propagation.
[0053] Said optical device 200 comprises a number of first optically effective surfaces
201a, 201b, ..., 201e, ..., wherein each first optically effective surface 201a, 201b,
...., 201e, ...has a first optical axis OA201a, OA201b.
[0054] The light rays S1 of the light bundle B1 coming from the lighting units 100a, 100b,
100c, 100d are focused by each first optically effective surface 201a, 201b, ...,
201e, ... into a focus point F201a, F201b, of the respective first optically effective
surface 201a, 201b, ...
[0055] Furthermore, the optical device 200 comprises a number of second optically effective
surfaces 202a, 202b, each second optically effective surface 202a, 202b having an
optical axis OA202a, OA202b and a respective focal point F202a, F202b, wherein each
second optically effective surfaces 202a, 202b is configured to form light rays, which
emanate from their respective focal point into a bundle of parallel (or essentially
parallel) light rays.
[0056] Each first optically effective surface 201a, 201b is assigned in a one-to-one manner
to precisely one second optically effective surface 202a, 202b, and the first optically
effective surfaces 201a, 201b and second optically effective surfaces 202a, 202b assigned
to each other are arranged relative to one another such that their focal points F202a,
F202b coincide. Each focal point F202a, F202b thus is arranged between its first optically
effective surface 201a, 201b and its second optically effective surface 202a, 202b.
[0057] The optical axes OA201a, OA201b, ..., OA202a, OA202b, ... of first optically effective
surfaces 201a, 201b and second optically effective surfaces 202a, 202b assigned to
each other run parallel to one another, and all optical axes of the first and second
optically surfaces are parallel to each other. Furthermore, the optical axes OA201a,
OA201b, ..., OA202a, OA202b, ... of first optically effective surfaces 201a, 201b
and second optically effective surfaces 202a, 202b assigned to each other coincide.
The optical axes OA201a, OA201b, ..., OA202a, OA202b cut the respective focal point
F201a, F201b; F202a, F202b, ...
[0058] The at least one lighting unit, in the example shown the four lighting units 100a
- 100d is/are arranged such with respect to the optical device 200 that the first
light emission direction X1 is parallel to the direction to the optical axes of the
first and second optically surfaces.
[0059] Accordingly, the light rays S1 of the light beam B1 emitted by the lighting units
100a, 100b, 100c, 100d and propagating in the first light emission direction X1 emerge,
after passing through the associated first optically effective surfaces 201 a, 201b,
and the second, optically effective surfaces 202a, 202b, ... as a modified light beam
B2 in a second light emission direction X2, wherein the light rays S2 of the light
beam B2 are parallel to the second light emission direction X2.
[0060] The second light emission direction X2 is identical to the first light emission direction
X1, so that the light distribution produced by the modified light beam B2 is identical
or essentially identical to the light distribution LV produced by the at least one
light unit 101a, 101b, 101c, 101d for itself alone.
[0061] As indicated in
Figure 2a, each first optically effective surface 201a, 201b, ... and its associated second
optically effective surface 202a, 202b, ... defines an optically transparent optical
body 1200a, 1200b, ..., 1200e, ....
[0062] In the case shown, these optically transparent bodies 1200a, 1200b, ... form so-called
micro lenses, which are arranged directly adjacent to one another and are preferably
integrally connected to one another, thus forming the optical device 200 in the form
of a micro lens array.
[0063] The first optically effective surfaces 201a, 201b, ... and the second optically effective
surfaces 202a, 202b, ... are curved, in particular convexly curved, in both the vertical
and horizontal directions in the embodiment shown, see
Figures 2b and 2c.
[0064] Accordingly, the beams are deflected in a qualitatively analogue manner in both the
vertical and horizontal directions, as shown in
Figure 2b and
Figure 2c.
[0065] As further can been seen from
Figure 2b and
Figure 2c, the focal points F201a, F201b, ... of the first optically effective surfaces 201a,
201b, ... and the focal points F202a, F202b of the second optically effective surfaces
202a, 202b, ... lie in a common plane E, and a normal vector nE to said common plane
E is parallel to the first light emission direction X1 of the light beam B1 emitted
from the at least one lighting unit 100a, 100b, 100c, 100d.
[0066] Figures 3, 3a, 3b and
3c show a second embodiment of the invention. Basically, this second embodiment is largely
identical to the first embodiment shown in
Figure 2, so that only the differences are described here.
[0067] In this embodiment according to
Figure 3, associated first and second optically effective surfaces 201a, 202a, 201b, 202b delimit
transversely lying optical bodies 1200a, 1200b made of an optically transparent material,
so-called cylindrical lenses. Again, these bodies 1200a, 1200b are directly adjacent
to one another and are formed in one piece to form the optical device 200 with a light
entry surface 201 and a light exit surface 202.
[0068] The first and second optically effective surfaces 201a, 202a, 201b, 202b are curved
in the vertical direction, in particular convexly curved. Instead of focal points,
each first and second optically effective surface 201a, 202a, 201b, 202b has a focal
line FL201a, FL201b, FL202a, FL202b, which lies between the first and second optically
effective surfaces 201a, 202a, 201b, 202b, whereby the focal lines of associated first
and second optically effective surfaces 201a, 202a, 201b, 202b coincide.
[0069] As in the first embodiment shown in
Figure 2, the focal lines lie in a common plane E with a normal vector nE
(Figure 3b, Figure 3c); the relationships with regard to the direction X1 are analogous to those in the embodiment
shown in
Figure 2.
[0070] Again, the optical axes OA201a, OA202a; OA201b, OA202b are parallel to each other
and coincide, and cut the respective focal line FL201a, FL201b; FL202a, FL202b.
[0071] If one looks at
Figure 3b, which shows a vertical section parallel to the direction X1, one can see that the
light beams/light rays behave in the same way as described in
Figures 2b and 2c and are parallel (in this vertical section) to the direction X1. In vertical sections,
the light rays S1 of light beam B1 are thus deflected twice, resulting in a light
beam B2 with a light emission direction X2 after the optical device 200, which second
light emission direction X2 is parallel to the first light emission direction X1.
[0072] In the horizontal direction, however, as shown in the horizontal section of
Figure 3c, the light rays S1 of the light beam B1 are not deflected.
[0073] Figure 4 shows a sub-variant of the second embodiment shown in
Figure 3. Here, in addition, a cylindrical lens 300, a so-called macro cylindrical lens, is
provided between the one or more lighting units 100a - 100d and the optical device
200 in the beam path after the lighting units 100a - 100d. The cylinder axes FL300
of said macro cylindrical lens 300 runs vertically and in particular perpendicular
to the first light emission direction X1 of the light beam(s) B1 emitted by the lighting
units 100a - 100d.
[0074] Figure 4a shows the behavior of light rays passing through a (macro) cylindrical lenses before
passing through the optical device in a horizontal section through the lighting device.
In the horizontal section shown in
Figure 4a the light rays emitted by the lighting unit 1 are not parallel to direction X1, but
are parallelized by the macro cylindrical lens 300.
[0075] An optical device 200 as described in
Figure 3 can only influence light beams in the vertical direction.
[0076] For example, an asymmetry can generally be realized with a cylindrical lens in such
a way that - depending on the orientation of the cylindrical lens - only vertical
edges or only horizontal edges are in focus (which corresponds to parallel light beams),
in the other direction the light distribution remains defocused/blurred.
[0077] Finally,
Figures 5 and 6 show, in purely schematic form, the influence of the invention on non-parallel light
beams.
Figure 5 shows an arrangement in which light beams S1000 emanating from a light source 1000
are parallelized by an optical system 1001 in a direction X1. Light rays S2000, which
are not emitted by the light source 1000, for example from an assembly level 1002,
such as a carrier plate on which the light source 1000 is arranged, usually strike
the optics 1001 in such a way that they are not parallelized by the optical system
1001. For example, ambient light that enters a lighting device is reflected in it
and the reflected light can then be detected by an observer 3000. Two such (reflected)
light beams S2000 emanating from a point on the plane 1002 in different directions
are directed by the optics 1001 into the eye of the observer 3000.
[0078] The optical device 200 - see
Figure 6 - does not affect the direction of parallel light beams, as described in detail above.
On the other hand, light rays S2000, which are not parallelized by the optical system
1001, are scattered in this case and, for example, reach the observer 3000 as light
rays S2000a, S2000b in the same direction, although they originate from different
points on the plane 1002.
[0079] It is therefore no longer possible to look at the plane 1002 through the optical
device 200 or at a lighting unit behind the optical device 200.
1. Lighting device (1) for a vehicle, in particular a motor vehicle, wherein the lighting
device (1) comprises at least one lighting unit (100a, 100b, 100c, 100d) which is
configured to emit a light beam (B1) in a first light emission direction (X1), wherein
the light rays (S1) of said light beam (B1) are parallel or essentially parallel to
the first light emission direction (X1)
• in cutting planes parallel to a vertical plane containing the first light emission
direction (X1), or
• in cutting planes parallel to a horizontal plane containing the first light emission
direction (X1), or
• in cutting planes parallel to the vertical plane containing the first light emission
direction (X1) and in cutting planes parallel to a horizontal plane containing the
first light emission direction (X1), wherein
the at least one lighting unit (100a, 100b, 100c, 100d) is configured to produce for
itself alone a light distribution with said light beam (B1) emitted by it in an area
in front of the lighting unit (100a, 100b, 100c, 100d), in particular in a traffic
area, e.g. on a road,
characterized in that
an optical device (200) is provided after the at least one lighting unit (100a, 100b,
100c, 100d) seen in the direction of light propagation, wherein the optical device
(200) comprises
- a number of first optically effective surfaces (201a, 201b, ..., 201e, ...), wherein
each first optically effective surface (201a, 201b, ...., 201e, ...) has a first optical
axis (OA201a, OA201b, ..., OA201e, ...), wherein light rays (S1) of the light bundle
(B1) coming from the at least one lighting unit (100a, 100b, 100c, 100d) are focused
by each first optically effective surface (201a, 201b, ..., 201e, ...) into a focus
point (F201a, F201b, ..., F201e, ...) or a focal line (FL201a, FL201b, ...) of the
respective first optically effective surface (201a, 201b, ...), and
- a number of second optically effective surfaces (202a, 202b, ...), each second optically
effective surface (202a, 202b, ..) having an optical axis (OA202a, OA202b, ..., OA202e,
...) and a respective focal point or focal line (F202a, F202b, ...; FL202a, FL202b,
...), wherein each second optically effective surfaces (202a, 202b, ...) is configured
to form light rays, which emanate from their respective focal point or their respective
focal line (F202a, F202b, ...; FL202a, FL202b, ...), into a bundle of parallel or
essentially parallel light rays,
wherein each first optically effective surface (201a, 201b, ...) is assigned in a
one-to-one manner to precisely one second optically effective surface (202a, 202b,
...),
and wherein the first optically effective surfaces (201a, 201b, ...) and second optically
effective surfaces (202a, 202b, ...) assigned to each other are arranged relative
to one another such that their focal points or focal lines (F202a, F202b, ...; FL202a,
FL202b, ...) coincide and wherein each focal point or focal line (F202a, F202b, ...;
FL202a, FL202b, ...) is arranged between its first optically effective surface (201a,
201b, ...) and its second optically effective surface (202a, 202b, ...),
and wherein the optical axes (OA201a, OA201b, ..., OA202a, OA202b, ...) of first optically
effective surfaces (201a, 201b, ...) and second optically effective surfaces (202a,
202b, ...) assigned to each other run parallel to one another,
and wherein all optical axes of the first and second optically surfaces are parallel
to each other,
and wherein the first light emission direction (X1) is parallel to the direction to
the optical axes of the first and second optically surfaces,
so that the light rays (S1) of the light beam (B1) emitted by the at least one lighting
unit (100a, 100b, 100c, 100d) and propagating in the first light emission direction
(X1) emerge, after passing through the associated first optically effective surfaces
(201 a, 201b, ...) and the second, optically effective surfaces (202a, 202b, ...)
as a modified light beam (B2) propagating in a second light emission direction (X2),
wherein the light rays (S2) of said modified light beam (B2) are parallel or essentially
parallel to the second light emission direction (X2)
• in cutting planes parallel to a vertical plane containing the second light emission
direction (X2), or
• in cutting planes parallel to a horizontal plane containing the second light emission
direction (X2), or
• in cutting planes parallel to the vertical plane containing the second light emission
direction (X2) and in cutting planes parallel to a horizontal plane containing the
second light emission direction (X2), wherein
the second light emission direction (X2) is identical to the first light emission
direction (X1).
2. Lighting device according to claim 1, wherein the optical axes (OA201a, OA201b, ...,
OA202a, OA202b, ...) of first optically effective surfaces (201a, 201b, ...) and second
optically effective surfaces (202a, 202b, ...) assigned to each other coincide.
3. Lighting device according to anyone of the preceding claims, wherein each first optically
effective surface (201a, 201b, ...) and its associated second optically effective
surface (202a, 202b, ...) define an optically transparent optical body (1200a, 1200b,
..., 1200e).
4. Lighting device according to anyone of the preceding claims, wherein the optical bodies
(1200a, 1200b, ..., 1200e) are directly adjacent to one another, wherein, for example,
• the individual optical bodies are extending transversely, in particular horizontally,
and are arranged one above the other, or
• the individual optical bodies are arranged in an m x n array of columns and rows,
where m ≥ 2 and n ≥ 2.
5. Lighting device according to anyone of the preceding claims, wherein the first optically
effective surfaces (201a, 201b, ...) are directly adjacent to one another and form
a continuous light-inlet surface (201), and wherein the second optically effective
surfaces (202a, 202b, ...) are directly adjacent to one another and form a continuous
light-emitting surface (202).
6. Lighting device according to anyone of the claims 3 to 5, wherein the optical bodies
(200a', 200b', ...) are connected to one another in one piece and form the optical
device (200).
7. Lighting device according to one of the preceding claims, wherein the first optically
effective surfaces (201a, 201b, ...) and/or the second optically effective surfaces
(202a, 202b, ...) are curved, in particular convexly curved.
8. Lighting device according to one of the preceding claims, wherein the focal points
(F202a, F202b, ...) or focal lines (FL202a, FL202b, ...) of the first optically effective
surfaces (201a, 201b, ...) and the second optically effective surfaces (202a, 202b,
...) lie in a common plane (E).
9. Lighting device according to claim 8, wherein a normal vector (nE) to the common plane
(E) is parallel to the first light emission direction (X1) of the light beam (B1)
emitted from the at least one lighting unit (100a, 100b, 100c, 100d).
10. Lighting device according to one of the preceding claims, wherein the focal lines
(FL202a, FL202b, ...) run horizontally and transversely to the first light emission
direction (X1) of the light beam (B1) emitted by the at least one lighting unit (100a,
100b, 100c, 100d), in particular perpendicular to said first light emission direction
(X1).
11. Lighting device according to anyone of the preceding claim, wherein a cylindrical
lens (300) is provided in the beam path after the at least one lighting unit (100a,
100b, 100c, 100d), the cylinder axis (FL300) of which cylindrical lens (300) runs
vertically and in particular perpendicular to the first light emission direction (X1)
of the light beam (B1) emitted by the at least one lighting unit (100a, 100b, 100c,
100d).
12. Lighting device according to claim 10, wherein the cylindrical lens (300) is arranged
between the at least one lighting unit (100a, 100b, 100c, 100d) and the optical device
(200).
13. Lighting device according to one of the preceding claims, wherein the lighting unit
is configured to generate at least one of the following light functions and its corresponding
light distribution:
- a light function producing a light distribution with a cut-off line, in particular
an essentially horizontally cut-off line;
- a low-beam (light distribution);
- a high beam (light distribution) or a light function producing a part of a high
beam light distribution;
- a cornering light (light distribution);
- an adaptive driving beam (ADB) (light distribution);
- a part of a driving beam light (a light function producing a part of a driving beam
light distribution);
- a daytime running light (light distribution),
- a turn-indicator (light distribution).
14. Vehicle headlight comprising at least one lighting device (1) according to anyone
of the claims 1 to 13.
15. Vehicle, in particular a motor vehicle comprising at least one lighting device (1)
according to any one of claims 1 to 13 or at least one vehicle headlight according
to claim 14.