LIGHTING DEVICE FOR A MOTOR VEHICLE

Abstract

A lighting device for a motor vehicle, comprising a light source from which light is emitted during operation of the lighting device, a rod-shaped light guide which has a light entry surface on an end face for the light emitted from the light source and a light exit surface from which, during operation of the lighting device, the light which has entered through the light entry surface exits at least partially. The lighting device is set up to serve as a direction indicator, and wherein the lighting device comprises a controllable cover which is arranged at least partially in front of the light exit surface such that, during operation of the lighting device, at least a portion of the light exiting from the light exit surface enters an entry surface of the cover and exits from an exit surface of the cover.

Claims

1. A lighting device for a motor vehicle, the lighting device comprising: a light source from which light is emitted during operation of the lighting device; a rod-shaped light guide that has a light entry surface on an end face for the light emitted from the light source and a light exit surface that extends at least in sections over a longitudinal extent of the rod-shaped light guide and from which, during operation of the lighting device, the light that has entered through the light entry surface exits at least partially; and a controllable cover arranged at least partially in front of the light exit surface such that, during operation of the lighting device, at least a portion of the light exiting from the light exit surface enters an entry surface of the cover and exits from an exit surface of the cover, wherein the lighting device is set up to control the cover to selectively allow portions of the light incident on the entry surface to pass through the cover and not to allow other portions of the light incident on the entry surface to pass through the cover, and wherein the lighting device is set up to serve as a direction indicator.

2. The lighting device according to claim 1, wherein the cover has a plurality of segments adapted to be controlled independently of one another.

3. The lighting device according to claim 2, wherein the lighting device is set up to control the cover so that individual segments or segments adjacent in a direction of the longitudinal extent of the rod-shaped light guide allow portions of the light incident on the entry surface to pass through the cover sequentially in time.

4. The lighting device according to claim 1, wherein the cover is an LC display.

5. The lighting device according to claim 4, wherein the LC display is a passive LC display.

6. The lighting device according to claim 4, wherein the LC display is a guest-host display or a SmartGlass display.

7. The lighting device according to claim 4, wherein the LC display is an LC display doped with color pigments.

8. The lighting device according to claim 1, wherein the light guide or structures formed as prisms that deflect the light entering through the light entry surface in a direction of the light exit surface during operation of the lighting device, so that at least portions of the light, deflected in the direction of the light exit surface, exit from the light exit surface.

9. The lighting device according to claim 8, wherein the structures are arranged on the side of the light guide, the side of the light guide being opposite the light exit surface.

10. The lighting device according to claim 1, wherein the light guide and/or the cover are bent at least in sections.

11. A headlight for a motor vehicle comprising a lighting device according to claim 1.

12. A rear light for a motor vehicle comprising a lighting device according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0021] FIG. 1 shows a schematic front view of a first embodiment of a lighting device of the invention;

[0022] FIG. 2 shows a schematic front view of a second embodiment of a lighting device of the invention;

[0023] FIG. 3 shows a side view of the light guide of the first embodiment of a lighting device of the invention;

[0024] FIG. 4 shows a side view of the light guide of a third embodiment of a lighting device of the invention;

[0025] FIG. 5 shows a side view of the first embodiment of a lighting device of the invention;

[0026] FIG. 6 shows a side view of the third embodiment of a lighting device of the invention;

[0027] FIG. 7 shows a side view of the third embodiment of a lighting device of the invention with illustrated segments on the cover;

[0028] FIG. 8 shows a side view of a fourth embodiment of a lighting device of the invention with illustrated segments on the cover;

[0029] FIG. 9 shows a side view of a fifth embodiment of a lighting device of the invention with illustrated segments on the cover;

[0030] FIG. 10 shows a side view of a sixth embodiment of a lighting device of the invention with illustrated segments on the cover; and

[0031] FIG. 11 shows a side view of a seventh embodiment of a lighting device of the invention with illustrated segments on the cover.

DETAILED DESCRIPTION

[0032] The lighting device shown in the figures comprises a light source, a rod-shaped light guide 1, and a cover 2 (see, for example, FIG. 1 and FIG. 2). The light emitted from the light source can enter light guide 1 at an end face and exit light guide 1 at the side. Cover 2 is arranged in front of light guide 1 on the exit side.

[0033] The light source can have one or more light-emitting diodes. It is further possible that an optical system, in particular a collimating lens, is arranged between the at least one light-emitting diode and light guide 1.

[0034] The cross section of the rod-shaped light guide 1 can, for example, is formed predominantly of a circular convex section 3 and additionally have a planar section 4 (see FIG. 2). Alternatively, the cross section of the rod-shaped light guide 1 can have concave sections 5 in addition to the circular convex section 3 and planar section 4 (see FIG. 1), wherein concave sections 5 can have substantially the shape of an exit-side end of a trumpet.

[0035] It is entirely possible that the rod-shaped light guide 1 has a different cross section.

[0036] The cross section of light guide 1 remains substantially the same along the longitudinal extent of light guide 1. Light guide 1 can extend longitudinally in a non-changing direction (see FIG. 3). Alternatively, light guide 1 can also be bent so that the direction of the longitudinal extent of light guide 1 changes, in particular changes over larger parts of the longitudinal extent (see FIG. 4).

[0037] It is entirely possible for light guide 1 to have a different shape and/or a different course, wherein the shape and course of light guide 1 can be adapted to the particular design of the environment, thus, for example, to the design of a headlight or a rear light.

[0038] The rod-shaped light guide 1 has a light entry surface 6 on an end face for the light emitted from the light source (see FIG. 3 and FIG. 4). It is entirely possible for light guide 1 to have a light entry surface 6 at both end faces, wherein a light source can then be positioned in front of each light entry surface 6.

[0039] The rod-shaped light guide 1 further has a light exit surface 7 which is arranged in the circular convex section 3 and is opposite to planar surface 4. Light exit surface 7 extends in particular over the entire length of light guide 1. To cause or enhance the exit of light from light exit surface 7, planar surface 4 has structures (not shown) formed as prisms. The prisms in this case can be oriented in particular transversely to the longitudinal extent of light guide 1.

[0040] These prism optics reflect light incident on them in light guide 1 in the direction of light exit surface 7, so that it can exit light guide 1 and light guide 1 lights up. The size, design, and distribution of the prism optics influence the performance and illumination quality of light guide 1. When the light source is switched on, the entire light guide 1 lights up over its entire length, wherein the structures are designed in particular such that the light guide lights up relatively homogeneously over its entire length.

[0041] Cover 2 has an entry surface 8 and an exit surface 9. Cover 2 is positioned in front of light guide 1 such that the light exiting from light exit surface 7 of light guide 1 impinges in particular completely on entry surface 8 of the cover (see FIG. 1, FIG. 2, FIG. 5, and FIG. 6). In the figures, cover 2 is positioned relatively close in front of light exit surface 7 of light guide 1. It is entirely possible to provide a larger or smaller distance between light exit surface 7 of light guide 1 and entry surface 8 of cover 2.

[0042] Cover 2 is designed as a switchable cover 2. Cover 2 is divided into a plurality of segments 10 (see FIG. 7). It is possible to selectively control each of the segments 10 to allow light entering entry surface 8 in the region of that segment 10 to either exit through exit surface 8 or not to exit through exit surface 8.

[0043] Cover 2 is a passive LC display, which is designed as a so-called SmartGlass display or guest-host display. In particular, the LC display in this case can be a so-called dye-doped display, which is doped with color pigments which determine the color of the LC display in its non-operational state. The liquid crystals doped with color pigments (dye-doped liquid crystals) are enclosed between two substrate layers, in particular thin sheets of glass or plastic films that have an electrically conductive layer. Compared to conventional LC displays, an LC display of this type works without a polarizing filter and thus has a relatively high transmission. In an operational state (on-state), controlled segment 10 of the LC display serving as a cover 2 allows the light that has entered through the part of entry surface 8 of controlled segment 10 to exit at least partially, in particular for the most part, from exit surface 9, whereas in a non-operational state (off-state), controlled segment 10 of the LC display does not allow the light that has entered through the corresponding part of entry surface 8 to exit from exit surface 9.

[0044] The LC display can have different colors in the non-operational state or it can be made black. Because the LC display is black, for example, in the non-operational state, the light function can be hidden with a so-called black panel effect so that the individual segments 10 or the separations between segments 10 are barely visible. When switched on or transferred to the operational state (on-state), the LC display turns transparent so that the light guide function behind it can emit light unimpeded and fulfill the function of the direction indicator.

[0045] The LC display can have any segmentation and pixel size, which also provides different design options for different vehicle manufacturers. FIGS. 8 to 11 show exemplary segmentations with differently sized and differently arranged segments. It is entirely possible to provide segmentations other than those shown for the operating device. It is also possible to provide shapes of segments other than those shown. Both fine segmentations and coarse segmentations are possible.

[0046] If, with the activation of the light source, the LC display is also activated, wherein the individual segments 10 are activated sequentially in time or are turned transparent in a function similar to running lights or in the operational state, this appears to an observer as sequential switching on or sequential switching off and thus as a sweeping turn signal.

[0047] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.