Lighting device for motor vehicle and method for operating lighting device for motor vehicle

Abstract

The invention relates to a method for operating a lighting device for a motor vehicle, comprising a plurality of light-emitting diodes that can be controlled individually or in groups and a liquid crystal display having a plurality of segments that can be controlled independently of one another, the light-emitting diodes emitting light in an on-state and not emitting light in an off-state, segments of the liquid crystal display can be in a first switching state or a second switching state, and one of the segments of the liquid crystal display is assigned with at least one light-emitting diode, so that light emitted by the light-emitting diode impinges on the assigned segment and at least partially passes through the segment. In the first switching state of the segments, more light passes through the segments than in the second switching state, and at least one of the segments is assigned to a first segment of the light-emitting diode in the off state in the first switching state. The invention also relates to a lighting device for a motor vehicle.

Description

Technical Field

[0001] The invention relates to a method for operating a lighting device for a motor vehicle according to the preamble of claim 1 and to a lighting device for a motor vehicle according to the preamble of claim 3 . Background Art

[0002] The above-mentioned type of method and lighting device are known from DE 10 2021 129 672 A1. The lighting device described therein includes a circuit board (LED) on which a plurality of light-emitting diodes are arranged, an optical glass, a plurality of reflective partitions and a liquid crystal (LC) display, the liquid crystal display having a plurality of segments that can be controlled independently of each other, wherein one of the segments of the liquid crystal display is respectively assigned at least one light-emitting diode, so that the light emitted by the light-emitting diode is projected onto the assigned segment and at least partially passes through the segment. In this case, the partition is arranged between the light-emitting diode and the optical glass and the liquid crystal display is arranged on the side of the optical glass away from the partition. Symbols, animations and texts can be displayed on the liquid crystal display, for example. The method described in DE10 2021 129672A1 stipulates that the segments of the liquid crystal display assigned to the turned-off light-emitting diodes are controlled so that these segments are turned off and are therefore opaque or only slightly transparent. In addition, the segments of the liquid crystal display assigned to the turned-on light-emitting diodes are controlled so that these segments are turned on and are therefore transparent to a large extent.

[0003] The light-emitting diodes can have different colors, so that symbols, animations and texts displayed on the liquid crystal display can be displayed in color. By dimming the light-emitting diodes, these colors can be displayed brighter or darker. It is desirable that in addition to displaying these colors brighter or darker, gray tones can also be displayed in order to achieve a 3D effect, for example. Summary of the invention

[0004] The problem underlying the present invention is therefore to specify a method of the type mentioned at the outset and to provide a lighting device of the type mentioned at the outset which enable 3D effects to be achieved when displaying symbols and / or animations and / or texts on a liquid crystal display.

[0005] This is achieved according to the invention by a method of the type mentioned at the outset having the characterizing features of claim 1 and by a lighting device of the type mentioned at the outset having the characterizing features of claim 3. The dependent claims relate to preferred embodiments of the invention.

[0006] According to claim 1, at least one first segment assigned to a light-emitting diode in the off state in each segment is in a first switching state. In particular, at least one second segment assigned to a light-emitting diode in the off state in each segment is in a second switching state. In this way, the area of ​​the liquid crystal display that is not illuminated by the light-emitting diode can have different gray tones, so that a shadow-like structure can be generated at the edge of the illuminated area to achieve a 3D effect. The different gray tones of the area of ​​the liquid crystal display that is not illuminated by the light-emitting diode can be generated in the following way, that is, the segments of the liquid crystal display have different reflectivities in different switching states. For example, then different gray tones of the segments can be generated by reflecting light from the outside to different switched segments to different degrees. The segments can therefore display the shadow rendering pixels of symbols, animations or texts. In addition to the colored light components generated by the light-emitting diodes, other display colors that have not existed in the displays on motor vehicles so far can also be generated by gray tones.

[0007] According to claim 3 , the control device is provided for controlling the light emitting diode and the liquid crystal display so that the lighting device carries out the method according to the invention.

[0008] It can be provided that the segment is arranged to allow between 10% and 90%, in particular between 25% and 70%, preferably approximately 40% of the light impinging on the segment to pass through the segment in a first switching state of the segment and / or to allow between 70% and 100%, in particular between 80% and 90%, of the light impinging on the segment to be absorbed when passing through the segment in a second switching state of the segment.

[0009] It is possible that a segment of the liquid crystal display can be in at least one third switching state, wherein the segment is arranged so that in the first switching state of the segment more light passes through the segment than in the third switching state and in the third switching state of the segment more light passes through the segment than in the second switching state, in particular wherein the segment can be in a plurality of different third switching states which differ from one another due to different transmittances. Thus, the transmittance of the light emitted by the assigned light-emitting diode through the segment of the liquid crystal display can be varied, in particular steplessly, between the transmittance in the second switching state and the transmittance in the first switching state. This can generate a number of different gray tones. The stepless dimming of the segment of the liquid crystal display can be achieved, for example, by correspondingly changing the voltage applied to the segment.

[0010] It can be provided that the segments of the liquid crystal display are arranged side by side in at least one direction, preferably in two directions perpendicular or not perpendicular to each other, wherein at least one or more or each segment has a size between 2.0 mm and 40.0 mm, in particular a size between 2.5 mm and 10.0 mm in at least one direction in which the segments are arranged side by side. It can also be provided that at least one or more or each segment has a triangular, rectangular, pentagonal or hexagonal cross section or other polygonal cross section or a rhombus cross section. In this case, a plurality of segments of the liquid crystal display can differ from one another in terms of their size and / or in terms of their cross section.

[0011] It is possible that the liquid crystal display is a passive liquid crystal display, in particular the liquid crystal display is a liquid crystal display doped with a pigment, preferably the liquid crystal display is a dye-doped display. The color of the segments of the dye-doped display in the second or switched-off state depends on the pigment in the liquid of the liquid crystal display. These pigments can, for example, cause a basic coloration of the liquid from black to dark grey with a brown or blue color deviation, respectively.

[0012] It can be provided that the liquid crystal display is flat or curved. This allows the lighting device to be installed in different environments of the vehicle. For example, positioning at the front, rear or outside of the vehicle on one of the two sides of the vehicle is conceivable. In addition to being able to display symbols, animations and texts, the lighting device can also be used for lighting on the vehicle and, for example, also as a position light, daytime running light, tail light or brake light.

[0013] It is possible that the pixel grid formed by the segments arranged side by side is rectangular, in particular square, or rhombus, oblique square, triangle, hexagon or diamond-shaped. Such different designs also enable the lighting device to be arranged in different environments of the vehicle.

[0014] It can be provided that at least one or more or each light emitting diode is configured to emit light having a light color, which can be, for example, red or super red or white or green or blue or yellow or cyan. This allows, on the one hand, symbols, animations and texts to be designed in different colors. On the other hand, the lighting device can also be used to generate different signal functions.

[0015] It is possible that at least one or more or each light emitting diode is configured to be dimmed, in particular steplessly dimmed, in the switched-on state, so that it emits different amounts of light in different switched-on states, thereby changing the brightness of the light emitted by the light emitting diode, while the saturation of the color of the light emitted by the individual light emitting diodes can be changed by dimming the individual segments of the liquid crystal display.

[0016] It can be provided that the lighting device includes a plurality of partitions, which are respectively arranged between one of the light-emitting diodes and the assigned segment of the liquid crystal display. These partitions can have a reflective surface as in the prior art to ensure that as much light as possible emitted by the light-emitting diode is projected onto the assigned segment of the liquid crystal display.

[0017] It is possible that the lighting device has an optical glass with a scattering structure, in particular the optical glass is arranged between the partition and the liquid crystal display, preferably the optical glass is attached to the side of the liquid crystal display facing the partition. On the one hand, the optical glass can homogenize the light incident on the liquid crystal display. On the other hand, the optical glass can reflect the segmented sunlight that passes through the liquid crystal display in the off or second switching state back outward and thus contribute to the generation of gray tones. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is described in detail below with the aid of the accompanying drawings. The accompanying drawings are as follows:

[0019] Figure 1 A cross-sectional view showing a first embodiment of an illumination device according to the present invention;

[0020] Figure 2 Shown according to arrow II looking toward Figure 1 A view of an implementation method of

[0021] Figure 3 A schematic side view of a liquid crystal display showing a second embodiment of an illumination device according to the present invention. DETAILED DESCRIPTION

[0022] In the figures, identical and functionally identical parts are provided with the same reference symbols.

[0023] The lighting device according to the present invention Figure 1 and Figure 2 The embodiment shown in the figure comprises a circuit board 1 on which a plurality of light emitting diodes 2 are arranged. It can be provided that all light emitting diodes 2 emit light of the same color. Alternatively, it can be provided that a plurality of light emitting diodes 2 emit light of different colors from each other. The color of the light emitted by at least one or more or each light emitting diode 2 can be, for example, red or super red or white or green or blue or yellow or cyan.

[0024] The light emitting diodes 2 are controlled by a control mechanism (not shown). These light emitting diodes can be dimmed, in particular steplessly dimmed, in the switched-on state, so that the light emitting diodes emit different amounts of light in different switched-on states. Thus, the brightness of the light emitted by the light emitting diodes 2 can be changed.

[0025] The lighting device according to the present invention Figure 1and Figure 2 The embodiment shown in FIG. 1 further includes a plurality of partitions 3. The partitions 3 are respectively arranged between adjacent light emitting diodes 2 and extend from the circuit board 1 in the direction of the light emitted by the light emitting diodes 2. Here, the partitions 3 can surround the respective light emitting diodes 2 and the light emitted thereby, thereby similarly forming a channel for the light of the respective light emitting diodes 2. The partitions 3 can be configured to be reflective on the side facing the light emitting diodes 2 and the light of the respective light emitting diodes 2.

[0026] In addition, the lighting device according to the present invention Figure 1 and Figure 2 The embodiment shown in FIG. 4 comprises an optical glass 4 which is arranged on the end of the partition 3 facing away from the light-emitting diodes 2. The optical glass has a scattering structure which can be used to homogenize the light passing through the optical glass 4.

[0027] The lighting device according to the present invention Figure 1 and Figure 2 The embodiment shown in FIG. 1 further comprises a liquid crystal display 5 having a plurality of segments 6 which can be controlled independently of one another (see Figure 2 ). The liquid crystal display 5 is designed to be planar and is arranged on the side of the optical glass 4 facing away from the partition 3. In this case, the liquid crystal display 5 can be placed against the optical glass 4 in particular.

[0028] The light emitted by the LED 2 can sequentially pass through the optical glass 4 and the liquid crystal display 5. Here, at least one LED 2 is respectively assigned one of the segments 6, so that the light emitted by at least one LED 2 at least partially passes through the assigned segment 6.

[0029] The segments 6 are controlled by a control mechanism (not shown). The segments 6 can be controlled so that they are in at least one first switched-on state or a second switched-off state, wherein in the first switched-off state of each segment 6 more light passes through the segment 6 than in the second switched-off state. For example, in the first switched-on state, approximately 40% of the light impinging on the segment 6 can pass through the segment 6, while in the second switched-off state of the segment, approximately 80% to 90% of the light impinging on the segment 6 is absorbed when passing through the segment 6.

[0030] Alternatively, each segment 6 can be controlled in particular so that it can be in one of a plurality of different third switching states, which differ from one another due to different transmittances. Thus, the transmittance of the light emitted by the assigned light-emitting diode 2 through the segment 6 of the liquid crystal display 5 can be varied in particular steplessly between the transmittance in the second switching state and the transmittance in the first switching state. Such stepless dimming of the segment 6 of the liquid crystal display 5 can be achieved, for example, by correspondingly changing the voltage applied to the segment 6.

[0031] The liquid crystal display 5 is a passive liquid crystal display which is designed as a dye-doped display doped with pigments. The color of the segments 6 of the dye-doped display in the second or switched-off state depends on the pigments in the liquid of the liquid crystal display 5. These pigments can, for example, cause a basic coloration of the liquid from black to dark grey with a brown or blue color deviation.

[0032] The segments 6 of the liquid crystal display 5 are arranged side by side in two mutually perpendicular directions (see Figure 2 ). Alternatively, the segments 6 of the liquid crystal display 5 can be arranged side by side in two directions that are not perpendicular to each other. Here, at least one or more or each segment 6 can have a size between 2.0 mm and 40.0 mm, in particular a size between 2.5 mm and 10.0 mm, in the direction in which the segments 6 are arranged side by side.

[0033] In the embodiment shown, the segment 6 has a square cross section. Alternatively, it can be provided that at least one or more or each segment 6 has a triangular, pentagonal, hexagonal or non-square rectangular cross section or other polygonal cross section or a rhombus cross section. Furthermore, a plurality of segments 6 of the liquid crystal display 5 can differ from one another in their size and / or in their cross section.

[0034] In the exemplary embodiment shown, the pixel grid formed by the adjacent segments 6 is of square design. Alternatively, it can be provided that the pixel grid formed by the adjacent segments 6 is rhombus-shaped or rhombus-shaped or triangular or hexagonal or diamond-shaped or has a non-square rectangular design.

[0035] On the liquid crystal display 5, for example, symbols, animations and texts can be displayed by correspondingly controlling the light-emitting diodes 2. It is provided that at least some of the segments 6 of the liquid crystal display 5 that are assigned to the light-emitting diodes 2 that are turned off are still in the on state despite being assigned to the light-emitting diodes 2 that are turned off. The on state can be a first switching state, in which the transmittance through the segment 6 is maximum. However, it can also be a third switching state, in which the transmittance of the segment 6 is less than the maximum transmittance that can be achieved in the first switching state, but greater than the minimum transmittance that can be achieved in the second switching state. It can also be provided that one or more of the segments 6 that are assigned to the light-emitting diodes 2 that are in the off state are in the second off switching state.

[0036] By switching the segments 6 assigned to the turned-off light-emitting diodes into the turned-on state, it is possible, for example, to allow sunlight or artificial light impinging on the segments 6 from the outside to partially pass through the segments 6, be reflected by the optical glass 4 and then pass through the segments 6 again to the outside and escape from the liquid crystal display 5. As a result, the segments 6 assigned to the turned-off light-emitting diodes 2 can have a gray tone for the observer, which, for example, gives a three-dimensional design to the displayed symbols, displayed animations or displayed texts. This three-dimensional design is supported by the segments 6 assigned to the turned-off light-emitting diodes 2 and in the second turned-off switching state. The non-luminous areas of the liquid crystal display 5 can be suitably designed by the segments 6 in different switching states and having different gray tones.

[0037] Figure 3 The second embodiment shown in FIG. 1 is different from the first embodiment in that the liquid crystal display 5 has a curved shape. Figure 3 Components not shown, such as the optical glass 4 and the spacer 3, can be adapted to the shape of the liquid crystal display 5.

[0038] Reference numerals list

[0039] 1 Circuit Board

[0040] 2 LEDs

[0041] 3 Dividers

[0042] 4Optical glass

[0043] 5 LCD display

[0044] 6 LCD display segmentation

Claims

1. A method for operating a lighting device for a motor vehicle, wherein: The lighting device comprises a plurality of light-emitting diodes (2) which can be controlled individually or in groups, and a liquid crystal display (5) having a plurality of segments (6) which can be controlled independently of one another, wherein the light-emitting diodes (2) emit light in an on state and do not emit light in an off state, wherein the segments (6) of the liquid crystal display (5) can be in a first switching state or a second switching state, wherein at least one of the segments (6) of the liquid crystal display (5) is respectively assigned to at least one light-emitting diode, so that light emitted by the light-emitting diode (2) impinges on the assigned segment (6) and at least partially passes through the segment (6), and more light passes through the segment (6) in the first switching state than in the second switching state, and wherein at least one first segment of the segments (6) which is assigned to the light-emitting diode (2) in the off state is in the first switching state.

2. The method according to claim 1, characterized in that At least one second segment of the segments (6) which is assigned to the light-emitting diode (2) which is in the off state is in a second switching state.

3. Lighting devices for motor vehicles, including: A plurality of light-emitting diodes (2) which can be controlled individually or in groups, a liquid crystal display (5) having a plurality of segments (6) which can be controlled independently of one another, and a control mechanism for controlling the light-emitting diodes (2) and the liquid crystal display (5), wherein the light-emitting diodes (2) are configured to emit light in an on state and not to emit light in an off state, the segments (6) of the liquid crystal display (5) can be in a first switching state or a second switching state, at least one light-emitting diode is respectively assigned to one of the segments (6) of the liquid crystal display (5), so that light emitted by the light-emitting diode (2) impinges on the assigned segment (6) and at least partially passes through the segment (6), and the segment (6) is configured to allow more light to pass through the segment (6) in the first switching state of the segment (6) than in the second switching state, characterized in that the control mechanism is configured to control the light-emitting diodes (2) and the liquid crystal display (5) so that the lighting device performs the method according to any one of claims 1 or 2.

4. The lighting device according to claim 3, characterized in that: The segment (6) is designed to allow between 10% and 90%, in particular between 25% and 70%, preferably approximately 40%, of the light impinging on the segment (6) to pass through the segment (6) in a first switching state of the segment (6) and / or to allow between 70% and 100%, in particular between 80% and 90%, of the light impinging on the segment (6) to be absorbed when passing through the segment (6) in a second switching state of the segment (6).

5. The lighting device according to any one of claims 3 or 4, characterized in that: The segment (6) of the liquid crystal display (5) can be in at least one third switching state, the segment (6) is configured to allow more light to pass through the segment (6) in the first switching state of the segment (6) than in the third switching state, and to allow more light to pass through the segment (6) in the third switching state than in the second switching state, in particular the segment (6) can be in a plurality of different third switching states, which differ from each other due to different transmittances.

6. The lighting device according to any one of claims 3 to 5, characterized in that: The segments (6) of the liquid crystal display (5) are arranged side by side in at least one direction, preferably in two directions perpendicular or non-perpendicular to each other, and at least one or more or each segment (6) has a size between 2.0 mm and 40.0 mm, especially between 2.5 mm and 10.0 mm, in the at least one direction in which the segments (6) are arranged side by side.

7. The lighting device according to any one of claims 3 to 6, characterized in that: At least one or more or each segment (6) has a triangular, rectangular, pentagonal or hexagonal cross section or other polygonal cross section or a rhombus cross section.

8. The lighting device according to any one of claims 3 to 7, characterized in that: The plurality of segments (6) of the liquid crystal display (5) differ from one another in terms of their size and / or in terms of their cross-section.

9. The lighting device according to any one of claims 3 to 8, characterized in that: The liquid crystal display (5) is a passive liquid crystal display, in particular the liquid crystal display (5) is a liquid crystal display (5) doped with pigments, and preferably the liquid crystal display (5) is a dye-doped liquid crystal display.

10. The lighting device according to any one of claims 3 to 9, characterized in that: The liquid crystal display (5) is flat or curved.

11. The lighting device according to any one of claims 3 to 9, characterized in that: The pixel grid formed by the segments (6) arranged side by side is rectangular, in particular square, or rhombus, oblique square, triangle, hexagon or diamond-shaped.

12. The lighting device according to any one of claims 3 to 11, characterized in that: At least one or more or each light-emitting diode (2) is provided to emit light having a light color, which can be, for example, red or super red or white or green or blue or yellow or cyan.

13. The lighting device according to any one of claims 3 to 12, characterized in that: At least one or more or each light emitting diode (2) is provided for dimming, in particular steplessly dimming, in a switched-on state, so that the light emitting diodes emit different quantities of light in switched-on states that are different from one another.

14. The lighting device according to any one of claims 3 to 13, characterized in that: The lighting device comprises a plurality of partitions (3), each of which is arranged between one of the light-emitting diodes (2) and an associated segment (6) of a liquid crystal display (5).

15. The lighting device according to any one of claims 3 to 13, characterized in that: The lighting device comprises an optical glass (4) with a scattering structure, in particular the optical glass (4) is arranged between a partition (3) and a liquid crystal display (5), preferably the optical glass (4) is in contact with a side of the liquid crystal display (5) facing the partition (3).

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