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

Abstract

A method for operating a lighting device for a motor vehicle, wherein the lighting device comprises a plurality of individually or in groups controllable light-emitting diodes (2) and an LC display (5) with a plurality of independently controllable segments (6), wherein the light-emitting diodes (2) emit light when switched on and emit no light when switched off, wherein the segments (6) of the LC display (5) can be in a first switching state or in a second switching state, wherein at least one of the light-emitting diodes is assigned to each of the segments (6) of the LC display (5) such that the light emanating from the light-emitting diode (2) strikes the assigned segment (6) and at least partially passes through the segment (6), wherein in the first switching state of the segment (6) more light passes through the segment (6) than in the second switching state, and wherein at least a first of the segments (6),which is assigned to a light-emitting diode (2) in a switched-off state, is in the first switching state.,

Description

[0001] The present 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.

[0002] A method and a lighting device of the aforementioned type are known from DE 10 2021 129 672 A1. The lighting device described therein comprises a circuit board with a plurality of light-emitting diodes (LEDs) arranged thereon, an optical disk, a plurality of reflective separators, and an LC display with a plurality of independently controllable segments, wherein at least one of the LEDs is assigned to each of the segments of the LC display such that the light emanating from the LED strikes the assigned segment and at least partially passes through the segment. The separators are arranged between the LEDs and the optical disk, and the LC display is arranged on the side of the optical disk facing away from the separators. Symbols, animations, and text, for example, can be displayed on the LC display.The method described in DE 10 2021 129 672 A1 provides that those segments of the LCD display associated with a switched-off LED are controlled in such a way that they are switched off and thus not or only slightly transparent. Furthermore, those segments of the LCD display associated with a switched-on LED are controlled in such a way that they are switched on and thus largely transparent.

[0003] The LEDs can be of different colors, allowing the symbols, animations, and text displayed on the LCD to be shown in color. Dimming the LEDs allows these colors to be displayed brighter or darker. In addition to colors that are displayed brighter or darker, it is desirable to also be able to display shades of gray, for example, to create 3D effects.

[0004] The problem underlying the present invention is therefore to provide a method of the type mentioned at the outset and to create a lighting device of the type mentioned at the outset which enables the achievement of 3D effects when displaying symbols and / or animations and / or texts on the LC display.

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

[0006] According to claim 1, it is provided that at least a first of the segments, which is assigned to a light-emitting diode in a switched-off state, is in the first switching state. In particular, at least a second of the segments, which is assigned to a light-emitting diode in a switched-off state, can be in the second switching state. In this way, the areas of the LC display not illuminated by the light-emitting diodes can have different shades of gray, so that shadow-like structures can be generated at the edges of illuminated areas to achieve 3D effects. The different shades of gray of the areas of the LC display not illuminated by the light-emitting diodes can arise because the segments of the LC display have different reflectivity in different switching states.For example, varying degrees of reflection of external light striking differently switched segments can result in different shades of gray. The segments can thus display shaded pixels of a symbol, animation, or text. In addition to the colored light components generated by the LEDs, the shades of gray can create an additional display color that is not yet available in vehicle displays.

[0007] According to claim 3, it is provided that the control means are designed to control the light-emitting diodes and the LC display in such a way that the lighting device carries out a method according to the invention.

[0008] It can be provided that the segments are designed so that in the first switching state of a segment between 10% and 90%, in particular between 25% and 70%, preferably about 40%, of the light incident on the segment passes through the segment and / or that in the second switching state of a segment between 70% and 100%, in particular between 80% and 90% of the light incident on the segment is absorbed when passing through the segment.

[0009] It is possible for the segments of the LC display to be in at least one third switching state, wherein the segments are configured such that in the first switching state of a segment more light passes through the segment than in the third switching state and such that in the third switching state of a segment more light passes through the segment than in the second switching state, in particular wherein the segments can be in a plurality of different third switching states which differ from one another in terms of their different light transmittances. The transmission of the light emanating from the associated light-emitting diode through the segment of the LC display can therefore be changed, in particular, continuously between the transmission in the second switching state and the transmission in the first switching state. This makes it possible to generate many different shades of gray.The continuous dimming of the segments of the LC display can be achieved, for example, by a corresponding change in the voltage applied to the segment.

[0010] It can be provided that the segments of the LC display are arranged next to one another in at least one direction, preferably in two mutually perpendicular or non-perpendicular directions, wherein at least one or more or each of the segments has a dimension between 2.0 mm and 40.0 mm, in particular a dimension between 2.5 mm and 10.0 mm, in the at least one direction in which the segments are arranged next to one another. Furthermore, it can be provided that at least one or more or each of the segments has a triangular, a rectangular, a pentagonal or a hexagonal cross-sectional area or another polygonal cross-sectional area or a diamond-shaped cross-sectional area. In this case, several of the segments of the LC display can differ from one another in terms of their size and / or their cross-sectional area.

[0011] It is possible for the LC display to be a passive LC display, in particular one doped with color pigments, preferably a dye-doped LC display. In the second, or off, switching state, a segment of a dye-doped display exhibits a color that depends on the color pigments in the liquid of the LC display. These color pigments can, for example, cause the liquid to have a black to dark gray base color, each with a brownish or bluish hue.

[0012] The LCD display can be flat or curved. This allows the lighting device to be installed in various locations within the vehicle. For example, it can be positioned on the outside of the vehicle, at the front, rear, or either side of the vehicle. In addition to displaying symbols, animations, and text, the lighting device can also serve as a vehicle's lighting system and can be used, for example, as a position light, daytime running light, tail light, or brake light.

[0013] The pixel grid formed by the adjacent segments can be rectangular, especially square, or diamond-shaped, rhombus-shaped, triangular, hexagonal, or diamond-shaped. This different design also allows 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, of the LEDs is configured to emit light with a color, which can be, for example, red, super-red, white, green, blue, yellow, or cyan. This allows, on the one hand, the symbols, animations, and text 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 for at least one or more or each of the LEDs to be configured to be dimmed when switched on, in particular to be continuously dimmed, so that they emit different amounts of light in different switched-on states. This changes the brightness of the light emitted by the LEDs, whereas by dimming the individual segments of the LCD display, the color saturation of the light emitted by the individual LEDs can be changed.

[0016] The lighting device may comprise a plurality of separators, each arranged between one of the LEDs and the associated segment of the LCD display. These separators may have reflective surfaces, as in the prior art, to ensure that as much of the light emitted by the LEDs as possible hits the associated segment of the LCD display.

[0017] It is possible for the lighting device to have an optical disk with a scattering structure, in particular, wherein the optical disk is arranged between the separators and the LCD display, preferably wherein the optical disk rests against the side of the LCD display facing the separators. This optical disk can, on the one hand, homogenize the light incident on the LCD display. On the other hand, the optical disk can reflect sunlight passing through a segment of the LCD display in the off or second switching state back outwards, thus contributing to the generation of gray tones.

[0018] The invention is explained in more detail below with reference to the accompanying drawings. In the drawings: Fig. 1 is a sectional view of a first embodiment of a lighting device according to the invention; Fig. 2 a view according to arrow II of the embodiment according to Fig. 1; Fig. 3 a schematic side view of an LC display of a second embodiment of a lighting device according to the invention.

[0019] In the figures, identical and functionally identical parts are provided with the same reference numerals.

[0020] The Fig. 1 and Fig. The embodiment of a lighting device according to the invention depicted in Figure 2 comprises a circuit board 1 on which a plurality of light-emitting diodes 2 are arranged. It can be provided that all of the light-emitting diodes 2 emit light of the same color. Alternatively, it can be provided that several of the light-emitting diodes 2 emit light of different colors. The color of the light emitted by at least one or more or each of the light-emitting diodes 2 can be, for example, red or super red or white or green or blue or yellow or cyan.

[0021] The LEDs 2 are controlled by control means (not shown). They can be dimmed when switched on, in particular continuously dimmed, so that they emit different amounts of light in different switched-on states. This allows the brightness of the light emitted by the LEDs 2 to be varied.

[0022] The Fig. 1 and Fig. The embodiment of a lighting device according to the invention illustrated in Figure 2 further comprises a plurality of separators 3. The separators 3 are each arranged between adjacent LEDs 2 and extend from the circuit board 1 in the direction of the light emitted by the LEDs 2. The separators 3 can surround the individual LEDs 2 and the light emitted by them, so to speak, forming channels for the light of the individual LEDs 2. The separators 3 can be reflective on the side facing the LEDs 2 and the light of the respective LED 2.

[0023] The Fig. 1 and Fig. The embodiment of an inventive lighting device illustrated in Figure 2 further comprises an optical disk 4, which is arranged at the ends of the separators 3 facing away from the LEDs 2. The optical disk has scattering structures that can serve to homogenize the light passing through the optical disk 4.

[0024] The Fig. 1 and Fig. The embodiment of a lighting device according to the invention shown in Figure 2 further comprises an LC display 5 with a plurality of independently controllable segments 6 (see Fig. 2). The LC display 5 is flat and arranged on the side of the optical disk 4 facing away from the separators 3. The LC display 5 can, in particular, rest against the optical disk 4.

[0025] The light emitted by the LEDs 2 can pass successively through the optical disk 4 and the LCD display 5. At least one of the LEDs 2 is assigned to one of the segments 6 in such a way that light emitted by the at least one LED 2 passes at least partially through the assigned segment 6.

[0026] The segments 6 are controlled by the control means (not shown). The segments 6 can be controlled such that they are in at least a first, switched-on state or a second, switched-off state, wherein in the first switching state of each of the segments 6, more light passes through the segment 6 than in the second switching state. For example, in the first, switched-on state, approximately 40% of the light incident on the segment 6 can pass through the segment 6, whereas in the second, switched-off state of the segment, approximately 80% to 90% of the light incident on the segment 6 is absorbed as it passes through the segment 6.

[0027] Each of the segments 6 can alternatively be controlled in particular such that it can be in one of a plurality of different third switching states, which differ from one another by different light transmittances. The transmission of the light emanating from the associated LED 2 through the segment 6 of the LC display 5 can thus be continuously varied between the transmission in the second switching state and the transmission in the first switching state. This continuous dimming of the segments 6 of the LC display 5 can be achieved, for example, by a corresponding change in the voltage applied to the segment 6.

[0028] The LC display 5 is a passive LC display designed as a dye-doped display doped with color pigments. In the second, or off, switching state, a segment 6 of a dye-doped display exhibits a color that depends on the color pigments in the liquid of the LC display 5. These color pigments can, for example, cause the liquid to have a black to dark gray base color, each with a brownish or bluish hue.

[0029] The segments 6 of the LC display 5 are arranged next to each other in two mutually perpendicular directions (see Fig. 2). Alternatively, the segments 6 of the LCD display 5 can be arranged next to one another in two directions that are not perpendicular to one another. At least one or more or each of the segments 6 can have a dimension between 2.0 mm and 40.0 mm, in particular a dimension between 2.5 mm and 10.0 mm, in the directions in which the segments 6 are arranged next to one another.

[0030] In the illustrated embodiment, the segments 6 have a square cross-sectional area. Alternatively, at least one or more, or each, of the segments 6 may have a triangular, a pentagonal, a hexagonal, or a rectangular cross-sectional area other than a square, or another polygonal cross-sectional area, or a diamond-shaped cross-sectional area. Furthermore, several of the segments 6 of the LC display 5 may differ from one another in terms of their size and / or cross-sectional area.

[0031] In the illustrated embodiment, the pixel grid formed by the adjacent segments 6 is square. Alternatively, the pixel grid formed by the adjacent segments 6 can be rhombus-shaped, diamond-shaped, triangular, hexagonal, or diamond-shaped, or have a rectangular configuration other than a square.

[0032] By appropriately controlling the LEDs 2, symbols, animations, and text, for example, can be displayed on the LC display 5. It is provided that at least some of the segments 6 of the LC display 5 that are assigned to a switched-off LED 2 are in a switched-on state despite the assigned LED 2 being switched off. This switched-on state can be the first switching state in which the transmission through the segment 6 is maximum. However, it can also be a third switching state in which the transmission of the segment 6 is less than the maximum transmission achievable in the first switching state but greater than the minimum transmission achievable in the second switching state. It can also be provided that one or more of the segments 6 that are assigned to a LED 2 in a switched-off state are in the second, switched-off switching state.

[0033] By converting a segment 6 assigned to a switched-off LED into a switched-on state, it is possible, for example, for sunlight or artificial light striking the segment 6 from outside to partially pass through the segment 6, be reflected by the optical disk 4, and then exit again through the segment 6 to the outside of the LC display 5. As a result, segments 6 assigned to a switched-off LED 2 can have shades of gray for a viewer, which, for example, give a displayed symbol, animation, or text a three-dimensional design. This three-dimensional design is supported by segments 6 assigned to switched-off LEDs 2 that are in the second, switched-off state.The non-luminous areas of the LC display 5 can be suitably designed with different shades of gray by the segments 6 being in different switching states.

[0034] The Fig. The second embodiment shown in Figure 3 differs from the first embodiment in that the LC display 5 has a curved shape. In this case, the other Fig. 3 Components not shown, such as the optical disc 4 and the separators 3, must be adapted to the shape of the LC display 5. List of reference symbols 1 circuit board 2 LEDs 3 Separator 4 optical disc 5 LCD display 6 segments of the LCD display QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] DE 10 2021 129 672 A1

[0002]

Claims

[1] A method for operating a lighting device for a motor vehicle, wherein the lighting device comprises a plurality of individually or in groups controllable light-emitting diodes (2) and an LC display (5) with a plurality of independently controllable segments (6), wherein the light-emitting diodes (2) emit light in a switched-on state and emit no light in a switched-off state, wherein the segments (6) of the LC display (5) can be in a first switching state or in a second switching state, wherein at least one of the light-emitting diodes is assigned to each of the segments (6) of the LC display (5) in such a way that the light emanating from the light-emitting diode (2) strikes the assigned segment (6) and at least partially passes through the segment (6), and wherein in the first switching state of the segment (6) more light passes through the segment (6) than in the second switching state, characterized bythat at least a first of the segments (6) which is assigned to a light-emitting diode (2) in a switched-off state is in the first switching state. [2] Method according to claim 1, characterized by that at least a second of the segments (6) which is assigned to a light-emitting diode (2) in a switched-off state is in the second switching state. [3] Lighting device for a motor vehicle, comprising a plurality of individually or in groups controllable light-emitting diodes (2), an LC display (5) with a plurality of independently controllable segments (6) and control means for controlling the light-emitting diodes (2) and the LC display (5), wherein the light-emitting diodes (2) are designed to emit light in a switched-on state and not to emit light in a switched-off state, wherein the segments (6) of the LC display (5) can be in a first switching state or in a second switching state, wherein at least one of the light-emitting diodes (2) is assigned to each of the segments (6) of the LC display (5) in such a way that the light emanating from the light-emitting diode (2) strikes the assigned segment (6) and at least partially passes through the segment (6), and wherein the segments (6) are designed tothat in the first switching state of a segment (6) more light passes through the segment (6) than in the second switching state, , characterized by that the control means are designed to control the light-emitting diodes (2) and the LC display (5) such that the lighting device carries out a method according to one of claims 1 or 2. [4] Lighting device according to claim 3, characterized by that the segments (6) are designed so that in the first switching state of a segment (6) between 10% and 90%, in particular between 25% and 70%, preferably about 40%, of the light incident on the segment (6) passes through the segment (6) and / or that in the second switching state of a segment (6) between 70% and 100%, in particular between 80% and 90% of the light incident on the segment (6) is absorbed when passing through the segment (6). [5] Lighting device according to one of claims 3 or 4, characterized bythat the segments (6) of the LC display (5) can be in at least one third switching state, wherein the segments (6) are designed such that in the first switching state of a segment (6) more light passes through the segment (6) than in the third switching state and that in the third switching state of a segment (6) more light passes through the segment (6) than in the second switching state, in particular wherein the segments (6) can be in a plurality of different third switching states which differ from one another by different light transmittances. [6] Lighting device according to one of claims 3 to 5, characterized bythat the segments (6) of the LC display (5) are arranged next to one another in at least one direction, preferably in two mutually perpendicular or non-perpendicular directions, wherein at least one or more or each of the segments (6) in the at least one direction in which the segments (6) are arranged next to one another have a dimension between 2.0 mm and 40.0 mm, in particular a dimension between 2.5 mm and 10.0 mm. [7] Lighting device according to one of claims 3 to 6, characterized by that at least one or more or each of the segments (6) have a triangular, a rectangular, a pentagonal or a hexagonal cross-sectional area or another polygonal cross-sectional area or a diamond-shaped cross-sectional area. [8] Lighting device according to one of claims 3 to 7, characterized bythat several of the segments (6) of the LC display (5) are different from one another in terms of their size and / or their cross-sectional area. [9] Lighting device according to one of claims 3 to 8, characterized by that the LC display (5) is a passive LC display, in particular wherein the LC display (5) is an LC display (5) doped with color pigments, preferably wherein the LC display (5) is a dye-doped display. [10] Lighting device according to one of claims 3 to 9, characterized by that the LC display (5) is flat or curved. [11] Lighting device according to one of claims 3 to 9, characterized by that the pixel grid formed by the segments (6) arranged next to one another is rectangular, in particular square, or diamond-shaped or rhombus-shaped or triangular or hexagonal or diamond-shaped. [12] Lighting device according to one of claims 3 to 11, characterized bythat at least one or more or each of the light-emitting diodes (2) is designed to emit light with a light colour which can be, for example, red or super red or white or green or blue or yellow or cyan. [13] Lighting device according to one of claims 3 to 12, characterized by that at least one or more or each of the light-emitting diodes (2) is designed to be dimmed in the switched-on state, in particular to be continuously dimmed, so that it emits different amounts of light in different switched-on states. [14] Lighting device according to one of claims 3 to 13, characterized by that the lighting device comprises a plurality of separators (3), each of which is arranged between one of the light-emitting diodes (2) and the associated segment (6) of the LC display (5). [15] Lighting device according to one of claims 3 to 13, characterized bythat the lighting device has an optical disc (4) with a scattering structure, in particular wherein the optical disc (4) is arranged between the separators (3) and the LC display (5), preferably wherein the optical disc (4) rests on the side of the LC display (5) facing the separators (3).

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