Lighting device for motor vehicle

Abstract

The invention relates to a lighting device (100) for a motor vehicle, in particular a headlight, comprising a plurality of light modules for producing different light functions. According to the invention, the lighting device (100) has a segmented LC display (1) which is arranged in front of the light modules in the emission direction and which can be illuminated from the back by the light modules, one light module or a group of light modules being associated with each segment (11, 12, 13) of the LC display (1).

Description

Technical Field

[0001] The present invention relates to a lighting device for a motor vehicle, in particular a headlamp, which has a plurality of light modules for generating different light functions. Background Art

[0002] In the prior art, lighting devices for motor vehicles are known, which have a back-illuminable LC display (Liquid Crystal Display) for digitally controlling the light distribution and light intensity. For example, headlamps are known, the low beam and high beam functions of which are based on an LC display and, in combination with a suitable sensing mechanism, can generate a dynamic and adaptable illumination of the carriageway and other driving environments, so that the illumination can be adapted to the changing driving conditions in real time. In addition, daytime running lights or direction indicators for driving are known, which are based on a back-illuminated LC display. In the prior art, a separate LC display with optically characteristic and pixel arrangement adapted to the requirements is used for each light function.

[0003] For example, document DE 10 2021 129 672 A1 discloses a lighting device for a motor vehicle, having: a circuit board, which includes a plurality of light-emitting diodes arranged thereon; an optical lens and a segmented reflector element, wherein the reflector element is arranged between the circuit board and the optical lens; and an LC display arranged on the optical lens, which is designed to selectively switch pixels between a transparent and an opaque state. Summary of the Invention

[0004] Disclosure of the Invention

[0005] The object of the present invention is to provide an alternative embodiment of a lighting device for a motor vehicle including an LC display, which lighting device has a plurality of light modules for generating different light functions.

[0006] This object is solved by a lighting device according to claim 1. Advantageous further configurations of the present invention are given in the dependent claims.

[0007] The technical teaching of the present invention discloses that the lighting device has a segmented LC display, which is arranged in front of the light modules in the emission direction and can be back-illuminated by these light modules, wherein one light module or a group of light modules is assigned to each section of the LC display.

[0008] The present invention starts from the idea of creating an integrated LC display that determines the size and composition for modulating the light of multiple different optical modules, so that, different from the prior art, it is not necessary to install a separate LC display for each optical module. Thereby, the material and installation costs are advantageously reduced, and a particularly compact and aesthetic optical system can be produced, in which the internal space of the lighting device is completely covered on the light exit side by a large-area LC display in the form of a covering part.

[0009] In particular, the individual sections of the LC display have different optical properties from each other. The optical properties relevant for current applications are, for example, the transmittance in the open and closed states of the pixels in the relevant section, the reflectance in the closed state, and the color. The dynamics of the switching process, especially the switching time for the transformation between the closed and open states, can also be understood as an optical property in the sense of the current application. Depending on the light function to be implemented, the appropriately configured sections of the LC display with specific optical properties are assigned to the respective optical modules. For example, the low beam or high beam function should be equipped with sections having a particularly high transmittance.

[0010] For example, the individual sections of the LC display have different liquid crystal media from each other. Thereby, the optical properties of the individual sections can be appropriately adjusted. As suitable liquid crystal media, for example, liquid crystals with a nematic phase, a chiral nematic phase, or a smectic phase are considered. When using the nematic phase, for example, there can be an arrangement of the liquid crystal parallel to the display plane (in-plane switching), or the liquid crystal is oriented perpendicular to the display surface in the rest state. The first variant results in a small viewing angle dependence and a strong color impression, while the second variant provides a particularly high contrast between the open and closed states.

[0011] In particular, the sections of the LC display can have different color pigments from each other. For example, the liquid crystal layer of a selected section of the LC display can be doped with a black color pigment, so as to produce a black view in the opaque state.

[0012] In an advantageous embodiment, the individual sections of the LC display have pixels that are differently sized and / or have different structural profiles from each other. The pixels (“Pixel”) form the smallest specific switchable unit of the section and thus determine the position resolution of the light signals that can be displayed separately. In addition to the size of the pixels, the profile of the pixels can also vary between different sections, for example. In addition to a square profile, other polygonal profiles can also be provided.

[0013] In another embodiment, the individual segments of the LC display have different types of actuation. For example, individual segments can be configured as passive matrix displays, where the individual pixels are actuated passively, i.e., without additional electronic components in the individual pixels, by means of a matrix actuation device. Higher-performance segments can be configured as active matrix displays, where each pixel has its own circuitry, which is particularly suitable for large-area segments with high positional resolution. In particular, each segment can be actuated independently of the remaining segments.

[0014] The light functions that can be generated using the light modules of the lighting device include, in particular, high beam, low beam, daytime running lights, tail lights, position lights, direction indicators, front signal lights, and / or rear signal lights. For example, the high beam and the low beam can be grouped and assigned to a common segment of the LC display. For the light functions that serve as signal lights, the associated segments of the LC display can be configured to display different light images such as letters, symbols, and graphics, and, for example, to generate light signal characteristics that are dynamically adapted to the driving mode of the motor vehicle. Description of the drawings

[0015] Embodiments of the invention

[0016] The invention is then described with the aid of the description of the figures of an embodiment. The Figure 1 The front view of a lighting device 100 according to the invention, configured as a headlight for a motor vehicle, is shown in schematic form. Detailed description

[0017] The lighting device 100 has a plurality of light modules for generating different light functions and a segmented LC display 1, which is arranged in front of the light modules in the emission direction and can be illuminated from the back by these light modules, wherein one light module or a group of light modules is assigned to each segment 11, 12, 13 of the LC display 1. The segments 11, 12, 13 are shown in a completely closed, i.e., opaque, state, so that the light modules arranged behind them in the viewing direction are not visible. The LC display 1 is arranged directly behind a closed cover (lens) 2. The light modules for the high beam and for the low beam are arranged behind the segment 11, the light module for the daytime running lights is arranged behind the segment 12, and the light module for the direction indicators is arranged behind the segment 13. All segments 11, 12, 13 are adapted, in terms of their optical properties, the liquid crystal medium used, including the color pigments embedded therein, the size and profile of the individual pixels, and the type of actuation, to the requirements of the associated light function.

[0018] List of reference numerals

[0019] 100 Lighting device

[0020] 1 LC display

[0021] 11 segments of the LCD

[0022] 12 segments of the LCD

[0023] 13 segments of the LCD

[0024] 2 Enclosure cover

Claims

1. Lighting device (100) for a motor vehicle, in particular a headlight, having a plurality of light modules for generating different light functions, characterized in that, The lighting device (100) has a segmented LC display (1) which is arranged in front of the light module in the emission direction and can be illuminated from the back by these light modules, wherein one light module or a group of light modules is assigned to each segment (11, 12, 13) of the LC display (1).

2. The lighting device (100) according to claim 1, characterized in that, The segments (11, 12, 13) of the LC display (1) have different optical properties from one another.

3. The lighting device (100) according to claim 1 or 2, characterized in that, The segments (11, 12, 13) of the LC display (1) have different liquid crystal media from one another.

4. The lighting device (100) according to one of the above claims, characterized in that, The segments (11, 12, 13) of the LC display (1) have different color pigments from one another.

5. The lighting device (100) according to one of the above claims, characterized in that, The segments (11, 12, 13) of the LC display (1) have pixels of differently determined sizes and / or configured contours from one another.

6. The lighting device (100) according to one of the above claims, characterized in that, The segments (11, 12, 13) of the LC display (1) have different types of actuation from one another.

7. The lighting device (100) according to one of the preceding claims, characterized in that The light functions that can be generated by the light module include high beam, low beam, daytime running light, tail light, position light, direction indicator, front signal light and / or rear signal light.

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