Lighting device for vehicle
By combining a flat light guide and a liquid crystal display to form an overall structure, the problems of complex installation and high cost of existing vehicle lighting devices are solved, compact and low-cost manufacturing is achieved, and the needs of multiple signal functions are met.
Patent Information
- Application Number
- CN202410822625.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-26
- Filing Date
- 2024-06-25
- Publication Date
- 2024-12-27
AI Technical Summary
The existing vehicle lighting device consists of multiple independent components, resulting in complex installation and non-compact structure, increasing manufacturing costs.
By combining the flat light guide and the liquid crystal display, an integral structure is formed so that light passes through the liquid crystal layer from the exit surface of the light guide and passes through the non-light guide lens immediately, avoiding separate installation and positioning, and using a passive liquid crystal display to improve transmittance and reduce costs. , and switch signal functions by controlling the LCD display.
It realizes simpler and cheaper manufacturing, and designs a more compact lighting device, which meets the functions of taillights, tail brake lights, flashes, etc., while improving the brightness and flexibility of the light function.
Smart Images
Figure CN119196580A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a lighting device for a vehicle according to the preamble of claim 1 . Background Art
[0002] A lighting device of the above type is known from WO 2023 / 025626 A1. The lighting device described here comprises: a light-emitting module having at least one light source and a light-emitting surface illuminated by the light source, from which light is emitted when the lighting device is in operation; and a liquid crystal display, which is at least partially arranged in front of the light-emitting surface, so that at least a portion of the light emitted from the light-emitting surface is incident on the incident surface of the liquid crystal display and is emitted from the exit surface of the liquid crystal display when the lighting device is in operation, wherein the lighting device is configured to control the liquid crystal display so as to specifically allow (some) parts of the light incident on the incident surface to pass through the liquid crystal display and not allow other parts of the light incident on the incident surface to pass through the liquid crystal display. Here, the light-emitting module is a separate light-emitting module, on which the liquid crystal display is mounted. The disadvantage here is that the entire system consists of a plurality of components, which must be individually fixed and positioned relative to each other. This leads to a complex installation on the one hand and a loss of structural space on the other hand. Summary of the invention
[0003] Therefore, the problem of the present invention is to provide a lighting device of the above type, which can be manufactured more simply and / or more cost-effectively and can be designed to be more compact.
[0004] This is achieved according to the invention by a lighting device of the type mentioned at the outset having the characterizing features of claim 1. The dependent claims relate to preferred embodiments of the invention.
[0005] According to claim 1, one of the at least partially transparent lenses of the liquid crystal display is formed by a flat light guide, wherein the lighting device is arranged so that light emitted from at least one exit surface of the light guide at least partially passes through the liquid crystal layer of the liquid crystal display and directly passes through the lens of the liquid crystal display that is not formed by the light guide. In this way, the light guide and the liquid crystal display are formed integrally with each other, so that they do not need to be installed and positioned separately. In addition, by combining the light guide and the liquid crystal display together, the structure of the lighting device is more compact.
[0006] It is possible that the lighting device is configured to control the liquid crystal display so as to selectively allow part of the light emitted from at least one exit surface of the light guide to pass through the liquid crystal display and not allow other parts of the light emitted from at least one exit surface of the light guide to pass through the liquid crystal display. Thus, by controlling the liquid crystal display, individual segments of the illuminated surface formed by the exit surface of the light guide can be switched selectively. Thus, the lighting device can be configured to fulfill a signaling function, in particular a tail light or a tail brake light or a tail flasher or a position daytime running light or a position flasher.
[0007] It can be provided that the incident surface of the light guide is configured as an end surface, in particular, wherein the length and width of the light guide in a first direction and a second direction perpendicular to the first direction are significantly greater than the thickness of the light guide in a third direction perpendicular to the first and second directions, wherein at least one exit surface is arranged in a plane formed by the first and second directions, and the incident surface is arranged in a plane formed by the second and third directions. In particular, the thickness of the light guide can be several millimeters, for example between 2 millimeters and 3 millimeters, so that the structure of the lighting device is very compact.
[0008] It is possible that the light guide has a structure, wherein the lighting device is configured such that light moving through the light guide is at least partially deflected by the structure so that the light is emitted from the light guide through the exit surface. Here, the structure can be arranged on a surface opposite to the exit surface immediately adjacent to the liquid crystal layer. In particular, during operation of the lighting device, the scattering structure can scatter the light moving through the light guide, so that the light-emitting surface formed by the exit surface is evenly illuminated.
[0009] It can be provided that the lighting device has a reflective layer, which is arranged on a surface opposite to the exit surface. The reflective layer can ensure that most of the light moving through the light guide reaches the exit surface and is emitted from the exit surface.
[0010] Alternatively, it can be provided that the lighting device has a reflector arranged outside the light guide, wherein the lighting device is configured so that light emerges from a surface opposite to the exit surface, the light is reflected by the reflector again in the direction of the light guide, is incident on the light guide again through the surface opposite to the exit surface, and is emitted from the light guide through the exit surface, so that the light passes through the liquid crystal layer of the liquid crystal display and directly therewith passes through a lens of the liquid crystal display that is not formed by the light guide.
[0011] There is the possibility that the at least one light source is configured as a light emitting diode, wherein in particular a plurality of light emitting diodes are provided. Here, during operation of the lighting device, at least two of the light emitting diodes can generate light having mutually different colors. This allows for an attractive design for the signaling function of the lighting device to be produced with simple means. The light module can be implemented in all colors (e.g. red, yellow, white, blue, cyan or similar colors) by means of a variable LED configuration. When using blue, the light module is also suitable for implementing and designing marker lights for police vehicles. Two-color variants, such as red-yellow, yellow-white or white-cyan, can also be realized by corresponding LED configurations.
[0012] It can be provided that the LC display is a passive LC display. For light functions in a motor vehicle, small surfaces are usually used, from which a high light power or a high brightness must be achieved. Therefore, a high transmittance of the LC display is important in order to generate the legally required light intensity for the signal function. In contrast to active LC displays, passive LC displays have no active components such as transistors, so that the transmittance of passive LC displays is significantly higher than that of active LC displays. Furthermore, passive LC displays can be produced significantly more cost-effectively than active LC displays.
[0013] There is the possibility that the LCD is a guest-host display or smart glass display. In such an LCD, no polarizing filter is required, thus providing a higher transmittance, which is advantageous and decisive for fulfilling the light function in a small light-emitting element. In addition, due to the absence of a polarizer, the LCD is also independent of the viewing angle.
[0014] It can be provided that the liquid crystal display is a liquid crystal display doped with color pigments. In particular, the liquid crystal display can be a so-called dye-doped display, which is doped with color pigments which determine its color in the non-operating state of the liquid crystal display. Thus, for example, a black side can be seen, but also a red or blue or other desired color side.
[0015] There is the possibility that the liquid crystal display has a plurality of segments that can be controlled independently of one another. The segments of the liquid crystal display that can be controlled independently of one another can differ from one another in terms of their size and / or their shape. Advantageous to passive liquid crystal displays is the arbitrarily designed pixelation of the liquid crystal display. Therefore, the individually switchable pixels of the liquid crystal display can have any different shapes and sizes and thus actively define the desired design of the switchable matrix for the light function. For example, pixels of triangles, diamonds, squares or any other shapes or special graphic elements, such as letters, pictograms or trademarks can be preset and realized. Compared with active liquid crystal displays with very small pixelation for high resolution, passive liquid crystal displays, in particular passive liquid crystal displays for automotive applications, usually have larger pixel surfaces.
[0016] It can be provided that the optic of the liquid crystal display which is not formed by the light guide is made of glass or of an at least partially transparent plastic. In particular, the optic of the liquid crystal display which is not formed by the light guide and / or the light guide can be flexible. Thus, the shape of the lighting device or the shape of the illuminated surface of the lighting device can be adapted to the shape of a curved section of the vehicle body. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be explained in more detail below with reference to the accompanying drawings.
[0018] Figure 1 A schematic cross-sectional view showing an embodiment of a lighting device according to the present invention;
[0019] Figure 2 Show according to Figure 1 Front view of the lighting device. DETAILED DESCRIPTION
[0020] In the figures, identical and functionally identical parts are provided with the same reference numerals. For the sake of simplicity of orientation, a Cartesian coordinate system is drawn in the figures.
[0021] The lighting device shown in the figure comprises at least one light source 1 designed as a light emitting diode (LED), preferably a plurality of light sources 1 designed as light emitting diodes, which emit light 2 during operation of the lighting device. The light sources 1 are arranged on a common circuit board 3.
[0022] The lighting device also includes a flat (planar) light guide 4 having an incident surface 5 and at least one exit surface 6, wherein the lighting device is configured so that light 2 generated by at least one light source 1 is at least partially incident into the light guide 4 through the incident surface 5 and is at least partially emitted from the at least one exit surface 6.
[0023] The incident surface 5 of the light guide 4 is configured as an end surface, wherein the length and width of the light guide 4 in the first direction X and the second direction Y perpendicular thereto are significantly greater than the thickness of the light guide in the third direction Z perpendicular to the first and second directions X, Y (see Figure 1 and Figure 2 ). Here, the at least one exit surface 6 is arranged in an XY plane formed by the first and second directions, and the entrance surface 5 is arranged in a YZ plane formed by the second and third directions. In particular, the thickness of the light guide 4 in the Z direction may be several millimeters, for example between 2 and 3 millimeters.
[0024] The light guide 4 has a structure 8 on a surface 7 opposite to the exit surface 6, and the structure is designed so that the light 2 moving through the light guide 4 is at least partially deflected by the structure 8, so that it passes through the exit surface 6 from the light guide 4 to the exit surface 6. Figure 1 The beam is emitted to the right or in the positive Z direction.
[0025] The surface 7 opposite to the exit surface 6 may have a reflective layer, which can specifically reflect the light 2 incident on the surface 7 toward the exit surface 6. Alternatively, the lighting device may include a reflector (not shown), which is arranged outside the light guide 4, wherein the lighting device is configured so that the light 2 is emitted from the surface 7 opposite to the exit surface 6 in the negative Z direction, the light is reflected by the reflector again toward the light guide 4, is incident again into the light guide 4 through the surface 7 opposite to the exit surface 6, and is emitted through the exit surface 6. Figure 1 The light is emitted from the light guide 4 to the right or in the positive Z direction.
[0026] The lighting device further comprises a liquid crystal display (LC-Display). The liquid crystal display comprises a liquid crystal layer 9, which is connected to the exit surface 6 of the light guide 4 in the positive Z direction. In addition, the liquid crystal display comprises an at least partially transparent lens 10, which is arranged on the side of the liquid crystal layer 9 away from the light guide 4. Different from the prior art in which the liquid crystal layer 9 is arranged between two transparent lenses, in the embodiment shown, the liquid crystal layer 9 is arranged between the light guide 4 and the at least partially transparent lens 10.
[0027] The liquid crystal display also has a plurality of segments 11 which can be controlled independently of one another. Here, the segments 11 of the liquid crystal display which can be controlled independently of one another can differ from one another in terms of their size and / or their shape. Figure 2 A plurality of segments 11 are shown, which segments partially have different sizes and shapes.
[0028] For illustration, some of these segments 11 are in a state in which the light 2 emitted from the at least one exit surface 6 of the light guide 4 passes relatively unhindered through the region of the liquid crystal layer 9 of the liquid crystal display forming the corresponding segment 11 and, immediately therewith, through the lens 10 of the liquid crystal display. Furthermore, other of the segments 11 are shown in a state in which the light 2 emitted from the at least one exit surface 6 of the light guide 4 cannot pass through the region of the liquid crystal layer 9 forming the corresponding segment 11.
[0029] In order to control the segments 11, the lighting device includes a schematically represented control device 12, which is connected to the liquid crystal layer 9 and / or the lens 10 defining the liquid crystal layer 9 via a control line 13, so that it can appropriately switch the areas of the liquid crystal layer 9 that form the various segments from a light-transmitting state to an opaque state and from an opaque state to a light-transmitting state.
[0030] In the illustrated embodiment, the control device 12 is arranged together with the light source 1 on the printed circuit board 3. However, it is also entirely possible to arrange the control device 12 separately.
[0031] Reference numerals list
[0032] 1 Light Source
[0033] 2 Light emitted by a light source
[0034] 3 Circuit Board
[0035] 4 Light guide
[0036] 5 Light guide incident surface
[0037] 6. Light guide exit surface
[0038] 7 The surface of the light guide opposite to the exit surface
[0039] 8 Structure
[0040] 9 Liquid crystal layer of LCD
[0041] 10 At least partially transparent lens for a liquid crystal display
[0042] 11 LCD display segments
[0043] 12 LCD display control device
[0044] 13 LCD control line
Claims
1. A lighting device for a vehicle, comprising: at least one light source (1); A flat light guide (4) having an incident surface (5) and at least one exit surface (6), wherein the lighting device is arranged such that light (2) generated by the at least one light source (1) is at least partially incident into the light guide (4) through the incident surface (5) and is at least partially emitted from the at least one exit surface (6); A liquid crystal display comprising two mutually opposing, at least partially transparent lenses (10) and a liquid crystal layer (9) arranged between the lenses (10), The invention is characterized in that one of the at least partially transparent lenses of the liquid crystal display is formed by a flat light guide (4), wherein the lighting device is arranged so that the light (2) emitted from the at least one exit surface (6) of the light guide (4) at least partially passes through the liquid crystal layer (9) of the liquid crystal display and directly passes through the lens (10) of the liquid crystal display that is not formed by the light guide (4).
2. The lighting device according to claim 1, characterized in that: The lighting device is configured to control the liquid crystal display so as to specifically allow part of the light (2) emitted from the at least one exit surface (6) of the light guide (4) to pass through the liquid crystal display and not allow other parts of the light (2) emitted from the at least one exit surface (6) of the light guide (4) to pass through the liquid crystal display.
3. The lighting device according to any one of claims 1 or 2, characterized in that: The incident surface (5) of the light guide (4) is constructed as an end surface, in particular, the length and width of the light guide (4) in a first direction (X) and a second direction (Y) perpendicular to the first direction are significantly greater than the thickness of the light guide (4) in a third direction (Z) perpendicular to the first and second directions (X, Y), wherein the at least one exit surface (6) is arranged in a plane formed by the first and second directions (X, Y), and the incident surface (5) is arranged in a plane formed by the second and third directions (Y, Z).
4. The lighting device according to any one of claims 1 to 3, characterized in that: The light guide (4) has a structure (8), wherein the lighting device is arranged so that light (2) moving through the light guide (4) is at least partially deflected by the structure (8) so that the light is emitted from the light guide (4) through an exit surface (6).
5. The lighting device according to claim 4, characterized in that: The structure part (8) is arranged on a surface (7) opposite to the emission surface (6) which is adjacent to the liquid crystal layer (9).
6. The lighting device according to any one of claims 1 to 5, characterized in that: The lighting device comprises a reflective layer which is arranged on a surface (7) opposite to an exit surface (6).
7. The lighting device according to any one of claims 1 to 5, characterized in that: The lighting device comprises a reflector arranged outside the light guide (4), wherein the lighting device is configured such that light (2) is emitted from a surface (7) opposite to an exit surface (6), the light is reflected by the reflector again toward the light guide (4), is incident again into the light guide (4) through the surface (7) opposite to the exit surface (6), and is emitted from the light guide (4) through the exit surface (6), so that the light passes through a liquid crystal layer (9) of the liquid crystal display and immediately passes through a lens (10) of the liquid crystal display that is not formed by the light guide (4).
8. The lighting device according to any one of claims 1 to 7, characterized in that: The at least one light source (1) is designed as a light emitting diode, wherein in particular a plurality of light emitting diodes are provided.
9. The lighting device according to any one of claims 1 to 8, characterized in that: The liquid crystal display is a passive liquid crystal display.
10. The lighting device according to any one of claims 1 to 9, characterized in that: The liquid crystal display is a guest-host display or a smart glass display.
11. The lighting device according to any one of claims 1 to 10, characterized in that: The liquid crystal display is a liquid crystal display doped with color pigments.
12. The lighting device according to any one of claims 1 to 11, characterized in that: The liquid crystal display has a plurality of segments (11) which can be controlled independently of each other.
13. The lighting device according to claim 12, characterized in that: The segments (11) of the liquid crystal display which can be controlled independently of one another differ from one another in terms of their size and / or their shape.
14. The lighting device according to any one of claims 1 to 13, characterized in that: The lens (10) of the liquid crystal display which is not formed by the light guide (4) consists of glass or of at least partially transparent plastic.
15. The lighting device according to any one of claims 1 to 14, characterized in that: The lens (10) of the liquid crystal display that is not formed by the light guide (4) and / or the light guide (4) are flexible.