Projection system for a motor vehicle, motor vehicle and method for operating a projection system

Abstract

Projection system for a motor vehicle (10), comprising a first projection unit (22) configured to project a first projection image (PB1) onto a first projection surface (PF1), a second projection unit (24) configured to project a second projection image (PB2) onto a second projection surface (PF2), and a central control module (30) configured to specify the projection images (PB1, PB2) to be projected to the projection units (22, 24), wherein a correction module (30) is provided in which an overlap image area (UB1, UB2) is stored for each of the two projection images (PB1, PB2), which is assigned to an overlap area (U) of the projection surfaces (PF1, PF2), wherein the correction module (40) is configured to perform an image shift of at least one of the two projection images (PB1, PB2) if there is an overlap in the overlap image areas. (UB1, UB2) of both projection images (PB1,PB2) each contains a pixel to be illuminated.

Description

[0001] The invention relates to a projection system for a motor vehicle, comprising a first projection unit configured to project a first projection image onto a first projection surface, a second projection unit configured to project a second projection image onto a second projection surface, and a central control module configured to specify the projection images to be projected to the projection units.

[0002] Such projection systems for use in motor vehicles are generally known from the prior art, wherein the projection systems have several projection units for projecting projection images, such as lettering, a logo, a traffic sign, or other graphics, into the driver's field of vision. Each projection unit has a light-emitting chip comprising a plurality of light-emitting elements, in particular LEDs, arranged in a matrix and controllable separately. To project an image onto a projection surface, the projection unit generates a light matrix by means of a plurality of separate light beams produced by the light-emitting elements, with each projection unit receiving digital projection images, i.e.,Control images are fed to the projection units, each containing a corresponding matrix of pixels to which shades of gray or brightness levels are assigned. In other words, the digital projection images fed to the projection units have a corresponding matrix of pixels, with several pixels to be illuminated and several pixels not to be illuminated. Consequently, the light-emitting elements of the projection units can be controlled according to the brightness levels of the pixels in the projection image, so that ultimately an image of the projection image is generated on the projection surfaces of the projection units with the light matrix; that is, a projection image is projected onto the projection surface.

[0003] If each projection unit is intended to project an image onto the vehicle's surroundings, particularly onto the ground, the two images projected by the two units may overlap. When projecting onto the road or ground, the projection surfaces of the units are predefined by their positioning and orientation. Depending on this positioning and orientation relative to each other, the projection surfaces of the units overlap within a resulting area of ​​overlap. If both projection images are projected onto the projection surface, i.e.,If the images of the projections visible to a person on the projection surface extend into the overlap area, the projections projected onto the projection surfaces could overlap, and such an overlap could lead to undesirable effects.

[0004] From DE 10 2021 116 678 A1 a projection system for a motor vehicle is known, which comprises at least two projection units and a camera, wherein the images projected onto a projection surface by the two projection units are captured by the camera and a readjustment is carried out if an overlap of the captured images is detected.

[0005] The object of the invention is to provide a projection system for a motor vehicle which has several projection units and by which, when projection images are projected simultaneously by both projection units, an overlap of the projection images can be avoided in a simple and reliable manner.

[0006] The problem is solved by the features of claim 1.

[0007] According to the invention, a correction module is provided in which an overlap image area is stored for each of the two projection images, which is assigned to an overlap area of ​​the projection surfaces, wherein the correction module is configured to perform an image shift of at least one of the two projection images if there is a pixel to be illuminated, i.e. a pixel with a high brightness level, in the overlap image areas of both projection images.

[0008] The correction module can be located either inside the vehicle, for example integrated into the central control module, or outside the vehicle, so that the central control module already receives the image-shifted projection images, and the projection units are controlled based on these.

[0009] The pixels to be illuminated for the projection of the projection images are not distributed over the entire projection surface, i.e., the image of the projection projected onto the projection surface is smaller than the entire projection surface, so that an image shift or a shift of the pixels assigned to the projection image is possible at any time.

[0010] The correction module adjusts the projection images and their corresponding pixel matrix before the projection units are activated, reliably preventing overlap of the projected images on the projection surfaces. For this purpose, an overlap image area is defined for each projection image within the correction module. These overlap image areas are defined by the overlap area of ​​the two projection surfaces. The overlap area, in turn, is determined by the positioning and orientation of the projection units relative to each other. Thus, the overlap image areas are also defined by the predefined orientation and positioning of the projection units based on the overlap area.The crucial factor here is how the two projection units are positioned relative to each other in the longitudinal direction of the vehicle, in the transverse direction of the vehicle and in the vertical direction of the vehicle, and how the two projection units are aligned around an axis oriented in the vertical direction of the vehicle and around an axis oriented in the transverse direction of the vehicle.

[0011] An adjustment of a projection image only occurs if the projection images are such that both projection images contain a pixel to be illuminated in the corresponding overlapping image area, thus creating a risk of image content overlap. If both projection images contain pixels in the overlapping image areas, one of the two projection images, or rather its corresponding pixels, is shifted so that this projection image no longer contains any pixels in the corresponding overlapping image area. This image shift is understood as moving the pixels to be illuminated within the matrix. If there are no pixels to be illuminated, or only pixels from one of the two projection units to be illuminated, in the respective overlapping image area, no correction or image shift occurs.Image shift is understood as the displacement of a projected image, or its associated pixels, in one direction away from the other projection unit. In other words, if there is a left projection unit and a right projection unit, an image projected by the left projection unit will be shifted to the left, or an image projected by the right projection unit will be shifted to the right, if both projection images contain pixels in their respective overlapping image area.

[0012] In a preferred embodiment, the correction module is configured to shift both projection images if an image content or pixel to be illuminated is present in the overlapping image areas of both projection images. In this process, the projection images, or the pixels assigned to each projection image, are shifted in opposite directions relative to each other, i.e., the projection images are moved away from each other, if pixels to be illuminated are present in the overlapping image areas.

[0013] This provides a projection system that reliably prevents or eliminates overlapping of projected images onto the projection surfaces by shifting at least one projection image or its associated pixels as needed. To prevent overlapping, no detection of the projected images onto the projection surfaces, nor a distance sensor or similar device, is required.

[0014] In a preferred embodiment, the correction module is designed such that the image is shifted by a displacement dimension, the displacement dimension depending on the positioning and orientation of the projection units relative to each other, i.e., on the overlap area and thus on the overlapping image areas, and on the projection image to be shifted. The displacement dimension, i.e., an angular value or the number of pixels by which the image is to be shifted, depends on how far a projection image extends into the overlapping image area, with the displacement dimension being chosen such that no pixels to be illuminated remain in the overlapping image area.

[0015] The problem is also solved by a motor vehicle with a projection system according to any one of claims 1 to 5. For explanation and advantages, reference is made to the preceding paragraphs.

[0016] Preferably, each matrix headlight has one projection unit. Alternatively, a single matrix headlight has both projection units. For normal driving operation, the matrix headlights or the projection units are controlled in such a way that the driver's field of vision is illuminated as optimally as possible. The projected image can change dynamically, particularly to avoid glare for oncoming traffic. For projecting images, such as a graphic, onto the ground or a wall, the projection units can be controlled accordingly, with the light-emitting elements of the projection units being controlled according to the grayscale or brightness levels of the pixels in the projected image, so that ultimately an image of the projected image is generated on the projection surfaces of the projection units with the light matrix.

[0017] Because the matrix spotlights each comprise one projection unit, or a single matrix spotlight comprises two projection units, the projection units can be provided in a simple manner without requiring any additional components.

[0018] The task is further solved by a method for operating a projection system of a motor vehicle, which has two projection units for projecting projection images onto a projection surface, wherein the method comprises the following steps: - Providing one projection image per projection unit, - Determining an overlap image area for both projection images, which is assigned to an overlap area of ​​the projection surfaces, - Determine whether there is a pixel to be illuminated in the overlapping image areas of both projection images, - Image shift of at least one of the two projection images if there is a pixel to be illuminated in the overlapping image areas of both projection images.

[0019] For explanation and advantages, please refer to the preceding paragraphs.

[0020] An embodiment of the invention is explained in more detail with reference to the drawing.

[0021] Fig. Figure 1 shows a schematic representation of a motor vehicle with two matrix headlights.

[0022] The Fig. Figure 1 shows a motor vehicle 10, which has two matrix headlights 12, 14, i.e. a left matrix headlight 12 and a right matrix headlight 14, and a projection system 20.

[0023] The projection system 20 comprises a first projection unit 22, a second projection unit 24, a central control module 30 and a correction module 40.

[0024] The projection units 22, 24 are each components of a matrix headlight 12, 14. In other words, each matrix headlight 12, 14 comprises one projection unit 22, 24. The projection units 22, 24 each have a light emission chip (not shown) which comprises a plurality of light-emitting elements, in particular LEDs, arranged in a matrix, wherein the light-emitting elements are separately, i.e., individually, controllable. The matrix headlights 12, 14 and the projection units 22, 24 are rigidly arranged in the motor vehicle 10 such that the projection units 22, 24 are positioned relative to each other in a predetermined x-direction (i.e., longitudinal direction of the vehicle), y-direction (i.e., transverse direction of the vehicle), and z-direction (i.e., vertical direction of the vehicle). Furthermore, the projection units 22, 24 are aligned around an axis oriented in the vehicle's vertical direction and around an axis oriented in the vehicle's transverse direction.The fixed installation position of the projection units 22, 24, i.e., the fixed positioning and orientation of the projection units 22, 24, predetermines an illuminated area on a road in front of the motor vehicle 10, i.e., a projection surface PF1, PF2, for each projection unit 22, 24, wherein both the distance of the projection surfaces PF1, PF2 from the motor vehicle 10 and from the projection units 22, 24 respectively, and the dimensions of the projection surfaces PF1, PF2, i.e., the first projection surface PF1 assigned to the first projection unit 22 and the second projection surface PF2 assigned to the second projection unit 24, are predetermined by the installation positions of the projection units 22, 24.

[0025] The central control module 30 is connected to the projection units 22, 24 and to the matrix spotlights 12, 14 via signals and serves to specify the projection images PB1, PB2 to be projected onto the projection surfaces to the projection units 22, 24.

[0026] For normal driving operation of the motor vehicle, the matrix headlights 12, 14 or the projection units 22, 24 are controlled by the central control module 30 in such a way that the driver's field of vision is illuminated as optimally as possible, whereby the control image can change dynamically in order to avoid, in particular, a glare effect for oncoming road users.

[0027] For the projection of projection images PB1, PB2, i.e., text or other graphics, onto the corresponding projection surfaces PF1, PF2, the projection units 22, 24 each generate a light matrix using a multitude of separate light beams produced by the light-emitting elements. For this purpose, each projection unit 22, 24 is supplied with a digital projection image PB1, PB2, i.e., a control image, by the central control module 30. These images have a corresponding matrix of pixels to which grayscale levels or brightness levels are assigned. Subsequently, the light-emitting elements of the projection units 22, 24 can be controlled according to the brightness levels of the pixels of the projection image PB1, PB2, so that an image of the projection image PB1, PB2 is generated on the projection surfaces PF1, PF2 using the light matrix.

[0028] As shown in the figure, the projection surfaces PF1, PF2 overlap in an overlap area U. This overlap is due to the positioning and orientation of the projection units 22, 24, particularly their relative positioning and orientation. The overlap area U is defined by the relative positioning and orientation of the projection units 22, 24. If each projection unit 22, 24 is to project a projection image PB1, PB2—that is, a first projection image PB1 associated with the first projection unit 22 and a second projection image PB2 associated with the second projection unit 24—onto the corresponding projection surfaces PF1, PF2, the projection images PB1, PB2 projected by the two projection units 22, 24 may overlap due to the existing overlap area U.In this scenario, both projection images PB1 and PB2, projected onto projection surfaces PF1 and PF2, would extend into the overlap area U. Such an overlap leads to undesirable effects in the projection of the images PB1 and PB2.

[0029] To reliably prevent such an overlap of the projection images PB1, PB2 projected onto projection surfaces PF1, PF2, the correction module 40 is provided. In the correction module 40, an overlap image area UB1, UB2 is stored for both projection images PB1, PB2 of the projection units 22, 24, whereby the overlap image areas UB1, UB2 are derived from the overlap area U. The correction module 40 is designed, i.e., it includes a correction function such that before the projection images PB1, PB2 are transmitted to the projection units 22, 24, and thus before the projection images PB1, PB2 are projected onto the projection surfaces PF1, PF2, it is checked whether both projection images PB1, PB2 have pixels to be illuminated in the corresponding overlap image area UB1, UB2. If this is the case, one of the two projection images PB1, PB2, i.e.The corresponding pixels are shifted by a displacement dimension such that no pixels of the shifted projection image PB1, PB2 to be illuminated remain in the corresponding overlap image area UB1, UB2. The displacement dimension, i.e., an angular value or the number of pixels by which the image must be shifted, depends on the one hand on the positioning and orientation of the projection units 22, 24 relative to each other, i.e., on the overlap area U and thus on the overlap image areas UB1, UB2. On the other hand, the displacement dimension depends on how far the projection image PB1, PB2 to be shifted extends into the overlap image area U.

[0030] In other words, if there is a pixel to be illuminated in each of the overlapping image areas UB1, UB2 of both projection images PB1, PB2, one of the two projection images PB1, PB2 is shifted outwards from the center of the image; that is, the projection image PB1 assigned to projection unit 22 of the left matrix spotlight 12 is shifted to the left, or the projection image PB2 assigned to projection unit 24 of the right matrix spotlight 14 is shifted to the right. Alternatively, both projection images PB1, PB2 can be shifted out of the overlapping image areas UB1, UB2.

[0031] In an alternative embodiment, the correction module 40 can be provided outside the motor vehicle 10, wherein the central control module 30 already receives the corrected projection images PB1, PB2, i.e. a combination of the two projection images PB1, PB2, wherein one of the two projection images PB1, PB2 is shifted if necessary, and the projection units 22, 24 are controlled accordingly.

Claims

[1] Projection system for a motor vehicle (10), with a first projection unit (22) which is designed to project a first projection image (PB1) onto a first projection surface (PF1), a second projection unit (24) which is configured to project a second projection image (PB2) onto a second projection surface (PF2), and a central control module (30) which is designed to specify the projection images (PB1, PB2) to be projected to the projection units (22, 24), characterized by , that A correction module (40) is available which is executed to avoid an overlap of the images projected onto the projection surfaces (PF1, PF2) without capturing the images projected onto the projection surfaces (PF1, PF2), wherein in the correction module (40) an overlap image area (UB1, UB2) is stored for each of the two projection images (PB1, PB2), which is assigned to an overlap area (U) of the projection surfaces (PF1, PF2), wherein the correction module (40) is configured to perform an image shift of at least one of the two projection images (PB1, PB2) if there is a pixel to be illuminated in each of the overlap image areas (UB1, UB2) of both projection images (PB1, PB2). [2] Projection system according to claim 1, characterized by, that the image shift of at least one projection image (PB1, PB2) is carried out in such a way that the overlap image area (UB1, UB2) of the shifted projection image (PB1, PB2) is free of pixels to be illuminated. [3] Projection system according to claim 1 or 2, characterized by , that the correction module (40) is set up to perform an image shift of both projection images (PB1, PB2) when there is a pixel to be illuminated in the overlap image areas (UB1, UB2) of both projection images (PB1, PB2). [4] Projection system according to any one of the preceding claims, characterized by , that the overlap image area (U) and the overlap image areas (UB1, UB2) assigned to the overlap area (U) of the projection surfaces (PF1, PF2) are defined by a fixed positioning and orientation of the projection units (22, 24) relative to each other. [5] Projection system according to any one of the preceding claims, characterized by , that the correction module (40) is executed, that the image shift is made by a displacement dimension, the displacement dimension depending on the positioning and orientation of the projection units (22, 24) relative to each other and on the projection image (PB1, PB2) to be shifted. [6] Motor vehicle with a projection system (20) according to any one of claims 1 to 5. [7] Motor vehicle according to claim 6, characterized by , that each matrix spotlight (12, 14) has a projection unit (22, 24). [8] Motor vehicle according to claim 6, characterized by , that a single matrix spotlight (12, 14) has both projection units (22, 24). [9] Method for operating a projection system (20) of a motor vehicle (10), which is designed to avoid an overlap of the images projected onto the projection surfaces (PF1, PF2) without capturing the images projected onto the projection surfaces (PF1, PF2), which has two projection units for projecting projection images (PB1, PB2) onto a projection surface (PF1, PF2) each, comprising the following steps: - Providing one projection image (PB1, PB2) per projection unit (22, 24), - Determination of an overlap image area (UB1, UB2) for both projection images (PB1, PB2), which is assigned to an overlap area (U) of the projection surfaces (PF1, PF2), - Determine whether there is a pixel to be illuminated in the overlapping image areas (UB1, UB2) of both projection images (PB1, PB2), - Image shift of at least one of the two projection images (PB1) if there is a pixel to be illuminated in each of the overlapping image areas (UB1, UB2) of both projection images (PB1, PB2).

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