Displaying image content on a vehicle screen

Abstract

The invention relates to a method and a display device (100) for displaying image content (401) on one or more screens (203) of a vehicle (200). In the method, a head position (P1) of a driver (204) of the vehicle (200) is determined, and image content (401) is registered, so that the image content (401) is displayed larger the further it is displayed on a screen (203) from the head position (P1).

Description

[0001] The invention relates to a method and a display device for displaying image content on one or more screens of a vehicle.

[0002] A vehicle driver is shown a wide range of important information in their field of vision that relates to the vehicle's operating status and / or provides driver support. Displays indicating the vehicle's operating status include, for example, speed and energy levels (e.g., fuel level or battery charge level), and indicator lights for the vehicle's lighting. Displays that assist the driver include, for example, images from vehicle cameras (e.g., a rearview camera), displays from navigation devices for route determination and guidance, and a radio.

[0003] While many of these displays used to be analog, they were later largely replaced by digital displays. Screen solutions are now known in which many displays are shown as image content on one screen or multiple screens. Such a screen is arranged, for example, on a vehicle's dashboard. The statement that a screen is arranged on the vehicle's dashboard includes the possibility here and below that the screen is integrated into the dashboard. A screen or a combination of several screens arranged on the dashboard can have a considerable extent, even the entire width of the dashboard. Head-up displays are also known in which displays are projected onto a reflective, translucent projection surface, for example the windshield, in the driver's field of vision.

[0004] However, humans see from perspective, meaning that image content appears smaller the further away it is from a point the driver is looking at. Furthermore, visual acuity decreases rapidly with increasing deviation from the driver's line of sight, so that image content that is located in a direction different from the driver's line of sight from the driver's head position is only visible as outlines, even if this direction deviates only relatively slightly from the line of sight. This drastically reduces the amount of useful information that can be presented on an extended dashboard screen or a large vehicle head-up display so that the driver can perceive it all at once.

[0005] CN 209542964 U discloses a head-up display device comprising an eyeball tracking device, a controller, and an image projection device. The eyeball tracking device and the image projection device are each electrically connected to the controller. The controller performs image distortion correction, taking into account the different perspectives of the left and right eyes.

[0006] WO 2022 / 227753 A1 discloses a display system and a display method for binocular distortion correction. The display system comprises an image generation unit, a binocular parallax generation unit, and an optical lens group. The image generation unit generates pre-distorted images for each of the left and right eyes, and interleaves pixels in these pre-distorted images. The binocular parallax generation unit shifts the pixel-interleaved composite image to the two eyes of a viewer by means of the optical lens group, so that both eyes simultaneously receive undistorted images, which are then superimposed.

[0007] CN 115984122 A discloses a backlight display system and method for a head-up display. Among other things, a binocular camera system with two cameras arranged symmetrically around the center of the eye movement area is used. The images captured by the two cameras are corrected and adjusted using camera calibration parameters to combine them into images output by the head-up display.

[0008] DE 10 2019 219 244 B3 describes a method for displaying parts of an image on a screen arrangement with at least two screens that are arranged adjacent to one another, wherein a virtual distance of the image is determined perpendicular to a display plane of one of the screens, wherein a position of the head of a viewer is detected by means of a position detection device, wherein a distance of the head to the display plane is determined from the position of the head, wherein image sections are displayed on the at least two screens that are determined on the basis of the virtual distance and the position of the head as well as a respective size of the screens, wherein a change in the position of the head relative to the position detection device is detected, wherein the image sections are changed relative to the change in the position of the head.A distance between two adjacent screens is projected onto the image, whereby the image area hidden by the distance is divided and a part is displayed on each of the adjacent screens.

[0009] The invention is based on the object of enabling a display of image contents on an extended screen or several screens of a vehicle in the field of vision of a driver of the vehicle, which are improved with regard to their perceptibility by the driver.

[0010] The object is achieved according to the invention by a method for displaying image contents having the features of claim 1 and a display device for displaying image contents having the features of claim 9.

[0011] Advantageous embodiments of the invention are the subject of the subclaims.

[0012] A method according to the invention for displaying image content on one or more screens of a vehicle comprises the steps: - Determining a head position of a driver of the vehicle and - Distortion of the image content so that the further away from the head position an image content is displayed on a screen, the larger it is displayed.

[0013] Distortion of image content refers to a change in its shape and / or size. It is assumed that every image content is assigned a specific shape and size as a default format for its display. Distortion of image content therefore describes a deviation from this default format.

[0014] The method according to the invention takes into account that the image content displayed on the screen is perceived by the driver of the vehicle to be smaller the further it is displayed from a region of the screen to which the driver is directed. Visual acuity also decreases rapidly with increasing deviation from the driver's line of sight, so that image content displayed on the screen away from the region to which the driver is directed is perceived only as blurred. The invention aims to partially compensate for these limitations in perception by enlarging image content displayed on the screen away from the region to which the driver is directed.

[0015] The elementary form of the method according to the invention takes into account that the driver of the vehicle's gaze is primarily directed straight ahead at the road and that the screen is arranged in front of the driver. Therefore, the image content with the information most relevant to the driver is generally displayed in the area of ​​the screen closest to the driver's head position. The driver's gaze on the screen is therefore generally directed to the area of ​​the screen closest to the head position. Therefore, the elementary form of the method according to the invention provides for the distortion of the image content in such a way that the further away from the head position an image is displayed on the screen, the larger it is, or the more enlarged it is compared to its default format. This distortion of the image content is therefore static, as it is only tied to the driver's head position.

[0016] The magnification of image contents according to the invention thus differs from the prior art known from CN 209542964 U, WO 2022 / 227753 A1 and CN 115984122 A, which is primarily directed to the correction and composition of images for the left eye and the right eye of a viewer of the images.

[0017] In one embodiment of the method according to the invention, the image contents are recorded according to a spherical projection, the points of a spherical surface are projected onto a screen area of ​​the screen or screens.

[0018] This embodiment of the method according to the invention takes into account that the driver's reduced perception of image content off the line of sight is caused by the almost spherical shape of the eyeballs. Therefore, a distortion of the image content corresponding to a spherical projection can just compensate for the reduced perception of image content off the line of sight.

[0019] In a further embodiment of the method according to the invention, the head position is determined based on a body axis of the driver and a height of a headrest of a driver's seat of the vehicle.

[0020] According to this embodiment of the method according to the invention, the driver's head position is thus determined indirectly using the height of the headrest of a driver's seat of the vehicle. The driver's body axis is determined, for example, from the adjustment of the driver's seat of the vehicle.

[0021] In a further embodiment of the method according to the invention, the head position is determined by evaluating images from an interior camera of the vehicle.

[0022] This embodiment of the method according to the invention therefore requires that the vehicle has an interior camera. Images from the interior camera are used to determine the driver's head position.

[0023] In a further embodiment of the method according to the invention, the distortion of the image content is dynamically adapted to a viewing direction of the driver, so that the more the direction from the head position to a screen position at which the image content is displayed deviates from the viewing direction of the driver, the larger the image content is displayed.

[0024] In contrast to the static distortion of the image content described above, which only takes the driver's head position into account, this embodiment of the method according to the invention provides for a distortion of the image content that is dynamically adapted to the driver's current line of sight. In other words, the distortion of the image content is adapted to the area of ​​the screen to which the driver's gaze is currently directed.

[0025] In a further embodiment of the method according to the invention, images from an interior camera of the vehicle are evaluated in order to determine the driver's line of sight by eye tracking and / or by the driver's head position.

[0026] This embodiment of the method according to the invention also requires that the vehicle has an interior camera. The interior camera is used to determine the driver's line of sight. For this purpose, so-called eye tracking is used, for example, in which images from the interior camera are evaluated to determine the orientation of the eyes and, from this, the driver's line of sight. Alternatively or additionally, the driver's head posture is determined from the images from the interior camera and used to determine the driver's line of sight.

[0027] In a further embodiment of the method according to the invention, the image contents are displayed on one or more screens arranged on a dashboard of the vehicle or on a head-up display of the vehicle.

[0028] In a further embodiment of the method according to the invention, the image contents are displayed on a plurality of screens arranged on a dashboard of the vehicle and are movable between the screens, and an image content is displayed larger the further the screen on which it is displayed is from the head position.

[0029] The aforementioned embodiments of the method according to the invention specify various screens on which the image content can be displayed. On the one hand, these are one or more screens arranged on the vehicle's dashboard. As already mentioned at the beginning, this includes the possibility of the screen or screens being integrated into the dashboard. On the other hand, a screen can be a head-up display, in particular a head-up display whose projection surface is the vehicle's windshield.

[0030] A display device according to the invention for displaying image content on one or more screens of a vehicle comprises: - a detection device configured to detect a head position of a driver of the vehicle, and - a computing unit that is designed to map the image content so that the further away from the head position the image content is displayed on a screen, the larger it is displayed.

[0031] In one embodiment of the display device according to the invention, the detection device comprises an interior camera of the vehicle and the detection device is configured to determine the head position by evaluating images from the interior camera of the vehicle.

[0032] In a further embodiment of the display device according to the invention, the detection device is configured to evaluate images from the interior camera of the vehicle in order to determine a viewing direction of the driver by eye tracking and / or a head position of the driver, and the computing unit is configured to dynamically adapt the distortion of the image contents to the viewing direction of the driver, so that an image content is displayed larger, the more a direction from the head position to a screen position at which the image content is displayed on a screen deviates from the viewing direction of the driver.

[0033] In a further embodiment of the display device according to the invention, the screen or at least one of the screens is arranged on a dashboard of the vehicle.

[0034] In a further embodiment of the display device according to the invention, the screen or one of the screens is a head-up display of the vehicle.

[0035] The features of a display device according to the invention correspond to features of the method according to the invention. Therefore, the advantages of a display device according to the invention also correspond to the above-mentioned advantages of the method according to the invention.

[0036] Embodiments of the invention are explained in more detail below with reference to the drawings. Fig. 1 is a block diagram of an embodiment of a display device for displaying image content on one or more screens of a vehicle, Fig. 2 schematically shows a vehicle with a display device according to Fig. 1, Fig. 3 a geometric relationship for determining a distortion of image content, Fig. 4 a distortion of image content, Fig. 5 a spherical projection, Fig. 6 a visual acuity diagram of the direction dependence of visual acuity, Fig. 7 is a flowchart of an embodiment of a method for displaying image content on one or more screens of a vehicle.

[0037] Corresponding parts are provided with the same reference numerals in the figures.

[0038] Fig. 1 ( Fig. 1) shows a block diagram of an embodiment of a display device 100 for displaying image content on one or more screens of a vehicle. The display device 100 comprises a capture device 101 and a computing unit 102.

[0039] The display device 100 will also be described below with reference to the Fig. 2 to 6.

[0040] Fig. 2 ( Fig. 2) shows a vehicle 200 with a display device 100. In Fig. Figure 2 shows an outline 201 of the vehicle 200 in a top view. A dashboard 202 is arranged in the vehicle 200. To simplify the description and terminology, it is initially assumed below that the vehicle 200 has only one screen 203, for which the display device 100 is configured to display image content. Embodiments with more than one such screen 203 will be discussed below.

[0041] The screen 203 is arranged on the dashboard 202 and extends almost over the entire width of the dashboard 202. The display device 100 is arranged, for example, in or behind the dashboard 202, as Fig. 2 suggests. However, Fig. 2 is only a schematic drawing. The display device 100 can also be arranged at a different position in the vehicle 200. Furthermore, the detection device 101 and the computing unit 102 of the display device 100 can also be arranged at different positions in the vehicle 200. In other words, the detection device 101 and the computing unit 102 form a functional, but not necessarily a structural, unit. For example, the computing unit 102 can be integrated into a higher-level control unit. In particular, the computing unit 102 can be embodied as a software module that is executed by the control unit.

[0042] The detection device 101 is configured to detect a head position of a driver 204 of the vehicle 200. A screen surface 206 of the screen 203 faces the driver 204. The head 205 of the driver 204 is also in Fig. 2 shown.

[0043] In one embodiment of the display device 100, the detection device 101 comprises an interior camera 103 of the vehicle 200 and is configured to determine the head position of the driver 204 by evaluating images from this interior camera 103 of the vehicle 200.

[0044] In this embodiment of the display device 100, the detection device 101 can be configured, in particular, to evaluate images from this interior camera 103 of the vehicle 100 in order to determine, in addition to the head position of the driver 204, a viewing direction of the driver 204 by eye tracking and / or by a head posture of the driver 204.

[0045] The computing unit 102 of the display device 100 is configured to record the image content to be displayed on the screen 203 in such a way that the image content is displayed larger, the further away it is from a reference point on the screen 203. This will be explained below with reference to the Fig. 3 and Fig. 4 described.

[0046] Fig. 3 ( Fig. 3) shows a geometric relationship 300 for determining a distortion of image content. P1 denotes a head position of the driver 204. The head position P1 is, for example, a point between the eyes of the driver 204. E1 denotes a viewing plane in which the driver 204 looks at the screen 203, from which in Fig. 3, only a section is shown. E2 denotes a screen plane in which the screen surface 206 of the screen 203 lies, on which the image content is displayed. The screen 203 extends along a straight line G in which the viewing plane E1 and the screen plane E2 intersect. For example, the straight line G is a central axis of the screen surface 206 parallel to a longitudinal axis of the screen 203. P2 denotes the reference point to which the distortion of the image content is related.

[0047] For example, reference point P2 is the point on straight line G with the shortest distance from head position P1. In this case, reference point P2 is the base point of the perpendicular from head position P1 to straight line G. Every other point on straight line G is thus at a greater distance from head position P1 than reference point P2. In this case, the image content is displayed larger the further it is displayed from head position P1 on screen area 206 of screen 203.

[0048] Fig. 4 ( Fig. 4) shows a distortion 400 of image content 401. It was assumed that all image content 401 is of the same rectangular shape and size, i.e., that its undistorted representation has the same rectangular outer contour and size. Only image content 401 at or near the reference point P2 is displayed (almost) undistorted. The further away from the reference point P2 an image content 401 is displayed on the screen 203, the larger it appears. This affects the extension of the representation of the image content 401 both along the straight line G and orthogonally to the straight line G. As a result, the rectangular shape of the image content 401 is deformed into a trapezoidal shape with parallel sides of different lengths, which becomes increasingly more pronounced with increasing distance from the reference point P2.

[0049] The computing unit 102 can, in particular, be configured to record the image content 401 according to a spherical projection, which projects the points of a spherical surface stereographically onto the screen area 406 of the screen 203. The extents of the image content 401 along the straight line G and perpendicular to the straight line G are increased with increasing distance from the reference point P2 to the same extent as the lengths of lines in a projection plane increase with increasing distance from the image point of the projection center in a stereographic projection.

[0050] Fig. 4A ( Fig. 4A) shows a surface with checkerboard pattern before projection,

[0051] Fig. 4B ( Fig. 4B) shows a surface with a checkerboard pattern after spherical projection.

[0052] Fig. 5 ( Fig. 5) illustrates such a spherical projection 500 in the viewing plane E1. In this case, the projection center of the projection is the head position P1, and the projection plane of the projection is the screen plane E2. The image point of the projection center is the reference point P2. Also shown are several lines from the head position P1 to a point on the straight line G, with each two adjacent lines forming the same angle with each other.

[0053] Fig. 5A ( Fig. 5A) sketches a cross-section of the human eye and illustrates the principle of human vision: the further objects of the same size are from the projection center, the smaller they appear on the human retina.

[0054] In one embodiment of the display device 100, the detection device 101 is configured to evaluate images from the interior camera 103 of the vehicle 200 in order to determine a viewing direction of the driver 204 by eye tracking and / or by a head posture of the driver 204. The viewing direction is understood to be the direction from the head position P1 to the position on the screen 203 toward which the driver 204 is looking. In this embodiment of the display device 100, the computing unit 102 is configured to dynamically adapt the mapping of the image content 401 to the viewing direction of the driver 204, so that the more a direction from the head position P1 to a screen position at which the image content 401 is displayed on the screen 203 deviates from the viewing direction of the driver 204, the larger the image content 401 is displayed.In this case, the reference point P2 for recording the image content is the position on the screen 203 at which the driver 204 is looking.

[0055] This embodiment of the display device 100 takes into account that image content 401 is perceived by the driver 204 as smaller the further it is displayed from a point toward which the driver's 204 gaze is directed. Furthermore, it takes into account that human visual acuity is strongly concentrated in the direction of gaze. In other words, visual acuity is highest in the direction of gaze and decreases rapidly in directions deviating from the direction of gaze. This means that image content 401 is perceived by the driver 204 as only blurred when it is displayed on the screen 203 at a screen position that deviates relatively little from the position toward which the driver's 204 gaze is directed.

[0056] Fig. 6 ( Fig. 6) shows a visual acuity diagram 600 of the direction dependence of visual acuity S. A direction is represented by an angle α between the direction and the direction of gaze. For example, if the direction of gaze is the direction from the head position P1 to the reference point P2, the angle α shown in Fig. 3 the angle α indicates the direction to the screen position P3 shown there. Fig. Figure 6 shows the visual acuity S as a function of the angle α.

[0057] Fig. Figure 6 shows the strong concentration of visual acuity S in the direction of gaze. Visual acuity S is plotted as a percentage of visual acuity in the direction of gaze. Even at relatively small angles α of approximately 10°, visual acuity S(α) is only 20% of visual acuity S(0) in the direction of gaze.

[0058] Fig. 7 ( Fig. 7) shows a flowchart 700 of an embodiment of the method according to the invention with method steps 701 and 702 for displaying image content on one screen or several screens of a vehicle.

[0059] The method steps 701, 702 are carried out by means of a Fig. 1 to 6 described display device 100 and therefore also described below with reference to the Fig. 1 to 6. As in the description of the display device 100, it is initially assumed that image content 401 is displayed only on a screen 203 arranged on a dashboard 202 of the vehicle 200.

[0060] In a first method step 701, the head position P1 of the driver 204 of the vehicle 200 is determined by means of the detection device 101 of the display device 100.

[0061] If the detection device 101 does not have an interior camera 103 of the vehicle 200, the head position P1 of the driver 204 is determined, for example, based on a body axis of the driver 204 and a height of a headrest of a driver's seat of the vehicle 200. The body axis of the driver 204 is derived, for example, from an adjustment of the driver's seat.

[0062] If the detection device 101 has an interior camera 103 of the vehicle 200, the head position P1 of the driver 204 is determined, for example, by evaluating images from the interior camera 103. In this case, the detection device 101 additionally evaluates images from the interior camera 103, for example, in order to determine a viewing direction of the driver 204 through eye tracking and / or a head position of the driver, provided the detection device 101 is configured accordingly.

[0063] In a second method step 702, the image content 401 is distorted by the computing unit 102 of the display device 100, so that the image content 401 is displayed larger the further it is from a reference point P2 on the screen 203. The distortion 400 of the image content 401 can be static or dynamic, see below.

[0064] The image content 401 is recorded by the processing unit 102, for example, according to a spherical projection, and the points of a spherical surface are stereographically projected onto the screen surface 406 of the screen 203, with the reference point P2 being the image point of the projection center. The distances between any two points of an image content 401, and thus the size of an image content 401, are thereby increased according to the stereographic projection with increasing distance from the reference point P2.

[0065] With a static distortion 400 of the image content 401, the reference point P2 and the distortion remain constant over time. This is the case when only the head position P1 of the driver 204 is determined, but not their viewing direction. The reference point P2 is, for example, a point on the screen surface 406 that is located within a viewing angle of the driver 204 when the driver 204 is looking straight ahead at a roadway. Typically, the reference point P2 is the point on the screen surface 406 that is closest to the head position P1 of the driver 204.

[0066] With a dynamic distortion 400 of the image content 401, the reference point P2 and the distortion 400 change over time. This is the case when the viewing direction of the driver 204 is determined. The reference point P2 is then, for example, the point toward which the driver 204 is looking.

[0067] Static and dynamic distortion can also be combined by superimposing dynamic distortion on the static distortion.

[0068] In the above-mentioned Fig. 2 to 7, it was assumed that the image contents 401 are displayed on only one screen 203 arranged on the dashboard 202 of the vehicle 200 and that the screen 203 has a planar screen surface 406. However, the invention is also applicable, for example, to a plurality of screens 203 arranged side by side on the dashboard 202. In this case, the totality of these screens replaces the individual screen 203 of the Fig.2 to 7, and the entirety of the screen surfaces of these screens replaces the screen surface 406 of the individual screen 203. In the case of several adjacent screens 203, it can be provided, in particular, that the image content 401 can be moved between these screens 203. Furthermore, the invention is also applicable accordingly to a curved screen 203. In particular, the screen 203 can be a head-up display whose screen surface 406 is the windshield of the vehicle 200. List of reference symbols 100 display device 101 Detection device 102 computing unit 103 Interior camera 200 vehicles 201 Outline 202 Dashboard 203 Screen 204 drivers 205 head 206 screen area 300 geometric relationships 400 distortion 401 Image content 500 spherical projection 600 Visual acuity diagram 700 Flowchart 701, 702 Process step α angle E1 Viewing plane E2 screen level G Straight P1 Head position P2 reference point P3 screen position S Visual acuity

Claims

[1] Method for displaying image content (401) on one screen (203) or several screens (203) of a vehicle (200) comprising the steps: - determining a head position (P1) of a driver (204) of the vehicle (200) and - mapping the image contents (401) so that an image content (401) is displayed larger the further away from the head position (P1) it is displayed on a screen (203). [2] Method according to claim 1, wherein the image contents (401) are recorded according to a spherical projection (500) which projects points of a spherical surface onto a screen area (206) of the screen (203) or screens (203). [3] Method according to one of claims 1 or 2, wherein the head position (P1) is determined based on a body axis of the driver (204) and a height of a headrest of a driver's seat of the vehicle (200). [4] Method according to one of claims 1 or 2, wherein the head position (P1) is determined by evaluating images from an interior camera (103) of the vehicle (200). [5] Method according to claim 4, wherein the mapping of the image contents (401) is dynamically adapted to a viewing direction of the driver (204), so that an image content (401) is displayed larger, the more the direction from the head position (P1) to a screen position (P3) at which the image content (401) is displayed deviates from the viewing direction of the driver (204). [6] Method according to claim 5, wherein images of the interior camera (103) of the vehicle (200) are evaluated in order to determine the viewing direction of the driver (204) by eye tracking and / or by a head posture of the driver (204). [7] Method according to one of the preceding claims, wherein the image contents (401) are displayed on one or more screens (203) arranged on a dashboard (202) of the vehicle (200) or on a head-up display of the vehicle (200). [8] Method according to one of claims 1 to 6, wherein the image contents (401) are displayed on a plurality of screens (203) arranged on a dashboard (202) of the vehicle (200) and are movable between the screens (203), and wherein an image content (401) is displayed larger the further the screen (203) on which it is displayed is from the head position (P1). [9] Display device (100) for displaying image contents (401) on one screen (203) or several screens (203) of a vehicle (200), the display device (100) comprising: - a detection device (101) configured to detect a head position (P1) of a driver (204) of the vehicle (200), and - a computing unit (102) which is arranged to register the image contents (401) so that an image content (401) is displayed larger the further away from the head position (P1) it is displayed on a screen (203). [10] Display device (100) according to claim 9, wherein the detection device (101) comprises an interior camera (103) of the vehicle (200) and the detection device (101) is configured to determine the head position (P1) by evaluating images from the interior camera (103) of the vehicle (200). [11] Display device (100) according to claim 10, wherein the detection device (101) is configured to evaluate images of the interior camera (103) of the vehicle (200) in order to determine a viewing direction of the driver (204) by eye tracking and / or a head posture of the driver (204), and the computing unit (102) is configured to dynamically adapt the mapping of the image contents (401) to the viewing direction of the driver (204), so that an image content (401) is displayed larger, the more a direction from the head position (P1) to a screen position (P3) at which the image content (401) is displayed on a screen (203) deviates from the viewing direction of the driver (204). [12] Display device (100) according to one of claims 9 to 11, wherein at least one screen (203) is arranged on a dashboard (202) of the vehicle (200). [13] Display device (100) according to one of claims 9 to 12, wherein at least one screen (203) is a head-up display of the vehicle (200).

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