Vehicle display device

Abstract

To disclose a display apparatus for a vehicle that further reduces motion sickness of a passenger.SOLUTION: A display apparatus for a vehicle 10 comprises: a display device 12 fixed to a vehicle; and a display controller 14 that controls driving of the display device 12. The display controller 14 is configured to cause the display device 12 to simultaneously display a first image 40 indicating an optical flow and a second image 42 indicating a direction of gravity or a horizontal direction perpendicular to the direction of gravity.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This specification discloses a vehicle display device that displays an image on a display provided in a vehicle cabin.

Background Art

[0002] During vehicle travel, a passenger may experience motion sickness. As a cause of such motion sickness, the sensory conflict theory is known. The sensory conflict theory is the theory that motion sickness occurs due to a conflict in information detected by each of a plurality of sensory organs such as the vestibule and vision.

[0003] Here, Patent Document 1 discloses a technique for displaying an indicator indicating the direction of the driver's optical flow on an in-vehicle display. The optical flow is a vector indicating the direction of the flow of scenery.

[0004] According to the technique described in Patent Document 1, a passenger can visually grasp the moving direction of the vehicle. And thereby, since the conflict between the information detected visually and the information detected by the vestibule is reduced, the motion sickness of the passenger is reduced to some extent.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the prior art such as Patent Document 1, only an image indicating the optical flow is displayed. Therefore, in the prior art, the horizontal direction or the gravitational direction could not be visually grasped. As a result, in the prior art, motion sickness could not be sufficiently reduced.

[0007] Therefore, this specification discloses a vehicle display device that further reduces motion sickness among occupants. [Means for solving the problem]

[0008] The vehicle display device disclosed herein comprises a display unit fixed to a vehicle and a display controller that controls the driving of the display unit, wherein the display controller is configured to simultaneously display on the display unit a first image showing optical flow and a second image showing the direction of gravity or a horizontal direction perpendicular to the direction of gravity.

[0009] This configuration allows occupants to visually perceive the direction of the vehicle's movement and the direction of gravity. As a result, motion sickness among occupants is effectively reduced.

[0010] In this case, the display unit has a main display area for displaying content images and a support display area arranged to surround the main display area, and the display controller may be configured to perform a process for displaying the first image and the second image in the support display area in parallel with the process for displaying content images in the main display area.

[0011] This configuration allows occupants to visually perceive the vehicle's direction of movement and the direction of gravity while viewing the content images. As a result, occupants can comfortably use the content images without experiencing motion sickness.

[0012] Furthermore, the second image is a straight line figure parallel to the horizontal direction and passing through a predetermined reference point, and the display controller may be configured to change the display position of the first image so that the height position of the reference point changes in conjunction with changes in the acceleration of the vehicle.

[0013] This allows the occupants to clearly perceive changes in acceleration and horizontal movement. As a result, motion sickness among the occupants is effectively prevented.

[0014] In this case, the first image includes a plurality of arrows that radiate outwards or converge from a predetermined nozzle point, the reference point coincides with the nozzle point, the display controller is configured to display the linear figure superimposed on the plurality of arrows on the display, and the display controller may be configured to change the display position of the nozzle point within the display in conjunction with the vehicle's direction of movement and acceleration, and to change the direction of the arrows in conjunction with the vehicle's speed of movement.

[0015] This configuration allows occupants to clearly understand the direction of the vehicle's movement. As a result, motion sickness among occupants is effectively prevented.

[0016] Furthermore, the display controller may be configured to display the first image and the second image on the display in a manner in which their changes are less noticeable compared to when the rate of change of the first image and the second image exceeds a specified tolerance value.

[0017] This configuration effectively prevents motion sickness caused by the first and second images. [Effects of the Invention]

[0018] The technology disclosed herein effectively reduces motion sickness among occupants. [Brief explanation of the drawing]

[0019] [Figure 1] This is a block diagram showing the configuration of a vehicle display device. [Figure 2] This figure shows an example of the layout of the display area of ​​a display unit. [Figure 3] This figure shows an example of a support image. [Figure 4] This figure shows another example of a support image. [Figure 5] This figure shows another example of a support image.

Best Mode for Carrying Out the Invention

[0020] Hereinafter, the configuration of the vehicle display device 10 will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the display device 10. This display device 10 includes a display 12, an outside vehicle camera 20, an inclination sensor 22, and a display controller 14.

[0021] The display 12 is a device that is temporarily or permanently arranged inside the vehicle and displays images. The display 12 includes, for example, a liquid crystal display, an organic EL display, a projector, or a combination thereof. Further, the display 12 may be a display attached to the vehicle as an electrical component. For example, the display 12 may be a multimedia display attached to the passenger compartment to display map information or audio information. Also, the display 12 may be a portable display (e.g., a display incorporated in a smartphone) that can be used both inside and outside the vehicle. In this case, a holder for detachably holding the display 12 is provided inside the vehicle. Then, the display 12 is temporarily fixed to the vehicle by the holder.

[0022] FIG. 2 is a diagram showing an example of the layout of the display area of the display 12. As shown in FIG. 2, the display 12 includes a support display area 32 for displaying a support image 38. The support image 38 is an image for suppressing motion sickness of the passenger. This support image 38 includes a first image 40 showing an optical flow and a second image 44 showing the direction of gravity or the horizontal direction. Details of this support image 38 will be described later.

[0023] The display 12 may further include a main display area 30 for displaying a content image 34. The content image 34 is not particularly limited as long as it is an image other than the support image 38. Therefore, the content image 34 may be, for example, a video for entertainment, an operation screen for operating an electrical component, or a map image.

[0024] As shown in the upper part of Figure 2, the display unit 12 may have a main display area 30 and a support display area 32. In this case, the support display area 32 may be shaped to surround the main display area 30. Also, as shown in the lower part of Figure 2, the support display area 32a may be located inside the main display area 30. Furthermore, the support display area 32b may be located separately from the main display area 30. Moreover, the display unit 12 may have a support display area 32 but no main display area 30.

[0025] The external camera 20 is mounted on the front of the vehicle and captures images of the scenery in front of the vehicle. The captured images are transmitted to the display controller 14 as scenery images. Note that there may be more than one external camera 20.

[0026] The tilt sensor 22 detects the tilt of the vehicle relative to the direction of gravity. This tilt sensor 22 is, for example, an inertial measurement device that combines an accelerometer and a gyroscope. The tilt detected by the tilt sensor 22 is transmitted as tilt information to the display controller 14.

[0027] The display controller 14 controls the operation of the display unit 12. Physically, the display controller 14 is a computer having a processor 16 and memory 18. In Figure 1, the display controller 14 is shown as a single computer. However, the display controller 14 may be configured by combining two or more physically separated computers. Also, part or all of the display controller 14 may be located outside the vehicle. In this case, part or all of the display controller 14 has a communication interface for communicating with at least one of the display unit 12 and the computer inside the vehicle. The display controller 14 generates a support image 38 to be displayed on the display unit 12 based on the scenery image transmitted from the external camera 20 and the tilt information transmitted from the tilt sensor 22. Furthermore, the display controller 14 displays the generated support image 38 on the display unit 12.

[0028] Here, the support image 38 will be explained with reference to Figures 3 to 5. Figures 3 to 5 show examples of the support image 38. Note that Figures 3 to 5 show the case where the support display area 32 is completely independent from the main display area 30. However, as mentioned above, the main display area 30 may be placed inside the support display area 32.

[0029] Support image 38 includes the first image 40 and the second image 44. The first image 40 is an image showing optical flow, which is the direction in which the scenery is flowing. This will be explained in more detail. In this example, the scenery in front of the vehicle is captured by an external camera 20 mounted on the front of the vehicle. This allows external scenery images to be obtained at predetermined sampling periods. The display controller 14 extracts multiple feature points from each scenery image. To extract these feature points, the display controller 14 utilizes techniques such as gradient direction histograms, speed-up robustness characteristics, local binary patterns, Haar wavelets, and color histograms. Subsequently, the display controller 14 compares the multiple scenery images to determine the direction in which the feature points move over time. This determined direction of movement is the optical flow.

[0030] The display controller 14 causes a first image 40 showing the optical flow to be displayed in the support display area 32. This first image 40 is not particularly limited as long as it shows the optical flow. As shown in Figures 3 to 5, in this example, the first image 40 includes a plurality of arrows 42 spreading out from a predetermined nozzle point Pa, or a plurality of arrows 42 converging toward the nozzle point Pa.

[0031] The upper part of Figure 3 shows a support image 38a when the vehicle is moving straight at a constant speed. In this case, the first image 40 includes multiple arrows 42 radiating from the nozzle point Pa. At this time, the nozzle point Pa is located at the center of the camera's field of view, and therefore at the center of the support display area 32.

[0032] The lower part of Figure 3 shows support image 38b when the vehicle is moving forward while accelerating. In this case as well, the first image 40 includes multiple arrows 42 radiating from the nozzle point Pa. However, in this case, the nozzle point Pa has moved lower compared to support image 38a. This is because when the vehicle accelerates, the rear of the vehicle sinks slightly compared to the front. As the vehicle assumes a nose-up posture, the scenery outside the vehicle moves relatively downward with respect to the field of view of the external camera 20. Therefore, when the vehicle accelerates, the nozzle point Pa also moves lower compared to when it is not accelerating.

[0033] The upper part of Figure 4 shows support image 38c when the vehicle is moving forward while decelerating. In this case as well, the first image 40 includes multiple arrows 42 radiating outwards from the nozzle point Pa. At this time, the nozzle point Pa moves upward compared to the case of support image 38a. This is because when the vehicle decelerates, the front of the vehicle sinks slightly compared to the rear. As the vehicle assumes a rearward-upward posture, the scenery outside the vehicle moves relatively upward with respect to the field of view of the external camera 20. Therefore, when the vehicle decelerates, the nozzle point Pa also moves downward compared to when it is not accelerating. The lower part of Figure 4 shows support image 38d when the vehicle is moving backward at a constant speed. In this case, the first image 40 includes multiple arrows 42 converging radially toward the nozzle point Pa.

[0034] Figure 5 shows a support image 38e when the vehicle is turning left. In this case, the first image 40 includes multiple arrows 42 moving from left to right. Note that the arrowhead point Pa is located outside the support display area 32.

[0035] Next, the second image 44 will be described. The second image 44 is an image showing the direction of gravity or the horizontal direction perpendicular to the direction of gravity. As shown in Figures 3 to 5, in this example, the second image 44 includes a straight line figure 46 that shows the horizontal direction. The display controller 14 determines the horizontal direction based on the detection result of the tilt sensor 22. The display controller 14 then displays the straight line figure 46, which is parallel to the horizontal direction, in the support display area 32. Here, if the vehicle is not tilted to the left or right, the straight line figure 46 will be parallel to the top or bottom edge of the display unit 12, as shown in support images 38a, 38b, 38c, and 38d.

[0036] In this case, the linear figure 46 passes through a predetermined reference point Pb. The reference point Pb is a point that moves up and down due to the acceleration of the vehicle. In this example, the reference point Pb is the same point as the blowout point Pa. Therefore, when the vehicle is accelerating (i.e., in the case of support image 38b), the linear figure 46 moves downward compared to when the vehicle is traveling at a constant speed (i.e., in the case of support image 38a). Also, when the vehicle is decelerating (i.e., in the case of support image 38c), the linear figure 46 moves upward compared to when the vehicle is traveling at a constant speed (i.e., in the case of support image 38a).

[0037] Furthermore, if the vehicle is tilted to the left or right, the straight line figure 46 will tilt relative to the display unit 12. For example, when the vehicle turns left, the left side of the vehicle sinks slightly more than the right side. In this case, the straight line figure 46, which indicates the horizontal direction, will tilt upward to the right relative to the top or bottom edge of the display unit 12, as shown in Figure 5. Also, when the vehicle turns right, the straight line figure 46 will tilt upward to the left relative to the top or bottom edge of the display unit 12.

[0038] The display controller 14 superimposes the first image 40 and the second image 44 onto the same support display area 32. This allows the occupants to visually grasp the vehicle's direction of movement, acceleration, and tilt. As a result, motion sickness among occupants can be effectively reduced.

[0039] In other words, motion sickness is said to occur when information detected by the eyes contradicts information detected by the vestibular system. For example, when a vehicle tilts to the right, the occupants and the interior components of the vehicle also tilt to the right. As a result, the interior components appear not to be tilted relative to the occupants. In other words, in this case, the occupants cannot visually detect the tilt of the vehicle. On the other hand, the vestibular system detects the tilt of the body relative to the direction of gravity. Thus, motion sickness is more likely to occur when the information detected by the eyes does not match the information detected by the vestibular system. In particular, when an occupant is fixated on the content image 34 displayed in the main display area 30 of the display unit 12, the occupant hardly looks at the scenery outside the vehicle. Therefore, when an occupant is fixated on the content image 34, they can hardly visually detect the tilt of the vehicle. As a result, the degree of mismatch between vision and the vestibular system increases, making the occupant more susceptible to motion sickness.

[0040] In this example, as described above, the display controller 14 displays a first image 40 showing optical flow and a second image 44 showing the horizontal direction in the support display area 32. With this configuration, occupants can visually detect the direction of vehicle movement and the horizontal direction without having to look at the scenery outside the vehicle. As a result, inconsistencies between visual detection information and vestibular detection information are suppressed. This effectively prevents motion sickness in occupants. In addition, in this example, the outlet point Pa of the first image 40 and the reference point Pb of the second image 44 are moved up and down according to the acceleration. This allows occupants to visually detect acceleration, thus more effectively preventing motion sickness.

[0041] Furthermore, as shown in the upper part of Figure 2, if a support display area 32 is provided around the main display area 30, the occupant can view the support image 38 while simultaneously focusing on the content image 34 displayed in the main display area 30. This makes it possible to achieve both the prevention of motion sickness among the occupant and the use of the content image 34 by the occupant.

[0042] Incidentally, these support images 38 change continuously in response to the movement of the vehicle. For example, when the vehicle is driving on a rough off-road surface, the straight line figure 46, which is the second image 44, moves up and down in small increments and also oscillates like a seesaw. However, if the changes in the support images 38 are too rapid, it can easily cause motion sickness in the occupants. Therefore, when the rate of change of the support images 38 is above a predetermined tolerance value, the display controller 14 displays the support images 38 in a form in which the changes in the support images 38 are less noticeable compared to when the rate of change of the support images 38 is below the tolerance value.

[0043] For example, the display controller 14 makes the changes in the support image 38 less noticeable when the amount of change in the support image 38 per unit time is above a predetermined tolerance value, compared to when it is below a reference value. To make the changes in the support image 38 less noticeable, for example, the display controller 14 lightens the colors of the first image 40 and the second image 44. Alternatively, the display controller 14 may reduce the frame rate when displaying the support image 38. With such a configuration, motion sickness caused by the support image 38 is effectively suppressed.

[0044] It should be noted that the configurations described so far are all examples. As long as the vehicle display device 10 has the configuration described in claim 1, other configurations may be changed. For example, in the description so far, the display controller 14 superimposes the second image 44 on the first image 40. However, if the first image 40 and the second image 44 are to be displayed simultaneously, they may be displayed separately from each other (i.e., without overlapping each other). Also, the shapes of the first image 40 and the second image 44 may be changed as appropriate. For example, the first image 40 may consist of only one arrow 42. Also, the second image 44 may have a figure parallel to the direction of gravity in addition to, or instead of, a straight line figure 46 parallel to the horizontal direction.

[0045] Furthermore, as described above, the display controller 14 determines the optical flow and gravity direction based on information detected by the external camera 20 and the tilt sensor 22. However, the display controller 14 may determine the optical flow and gravity direction based on other information. For example, the display controller 14 may calculate the optical flow based on information used for vehicle driving control, such as vehicle speed, acceleration, and steering angle. In addition, an in-vehicle camera that captures images of the occupants may be placed inside the vehicle. The display controller 14 may then identify the occupants' viewpoints based on images captured by the in-vehicle camera and modify the optical flow according to the identified viewpoints. [Explanation of Symbols]

[0046] 10 Vehicle display device, 12 Display unit, 14 Display controller, 16 Processor, 18 Memory, 20 External camera, 22 Tilt sensor, 30 Main display area, 32 Support display area, 34 Content image, 38 Support image, 40 First image, 42 Arrow, 44 Second image, 46 Linear figure, Pa Callout point, Pb Reference point.

Claims

1. A display unit fixed to the vehicle, A display controller that controls the operation of the aforementioned display unit, Equipped with, The display controller is configured to simultaneously display on the display a first image showing optical flow and a second image showing the direction of gravity or a horizontal direction perpendicular to the direction of gravity. The second image is a straight line figure that is parallel to the horizontal direction and passes through a predetermined reference point. The display controller is configured to change the display position of the first image so that the height position of the reference point changes in conjunction with the change in the acceleration of the vehicle. The aforementioned first image includes multiple arrows that radiate or converge from a predetermined callout point. The aforementioned reference point coincides with the aforementioned blowout point, The display controller is configured to display the linear figure superimposed on the plurality of arrows on the display unit. The display controller is configured to change the display position of the nozzle point within the display unit in conjunction with the vehicle's direction of movement and acceleration, and to change the direction of the arrow in conjunction with the vehicle's speed of movement. A vehicle display device characterized by the following features.

2. A vehicle display device according to claim 1, The aforementioned display unit is The main display area for displaying content images, A support display area is arranged to surround the main display area, It has, The display controller is configured to perform the process of displaying the first image and the second image in the support display area in parallel with the process of displaying the content image in the main display area. A vehicle display device characterized by the following features.

3. A vehicle display device according to claim 1, The display controller is configured such that, when the rate of change of the first image and the second image exceeds a specified tolerance, the first image and the second image are displayed on the display in a manner in which the changes are less noticeable compared to when the rate of change of the first image and the second image does not exceed the tolerance. A vehicle display device characterized by the following features.

Images