Display device for vehicle

Abstract

A display device for a vehicle is installed in a vehicle and displays visual information to a driver by reflecting the visual information emitted from a display on a windshield. When a display distance of the visual information falls within a region of 4 m or more and 6 m or less, the display sets a display time of the visual information to 1.3 seconds or less.

Description

Technical Field

[0001] This disclosure relates to a display device for vehicles. Background Technology

[0002] An augmented reality head-up display (AR-HUD) is known to display various types of information (road information, navigation information, etc.) needed by the driver on the windshield of a vehicle by overlaying information onto the scene actually seen by the driver.

[0003] When a driver is looking at vehicles ahead, their gaze is not at the nearest point, such as the gauges on the dashboard. Therefore, when an AR-HUD displays information at the nearest distance, the driver may perceive the information as a double image due to binocular parallax.

[0004] In JP2007-008382A, visual information of a predetermined length in the horizontal direction is repeatedly displayed, and under specified conditions, the positions of the visual information seen by the left and right eyes overlap due to binocular parallax, so that the driver can see one piece of visual information. However, the horizontal width of the visual information is limited, and it cannot be said that the discomfort felt by the driver is sufficiently reduced.

[0005] This disclosure provides a vehicle display device that can alleviate the annoyance and discomfort caused by double images due to binocular parallax. Summary of the Invention

[0006] To achieve the above objectives, the vehicle display device according to this disclosure has the following features. The vehicle display device is installed in a vehicle and displays visual information emitted from the display to the driver by reflecting it onto the windshield. When the display distance of the visual information falls within an area of ​​4m to 6m, the display sets the display time of the visual information to 1.3 seconds or less.

[0007] According to this disclosure, even when the driver is looking ahead at the vehicle, such as the vehicle in front, the visual information can be displayed without causing the driver annoyance or discomfort due to double images caused by binocular parallax.

[0008] The present disclosure has been briefly described above. Furthermore, the details of the present disclosure can be further clarified by referring to the accompanying drawings and the following description of the modes for implementing the present disclosure (hereinafter referred to as "Embodiments"). Attached Figure Description

[0009] Figure 1 This is a block diagram of a vehicle display system including a vehicle display device according to a first embodiment of the present disclosure;

[0010] Figure 2This is a schematic diagram illustrating a display showing visual information at a specified display distance;

[0011] Figure 3 The relationship between visual information, fixation point, and binocular parallax observed from the driver is shown.

[0012] Figure 4 This is a schematic diagram of visual information displayed by a vehicle display device according to the first embodiment;

[0013] Figure 5 This demonstrates the relationship between the horizontal width of visible information and the sensory evaluation value related to the appearance of the visible information in a sensory test at a display distance of 2m.

[0014] Figure 6 This demonstrates the relationship between the horizontal width of the visible information and the sensory evaluation value related to the appearance of the visible information when the display distance is 4m in a sensory test.

[0015] Figure 7 This demonstrates the relationship between the horizontal width of the visible information and the sensory evaluation value related to the appearance of the visible information when the display distance is 6m in a sensory test.

[0016] Figure 8 This demonstrates the relationship between the horizontal width of the visible information and the sensory evaluation value related to the appearance of the visible information when the display distance is 8m in a sensory test.

[0017] Figure 9 The results of the sensory tests are shown;

[0018] Figure 10 The relationship between visual information display distance and horizontal width is shown for displaying non-annoying visual information derived from the results of sensory tests;

[0019] Figure 11 The brightness distribution of visible information is shown when the distance to the vehicle in front is relatively long;

[0020] Figure 12 The brightness distribution of visible information is shown when the distance to the vehicle in front is short;

[0021] Figure 13 The relationship between the movement of visual information and the sensory evaluation value related to the appearance of the visual information in a second sensory test of visual information displayed on a vehicle display device according to the second embodiment is shown.

[0022] Figure 14 This is a schematic diagram illustrating the movement of visual information displayed by a vehicle display device according to the second embodiment;

[0023] Figures 15A to 15C The movement of visual information displayed by the vehicle display device according to the second embodiment during a right or left turn is illustrated, wherein... Figure 15A This shows the movement at points far from the right or left turn points. Figure 15B It shows the movement at points near the right or left turn points. Figure 15C This shows the movement at the point closest to the right or left turn point;

[0024] Figure 16 This is a schematic diagram of visual information displayed by a vehicle display device according to the third embodiment; and

[0025] Figure 17 The relationship between the display time of visual information and the proportion of people who feel annoyed is shown. Detailed Implementation

[0026] Specific embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0027] First Embodiment

[0028] Figure 1 This is a block diagram of a vehicle display system including a vehicle display device according to a first embodiment of the present disclosure. The vehicle display system 1 installed in a vehicle includes a vehicle display device 10 and a display 20, and corresponds to a so-called AR-HUD.

[0029] The vehicle display device 10 includes a control unit 11, an operation unit 12, a storage unit 13, and an output unit 14. The control unit 11 is a so-called arithmetic processing device or processor, and is a computer that controls the entire vehicle display device 10. The operation unit 12 includes switches, buttons, touch panels, etc., for the driver or other personnel of the vehicle to perform inputs for operating the vehicle display device 10. The storage unit 13 stores various programs, data, etc. For example, by reading programs stored in the storage unit 13, the control unit 11 performs various processes on the vehicle display device 10, including the processes described in the embodiments below. The output unit 14 outputs, for example, an image generated by the control unit 11 to the display 20.

[0030] The display 20 includes a head-up display, a projector, etc., that outputs images from the output unit 14. Figure 2 This is a schematic diagram illustrating a situation where the display 20 displays visual information as an output image at a predetermined display distance X [m]. The display 20 emits the visual information in a manner that makes it appear at a predetermined virtual display distance from the gaze point of the driver M of the vehicle V. The visual information is reflected by the windshield of the vehicle V and displayed at the predetermined display distance.

[0031] Figure 3This illustrates the relationship between visual information, gaze point, and binocular parallax as observed by driver M. Driver M drives while looking at the scene ahead, with their gaze point ranging from tens to hundreds of meters in front. On the other hand, existing vehicle display devices can display visual information several meters in front of driver M's gaze point. In this case, due to the distance difference between the gaze point and the visual information, as well as driver M's binocular parallax, the visual information appears as a double image when viewed from driver M's perspective, causing driver M distress or discomfort.

[0032] Figure 4 This is a schematic diagram of visual information displayed by the vehicle display device 10 according to the first embodiment. The visual information is displayed as, for example, a location A where the driver is following a vehicle ahead via adaptive cruise control (ACC). Information such as location A is typically displayed at a distance of a few meters. In prior art devices, when the driver M is driving and looking at the scene ahead, such as a vehicle in the distance, location A may be perceived as a double image, which may cause the driver M annoyance or discomfort.

[0033] On the other hand, in the vehicle display device 10 according to this embodiment, the display 20 emits visual information to a specific visual information emission area, making the driver M feel less annoyed or uncomfortable, and solving the problems of prior art devices. The vehicle display device 10 can also display other information (speed, navigation information, etc.) B as in the prior art; however, when viewing this information, the driver M usually moves his gaze to the vicinity to confirm the information, and the problem of double images is unlikely to occur.

[0034] Next, the range of the visual information emitted by the display 20 will be described. The emission range is generally defined by the display distance X and the horizontal width Y [°] (the range of display angles observed from the driver M's gaze point) mentioned above. The inventors conducted sensory tests to check whether viewers who see the visual information feel annoyed or uncomfortable by setting the horizontal width Y at a display distance of X = 2m to 8m in a typical setting. Figures 5 to 8 This illustrates the relationship between the horizontal width of visible information at specific display distances and sensory evaluation values ​​related to the appearance of the visible information in sensory tests. The display distances in each figure are... Figure 5 The middle is 2m, in Figure 6 The middle is 4m, in Figure 7 The middle is 6m, in Figure 8 The width is 8m. The horizontal width Y is set to 1.5°, 3.1°, and 4.8° within the general setting range.

[0035] The test results were evaluated using a five-level sensory evaluation scale (1, 2, 3, 4, 5). A sensory evaluation scale of 1 indicates that the visual information becomes a double image and is quite annoying. A sensory evaluation scale of 5 indicates that the visual information does not become a double image and is barely annoying. A sensory evaluation scale of 3 is between sensory evaluation scales 1 and 5, meaning that the annoyance is within the acceptable range (passing grade).

[0036] when Figure 5 When the display distance X is 2m, displaying it at any horizontal width Y is problematic and yields undesirable results. When Figure 6 When the display distance X is 4m, no acceptable results were obtained at a horizontal width Y=1.5°, while acceptable results were obtained at horizontal widths Y=3.1° and 4.8°. Therefore, between horizontal widths Y=3.1° and Y=4.8°, a horizontal width Y=2.4° with a sensory evaluation value of 3 is an acceptable threshold.

[0037] when Figure 7 When the display distance X is 6m, no acceptable results were obtained at a horizontal width Y = 1.5°, while acceptable results were obtained at horizontal widths Y = 3.1° and 4.8°. It can be concluded that between horizontal widths Y = 1.5° and Y = 3.1°, a horizontal width Y = 1.8° with a sensory evaluation value of 3 is an acceptable threshold. Figure 8 When the display distance X is 8m, acceptable results are obtained at any horizontal width Y.

[0038] Figure 9 The results of the sensory tests are summarized. Cases where the distance X is 8m are omitted. Figure 10 This figure illustrates the relationship between display distance and horizontal width for displaying visual information that does not cause annoyance, derived from sensory test results. The graph is a summary of... Figures 5 to 8 It was obtained from the test results.

[0039] from Figure 5 As can be seen, a display distance of 2m for X cannot be set because no permission was obtained. Figure 8 It can be seen that setting the display distance X to 8m seems to be fine. However, due to the convenience of image generation, extending the display distance would lead to an increase in the size of the monitor 20, and from the perspective of device size limitations, it is impossible to set the display distance X to 8m.

[0040] Therefore, the inventors investigated the permissible range of the horizontal width Y when the display distance X is between 4m and 6m. According to... Figure 6 and Figure 7 The results showed that... Figure 10 The formula y = -0.3x + 3.6 represents the boundary of whether the horizontal width Y is permissible, and a permissible result is obtained when the horizontal width Y is equal to or greater than this formula. That is, as a result of the sensory test, the vehicle display device 10 and the display 20 should emit visual information that satisfies the conditions of the following formulas (3) and (4).

[0041] Y≥-0.3X+3.6…(3)

[0042] 4≤X≤6…(4)

[0043] According to the vehicle display device 10 in this embodiment, even when the driver is looking at the front of the vehicle, such as the vehicle in front, the information can be displayed without causing the driver annoyance or discomfort due to double images caused by binocular parallax.

[0044] Figure 11 The diagram shows the brightness distribution of visible information when the distance to the vehicle M1 ahead is relatively long. The vehicle display device 10 adjusts the brightness distribution of the visible information I according to this diagram, and the display 20 displays the visible information according to the brightness distribution.

[0045] In this example, the display 20 displays the visual information I at high brightness in the center a1, and the brightness decreases towards the outer edge in the peripheral b1. Therefore, the brightness decreases towards the outer edge of the visual information I, which can further reduce the discomfort of double images.

[0046] Due to this change in brightness information, the display 20 displays the visual information I with a blurred outer edge. Therefore, the change in the outer edge is gradual, and it can further reduce the discomfort of double images.

[0047] Figure 12 The diagram shows the brightness distribution of visible information I when the distance to the vehicle M1 ahead is short. The vehicle display device 10 adjusts the brightness distribution of visible information I according to this diagram, and the display 20 displays the visible information according to the brightness distribution.

[0048] Figure 12 It shows the relationship with Figure 11 Compared to cases where the distance to the vehicle M1 in front is relatively long, the area of ​​the bright central portion a2 of the visible information I is larger, while the area of ​​the low-brightness peripheral portion b2 of the visible information is smaller. As the vehicle M1 in front gets closer, the driver's gaze point becomes closer, and the problem of double images is mitigated, thus allowing for the setting of appropriate brightness based on the distance to the vehicle M1 in front.

[0049] Second Embodiment

[0050] It is well known that adding movement to visual information can alleviate annoyance and discomfort. Therefore, the inventors conducted a second sensory test in which movement was added to the visual information to verify how the annoyance or discomfort of the viewer to the visual information changed. Figure 13 The diagram illustrates the relationship between the movement of the visual information and the sensory evaluation value related to the appearance of the visual information in a second sensory test, as shown by the visual information displayed on the vehicle display device 10 in the second embodiment.

[0051] from Figure 13 It can be confirmed that adding movement to the visual information can alleviate the annoyance caused by dual images.

[0052] Figure 14 This is a schematic diagram illustrating the movement of visual information displayed on the vehicle display device 10 according to the second embodiment. Figure 14 The visual information in the image is an arrow indicating a specific direction. As shown in this example, adding movement is a technique suitable for displaying information used to indicate a specific direction or guide vehicles (route guidance, etc.).

[0053] When visual information is a single movement, the driver may not notice it, so it is desirable to display the visual information repeatedly. In this case, when the repetition frequency is high, the driver may feel annoyed, threatened, or otherwise, so it is desirable to display the visual information at a repetition frequency of about 1 Hz or less.

[0054] Figures 15A to 15C The movement of visual information displayed by the vehicle display device 10 according to the second embodiment is shown during a right turn, wherein... Figure 15A It shows the movement at points far from the right turn point. Figure 15B It shows the movement at the point near the right turn point. Figure 15C This shows the movement of the point closest to the right turn point. For example, when a driver is notified of a right or left turn point and the arrow is repeatedly displayed, the driver may find it difficult to determine the timing of the turn. Therefore, as... Figures 15A to 15C As shown, changing the display mode of visual information is effective when the vehicle approaches a turning point (a right turn point in this example).

[0055] In this example, as the vehicle approaches the right turn point, the distance of the right-pointing arrow, which serves as visual information, gradually increases, and the display size also gradually increases. There are no particular restrictions on the display mode; it can be a change from a hollow display to a solid display. The number of flowing arrows can be changed. For example, the number of arrows displayed can be increased, such that there is one arrow in the first display, two arrows in the second display, and three arrows in the third display. Furthermore, when displaying this visual information, at least one of the following can be changed based on the distance between the vehicle and the target location: size, color, movement speed, and cycle time.

[0056] The movement of visual information is not limited to, for example Figures 14 to 15C As shown in the horizontal direction, movement is permitted in any direction as long as the displayed distance is within that range.

[0057] Third Embodiment

[0058] Figure 16 This is a schematic diagram of visual information displayed by the vehicle display device 10 according to the third embodiment. In this embodiment, the visual information is a lane L displayed corresponding to, for example, a lane keeping assist system (LKA), rather than a location A detected by ACC in the first embodiment. The content of the visual information is not particularly limited.

[0059] The inventors noticed that viewers may become annoyed by double images when visual information is displayed for extended periods, and verified the display time of the visual information and the proportion of people who felt annoyed. Figure 17 The relationship between the display time of the visual information obtained as a verification result and the proportion of people who are bothered by the double image is shown.

[0060] The graph shows that when the display time of the visual information is less than 1.3 seconds, less than 10% of the people are bothered by the double image, while when the display time of the visual information is less than 1.2 seconds, less than 5% of the people are bothered.

[0061] Therefore, by setting the display time of the visual information to less than 1.3 seconds, discomfort with dual images can be reduced for most drivers. Furthermore, setting the time to less than 1.2 seconds can further reduce discomfort with dual images for most drivers, which is even better.

[0062] Visual information about the display time can be a blinking display of visual information or an animation that switches the display position or content during the display time.

[0063] The contents of the first to third embodiments can be implemented individually or in combination.

[0064] Although various embodiments have been described above with reference to the accompanying drawings, it is clear that this disclosure is not limited to these embodiments. It will be apparent to those skilled in the art that various improvements or modifications can be made within the scope of the claims, and it should be understood that such improvements or modifications naturally fall within the technical scope of this disclosure. Furthermore, the components described in the above embodiments can be freely combined without departing from the spirit of this disclosure.

[0065] Hereinafter, the features of the above-described embodiments of the vehicle display device according to the present disclosure are briefly summarized and listed in [1] to [3].

[0066] [1] A vehicle display device (vehicle display device 10) is installed in a vehicle (vehicle V) and displays information to the driver by reflecting visual information emitted from a display (display 20) onto the windshield, wherein,

[0067] When the display distance of the visible information falls within the range of 4 meters to 6 meters, the display will set the display time of the visible information to less than 1.3 seconds.

[0068] According to the vehicle display device with [1] configuration, even when the driver is looking at the front of the vehicle, such as the vehicle in front, the information can be displayed without causing the driver annoyance or discomfort due to double images caused by binocular parallax.

[0069] [2] According to the vehicle display device described in [1], wherein,

[0070] The display sets the display time of the visual information to less than 1.2 seconds.

[0071] According to the vehicle display device with [2] configuration, it is possible to further reduce the discomfort caused by dual images to most drivers.

[0072] [3] According to the vehicle display device described in [1], wherein,

[0073] The display shows the visual information in a flashing manner.

[0074] According to the vehicle display device with [3] configuration, the discomfort caused by dual images can be further reduced.

Claims

1. A display device for a vehicle, installed in a vehicle, which displays visual information to the driver by reflecting visual information emitted from a display onto the windshield, wherein, When the display distance of the visual information falls within the range of 4m to 6m, the display will set the display time of the visual information to less than 1.3 seconds.

2. The vehicle display device according to claim 1, wherein, The display sets the display time of the visual information to less than 1.2 seconds.

3. The vehicle display device according to claim 1, wherein, The display shows the visual information in a flashing manner.

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