JP7563111B2 - Head-up display device - Google Patents

Description

The present invention relates to a head-up display device.

There is known a head-up display (HUD) device that projects display light onto a translucent member such as a windshield installed in a vehicle, and displays a virtual image of the image indicated by the display light in front of the translucent member. For example, the HUD device described in Patent Document 1 can execute, as virtual image display modes, a mode that displays an overhead image that shows an area including the current location of the vehicle from an overhead view, and a mode that displays a superimposed image that is viewed superimposed on a forward object located in front of the vehicle.

JP 2020-47153 A

Simply changing the display mode on a HUD device can make it difficult for the user to understand which mode they have switched from.

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide a head-up display device that allows the user to easily understand the transition of display modes.

In order to achieve the above object, a head-up display device according to the present invention comprises:
A head-up display device that projects display light onto a translucent member provided in a vehicle, and displays a virtual image of an image indicated by the display light on a virtual plane set in front of the translucent member,
a display control means capable of executing a first display mode in which a first image based on a first virtual viewpoint is displayed as the virtual image, and a second display mode in which a second image based on a second virtual viewpoint set at a position lower than the first virtual viewpoint is displayed as the virtual image, and capable of switching the display mode from one of the first display mode and the second display mode to the other;
an adjustment means for adjusting an angle of the virtual plane with respect to a road surface in front of the vehicle;
An acquisition means for acquiring surrounding information of the vehicle,
The display control means
determining the display mode to be executed based on the peripheral information acquired by the acquisition means;
When the first display mode is executed, the first image is displayed on the virtual plane adjusted by the adjustment means to a first angle, which is an acute angle;
When the second display mode is executed, the second image is displayed on the virtual surface with the angle adjusted by the adjustment means to a second angle different from the first angle.

The present invention allows the user to easily understand the transition of display modes.

1 is a diagram showing a state in which a head-up display (HUD) device according to an embodiment of the present invention is mounted on a vehicle. 1 is a schematic side view for explaining a configuration of a HUD device according to an embodiment of the present invention. 1 is a block diagram of a vehicle display system according to an embodiment of the present invention; 1A to 1C are diagrams showing examples of display in each display mode according to one embodiment of the present invention, where (a) shows a first image in a first display mode, (b) shows an intermediate image in an intermediate display mode, and (c) shows a second image in a second display mode. 5 is a schematic diagram for explaining an angle of a virtual surface with respect to a road surface according to an embodiment of the present invention; FIG. 5 is a flowchart showing an example of a display mode control process according to an embodiment of the present invention.

One embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the head-up display (HUD) device 100 according to this embodiment projects display light L onto a windshield 2 (an example of a translucent member) provided on a vehicle 1. The display light L reflected by the windshield 2 travels toward a user 4 (mainly the driver of the vehicle 1). By placing the viewpoint within an eye box E, the user 4 can visually recognize a virtual image V represented by the display light L in front of the windshield 2. In other words, the HUD device 100 displays a virtual image V in front of the windshield 2.

The HUD device 100 displays a virtual image V on a virtual surface A set in front of the windshield 2. The virtual surface A corresponds to a display surface 31 of a screen 30 described below. For example, the virtual surface A has a rectangular shape when viewed from its normal direction. The positions, sizes, and shapes of the virtual surface A and the eye box E are determined according to the optical system in the HUD device 100.

The HUD device 100 is provided, for example, inside the dashboard 3 of the vehicle 1. By displaying a virtual image V, the HUD device 100 can notify the user 4 of not only information related to the vehicle 1 (hereinafter referred to as vehicle information) but also information other than the vehicle information in an integrated manner. Note that the vehicle information includes not only information about the vehicle 1 itself, but also information outside the vehicle 1 related to the traveling of the vehicle 1. The HUD device 100 constitutes a part of the vehicle display system S shown in FIG. 3.

The vehicle display system S is mounted on a vehicle 1 and includes a HUD device 100, a surrounding information acquisition unit 200, a map information storage unit 300, and a viewpoint detection unit 400.

As shown in Figures 2 and 3, the HUD device 100 includes a display 10, first to third mirrors 21 to 23, a screen 30, a concave mirror 40, a housing 50, a screen driver 60, and a controller 70. First, the configuration shown in Figure 2 will be described.

The display device 10 is configured to generate and radiate display light L, and is, for example, a projector using a reflective display device such as a DMD (Digital Micro Mirror Device) or LCOS (Liquid Crystal On Silicon). The display device 10 radiates the display light L generated under the control of the control unit 70 toward the first mirror 21. The display light L from the display device 10 reflected by the first mirror 21 is directed toward the screen 30.

The screen 30 is composed of a transmissive screen such as a holographic diffuser, a microlens array, or a diffusion plate. The screen 30 displays an image indicated by the display light L on a display surface 31 on the rear side of the surface that receives the display light L. Accordingly, the display light L corresponding to the image displayed on the display surface 31 is emitted toward the second mirror 22. The screen 30 is provided so as to be rotatable about an axis AX, and is rotationally driven by a screen drive unit 60. The angle of the virtual surface A with respect to the road surface in front of the vehicle 1 changes in accordance with the rotation of the display surface 31 of the screen 30. In other words, the display surface 31 and the virtual surface A are in an optically conjugate relationship.

The display light L from the screen 30 is reflected by the second mirror 22 and the third mirror 23 in that order before heading toward the concave mirror 40. In this embodiment, three mirrors, the first to third mirrors 21 to 23, are used as folding mirrors that fold the optical path of the display light L, but the number of folding mirrors and how the optical path of the display light L is folded can be changed as appropriate depending on the design. The folding mirrors may be either flat or curved mirrors.

The concave mirror 40 reflects the display light L from the third mirror 23 toward the windshield 2 while magnifying it. The concave mirror 40 may be rotatable by an actuator (not shown). The reflection angle of the display light L may be changed in response to the rotation of the concave mirror 40, thereby making it possible to adjust the display position (height) of the virtual image V. This adjustment may be performed under the control of the control unit 70 in response to a user's operation from an operation unit (not shown) or the viewpoint position of the user 4 detected by the viewpoint detection unit 400.

The housing 50 is formed in a box shape with light-blocking properties and has an opening through which the display light L reflected by the concave mirror 40 passes. A translucent cover 51 through which the display light L passes is attached to the opening of the housing 50.

The screen drive unit 60 shown in FIG. 3 drives the screen 30 to rotate around the axis AX. The screen drive unit 60 is configured to include, for example, a motor that is driven under the control of the control unit 70, and a gear mechanism that transmits the power of the motor to the screen 30.

The control unit 70 is composed of a microcomputer that controls the overall operation of the HUD device 100. For example, the control unit 70 is configured with a ROM (Read Only Memory) that stores operation programs and image data in advance, a RAM (Random Access Memory) that temporarily stores various calculation results, a CPU (Central Processing Unit) that executes the operation programs stored in the ROM, and a GPU (Graphics Processing Unit) that works with the CPU to execute image processing. The configuration of the control unit 70 is arbitrary as long as it satisfies the functions described below. The control unit 70 may be composed of one computer, or may be composed of multiple computers that communicate with each other. The main functions of the control unit 70 will be described later.

The surrounding information acquisition unit 200 is configured to transmit surrounding information about the vehicle 1 to the control unit 70, and includes a forward sensing unit 210 and an outside-vehicle information acquisition unit 220.

The forward sensing unit 210 is configured to identify forward objects located in front of the vehicle 1. The forward sensing unit 210 is configured, for example, with a stereo camera, a LIDAR (Laser Imaging Detection And Ranging), a sonar, an ultrasonic sensor, a millimeter wave radar, etc., and identifies forward objects using a known analysis method.

The outside-vehicle information acquisition unit 220 is configured to acquire information from outside the vehicle 1. The outside-vehicle information acquisition unit 220 is composed of various modules that enable communication between the vehicle 1 and a wireless network (V2N: Vehicle To cellular Network), communication between the vehicle 1 and other vehicles (V2V: Vehicle To Vehicle), communication between the vehicle 1 and pedestrians (V2P: Vehicle To Pedestrian), and communication between the vehicle 1 and roadside infrastructure (V2I: Vehicle To Roadside Infrastructure). In other words, the surrounding information acquisition unit 200 enables communication between the vehicle 1 and the outside of the vehicle 1 by V2X (Vehicle To Everything).

For example, (i) the outside-vehicle information acquisition unit 220 includes a communication module that can directly access a WAN (Wide Area Network), a communication module for communicating with an external device (such as a mobile router) that can access the WAN, an access point of a public wireless LAN (Local Area Network), and the like, and performs Internet communication. The outside-vehicle information acquisition unit 220 also includes a GPS controller that calculates the position of the vehicle 1 based on a GPS (Global Positioning System) signal received from an artificial satellite or the like. These configurations enable communication by V2N. (ii) The outside-vehicle information acquisition unit 220 also includes a wireless communication module that complies with a predetermined wireless communication standard, and performs communication by V2V or V2P. (iii) The outside-vehicle information acquisition unit 220 also has a communication device that wirelessly communicates with roadside infrastructure, and acquires object information and traffic information around the vehicle 1 from, for example, a base station of a driving safety support system (DSSS) via a roadside wireless device installed as infrastructure. This enables communication by V2I.

In this embodiment, the outside-vehicle information acquisition unit 220 acquires object information indicating the positions, sizes, attributes, etc. of various objects such as vehicles, traffic lights, and pedestrians that exist outside the vehicle 1 via V2I, and supplies the object information to the control unit 70. Note that the object information is not limited to V2I, and may be acquired via any communication method including V2X. In addition, the outside-vehicle information acquisition unit 220 acquires traffic information including the positions and shapes of roads around the vehicle 1 via V2I, and supplies the traffic information to the control unit 70.

The map information storage unit 300 is composed of a solid state drive (SSD), a hard disk drive (HDD), etc., and stores digital map data consisting of map information and three-dimensional coordinate information (three-dimensional information) for indicating the shape of the road. The digital map data is composed of various data such as road shape data indicating the shape of the road, height data indicating the reference height of the road (e.g. above sea level), gradient data indicating the longitudinal inclination (gradient) of the road, gradient data indicating the widthwise inclination of the road, curvature data indicating the curvature of the road, and speed limit data indicating the speed limit of the road, for each predetermined position (predetermined latitude and longitude) of the road. The digital map data is used when the control unit 70 executes the drawing process. The control unit 70 also functions as a car navigation controller that reads out map information and data indicating the road shape near the current position from the map information storage unit 300 based on position information from the GPS controller included in the outside vehicle information acquisition unit 220, and determines a guide route to a destination set by the user 4.

The viewpoint detection unit 400 is a known configuration for detecting the viewpoint position of the user 4, and is composed of an infrared camera, a stereo camera, a TOF (Time of Flight) camera, etc. The viewpoint detection unit 400 detects the viewpoint position of the user 4 by analyzing the image data obtained by imaging the face of the user 4 using a known method. The viewpoint detection unit 400 supplies detection data indicating the detected viewpoint position to the control unit 70. Note that the viewpoint detection unit 400 may detect the line of sight of the user 4, and supply detection data indicating the detected line of sight to the control unit 70.

The control unit 70 can also obtain various information about the vehicle 1, such as vehicle speed and accumulated mileage, from an ECU (Electronic Control Unit) that controls each part of the vehicle 1 (not shown).

From here, the main functions of the control unit 70 will be explained. The control unit 70 has, as functional units, an information acquisition unit 71 (an example of an acquisition means), a virtual surface adjustment unit 72 (an example of an adjustment means), and a display control unit 73 (an example of a display control means).

The information acquisition unit 71 acquires peripheral information from the peripheral information acquisition unit 200. The peripheral information includes information on forward objects transmitted from the forward sensing unit 210, current position information of the vehicle 1 transmitted from the outside-vehicle information acquisition unit 220, object information outside the vehicle 1, traffic information, and the like. The information acquisition unit 71 also acquires digital map data from the map information storage unit 300, and acquires detection data indicating the viewpoint position of the user 4 from the viewpoint detection unit 400.

The virtual surface adjustment unit 72 rotates the screen 30 via the screen drive unit 60 to adjust the angle of the virtual surface A with respect to the road surface R ahead of the vehicle 1, as shown in FIG. 5. The shape of the road surface R that is the reference for the angle can be determined, for example, based on the current position information of the vehicle 1 acquired from the vehicle exterior information acquisition unit 220 and the digital map data stored in the map information storage unit 300. Alternatively, the shape of the road surface R may be estimated based on a reference horizontal plane previously set in the vehicle 1, may utilize analysis by the forward sensing unit 210, or may utilize traffic information that can be acquired from the vehicle exterior information acquisition unit 220.

The display control unit 73 controls the operation of the display unit 10 and can execute multiple display modes, including a first display mode and a second display mode, as display modes for the virtual image V. Below, the display modes set in this embodiment will be described in order.

(First display mode)
The first display mode is a display mode that realizes VR (Virtual Reality) in which a virtual image V is displayed superimposed on a real scene (forward scenery) seen by the user 4 through the windshield 2, but additional information is not added to a specific object in the real scene. In the first display mode, the display control unit 73 displays a first image V1 based on a first virtual viewpoint as a virtual image V, as shown in FIG. 4(a). The first image V1 is an overhead image showing a range including the current location of the vehicle 1 from an overhead or bird's-eye view. In this case, the first virtual viewpoint is set as if it were at an arbitrary position in the sky. The first virtual viewpoint can be arbitrarily set by drawing control of the display control unit 73 based on digital map data. The first image V1 is a so-called Small World type image depicting a virtual world seen from the first virtual viewpoint, and can present side and rear information to the user 4 in addition to forward information.

The first image V1 illustrated in FIG. 4(a) includes a map image F1 displayed in VR mode, a current location image G1 showing the current location of the vehicle 1, a destination image H1 showing the destination set by the user 4, and a route guidance image J1 showing the route to the destination. Note that the route guidance image J1 is an example of a first notification image that notifies information related to the travel of the vehicle 1. Also, at least one of the map image F1, the current location image G1, and the destination image H1 is an example of a related image that notifies information related to the first notification image.

When the first display mode is executed, the virtual surface adjustment unit 72 adjusts the angle of the virtual surface A with respect to the road surface R ahead of the vehicle 1 to an acute first angle α (0°<α<90°) as shown in FIG. 5. The display control unit 73 displays the first image V1 on the virtual surface A adjusted in this way and forming the first angle α with respect to the road surface R. Note that the first angle α can be any angle as long as it is smaller than the second angle β described below.

(Second display mode)
The second display mode is a display mode that realizes AR (Augmented Reality) that adds additional information to a specific object in the real scene seen by the user 4 through the windshield 2. In the second display mode, the display control unit 73 displays a second image V2 based on a second virtual viewpoint as a virtual image V, as shown in FIG. 4C. The second image V2 includes a superimposed image that is viewed superimposed on a forward object K. The display control unit 73 can control the display of the superimposed image based on, for example, the forward object K identified by the forward sensing unit 210 and the viewpoint position of the user 4 detected by the viewpoint detection unit 400. The display control unit 73 may execute display control of the superimposed image based on, for example, the forward object K identified by the forward sensing unit 210 and the line of sight direction of the user 4 detected by the viewpoint detection unit 400. The display control unit 73 may control the display of the superimposed image using information acquired from the outside vehicle information acquisition unit 220 or information based on the digital map data of the map information storage unit 300. In this case, the second virtual viewpoint is set by the display control unit 73 at a position lower than the first virtual viewpoint and in accordance with the viewpoint of the user 4 indicated by the detection data of the viewpoint detection unit 400 .

The second image V2 illustrated in FIG. 4(c) includes a route guidance image J2 displayed in an AR mode. This route guidance image J2 is viewed while being superimposed on the road shape as the forward object K, and shows the route to the destination set by the user 4. Note that the portion indicated by the dashed line in the area of the second image V2 in FIG. 4(c) represents the road shape as an actual view that is not a component of the second image V2. The second image V2 according to this embodiment does not include the map image F1, the current location image G1, and the destination image H1, which are examples of the related images. In this way, by not displaying at least a part of the related image displayed in the first image V1 in the second image V2, the second notification image J2 in the second image V2 has higher visibility than the first notification image J1 in the first image V1. This allows the user 4 (mainly the driver of the vehicle 1) to pay attention to the content that should be recognized. The visibility of the second notification image J2 may be improved by using an image with a higher display brightness than the first notification image J1 or by using a more conspicuous color for the second notification image J2. The route guidance image J2 is an example of a second notification image that notifies the same content as the route guidance image J1, which is an example of a first notification image. In addition, if the actual view visible from the vehicle 1 includes a destination set by the user 4, a destination image showing the destination may be included in the second image V2.

When the second display mode is executed, the virtual surface adjustment unit 72 adjusts the angle of the virtual surface A with respect to the road surface R in front of the vehicle 1 to a second angle β larger than the first angle α, as shown in Fig. 5. The display control unit 73 displays the second image V2 on the virtual surface A adjusted in this manner and forming the second angle β with respect to the road surface R. Note that the second angle β is any angle, for example, as long as the angle with respect to the road surface R is 90° or less and is larger than the first angle α.
According to the HUD device 100, when transitioning from the first display mode to the second display mode, the virtual viewpoint changes from an overhead VR display to an AR display (so-called driver's view), and the inclination of the virtual surface A on which the virtual image V is displayed also changes, allowing the user 4 to easily understand the transition of the display mode.

(Intermediate display mode)
The display control unit 73 can switch the display mode of the virtual image V from one of the first display mode and the second display mode to the other. However, if the switching is suddenly performed, there is a risk that the display mode may change without the user 4 noticing, or that the user 4 may be surprised. For this reason, when switching from the first display mode to the second display mode, the display control unit 73 switches to the second display mode after executing the intermediate display mode. The intermediate display mode is a display mode that realizes VR like the first display mode. In the intermediate display mode, as shown in FIG. 4B, the display control unit 73 displays an intermediate image V3 based on a third virtual viewpoint that is lower than the first virtual viewpoint and higher than the second virtual viewpoint as the virtual image V. The intermediate image V3 is an overhead image that shows a range including the current location of the vehicle 1 in an overhead or bird's-eye view, and is an image in the Small World mode. In this case, the third virtual viewpoint can be set by drawing control of the display control unit 73 based on digital map data, like the first virtual viewpoint.

The intermediate image V3 illustrated in FIG. 4(b) includes a map image F3 displayed in VR mode, a current location image G3 showing the current location of the vehicle 1, a destination image H3 showing the destination set by the user 4, and a route guidance image J3 showing the route to the destination. Since the virtual viewpoint when drawing these images is lower in the intermediate display mode than in the first display mode, the intermediate image V3 appears to the user 4 as if zoomed in from the first display mode. In other words, the intermediate image V3 displays information closer to the vehicle 1 than the first image V1, and can inform the user 4 of information within a range of several hundred meters to several tens of meters from the vehicle 1, for example.

When the intermediate display mode is executed, the angle of the virtual plane A with respect to the road surface R in front of the vehicle 1 is adjusted to a third angle γ between the first angle α and the second angle β by the virtual plane adjustment unit 72, as shown in FIG. 5. The display control unit 73 displays the intermediate image V3 on the virtual plane A adjusted in this way and forming the third angle γ with respect to the road surface R.

When switching the display mode of the virtual image V from the first display mode to the second display mode, the display control unit 73
It is preferable to make the length of the period from the first display mode to the intermediate display mode (hereinafter referred to as the first period) different from the length of the period from the intermediate display mode to the second display mode (hereinafter referred to as the second period). This can further enhance the dramatic effect when the display mode is switched, and can effectively make the user 4 aware of the change in the display mode. It is arbitrary which of the first period and the second period is made longer, and it may be a period of several seconds, for example.

The first period can be rephrased as the transition speed from the first display mode to the intermediate display mode. The second period can be rephrased as the transition speed from the intermediate display mode to the second display mode. The first period can be rephrased as the period or speed until the angle of the virtual surface A with respect to the road surface R moves from the first angle α to the third angle γ. The second period can be rephrased as the period or speed until the angle of the virtual surface A with respect to the road surface R moves from the third angle γ to the second angle β. The change mode until the first image V1 is changed to the intermediate image V3, or the change mode until the intermediate image V3 is changed to the second image V2, may be expressed in an animation mode in which the images gradually transition.

The display control unit 73 also determines the display mode to be executed based on the surrounding information acquired by the information acquisition unit 71. For example, when the forward object K to be displayed in AR approaches a specific distance from the current vehicle 1 during execution of the first display mode, the display control unit 73 determines that the switching condition from the first display mode to the second display mode is established. The forward object K to be displayed in AR can be identified based on information from at least one of the forward sensing 210 and the vehicle outside information acquisition unit 220, and may be, for example, an intersection, a destination, or a POI (Point Of Interest). In other words, the forward object K on which the second image V2 displayed in the AR mode is superimposed is not limited to analysis by the forward sensing unit 210, but may be identified based on information from the vehicle outside information acquisition unit 220. For example, when the vehicle 1 passes the forward object K to be displayed in AR during execution of the second display mode, the display control unit 73 determines that the switching condition from the second display mode to the first display mode is established.

The first image V1 shown in FIG. 4(a) is drawn as seen by the user 4 when the first image V1 is displayed on a virtual plane A at a first angle α with respect to the road surface R. Similarly, the second image V2 shown in FIG. 4(c) is drawn as seen by the user 4 when the second image V2 is displayed on a virtual plane A at a second angle β with respect to the road surface R. Similarly, the intermediate image V3 shown in FIG. 4(b) is drawn as seen by the user 4 when the intermediate image V3 is displayed on a virtual plane A at a third angle γ with respect to the road surface R.

Next, an example of the display mode control process executed by the control unit 70 of the HUD device 100 will be described with reference to FIG. 6. The display mode control process is executed continuously while the ignition of the vehicle 1 is on and the HUD device 100 is operating, for example.

(Display mode control process)
When the control unit 70 starts the display mode control process, the control unit 70 first executes the first display mode (step S1). That is, the control unit 70 displays the first image V1 on the virtual plane A whose angle with respect to the road surface R is adjusted to the first angle α.

Next, the control unit 70 determines whether or not a mode switching condition, which is a condition for switching from the first display mode to the second display mode, is satisfied based on the peripheral information acquired from the peripheral information acquisition unit 200 using the method described above (step S2). If the mode switching condition is not satisfied (step S2; No), the control unit 70 continues the first display mode (step S1).

If the mode switching condition is met in step S2 (step S2; Yes), the control unit 70 executes control to change to the intermediate display mode (step S3). Specifically, the control unit 70 executes drawing control to transition the first image V1 to the intermediate image V3, and changes the angle of the virtual surface A with respect to the road surface R from the first angle α to the third angle γ.

Next, the control unit 70 determines whether or not switching to the intermediate display mode has been completed (step S4). Specifically, the control unit 70 determines that switching to the intermediate display mode has been completed when drawing of the intermediate image V3 has been completed and the angle of the virtual surface A with respect to the road surface R has reached the third angle γ (step S4; Yes). Here, the period from when the mode switching condition is satisfied in step S2 (step S2; Yes) to when switching to the intermediate display mode is completed (step S4; Yes) corresponds to the first period. If switching to the intermediate display mode has not been completed (step S4; No), the control unit 70 continues to control the change to the intermediate display mode (step S3).

When the switching to the intermediate display mode is completed in step S4 (step S4; Yes), the control unit 70 executes change control to the second display mode (step S5). Specifically, the control unit 70 executes drawing control to transition the intermediate image V3 to the second image V2, and changes the angle of the virtual surface A with respect to the road surface R from the third angle γ to the second angle β.

Next, the control unit 70 determines whether or not switching to the second display mode has been completed (step S6). Specifically, the control unit 70 determines that switching to the second display mode has been completed when the drawing of the second image V2 has been completed and the angle of the virtual surface A with respect to the road surface R has reached the second angle β (step S6; Yes). Here, the period from when switching to the intermediate display mode is completed in step S4 (step S4; Yes) to when switching to the second display mode is completed (step S6; Yes) corresponds to the second period. If switching to the second display mode has not been completed (step S6; No), the control unit 70 continues to control the change to the second display mode (step S5).

Next, while executing the second display mode (step S7), the control unit 70 determines whether or not a mode switching condition, which is a switching condition from the second display mode to the first display mode, is satisfied based on the peripheral information acquired from the peripheral information acquisition unit 200 using the method described above (step S8). If the mode switching condition is not satisfied (step S8; No), the control unit 70 continues the second display mode (step S7). On the other hand, if the mode switching condition is satisfied (step S8; Yes), the control unit 70 switches the second display mode to the first display mode and executes the first display mode (step S1). This completes the display mode control process.

The present invention is not limited to the above-described embodiments and drawings. Appropriate modifications (including the deletion of components) may be made to the embodiments without departing from the spirit of the present invention.

(Modification)
In the above, an example has been shown in which the first notification image included in the first image V1 is the route guidance image J1, and the second notification image included in the second image V2 is the route guidance image J2, but the first notification image and the second notification image are not limited to this type of route guidance image and are arbitrary. For example, the first notification image and the second notification image may be an image showing a destination set by the user 4, an image showing a POI, an image showing a construction zone, etc. In this case, the second notification image in the AR mode may be a superimposed image that is visually recognized superimposed on the destination, POI, construction zone, etc. (examples of a forward target) as an actual scene. In addition, the second image V2 may include an image in a mode other than an AR image as long as it includes at least the second notification image as a superimposed image (hereinafter also referred to as an AR image).

Although an example of transition from the first display mode to the second display mode via the intermediate display mode has been described above, the intermediate display mode may not be provided. In addition, a plurality of intermediate display modes may be provided in the middle of transition from the first display mode to the second display mode. Here, if the plurality of intermediate display modes include the first intermediate display mode and the second intermediate display mode, the angle of the virtual plane A displaying the intermediate image with respect to the road surface R in the first intermediate display mode and the second intermediate display mode may be made different, and intermediate images based on different virtual viewpoints may be displayed. The transition from the first display mode to the second display mode can be arbitrarily changed as long as the height of the virtual viewpoint set during drawing control and the angle of the virtual plane A with respect to the road surface R are displaced in sequence. For example, the intermediate image V3 displayed in the intermediate display mode may not be an overhead image, but may be an image similar to the second image V2 of the AR aspect displayed in the second display mode. In this way, by making the intermediate image V3 an image that approximates the AR aspect, it is possible to ensure a long period of time during which the user 4, who is mainly the driver of the vehicle 1, feels AR, and it is possible to present information close to the viewpoint of the user 4 to the user 4 for a longer period of time.

Although an example has been described above in which no intermediate display mode is provided when transitioning from the second display mode to the first display mode, the control unit 70 may also transition the display mode to the first display mode via the intermediate display mode when transitioning from the second display mode to the first display mode. In addition, the intermediate image V3 in the intermediate display mode may have less display content than the first image V1 in the first display mode.

In the above, an example in which VR display is realized in the first display mode and AR display is realized in the second display mode has been described, but this is not limited to this. As long as the condition is satisfied that the first image V1 is displayed on the virtual plane A whose angle with respect to the road surface R is adjusted to the first angle α when the first display mode is executed, and the second image V2 is displayed on the virtual plane A whose angle with respect to the road surface R is set to the second angle β when the second display mode is executed, the second display mode may also be a VR display. In other words, the control unit 70 may be capable of executing a first display mode in which the first image V1 based on the first virtual viewpoint is displayed in a VR manner, and a second display mode in which the second image V2 based on the second virtual viewpoint set at a position lower than the first virtual viewpoint is displayed in a VR manner. In addition, the second angle β may be set arbitrarily as long as the angle of the virtual plane A with respect to the road surface R is different from the first angle α, which is an acute angle. For example, the second angle β may be smaller than the first angle α.

The display 10 is not limited to the configuration example shown above, and may be an image display such as a liquid crystal display or an organic EL (Electro Luminescence) display. The angle adjustment mechanism of the virtual surface A with respect to the road surface R is also not limited to the example shown above, and is arbitrary. For example, the image display itself may be configured to be rotatable, and the angle of the virtual surface A may be adjusted by tilting the display surface of the display. Also, a configuration may be adopted in which the screen 30 that receives the display light L emitted by the image display is rotatably driven in the same manner as in the above embodiment.

The projection target (translucent member) of the display light L is not limited to the windshield 2 of the vehicle 1, but may be a combiner composed of a plate-shaped half mirror, a hologram element, or the like. The type of vehicle 1 on which the HUD device 100 is mounted is not limited and may be any type, such as a four-wheeled motor vehicle or a motorcycle. The HUD device 100 may also include at least some of the functions of the surrounding information acquisition unit 200, the map information storage unit 300, and the viewpoint detection unit 400.

In the above explanation, explanations of well-known technical matters have been omitted as appropriate to facilitate understanding of the present invention.

The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

100... Head-up display (HUD) device 10... Display 21-23... First to third mirrors 30... Screen, 31... Display surface 40... Concave mirror 50... Housing 60... Screen driving unit 70... Control unit 71... Information acquisition unit (an example of an acquisition means)
72...Virtual surface adjustment unit (an example of an adjustment means)
73: Display control unit (an example of a display control means)
200...peripheral information acquisition unit 300...map information storage unit 400...viewpoint detection unit S...vehicle display system 1...vehicle, 2...windshield, 3...dashboard, 4...user L...display light, A...virtual surface, V...virtual image, E...eye box V1...first image, V2...second image, V3...intermediate image J1...route guidance image (an example of a first notification image), F1...map image (an example of a related image)
J2: Route guidance image (an example of a second notification image)
α: first angle, β: second angle, γ: third angle

Claims (7)

A head-up display device that projects display light onto a translucent member provided in a vehicle, and displays a virtual image of an image indicated by the display light on a virtual plane set in front of the translucent member,
a display control means capable of executing a first display mode in which a first image based on a first virtual viewpoint is displayed as the virtual image, and a second display mode in which a second image based on a second virtual viewpoint set at a position lower than the first virtual viewpoint is displayed as the virtual image, and capable of switching the display mode from one of the first display mode and the second display mode to the other;
an adjustment means for adjusting an angle of the virtual plane with respect to a road surface in front of the vehicle;
An acquisition means for acquiring surrounding information of the vehicle,
The display control means
determining the display mode to be executed based on the peripheral information acquired by the acquisition means;
When the first display mode is executed, the first image is displayed on the virtual plane adjusted by the adjustment means to a first angle, which is an acute angle;
When the second display mode is executed, the second image is displayed on the virtual plane whose angle has been adjusted by the adjustment means to a second angle different from the first angle.
Head-up display device. When switching the display mode from the first display mode to the second display mode, the display control means executes an intermediate display mode in which an intermediate image based on a third virtual viewpoint that is lower than the first virtual viewpoint and higher than the second virtual viewpoint is displayed as the virtual image, and then switches the display mode to the second display mode.
The head-up display device according to claim 1 . When the intermediate display mode is executed, the display control means displays the intermediate image on the virtual plane whose angle has been adjusted by the adjustment means to a third angle between the first angle and the second angle.
The head-up display device according to claim 2 . a period until the first display mode is switched to the intermediate display mode and a period until the intermediate display mode is switched to the second display mode are different in length;
The head-up display device according to claim 2 or 3. The first image includes a first notification image that notifies information related to traveling of the vehicle,
The second image includes a second notification image that notifies a content common to the first notification image,
The second notification image in the second image has higher visibility than the first notification image in the first image.
The head-up display device according to any one of claims 1 to 4. The first image includes a first notification image that notifies information related to traveling of the vehicle and a related image that notifies information related to the first notification image,
The second image includes a second notification image notifying a content common to the first notification image, but does not include an image showing a content common to the related image.
The head-up display device according to any one of claims 1 to 4. the first image is an overhead image showing an area including a current location of the vehicle,
The second notification image included in the second image is a superimposed image that is visually recognized superimposed on a forward object located in front of the vehicle.
The head-up display device according to claim 5 or 6.

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