JP7739781B2 - Virtual image display device - Google Patents

Description

The present invention relates to a virtual image display device that displays a virtual image that can be viewed by vehicle occupants.

As disclosed in Patent Document 1, a head-up display is known that displays a virtual image visible to vehicle occupants on the windshield or other surface of the vehicle. Note that in this specification, head-up displays may be abbreviated as HUDs.

International Publication No. 2015/118859

The virtual images displayed by the HUD can be classified into non-superimposed content, which is not superimposed on the scenery in front of the vehicle, such as content showing the vehicle's speed, and superimposed content, which is superimposed on the scenery in front of the vehicle, such as content related to vehicle driving assistance. Currently, it is being considered to display, as superimposed content, lane change content related to automated lane change assistance, which provides various types of assistance related to lane changes, changing the lane in which the vehicle is traveling. Note that in this specification, automated lane change assistance may be abbreviated as LCA.

However, the field of view of a HUD cannot be expanded indefinitely, and is limited to a finite range determined by the HUD specifications, vehicle specifications, etc. With conventional HUDs, it has been difficult to display both non-superimposed content and superimposed lane change content at the appropriate time and in the appropriate position within such a finite field of view.

The present invention was made in consideration of the above circumstances, and its purpose is to provide a virtual image display device that can display both non-overlapping content and overlapping content, such as lane change content, at the appropriate timing and in the appropriate position.

The virtual image display device described in claim 1 is a device that displays a virtual image visible to an occupant of a vehicle (A), and includes a switching mechanism (13) and a display control unit (143). The switching mechanism switches the angle of view at which the virtual image is displayed between a plurality of positions including a first position and a second position defined above the first position. The display control unit displays the virtual images associated with the first position and the second position in response to the switching of the angle of view by the switching mechanism.

The switching mechanism moves the angle of view from the first position to the second position when an automated lane change assist operation is started, which provides various types of assistance related to lane changes to change the lane in which the vehicle is traveling. Furthermore, the switching mechanism moves the angle of view from the second position to the first position when the automated lane change assist operation is completed. The display controller displays non-superimposed content, which is a display object not used for Augmented Reality display, within the angle of view at the first position. Furthermore, the display controller displays lane change content, which is superimposed content on a road surface in the foreground and represents the operating state of the vehicle when the automated lane change assist is performed , within the angle of view at the second position. The non-superimposed content includes content representing the distance between the host vehicle and a leading vehicle traveling ahead of the vehicle.

With the above configuration, when the automated lane change assist is performed, the angle of view is moved to a second position, which is a relatively higher position, and lane change content is displayed within that angle of view. The automated lane change assist is performed when the vehicle is traveling at a relatively high speed, such as when the vehicle is traveling on a highway or expressway. The faster the vehicle's speed, the more the driver's line of sight (occupant) rises to view the distance. Therefore, with the above configuration, when the automated lane change assist is performed, the lane change content is displayed at an appropriate position to match the occupant's elevated line of sight, allowing the occupant to easily and accurately grasp the operating status of the vehicle operating in response to the automated lane change assist.

Furthermore, with the above configuration, when the automated lane change assist operation is not being performed, the angle of view is moved to a first position, which is a relatively lower position, and non-superimposed content is displayed within that angle of view. The non-superimposed content is not necessarily information necessary for the occupants when the automated lane change assist operation is being performed, and is content that is not superimposed on the scenery in the foreground, so it is displayed at this timing and in this position. In this way, with the above configuration, the excellent effect of being able to display both the non-superimposed content and the superimposed content, the lane change content, at the appropriate timing and in the appropriate position is achieved.

FIG. 1 is a diagram illustrating an example of a head-up display mounted on a vehicle according to an embodiment; FIG. 1 is a diagram illustrating a configuration of a display system including a head-up display according to an embodiment. FIG. 10 is a diagram showing a specific example of a display mode of a HUD in a reference state of virtual image display according to an embodiment; FIG. 10 is a diagram showing a specific example of a display mode of a HUD immediately after an instruction to perform LCA is given according to an embodiment; FIG. 1 is a diagram illustrating a specific example of a display mode of a HUD when the angle of view moves from a first position to a second position according to an embodiment. FIG. 2 is a diagram illustrating a specific example of a display mode of the HUD when the angle of view moves from a first position to a second position according to an embodiment. FIG. 1 is a diagram showing a specific example of a display mode of the HUD after the angle of view has been moved to the second position according to an embodiment. FIG. 2 is a diagram illustrating a specific example of a display mode of the HUD after the angle of view has been moved to the second position according to an embodiment. FIG. 3 is a diagram showing a specific example of a display mode of the HUD after the angle of view has been moved to the second position according to an embodiment. FIG. 4 is a diagram showing a specific example of a display mode of the HUD after the angle of view has been moved to the second position according to an embodiment. FIG. 1 is a diagram illustrating a specific example of a display mode of a HUD when the angle of view moves from a second position to a first position according to an embodiment. FIG. 2 is a diagram illustrating a specific example of a display mode of the HUD when the angle of view moves from the second position to the first position according to an embodiment. FIG. 10 shows a first modified example of LCA content. FIG. 2 shows a second modified example of LCA content. FIG. 3 shows a third modified example of LCA content. FIG. 4 shows a fourth modified example of LCA content. FIG. 5 shows a fifth modified example of LCA content.

Hereinafter, an embodiment of a virtual image display device will be described with reference to the drawings.
1 and 2 , a head-up display 1 of this embodiment functions as a virtual image display device that displays a virtual image visible to an occupant of vehicle A, and together with a meter display device 2 and the like, constitutes a display system 3. In the following description, vehicle A may be referred to as host vehicle A to distinguish it from other vehicles. The display system 3 is used in vehicle A, and presents various information related to vehicle A to a driver who is an occupant of vehicle A by linking the virtual image display by the HUD 1 with the screen display by the meter display device 2 and the like.

The HUD 1 and meter display device 2 are communicatively connected to a communication bus of an in-vehicle network installed in vehicle A. Other in-vehicle ECUs, such as a perimeter monitoring sensor 4, a vehicle control ECU 5, and a driving assistance ECU 6, are also connected to the communication bus of the in-vehicle network. Note that ECU is an abbreviation for Electronic Control Unit. These components, connected as nodes on the communication bus, can communicate with each other.

The perimeter monitoring sensor 4 is a sensor that monitors the environment surrounding the host vehicle A, and in this case, is provided as an autonomous sensor that operates autonomously. The perimeter monitoring sensor 4 detects objects present in the vicinity of the host vehicle A, such as dynamic targets that move around the host vehicle A, such as humans such as pedestrians, non-human animals, and vehicles other than the host vehicle A, as well as static targets that are stationary around the host vehicle A, such as fallen objects on the road, and guardrails, curbs, and trees that are present around the road.

The perimeter monitoring sensor 4 can also detect the distance to a vehicle ahead of vehicle A, as well as markings such as lane markings, stop lines, pedestrian crossings, road signs, and road markings on the roads surrounding vehicle A. The perimeter monitoring sensor 4 then sequentially outputs the obtained sensing data to the communication bus. The perimeter monitoring sensor 4 may be composed of, for example, a perimeter monitoring camera that captures images of a predetermined area around the vehicle, or a search wave sensor such as millimeter-wave radar, sonar, or LIDAR that emits search waves within a predetermined area around the vehicle.

The search wave sensor sequentially outputs the scanning results, based on the received signals obtained by receiving the reflected waves from the object, to the communication bus as sensing data. More specifically, the search wave sensor measures the distance from the search wave sensor to the object based on the time between transmitting the search wave and receiving the reflected wave reflected by the object. The search wave sensor also measures the orientation of the object relative to the search wave sensor based on the angle at which the reflected wave is received. The orientation can be expressed, for example, as an azimuth angle; for example, clockwise from the front of the vehicle as the reference direction can be expressed as a positive azimuth angle, and counterclockwise as a negative azimuth angle.

In this case, the perimeter monitoring sensor 4 is configured to include at least a camera 41 whose imaging range is a predetermined range around the host vehicle A, and a millimeter-wave radar 42 whose detection range is a predetermined range around the host vehicle A. The camera 41 can be mounted, for example, on the rearview mirror or the top surface of the instrument panel of the host vehicle A. The millimeter-wave radar 42 can be mounted, for example, on the front grille or front bumper of the host vehicle A. The millimeter-wave radar 42 transmits millimeter waves or quasi-millimeter waves while scanning a sensing range, such as in front of the host vehicle A, and receives the waves reflected by the object to measure the distance and direction to the object relative to the millimeter-wave radar 42.

The sensing range of the camera 41 and the sensing range of the millimeter-wave radar 42 may or may not be the same. Furthermore, the sensing range of the camera 41 and the sensing range of the millimeter-wave radar 42 may or may not overlap at least partially. Furthermore, multiple perimeter monitoring sensors 4 may be provided at different locations on the host vehicle A.

The vehicle control ECU 5 includes a microcomputer and other components, and performs, for example, control of acceleration and deceleration, steering, and braking of the host vehicle A. The vehicle control ECU 5 includes a power unit control ECU that controls acceleration and deceleration of the host vehicle A, a steering control ECU that controls steering of the host vehicle A, and a brake control ECU that controls braking of the host vehicle A.

The vehicle control ECU 5 outputs control signals to various driving control devices, such as an electronically controlled throttle, brake actuator, and EPS motor, based on detection signals output from various sensors installed in the host vehicle A, such as an accelerator position sensor, brake pedal force sensor, steering angle sensor, and wheel speed sensor. EPS is an abbreviation for Electric Power Steering. The vehicle control ECU 5 can also output detection signals obtained from the various sensors to a communication bus.

The driving assistance ECU 6 includes a microcomputer and other components, and works in cooperation with the vehicle control ECU 5 to implement multiple assistance functions that assist the driver of vehicle A. In this case, the driving assistance ECU 23 has driving assistance functions such as LDW, ACC, and LCA. Note that LDW is an abbreviation for Lane Departure Warning, and ACC is an abbreviation for Adaptive Cruise Control. In this case, the assistance provided by the driving assistance ECU 6 also includes an automatic driving function that automatically controls the driving of vehicle A.

The LDW function determines whether the vehicle has deviated from its own lane, such as going beyond the lane markings, based on detection information about the lane markings obtained from the perimeter monitoring sensor 4. When the driving assistance ECU 6 determines that the vehicle has deviated from its own lane using the LDW function, it provides lane departure information to the HUD 1 and meter display device 2 and issues a lane departure warning to the driver.

The ACC function either causes vehicle A to travel at a constant target speed, or causes vehicle A to follow a vehicle ahead while maintaining a safe distance from the vehicle ahead based on detection information about the vehicle ahead obtained from the perimeter monitoring sensor 4. When the ACC function is operating, the driving assistance ECU 6 provides status information indicating the control state of the ACC function to the HUD 1 and meter display device 2.

The LCA function provides various types of assistance related to lane changes, which change the lane in which vehicle A is traveling. These types of assistance include monitoring the destination when changing lanes, steering operations for lane changes, and acceleration/deceleration. The driving assistance ECU 6 activates the LCA function when a specified ON operation is performed to instruct the implementation of LCA, or when the autonomous driving function determines that LCA should be implemented. An example of an ON operation is to half-press the turn signal switch to activate the turn signal for a specified period of time.

The driving assistance ECU 6 is also capable of halting the execution of the LCA function if a predetermined cancellation operation is performed to cancel the implementation of LCA after an ON operation or other operation has been performed. Examples of cancellation operations include operating a turn signal switch in the opposite direction to the ON operation, steering, accelerator operation, or braking operation that exceeds a specific operation amount, etc.

Lane changes using the LCA function are performed as follows: In other words, in the start-up state, which is immediately after receiving an on-operation or immediately after the autonomous driving function has determined that LCA will be performed, the driving assistance ECU 6 checks whether there is another vehicle in the destination lane, which is the adjacent lane to which the vehicle will move during the lane change, based on various detection information obtained from the perimeter monitoring sensor 4.

When the driving assistance ECU 6 determines that there is another vehicle in the destination lane that may prevent vehicle A from changing lanes, it enters a standby state, waiting to execute a lane change using the LCA function. Furthermore, when the driving assistance ECU 6 determines that there is no other vehicle in the destination lane that may prevent vehicle A from changing lanes, it enters an execution state, starting to execute a lane change using the LCA function.

When the driving assistance ECU 6 enters the execution state, it automatically controls the steering angle of the steering wheels of vehicle A, thereby moving vehicle A from the current lane to the destination lane, i.e., changing lanes for vehicle A. At this time, the driving assistance ECU 6 also automatically turns on the turn signal corresponding to the direction vehicle A is moving in as the lane changes. When the LCA function is operating, the driving assistance ECU 6 provides LCA information, which is information related to LCA, to the HUD 1 and the meter display device 2. The LCA information includes information indicating the planned movement direction, which is the direction vehicle A is planned to move in by LCA; information indicating the planned driving trajectory, which is the trajectory vehicle A is planned to travel by LCA; and a status indicating whether the operating state of the LCA function is in the activation state, standby state, or execution state.

Next, the detailed configuration of the HUD 1 and meter display device 2 will be described. In this case, the up-down direction in FIG. 1 is the up-down direction of vehicle A, the left-right direction in FIG. 1 is the fore-and-aft direction of vehicle A, and the direction perpendicular to the plane of the paper in FIG. 1 is the left-and-aft direction of vehicle A. The fore-and-aft and left-and-right directions of vehicle A are defined with vehicle A stationary on a horizontal plane as the reference. Specifically, the fore-and-aft direction of vehicle A is defined along the direction of travel of vehicle A. Furthermore, the left-and-right direction of vehicle A is defined along the width direction of vehicle A. The up-and-down direction of vehicle A is defined along the vertical direction of the horizontal plane that defines the fore-and-aft and left-and-right directions. Hereinafter, when simply referred to as up, down, front, rear, left, and right, these directions are meant.

The meter display device 2 is one of multiple display devices installed in vehicle A, and presents information to the driver by displaying images on a display screen. The meter display device 2 has a configuration equivalent to a combination meter, and is housed in the instrument panel 7 with its display screen facing the driver's seat. The meter display device 2 is installed, for example, in a front position within the passenger compartment of vehicle A that allows it to be easily viewed by the driver seated in the driver's seat. The meter display device 2 includes a meter display 21 and a meter ECU 22.

The meter display 21 is, for example, a liquid crystal display or an organic EL display. Based on the video data acquired from the meter ECU 22, the meter display 21 displays a speedometer image, a tachometer image, a navigation map image, a driving assistance image, and the like on the display screen.

The meter ECU 22 functions as the HCU in the display system 3 and is an electronic control unit that manages the user interface functions of vehicle A. HCU is an abbreviation for Human Machine Interface Control Unit. The meter ECU 22 comprehensively controls the displays of display devices such as the meter display 21, HUD 1, and center display. The meter ECU 22 generates video data to be provided to the meter display 21 based on various information output to the communication bus.

The meter ECU 22 includes a microcomputer and works in conjunction with the head-up ECU 14 (described later) to perform calculations for virtual image display. Specifically, the meter ECU 22 generates image data used to display the virtual image Vi and sequentially outputs the generated image data to the HUD 1. The meter ECU 22 generates image data used to display virtual images such as the operating status of vehicle A when LCA is performed, lane departure warning, ACC status, turn-by-turn, and sign recognition, and provides this data to the HUD 1.

HUD1 is one of multiple display devices installed in vehicle A, and presents information to the driver by forming a virtual image Vi in the space in front of the driver. HUD1 is housed in a storage space provided inside instrument panel 7. HUD1 projects virtual image light Lvi, which is light that is formed as a virtual image Vi, toward the projection range PA of the windshield WS. The virtual image light Lvi projected onto the windshield WS is reflected toward the driver's seat in the projection range PA and perceived by the driver. The driver sees a display in which the virtual image Vi is superimposed on the foreground visible through the projection range PA.

The HUD 1 includes a PGU 11, a magnifying optical system 12, an actuator 13, and a head-up ECU 14. PGU is an abbreviation for Picture Generation Unit. The PGU 11 includes an LCD panel and a backlight. LCD is an abbreviation for Liquid Crystal Display. The PGU 11 is fixed to the housing of the HUD 1 with the display surface of the LCD panel facing the magnifying optical system 62.

The PGU 11 displays each frame image of the video data on the display surface of the LCD panel, and by transmitting illumination through the display surface with a backlight, emits virtual image light Lvi, which is focused as a virtual image Vi, toward the magnifying optical system 12. The magnifying optical system 12 includes at least one concave mirror made of a base material such as synthetic resin or glass, on the surface of which a metal such as aluminum is vapor-deposited. The magnifying optical system 12 reflects and expands the light emitted from the PGU 11, and projects it into the projection range PA above.

The actuator 13 is a mechanism that mechanically moves the area of the windshield WS that becomes the projection range PA. The projection range PA is the range onto which the virtual image light Lvi is projected, and is the range onto which the virtual image Vi appears as seen by the driver. The actuator 13 rotates the concave mirror of the magnifying optical system 12 around a rotation axis defined by the concave mirror, changing the emission direction of the virtual image light Lvi from the magnifying optical system 12 toward the windshield WS. By changing the position of the concave mirror, the actuator 13 moves the projection range PA of the virtual image light Lvi, and therefore the position of the angle of view VA as viewed by the driver, at least in the vertical direction.

If the imaginary range in space where the virtual image Vi can be formed is defined as the imaging plane IS, the field of view VA is the field of view defined based on the imaginary line connecting the driver's eye point EP and the outer edge of the imaging plane IS. The field of view VA is the angular range in which the driver can view the virtual image Vi from the eye point EP. With HUD1, the vertical field of view in the vertical direction is, for example, about 2°, and the horizontal field of view in the horizontal direction is, for example, about 6°. In other words, with HUD1, the horizontal field of view is larger than the vertical field of view.

As the angle of view VA moves up and down, the forward range within the angle of view VA changes. For example, if the actuator 13 positions the angle of view VA at its lowest point, such as a depression angle of about 3°, the range within the angle of view VA is between 10 and 20 meters forward. In contrast, if the actuator 13 positions the angle of view VA at its highest point, such as a depression angle of about 1°, the range within the angle of view VA is between 30 and 80 meters forward.

The head-up ECU 14 is a control circuit for the HUD 1 that provides integrated control of the PGU 11 and the actuator 13. The head-up ECU 14 includes a microcomputer and other components. The head-up ECU 14 also includes drive circuits for driving the LCD panel, backlight, and actuator 13.

The head-up ECU 14 changes the content displayed as the virtual image Vi in association with the position of the field of view VA. Specifically, the head-up ECU 14 controls the drive of the actuator 13 to switch the position of the field of view VA at which the virtual image Vi is displayed between multiple positions, including a first position VP1 and a second position VP2. The head-up ECU 14 displays the virtual image Vi associated with each of the first position VP1 and the second position VP2 in response to the switching of the field of view VA by the actuator 13. In this embodiment, the actuator 13 functions as a switching mechanism.

The first position VP1 is a viewing angle position where non-superimposed content is primarily displayed as a virtual image Vi. Non-superimposed content is a display object that is not superimposed on the scenery in the foreground of vehicle A, i.e., a non-AR display object. AR is an abbreviation for Augmented Reality. Non-superimposed content is displayed at a specific position within the projection range PA, i.e., the viewing angle VA. Therefore, the non-superimposed content is perceived by the driver as if it were fixed relative to vehicle components such as the windshield WS. The state in which vehicle information such as the traveling speed of vehicle A, i.e., vehicle speed, is displayed using non-superimposed content at first position VP1 is the reference state for virtual image display by HUD1.

The second position VP2 is a field of view position where the superimposed content is primarily displayed as a virtual image Vi. The second position VP2 is a position defined above the first position VP1. The superimposed content is an AR display object used for AR display. The display position of the superimposed content is associated with a specific superimposed object present in the foreground of vehicle A, such as a specific position on the road surface, a vehicle ahead, a pedestrian, or a road sign.

The superimposed content is displayed superimposed on a specific superimposed target within the field of view VA, and can move relative to the superimposed target, following the superimposed target, as if fixed relative to the superimposed target, as seen by the driver. The shape of the superimposed content is continually updated at a predetermined interval to match the relative position and shape of the superimposed target. The superimposed content is displayed in a more horizontal orientation than non-superimposed content, and is displayed in a shape that extends in the depth direction as seen by the driver, for example. For example, when a specific event occurs that should be notified to the driver, the HUD1 moves the field of view VA from a first position VP1 to a second position VP2 and displays the superimposed content.

To achieve this virtual image display control that links the field of view position and content, the head-up ECU 14 has multiple functional units that are realized when a processing unit in the microcomputer executes a virtual image display program, which is a computer program stored in storage in the microcomputer. Specifically, the head-up ECU 14 has functional units such as an information acquisition unit 141, a data storage unit 142, and a display control unit 143.

The information acquisition unit 141 is connected to the communication bus and the meter ECU 22. The information acquisition unit 141 acquires various types of information from the communication bus, such as road sign recognition information from the perimeter monitoring sensor 4, and lane departure information and status information from the driving assistance ECU 6. Image data for virtual image display generated by the meter ECU 22 is sequentially input to the information acquisition unit 141. The information acquisition unit 141 is electrically connected to the AR switch 8. The AR switch 8 is a switch that switches AR display using superimposed content on and off. The information acquisition unit 141 detects the on and off states of the AR switch 8.

The data storage unit 142 is a storage area that stores multiple pieces of data referenced by the display control unit 143. The data storage unit 142 may be a storage area allocated within the RAM of the microcomputer of the head-up ECU 14, or may be a partial storage area within the storage of the microcomputer. The data storage unit 142 stores lookup tables, mirror position data, and graphic data.

The lookup table is information that links the field of view position with content. The mirror position data is information that specifies the angular position of the concave mirror when the field of view VA is set to the first position VP1, and information that specifies the angular position of the concave mirror when the field of view VA is set to the second position VP2. The mirror position data may be a value that can be adjusted by the driver to match the position of the driver's eye point EP. The graphics data is image data that is used when the field of view VA is at the first position VP1, and image data that is used when the field of view VA is at the second position VP2.

The display control unit 143 is a control unit that performs integrated control of the PGU 11 and the actuator 13, and generates video data and control signals to be output to the PGU 11, and a drive signal to be output to the actuator 13. The display control unit 143 switches between enabling and disabling the operation of moving the angle of view VA to the second position VP2 based on the on/off state of the AR switch 8 grasped by the information acquisition unit 141. When the AR switch 8 is in the off state, the display control unit 143 fixes the angle of view VA to the first position VP1 and suspends the display of the superimposed content.

The display control unit 143 determines the position of the angle of view VA based on the information acquired by the information acquisition unit 141 and the contents of the lookup table described above, and selects content to be displayed as a virtual image based on the determined angle of view position. Based on the content selection result, the display control unit 143 extracts image material data to be used to generate video data from the graphics data described above. The display control unit 143 appropriately combines image data generated from the graphics data with image data provided by the meter ECU 22 to generate each frame image of the video data. The display control unit 143 sequentially outputs video data consisting of a large number of consecutive frame images to the PGU 11.

In the above configuration, when LCA operation begins, the head-up ECU 14 controls the actuator 13 to move the field of view VA from the first position VP1 to the second position VP2. Also, in the above configuration, when LCA operation ends, the head-up ECU 14 controls the actuator 13 to move the field of view from the second position VP2 to the first position VP1. In this case, the display control unit 143 displays non-superimposed content within the field of view VA at the first position VP1, and displays LCA content, which is superimposed content that is superimposed on the road surface in the foreground and represents the operating state of vehicle A when LCA is performed, within the field of view VA at the second position VP2.

In this case, when the LCA operation starts, the display control unit 143 displays notification content within the field of view VA at the first position VP1 to notify occupants such as the driver that the LCA operation has started. Furthermore, in this case, the display control unit 143 also displays the LCA content within the field of view VA at intermediate positions as the field of view VA moves from the first position VP1 to the second position VP2 due to drive control of the actuator 13 by the head-up ECU 14. The LCA content corresponds to lane change content.

Next, specific examples of display modes related to LCA performed by the HUD 100 having the above configuration will be described with reference to FIGS.
[1] Before the LCA operation starts As shown in Fig. 3, before the LCA operation starts, that is, before the LCA is turned on, the position of the field of view VA is the first position VP1. At this time, multiple pieces of content Cn1 to Cn6, which are all non-superimposed content, are displayed in the field of view VA at the first position VP1.

Content Cn1 represents the vehicle speed, which is the traveling speed of the host vehicle A. Content Cn2 represents the detection result of the vehicle ahead Af. Content Cn3 represents the length of the inter-vehicle distance between the host vehicle A and the vehicle ahead Af. Contents Cn4 and Cn5 represent the detection result of the lane markings Lml and Lmr. Content Cn6 represents the upper limit vehicle speed when vehicle A is cruising at a constant speed using the ACC function. In this way, the reference state for virtual image display by HUD1 is reached before LCA operation begins.

[2] Immediately after an instruction to perform LCA is given As shown in FIG. 4, immediately after an ON operation or the like is given to give an instruction to perform LCA, the position of the angle of view VA remains at the first position VP1. At this time, content Cn7, which is non-superimposed content, is displayed at a predetermined position, such as the right end position, within the angle of view VA at the first position VP. Content Cn7 is an example of notification content for notifying a driver or other occupants of the start of LCA operation when LCA operation is initiated. At this time, the display of contents Cn1 to Cn6 may be continued or stopped.

Content Cn7 is an icon that includes, for example, an arrow-shaped image representing the planned driving trajectory that smoothly connects the center of the vehicle's lane with the adjacent lane that is the destination lane, and images representing each lane marking, including the lane marking that is the boundary line that vehicle A will cross when changing lanes. In this case, content Cn7 is displayed flashing, repeatedly turning on and off a predetermined number of times.

[3] When the angle of view VA moves from the first position VP1 to the second position VP2 Then, as shown in Figures 5 and 6, the angle of view VA moves from the first position VP1 to the second position VP2. Note that the white arrows pointing up and down in Figures 5 and 6 indicate the direction of movement of the angle of view VA. In this embodiment, the LCA content Cs1, which is superimposed content, is also displayed within the angle of view VA at positions along the way during such movement. In this case, the LCA content Cs1 includes content Cs11 representing the planned travel path of vehicle A based on LCA, and content Cs12 representing each lane marking, including lane markings that vehicle A will cross when changing lanes.

Contents Cs11 and Cs12 are both superimposed and displayed as if glued to the road surface. Content Cs11 is a collection of multiple triangular images arranged along the planned driving trajectory of vehicle A according to LCA. In this case, each triangular image is arranged so that a specific vertex faces the planned direction of travel of vehicle A according to LCA at that time. Content Cs12 is shaped to overlap the corresponding lane marking or to extend along the corresponding lane marking. Content Cs12 is displayed in red and flashes in standby mode, and in blue in execution mode.

[4] After the movement of the angle of view VA to the second position VP2 is completed As shown in Figures 7 to 10, after the movement of the angle of view VA to the second position VP2 is completed, the execution of a lane change using the LCA function is initiated, and the content Cs1 is displayed to move in accordance with the foreground at that time. In Figures 7 and 8, the triangular image located at the bottom of the content Cs11 is located to the left of the content Cs12 corresponding to the lane marking that the vehicle A will cross during the lane change. In other words, in Figure 7, the display indicates that the vehicle A is still traveling in its own lane and will then cross the lane marking to move to the adjacent destination lane.

In addition, in Figures 8 and 9, the triangular image located at the bottom of content Cs11 is located to the right of content Cs12, which corresponds to the lane marking that the vehicle was scheduled to cross when changing lanes. In other words, Figures 8 and 9 show that vehicle A has moved from its own lane across the lane marking to the destination lane, and that it will then move to the center of the destination lane. In addition, in Figure 10, multiple triangular images of content Cs11 are arranged side by side along the center of the destination lane. In other words, Figure 10 shows that the lane change has been completed and vehicle A is traveling in the center of the destination lane.

[5] When the angle of view VA moves from the second position VP2 to the first position VP1 After that, the angle of view VA moves from the second position VP2 to the first position VP1 as shown in Figures 11 and 12. In this embodiment, the LCA content Cs1, which is the superimposed content, is also displayed within the angle of view VA at positions along the way.

[6] After the movement of the angle of view VA to the first position VP1 is completed, after the movement of the angle of view VA to the second position VP2 is completed, the angle of view VA at the first position VP1 displays multiple contents Cn1 to Cn6, all of which are non-superimposed contents, in other words, the standard state of virtual image display by HUD1 as shown in Figure 3.

According to the HUD1 of this embodiment described above, when LCA operation is performed, the field of view VA is moved to the second position VP2, which is a relatively higher position, and the LCA content Cs1 is displayed within that field of view VA. LCA operation is performed when vehicle A is traveling at a relatively high speed, such as when vehicle A is traveling on a highway or a motorway. The faster vehicle A's traveling speed becomes, the more the driver, who is an occupant, will raise his or her line of sight to view distant objects. Therefore, according to the HUD1 of this embodiment, when LCA operation is performed, LCA content Cs1 is displayed at an appropriate position to match the driver's elevated line of sight, allowing the driver to easily and accurately grasp the operating state of vehicle A when LCA is performed without having to avert his or her eyes.

Furthermore, with the above configuration, when the LCA is not operating, the angle of view is moved to a first position VP1, which is a relatively lower position, and non-superimposed content is displayed within that angle of view VA. The non-superimposed content is not necessarily information necessary for the driver when the LCA is operating, such as the vehicle speed of the vehicle A, and is content that is not superimposed on the scenery in the foreground, so it is displayed at this timing and in this position. In this way, this embodiment has the excellent effect of being able to display both the non-superimposed content and the superimposed content, the LCA content Cs1, at the appropriate timing and in the appropriate position.

In this embodiment, LCA content Cs1 includes content Cs11 representing the planned driving trajectory of vehicle A according to LCA, and content Cs12 representing each lane marking, including the marking line that vehicle A will cross when changing lanes. In this way, when LCA operation begins, the driver knows that vehicle A will correctly recognize the boundary line and will implement appropriate control to change lanes so as to cross that boundary line, giving the driver a sense of security about the upcoming LCA operation.

In this case, content Cs12 representing each lane marking is displayed in red and flashes in standby mode, and in blue in execution mode. In other words, in this case, when the presence of another vehicle in the destination lane that may be obstructing vehicle A's lane change is confirmed and the vehicle transitions to standby mode, content Cs12 is displayed in a manner that attracts the driver's attention, compared to when the vehicle transitions to execution mode, in which the LCA function begins executing a lane change.

In this way, the driver can easily understand that the LCA function is waiting to execute a lane change because it has been confirmed that there is another vehicle in the destination lane that will prevent vehicle A from changing lanes. Therefore, even if the lane change execution does not begin despite the driver turning on the LCA, the driver will be able to correctly understand the reason and will no longer feel uneasy or distrustful about the control of vehicle A.

In this embodiment, when the LCA operation is initiated, content Cn7, which is notification content for notifying the driver that the LCA operation has begun, is displayed within the field of view VA of the first position VP1. This allows the driver to easily and reliably know that the LCA operation is about to begin before the LCA actually begins to change lanes. Therefore, if the LCA operation is about to begin unintentionally due to, for example, the driver's own erroneous operation, the driver can immediately cancel the LCA operation.

In this embodiment, the LCA content Cs1 is also displayed within the field of view VA at positions along the way as the field of view VA moves from the first position VP1 to the second position VP2. In this way, compared to when the field of view VA is not displayed while it moves from the first position VP1 to the second position VP2, the display of the LCA content Cs1 begins without a significant delay after an ON operation, etc., is performed to instruct the implementation of LCA, and the display of the LCA content Cs1 continues without interruption until the LCA operation is completed. This allows the driver to more reliably grasp the operating state of vehicle A when LCA is being performed.

<Modifications regarding LCA content>
The LCA content may be superimposed content that represents the operating state of vehicle A when LCA is performed, and the specific form of the content may be changed as appropriate. Here, several modified examples of the LCA content will be described with reference to FIGS. 13 to 17.

[1] First Modification The LCA content Cs1a of the first modification shown in Fig. 13 differs from the LCA content Cs1 shown in Fig. 6 etc. in that it includes content Cs11a instead of content Cs11. Content Cs11a is a plurality of elliptical images arranged along the planned travel path of vehicle A calculated by LCA, and like content Cs11, is superimposed and displayed in a manner that appears to be attached to the road surface. The LCA content Cs1a of the first modification has a simpler display than content Cs1, and is less likely to give the driver an impression of clutter.

[2] Second Modification The LCA content Cs1b of the second modification shown in Fig. 14 differs from the LCA content Cs1 shown in Fig. 6 etc. in that it has content Cs11b instead of content Cs11. Like content Cs11, content Cs11b is a plurality of triangular images arranged side by side along the planned travel path of vehicle A calculated by LCA, and is superimposed and displayed as if glued to the road surface.

In this case, however, the multiple triangular images in content Cs11b are animated to appear to move in the planned direction of travel of vehicle A. This second variant of LCA content Cs1b allows the driver to more strongly sense that vehicle A is changing lanes through automatic control.

[3] Third Modification The LCA content Cs1c of the third modification shown in FIG. 15 differs from the LCA content Cs1 shown in FIG. 6 and the like in that it includes content Cs11c instead of content Cs11. Content Cs11c is an arrow-shaped image representing a planned driving trajectory that smoothly connects the center of the vehicle's lane and the adjacent lane that is the destination lane, and is superimposed and displayed as if glued to the road surface, similar to content Cs11. The LCA content Cs1c of the third modification allows the driver to more intuitively and accurately grasp the planned driving trajectory of vehicle A based on LCA, compared to the LCA contents Cs1, Cs1a, and Cs1b.

In contrast, with LCA contents Cs1, Cs1a, and Cs1b, the area of the scenery in the foreground of vehicle A obscured by contents Cs11, Cs11a, and Cs11b, which represent the planned driving trajectory of vehicle A by LCA, is kept small compared to LCA content Cs1c of the third variant. Therefore, with LCA contents Cs1, Cs1a, and Cs1b, the driver can check the operating state of vehicle A when LCA is performed while fully checking the scenery in the foreground.

[4] Fourth Modification The LCA content Cs1d of the fourth modification shown in Fig. 16 differs from the LCA content Cs1c of the third modification shown in Fig. 15 in that it has content Cs11d instead of content Cs11c. Like content Cs11c, content Cs11d is an arrow-shaped image that represents a planned driving trajectory that smoothly connects the center of the vehicle's lane and the adjacent lane that is the destination lane, and is superimposed and displayed as if it were attached to the road surface.

In this case, however, the arrow-shaped image of content Cs11d is animated to appear to move in the planned direction of travel of vehicle A. Like LCA content Cs1c of the third variant, LCA content Cs1d of the fourth variant allows the driver to more intuitively and accurately grasp the planned driving trajectory of vehicle A according to LCA. Furthermore, LCA content Cs1d of the fourth variant allows the driver to more strongly sense that vehicle A is currently changing lanes through automatic control.

[5] Fifth Modification The LCA content Cs1e of the fifth modification shown in FIG. 17 differs from the LCA content Cs1 shown in FIG. 6 and other figures in that it includes content Cs11e instead of content Cs11. Content Cs11e is an image that indicates the direction of a lane change by LCA, and is placed near content Cs12. In this case, the image of content Cs11e is a triangular image, but it may also be an arrow-shaped image. Content Cs11e is superimposed and displayed in a manner that makes it appear as if it is floating above the road surface.

In this case, the image of content Cs11e is animated to move in the direction of the lane change due to LCA, but a blinking display or the like can also be used instead of this animation. This fifth variant allows the driver to reliably know the most important information when a lane change due to LCA is being performed, namely whether the lane change will be to the left or right of the adjacent lane adjacent to the vehicle's lane.

(Other embodiments)
The present invention is not limited to the embodiments described above and illustrated in the drawings, but can be arbitrarily modified, combined, or expanded without departing from the spirit of the invention.
The numerical values and the like shown in the above embodiment are examples and are not limited to these.

The images and the like included in each content shown in the above embodiment can be appropriately changed in shape, size, color, display mode, and the like, as long as they can fulfill the same role.
The display control unit 143 can omit displaying the content Cn7, which is the notification content.

The display control unit 143 can omit display of LCA content Cs1 and the like at positions along the way as the angle of view VA is moved by the actuator 13 from the first position VP1 to the second position VP2. In this way, when an ON operation or the like is performed to instruct the implementation of LCA, the display state changes from, for example, the display state shown in FIG. 3, i.e., the reference state of virtual image display by the HUD 1 in which the angle of view VA is at the first position VP1, to a state in which the display is temporarily stopped, and then to, for example, the display state shown in FIG. 7, i.e., a state in which the angle of view VA is at the second position VP1 and the LCA content Cs1 is displayed within the angle of view VA.

In this case, when the display is stopped, the driver may mistakenly believe that the HUD1 may have malfunctioned. However, even in this case, if the notification content Cn7 is being displayed when the LCA operation begins, the driver will recognize that the HUD1 display has simply been stopped as a preparation step for displaying the LCA content Cs1, eliminating the risk of the above-mentioned mistake occurring.

The display control unit 143 can change the display format of the LCA content between the period after the LCA operation has started and until it is confirmed that there are no other vehicles in the destination lane that will be used for the lane change, i.e., the period when the LCA function is in a startup state or standby state, and the period after it is confirmed that there are no other vehicles in the destination lane, i.e., the period when the LCA function is in an execution state.

For example, the display control unit 143 can display the LCA content Cs1a of the first modified example as the LCA content while the operation of the LCA function is in the startup state or standby state, and can display the LCA content Cs1 as the LCA content while the operation state of the LCA function is in the execution state. In this way, the driver can easily and reliably grasp the current operation state of the LCA function based on changes in the display mode of the LCA content. Therefore, even if a lane change is not initiated despite the LCA being turned on, the driver can correctly understand the reason and will not feel anxious or distrustful about the control of vehicle A.

While the present disclosure has been described with reference to exemplary embodiments, it is understood that the present disclosure is not limited to those embodiments or structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

The control unit and the method described in this disclosure may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and the method described in this disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in this disclosure may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium.

1...head-up display, 13...actuator, 143...display control unit, A...vehicle.

Claims (4)

A virtual image display device (1) that displays a virtual image visible to an occupant of a vehicle (A),
a switching mechanism (13) that switches the position of the angle of view at which the virtual image is displayed between a plurality of positions including a first position and a second position defined above the first position;
a display control unit (143) that displays the virtual images associated with the first position and the second position in response to switching of the angle of view position by the switching mechanism;
Equipped with
the switching mechanism moves the angle of view from the first position to the second position when an operation of an automobile lane change assistance that performs various types of assistance related to a lane change to change the lane in which the vehicle is traveling is started, and moves the angle of view from the second position to the first position when the operation of the automobile lane change assistance is ended;
The display control unit
Displaying non-superimposed content , which is a display object not used for Augmented Reality display , within the angle of view of the first position;
displaying lane change content, which is superimposed content that represents an operating state of the vehicle when the lane change assistance is performed , superimposed on a road surface in the foreground within the angle of view of the second position;
The virtual image display device, wherein the non-superimposed content includes content representing a distance between the host vehicle, which is the vehicle, and a leading vehicle traveling in front of the vehicle . The virtual image display device described in claim 1, wherein the display control unit, when the operation of the automated lane change assistance system is started, displays notification content within the angle of view of the first position to notify the driver that the automated lane change assistance system has started. A virtual image display device according to claim 1 or 2, wherein the display control unit also displays the lane change content within the angle of view at intermediate positions as the angle of view is moved by the switching mechanism from the first position to the second position. A virtual image display device according to any one of claims 1 to 3, wherein the display control unit changes the display format of the lane change content between the period from when the lane change assist operation is initiated until it is confirmed that no other vehicles exist in the destination lane to which the vehicle will move upon lane change, and the period after it is confirmed that no other vehicles exist in the destination lane.