Display control device and display control program

Abstract

To provide a display control device or the like that can improve the convenience of the driver by showing detailed information on reverse-way driving in an easy-to-understand manner.SOLUTION: An HCU is used in a vehicle A and has the function of a display control device that controls display through a head-up display. The HCU determines whether or not the driving scene of the vehicle A is a predetermined reverse-way driving scene SnX assumed in advance in relation to its reverse-way driving. When determining that it has become the predetermined reverse-way driving scene SnX, the HCU causes reverse-way driving prevention content CTp for guiding the vehicle A to drive in a correct driving lane Lnc to be superimposed and displayed on a road surface in the foreground through an HUD 20.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The disclosure according to this specification relates to a display control device and a display control program for controlling the display by a head-up display.

Background Art

[0002] For example, Patent Document 1 describes a reverse travel warning device that determines whether the host vehicle is traveling in reverse using image data obtained by imaging with an in-vehicle camera, and warns the driver when it is determined that the host vehicle is traveling in reverse. In Patent Document 1, a warning to the driver is implemented by the sound of a speaker and the display screen of a display device or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As in Patent Document 1, simply warning of reverse travel makes it difficult for the driver to grasp information such as which lane the host vehicle is currently traveling in and where it should travel, even if the driver can grasp the state of reverse travel. Thus, the convenience for the driver may be insufficient in the reverse travel warning as in Patent Document 1.

[0005] An object of the present disclosure is to provide a display control device and a display control program capable of enhancing the convenience for the driver by clearly showing detailed information related to reverse travel.

Means for Solving the Problems

[0006] To achieve the above object, one disclosed aspect is a display control device used in a vehicle (A) for controlling the display by a head-up display (20), including a scene determination unit (73) that determines whether or not it is a predetermined reverse driving scene (SnX) assumed in advance in relation to the reverse driving of the vehicle, and a reverse driving prevention content (CTp) that guides the vehicle to travel on the correct driving lane (Lnc) when it becomes a predetermined reverse driving scene, and a display control unit (76) that superimposes and displays the reverse driving prevention content on the road surface in the foreground by the head-up display. , the display control unit starts displaying reverse-travel prevention content based on the ON operation of the vehicle's turn indicator (64), and changes the reverse-travel prevention content displayed based on the ON operation to an emphasized state based on a steering operation that brings the vehicle closer to the center line (CL) that is the boundary between the driving lane and the oncoming lane (Lnw). It is the display control device described above. Also disclosed is one aspect which is a display control device used in a vehicle (A) for controlling the display by a head-up display (20), including a scene determination unit (73) that determines whether or not it is a predetermined reverse-travel scene (SnX) assumed in advance in relation to reverse travel of the vehicle, and a display control unit (76) that superimposes and displays reverse-travel prevention content (CTp) for guiding the vehicle to travel in the correct driving lane (Lnc) on the road surface in the foreground by the head-up display when it becomes a predetermined reverse-travel scene. The scene determination unit further determines the presence or absence of an obstacle (Ob) existing between the driving lane and the oncoming lane (Lnw), and the display control unit is a display control device that interrupts the superimposed display of the reverse-travel prevention content by the head-up display when an obstacle exists.

[0007] Another disclosed aspect is a display control program used in a vehicle (A) for controlling the display by a head-up display (20), which causes at least one processing unit (11) to determine whether or not it is a predetermined reverse driving scene (SnX) assumed in advance in relation to the reverse driving of the vehicle (S101, S104, S202, S206), and when it becomes a predetermined reverse driving scene, to superimpose and display reverse driving prevention content (CTp) that guides the vehicle to travel on the correct driving lane (Lnc) on the road surface in the foreground by the head-up display (S102, S105, S203, S210), and includes performing a process including this. , in the process of superimposing and displaying the reverse-travel prevention content, the display of the reverse-travel prevention content is started based on the ON operation of the vehicle's turn indicator (64), and the reverse-travel prevention content displayed based on the ON operation is changed to an emphasized state based on a steering operation that brings the vehicle closer to the center line (CL) that is the boundary between the driving lane and the oncoming lane (Lnw). It is the display control program described above. Also disclosed is one aspect which is a display control program used in a vehicle (A) for controlling the display by a head-up display (20), causing at least one processing unit (11) to determine whether or not it is a predetermined reverse-travel scene (SnX) assumed in advance in relation to reverse travel of the vehicle (S101, S104, S202, S206), and when it becomes a predetermined reverse-travel scene, superimpose and display reverse-travel prevention content (CTp) for guiding the vehicle to travel in the correct driving lane (Lnc) on the road surface in the foreground by the head-up display (S102, S105, S203, S210), further determine the presence or absence of an obstacle (Ob) existing between the driving lane and the oncoming lane (Lnw), and interrupt the superimposed display of the reverse-travel prevention content by the head-up display when an obstacle exists, and is a display control program that causes the above-described processing to be performed.

[0008] In these aspects, when it is determined that the driving scene of the vehicle is a predetermined reverse driving scene, reverse driving prevention content that guides the vehicle to travel on the correct driving lane is superimposed and displayed on the road surface in the foreground by the head-up display. Therefore, it becomes easier for the driver to grasp information such as which lane the vehicle is currently traveling in and where it should travel. In this way, by easily showing detailed information related to reverse driving by superimposing and displaying the reverse driving prevention content, it is possible to improve the convenience for the driver.

[0009] Furthermore, the reference numbers in parentheses in the above and the claims only show an example of the correspondence with the specific configurations in the embodiments described later, and do not limit the technical scope in any way.

Brief Description of the Drawings

[0010]

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Modes for Carrying Out the Invention

[0011] Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be assigned to corresponding components, and redundant explanations may be omitted. When only a part of the configuration is described in each embodiment, the configuration of other embodiments described previously can be applied to other parts of the said configuration. Also, not only the combinations of configurations explicitly shown in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined with each other as long as there is no problem with the combination, even if not explicitly stated. And combinations not explicitly stated between the configurations described in a plurality of embodiments and variations are also considered to be disclosed by the following description.

[0012] (First Embodiment) The functions of the display control device according to the first embodiment of the present disclosure are realized by the HCU (Human Machine Interface Control Unit) 100 shown in FIGS. 1 to 3. The HCU 100 constitutes the HMI (Human Machine Interface) system 10 used in the vehicle A together with in-vehicle display devices such as a head-up display (hereinafter referred to as HUD) 20. The HMI system 10 further includes an operation device 26 and a driver status monitor (hereinafter referred to as DSM) 27. The HMI system 10 has an input interface function for receiving user operations by the occupants (for example, the driver) of the vehicle A and an output interface function for presenting information to the driver.

[0013] The HMI system 10 is communicably connected to the communication bus 99 of the in-vehicle network 1 mounted on the vehicle A. The HMI system 10 is one of a plurality of nodes provided in the in-vehicle network 1. Peripheral monitoring sensors 30, a locator 40, a driving support ECU (Electronic Control Unit) 50, a navigation device 52, a steer ECU 61, a body ECU 63, etc. are connected as nodes to the communication bus 99 of the in-vehicle network 1. These nodes connected to the communication bus 99 can communicate with each other. Specific nodes among these devices and each ECU may be directly electrically connected to each other and can communicate without going through the communication bus 99.

[0014] In addition, the front-back (refer to the front Ze and the rear Go in FIG. 2) and left-right (refer to the side Yo in FIG. 2) directions in the following description are defined based on the vehicle A stationary on the horizontal plane. Specifically, the front-back direction is defined along the longitudinal direction (travel direction) of the vehicle A. The left-right direction is defined along the width direction of the vehicle A. Further, the up-down (refer to the upper Ue and the lower Si in FIG. 2) direction is defined along the vertical direction of the horizontal plane defining the front-back direction and the left-right direction. Also, for the sake of simplicity of description, the description of the symbols indicating each direction may be omitted as appropriate.

[0015] The surrounding monitoring sensor 30 is an autonomous sensor that monitors the surrounding environment of vehicle A. The surrounding monitoring sensor 30 can detect moving objects such as pedestrians, cyclists, animals other than humans, and other vehicles, as well as road debris, guardrails, curbs, road signs, road surface markings such as lane lines, and stationary objects such as structures on the roadside, from the detection range around the host vehicle. The surrounding monitoring sensor 30 provides the detection information obtained by detecting the objects around vehicle A to the driving support ECU 50 etc. through the communication bus 99.

[0016] The surrounding monitoring sensor 30 has a front camera 31 and a millimeter-wave radar 32 as a detection configuration for object detection. The front camera 31 outputs at least one of the imaging data obtained by photographing the front range of vehicle A and the analysis result of the imaging data as detection information. A plurality of millimeter-wave radars 32 are arranged at intervals on each of the front and rear bumpers of vehicle A, for example. The millimeter-wave radar 32 irradiates millimeter waves or quasi-millimeter waves toward the front range, the front side range, the rear range, the rear side range, etc. of vehicle A. The millimeter-wave radar 32 generates detection information by receiving the reflected waves reflected by moving objects and stationary objects etc. Note that detection configurations such as lidar and sonar may be included in the surrounding monitoring sensor 30.

[0017] The locator 40 generates high-precision position information etc. of vehicle A by composite positioning that combines a plurality of acquired information. The locator 40 can identify, for example, one lane in which vehicle A travels on a road including a plurality of lanes. The locator 40 includes a GNSS (Global Navigation Satellite System) receiver 41, an inertial sensor 42, a high-precision map database (hereinafter referred to as high-precision map DB) 43, and a locator ECU 44.

[0018] The GNSS receiver 41 receives positioning signals transmitted from a plurality of artificial satellites (positioning satellites). The GNSS receiver 41 can receive positioning signals from each positioning satellite of at least one satellite positioning system among satellite positioning systems such as GPS, GLONASS, Galileo, IRNSS, QZSS, and Beidou. The inertial sensor 42 has, for example, a gyro sensor and an acceleration sensor.

[0019] The high-precision map DB 43 is mainly composed of a non-volatile memory and stores map data (hereinafter referred to as high-precision map data) that is more accurate than the map data used in the navigation device 52. The high-precision map data holds detailed information at least about the height (z) direction. The high-precision map data includes information that can be used for highly automated driving or autonomous driving, such as three-dimensional shape information of roads, number-of-lanes information, and information indicating the allowed driving directions for each lane. The high-precision map data is updated to the latest content by the communication function of an in-vehicle communication device such as a DCM (Data Communication Module).

[0020] The locator ECU 44 mainly includes a microcontroller equipped with a processor, a RAM, a storage unit, an input / output interface, and a bus connecting these components. The locator ECU 44 combines the positioning signals received by the GNSS receiver 41, the measurement results of the inertial sensor 42, and the vehicle speed information output to the communication bus 99, etc., and sequentially measures the position of the host vehicle and the traveling direction of the vehicle A. The locator ECU 44 provides the position information and azimuth information (hereinafter referred to as locator information) of the vehicle A based on the positioning result to the navigation device 52, the HCU 100, the driving support ECU 50, etc. through the communication bus 99. In addition, the locator ECU 44 provides the high-precision map data read from the high-precision map DB 43 to the ECU that is the requester in response to requests from the HCU 100, the driving support ECU 50, etc.

[0021] The driving support ECU 50 is an in-vehicle computer mainly including a control circuit equipped with a processor, a RAM, a storage unit, an input / output interface, and a bus connecting these components. The driving support ECU 50, together with the HCU 100 etc., constitutes an in-vehicle system that executes most of the operations related to vehicle control. The driving support ECU 50 has a driving support function to assist the driver's driving operation. As an example, the driving support ECU 50 enables partial automatic driving control (advanced driving assistance) at level 2 or below in the automatic driving levels defined by the Society of Automotive Engineers of the United States.

[0022] The driving support ECU 50 has functional units such as an environment recognition unit and a behavior control unit etc. to enable driver support. The environment recognition unit recognizes the driving environment around the host vehicle based on the detection information obtained from the surrounding monitoring sensor 30, the locator information obtained from the locator 40, and the high-precision map data etc. The behavior control unit controls the behavior of the host vehicle in cooperation with the driving control ECU etc. using the recognition result of the driving environment by the environment recognition unit.

[0023] The driving support ECU 50 can implement driving support functions such as LDW, ACC, LTC, and LCA etc. LDW (Lane Departure Warning) is a function that issues an alarm to the driver when the host vehicle is about to deviate from the lane during driving. ACC (Adaptive Cruise Control) is a function that makes the host vehicle cruise at a target vehicle speed or makes the host vehicle follow the preceding vehicle while maintaining the inter-vehicle distance from the preceding vehicle. LTC (Lane Trace Control) is a function that cooperates with ACC to control the steering angle of the steering wheel of the host vehicle so as to follow the lane during driving and continue driving within the road. LCA (Lane Change Assist) is a function that implements steering angle control in place of LTC and makes vehicle A change lanes from the driving lane to an adjacent lane. The driving support ECU 50 provides the HCU 100 with status information indicating the operating state of each support function, control information indicating the control content executed by the operating function, etc. as ADAS (Advanced Driver Assistance System) information.

[0024] The navigation device 52 is an in-vehicle device that cooperates with the HMI system 10 and performs route guidance to a destination set by a driver or the like. The navigation device 52 performs guidance such as straight-ahead, right / left turns, and lane changes in a guidance area GA (see FIG. 18 etc.) including intersections, branch points, and merging points in the set route by displaying a guidance image and playing a guidance voice. When a destination is set, the navigation device 52 provides the HCU 100 with navigation information related to route guidance. The navigation information includes route information to the destination and a guidance execution request for instructing the start of the above guidance. The guidance execution request is output from the navigation device 52 to the HCU 100, for example, when the remaining distance to the guidance area GA becomes less than a predetermined value.

[0025] Note that instead of the navigation device 52, a user terminal such as a smartphone may be connected to the in-vehicle network 1 or the HCU 100. In an application (for example, a map application or a navigation application etc.) executed on the user terminal, a route to a destination is set based on a user operation by a driver or the like. The user terminal performs route guidance in the guidance area GA and provides the HCU 100 with navigation information, similar to the navigation device 52.

[0026] The Steer ECU 61 is an ECU provided in the steering control system of the vehicle A and has a configuration mainly including a microcontroller. The Steer ECU 61 controls the operation of the steering actuator based on at least one of a steering operation by the driver and a control command obtained from the Driving Support ECU 50, and defines the direction of the steering wheel and thus the traveling direction of the vehicle A. The Steer ECU 61 provides operation information (steering information) indicating the rotation direction and rotation angle (steering wheel angle) of the steering wheel detected by the steering angle sensor 62 to the Driving Support ECU 50, the HCU 100, etc. Note that the steering information may be the steering direction and the actual steering angle of the steering wheel.

[0027] The body ECU 63 is a control device mainly including a microcontroller. The body ECU 63 has at least a function of controlling the operation of the lighting device mounted on the vehicle A. A turn signal switch 64 is electrically connected to the body ECU 63. The turn signal switch 64 is a lever-shaped operation part provided in the steering column part 8. The body ECU 63 starts the blinking of the turn indicator in either the left or right direction corresponding to the operation direction based on the detection of the user operation input to the turn signal switch 64.

[0028] In addition to the normal user operation for starting the blinking operation of the turn indicator, an on operation for instructing the activation of the LCA is input to the turn signal switch 64. As an example, a user operation of pressing the turn signal switch 64 in a half-pressed state for a predetermined time (for example, about 1 to 3 seconds) with the LTC activated is regarded as the on operation of the LCA. When a user operation is input to the turn signal switch 64, the body ECU 63 provides operation information (winker information) indicating the content of the user operation to the driving support ECU 50, the HCU 100, etc.

[0029] Next, the details of the operation device 26, DSM 27, HUD 20, and HCU 100 included in the HMI system 10 will be described in order.

[0030] The operation device 26 is an input part that receives user operations by the driver or the like. User operations for switching the start and stop of, for example, the driving support function and the autonomous driving function are input to the operation device 26. Specifically, a steering switch provided in the spoke part of the steering wheel, an operation lever provided in the steering column part 8, and a voice input device for detecting the driver's speech are included in the operation device 26.

[0031] DSM27 is configured to include a near-infrared light source, a near-infrared camera, and a control unit for controlling them. DSM27 is installed, for example, on the upper surface of the steering column unit 8 or the upper surface of the instrument panel 9 in a posture where the near-infrared camera is directed at the headrest of the driver's seat. DSM27 captures the driver's head irradiated with near-infrared light by the near-infrared light source using the near-infrared camera. The imaging image captured by the near-infrared camera is analyzed for images by the control unit. The control unit extracts information such as the position of the eye point EP and the line-of-sight direction from the imaging image, and sequentially outputs the extracted state information to the HCU100.

[0032] HUD20 is mounted on vehicle A as one of a plurality of in-vehicle display devices together with a meter display, a center information display, and the like. HUD20 is electrically connected to the HCU100 and sequentially acquires the video data generated by the HCU100. HUD20 presents various information related to vehicle A to the driver using the virtual image Vi based on the video data.

[0033] HUD20 is housed in a housing space within the instrument panel 9 below the windshield WS. HUD20 projects the light imaged as the virtual image Vi toward the projection range PA of the windshield WS. The light projected onto the windshield WS is reflected toward the driver's seat within the projection range PA and is perceived by the driver. The driver visually recognizes the display with the virtual image Vi superimposed on the foreground visible through the projection range PA.

[0034] The HUD 20 includes a projector 21 and a magnifying optical system 22. The projector 21 has an LCD (Liquid Crystal Display) panel and a backlight. The projector 21 is fixed to the housing of the HUD 20 in a posture with the display surface of the LCD panel facing the magnifying optical system 22. The projector 21 displays each frame image of video data on the display surface of the LCD panel, and transmits and illuminates the display surface with the backlight, thereby emitting light that forms a virtual image Vi toward the magnifying optical system 22. The magnifying optical system 22 is configured to include at least one optical element such as a concave mirror. The magnifying optical system 22 projects the light emitted from the projector 21 onto the upper projection range PA while spreading it by reflection.

[0035] The above HUD 20 is set with an angular field of view VA. Assuming that the virtual range in the space where the virtual image Vi can be formed by the HUD 20 is the imaging surface IS, the angular field of view VA is a viewing angle defined based on a virtual line connecting the driver's eye point EP and the outer edge of the imaging surface IS. The angular field of view VA is the angular range within which the driver can visually recognize the virtual image Vi when viewed from the eye point EP. In the HUD 20, the horizontal angular field of view (for example, about 10 to 12°) in the horizontal direction is larger than the vertical angular field of view (for example, about 4 to 5°) in the vertical direction. When viewed from the eye point EP, the forward range (for example, a range of about ten-odd meters to 100 m) overlapping the imaging surface IS is within the range of the angular field of view VA.

[0036] The HUD 20 can display superimposed content CTs (see FIGS. 4 to 6, etc.) and non-superimposed content as a virtual image Vi. The superimposed content CTs are AR display objects used for Augmented Reality (hereinafter referred to as AR) display. The display position of the superimposed content CTs is associated with specific superimposed objects existing in the foreground, such as specific positions on the road surface, the vehicle ahead, pedestrians, and road signs. The superimposed content CTs are superimposed on a specific superimposed object in the foreground and can move in the driver's view following the superimposed object as if it were relatively fixed to the superimposed object. That is, the relative positional relationship among the driver's eye point EP, the superimposed object in the foreground, and the superimposed content CTs is continuously maintained. Therefore, the shape of the superimposed content CTs continues to be updated at a predetermined cycle according to the relative position and shape of the superimposed object. The superimposed content CTs are displayed in a posture closer to horizontal than the non-superimposed content and have a display shape extending in the depth direction as seen from the driver, for example.

[0037] The non-superimposed content is a non-AR display object excluding the superimposed content CTs among the display objects superimposed on the foreground. Different from the superimposed content CTs, the non-superimposed content is superimposed on the foreground without specifying a superimposed object. The display position of the non-superimposed content is not associated with a specific superimposed object. The display position of the non-superimposed content is set at a fixed position within the projection range PA (the above-mentioned viewing angle VA). Therefore, the non-superimposed content is displayed as if it were relatively fixed to a vehicle component such as the windshield WS. In addition, the shape of the non-superimposed content is substantially constant. Note that due to the positional relationship between the vehicle A and the superimposed object, there may be a scene where even the non-superimposed content is displayed overlapping the superimposed object of the superimposed content CTs.

[0038] The HCU 100 is an electronic control device that integrally controls the displays by a plurality of in-vehicle display devices including the HUD 20 in the HMI system 10. The HCU 100, the HUD 20, etc. constitute a virtual image display system.

[0039] HCU100 mainly includes a computer equipped with a processing unit 11, a RAM 12, a storage unit 13, an input / output interface 14, and a bus connecting these components. The processing unit 11 is hardware for arithmetic processing combined with the RAM 12. The processing unit 11 includes at least one arithmetic core such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The processing unit 11 may further include an FPGA (Field-Programmable Gate Array), an NPU (Neural network Processing Unit), and an IP core with other dedicated functions. The RAM 12 may include a video RAM for video generation. The processing unit 11 executes various processes for realizing the functions of each functional unit described later by accessing the RAM 12. The storage unit 13 includes a non-volatile storage medium. Various programs (such as a display control program) executed by the processing unit 11 are stored in the storage unit 13.

[0040] HCU100 has a plurality of functional units for controlling the display of the virtual image Vi by the HUD20 by executing the display control program stored in the storage unit 13 by the processing unit 11. Specifically, functional units such as a viewpoint position specifying unit 71, an information acquisition unit 72, a scene determination unit 73, and a display generation unit 76 are constructed in the HCU100.

[0041] Based on the state information obtained from the DSM27, the viewpoint position specifying unit 71 specifies the position of the driver's eye point EP sitting in the driver's seat. The viewpoint position specifying unit 71 generates three-dimensional coordinates indicating the position of the eye point EP (hereinafter referred to as eye point coordinates), and sequentially provides the generated eye point coordinates to the display generation unit 76.

[0042] The information acquisition unit 72 acquires various information necessary for display by the in-vehicle display device through the communication bus 99. Specifically, the information acquisition unit 72 acquires locator information and high-precision map data around the host vehicle from the locator 40, acquires ADAS information from the driving support ECU 50, and acquires navigation information from the navigation device 52. Further, the information acquisition unit 72 acquires operation information from the steer ECU 61 and the body ECU 63. Note that the information acquisition unit 72 may acquire at least one of the imaging data of the front camera 31 and the detection information of the surrounding monitoring sensor 30 as information corresponding to a part of the ADAS information. Also, when the information acquisition unit 72 cannot acquire the high-precision map data from the locator 40, it may acquire alternative navigation map data from the navigation device 52.

[0043] The scene determination unit 73 determines the current driving scene of the vehicle A based on various information acquired by the information acquisition unit 72. The scene determination unit 73 has a function of determining whether the current driving scene is a predetermined reverse driving scene (hereinafter, the predetermined reverse driving scene SnX). The predetermined reverse driving scene SnX is a driving scene assumed in advance in relation to the reverse driving of the vehicle A. The determination as to whether or not it is the predetermined reverse driving scene SnX performed by the scene determination unit 73 includes a first scene determination for determining whether it is the first reverse driving scene Sn1 and a second scene determination for determining whether it is the second reverse driving scene Sn2. The first reverse driving scene Sn1 is a driving scene in which the vehicle A is likely to reverse. Currently, it has not reached reverse driving, but if the current driving state continues, it is a driving scene with a high probability of reverse driving occurring. On the other hand, the second reverse driving scene Sn2 is a driving scene in which the vehicle A is actually reversing.

[0044] The scene determination unit 73 performs a first scene determination and a second scene determination based on the locator information, the high-precision map data, and the operation information related to the operation of the driver driving the vehicle A. Specifically, the scene determination unit 73 grasps the correct driving direction of each of the plurality of lanes included in the road on which the vehicle A is currently traveling based on the locator information and the high-precision map data. Further, the scene determination unit 73 identifies the lane in which the vehicle A is currently traveling among the plurality of lanes, and determines the consistency between the current driving direction of the vehicle A based on the locator information and the driving direction defined for the lane during driving (second scene determination). When the driving direction of the vehicle A is different from the driving direction defined for the lane during driving, the scene determination unit 73 determines that the vehicle A is traveling in the oncoming lane Lnw and the current driving scene is the second reverse driving scene Sn2.

[0045] Here, the scene determination unit 73 may perform the second scene determination by image analysis of the imaging data of the front camera 31. As an example, the scene determination unit 73 recognizes road signs on the side of the road and road markings laid on the road surface from the imaging data of the front camera 31. The scene determination unit 73 can estimate that the vehicle A is traveling in the oncoming lane Lnw based on the fact that the back side of the road sign is captured and the direction of the road marking is reversed.

[0046] In addition, the process of determining whether the vehicle A is traveling in the oncoming lane Lnw based on the locator information and the high-precision map data may be performed by the locator ECU 44 or the driving support ECU 50. Similarly, the process of determining whether the vehicle A is traveling in the oncoming lane Lnw from the imaging data of the front camera 31 may be performed by the driving support ECU 50. In these forms, the scene determination unit 73 refers to the determination results provided to the information acquisition unit 72 from each of the ECUs 44 and 50 and performs the second scene determination.

[0047] On the one hand, when the traveling direction of vehicle A coincides with the traveling direction defined for the lane in which it is traveling, the scene determination unit 73 determines that vehicle A is traveling in the correct lane (hereinafter, the traveling lane Lnc). In this case, the scene determination unit 73 further determines whether the traveling lane Lnc is adjacent to the oncoming lane Lnw. When the traveling direction defined for the adjacent lane is opposite to the traveling direction of the traveling lane Lnc, the scene determination unit 73 determines that the traveling lane Lnc is adjacent to the oncoming lane Lnw. In this case, the scene determination unit 73 performs a first scene determination to detect signs or omens of oncoming traffic.

[0048] Specifically, in the first scene determination, the scene determination unit 73 determines whether there is a driving operation of the driver attempting to move toward the oncoming lane Lnw based on the operation information of the driver. As an example, driving operations such as a turn signal operation toward the oncoming lane Lnw side, an activation operation of the LCA, and a steering operation (hereinafter, oncoming traffic omen operation) are used in the first scene determination. When there is an oncoming traffic omen operation, the scene determination unit 73 determines that the current driving scene is the first oncoming traffic scene Sn1.

[0049] In addition, the scene determination unit 73 further has a function of determining the presence or absence of an obstacle (hereinafter, a delineation marker Ob, see FIG. 7) installed on the center line CL in relation to the determination function of the predetermined oncoming traffic scene SnX. The center line CL is a dividing line that divides each lane and separates the traveling lane Lnc in which vehicle A is traveling from the oncoming lane Lnw adjacent to this traveling lane Lnc. When a three-dimensional object such as a pole, a fence, or a block that obstructs movement toward the oncoming lane Lnw is installed on the center line CL, the scene determination unit 73 determines that there is a delineation marker Ob. The scene determination unit 73 may perform image processing to recognize the delineation marker Ob shown in the imaging data, or may acquire detection information indicating the presence of the delineation marker Ob from the surrounding monitoring sensor 30. Further, the scene determination unit 73 may grasp the presence of the delineation marker Ob from at least one of the result of environmental recognition by the driving support ECU 50 and the high-precision map data.

[0050] The display generation unit 76 controls the information presentation to the driver by the HUD 20 by generating video data to be sequentially output to the HUD 20. The display generation unit 76 draws the original images of the respective contents displayed as the virtual image Vi on the individual frame images constituting the video data. When the display generation unit 76 draws the original image of the superimposed content CTs (see FIG. 4 etc.) on the frame image, it corrects the drawing position and drawing shape of the original image in the frame image according to the eye point EP and each position of the superimposed object. As a result, the superimposed content CTs are displayed at the positions and in the shapes correctly superimposed on the superimposed object when viewed from the eye point EP.

[0051] The display generation unit 76 has a content selection function and a virtual layout function in order to realize the generation of the above-described video data. The content selection function is a function of selecting the content to be used for information presentation from among a plurality of superimposed contents CTs and a plurality of non-superimposed contents prepared in advance. The display generation unit 76 selects the content to be drawn in the video data based on various information acquired by the information acquisition unit 72 and the determination result of the scene determination unit 73 etc. For example, when the display generation unit 76 acquires a guidance execution request (navigation information) by the information acquisition unit 72, it selects the superimposed content CTs in the shape of an arrow etc. for route guidance (see FIG. 19, route guidance content CTnv) as the object to be drawn in the video data. Also, when the display generation unit 76 acquires status information (ADAS information) indicating the start of operation of driving support functions such as LDW, ACC, LTC, LKA etc., it selects the superimposed content CTs (driving support content) associated with each driving support function as the object to be drawn in the video data. Further, when the scene determination unit 73 determines that it is a predetermined reverse driving scene SnX, the display generation unit 76 selects the reverse driving prevention content CTp (see FIGS. 4 to 6) as the object to be drawn in the video data.

[0052] The virtual layout function is a function that simulates the display layout of the superimposed content CTs based on various information provided to the display generation unit 76. When a display including the superimposed content CTs is selected by the content selection function, the display generation unit 76 reproduces the current driving environment of the vehicle A in a virtual space based on locator information, high-precision map data, detection information, etc. Note that when the high-precision map data cannot be acquired, the display generation unit 76 may use navigation map data instead of the high-precision map data.

[0053] Specifically, the display generation unit 76 arranges the host vehicle object at the reference position in the virtual three-dimensional space, and maps the road model based on the high-precision map data to the three-dimensional space in association with the host vehicle object. In addition, the display generation unit 76 sets a virtual camera position corresponding to the driver's eye point EP in association with the host vehicle object. The display generation unit 76 sequentially corrects the virtual camera position with respect to the host vehicle object based on the latest eye point coordinates acquired by the viewpoint position specifying unit 71. The display generation unit 76 sets, as a superimposition range in which the superimposed content CTs can be superimposed, a forward range that is inside the imaging surface IS when looking forward from the virtual camera position, based on the virtual camera position and the outer edge position (coordinates) information of the imaging surface IS pre-stored in the storage unit 13 or the like. This superimposition range is within the viewing angle VA when viewed from the eye point EP.

[0054] The display generation unit 76 arranges a virtual object corresponding to the superimposed content CTs selected as the drawing target on the road surface of the road model in the three-dimensional space. The display generation unit 76 determines the drawing shape of the original image of the superimposed content CTs to be drawn in the video data by performing an arithmetic process of projecting the virtual object onto the imaging surface IS along the virtual projection line connecting the virtual camera position and the virtual object. As a result, the shape of the virtual object when viewed from the virtual camera position becomes the virtual image shape of the superimposed content CTs visually recognized from the eye point EP.

[0055] As described above, when the predetermined reverse driving scene SnX occurs, the display generation unit 76 superimposes and displays reverse driving prevention content CTp as shown in FIGS. 4 to 6 on the road surface in the foreground by the HUD 20. The reverse driving prevention content CTp is superimposed content CTs that is displayed for the purpose of preventing the vehicle A from reverse driving and guides the vehicle A to drive on the correct driving lane Lnc. The display generation unit 76 causes the first reverse driving prevention content CTp1 (see FIGS. 4 and 5) and the second reverse driving prevention content CTp2 (see FIG. 6) to be displayed as the reverse driving prevention content CTp.

[0056] The first reverse driving prevention content CTp1 alerts the driver to the lane change attempt to the adjacent lane (oncoming lane Lnw), thereby guiding the vehicle A to drive on the correct driving lane Lnc. The first reverse driving prevention content CTp1 starts to be displayed when it is determined to be the first reverse driving scene Sn1 by the first scene determination of the scene determination unit 73. The first reverse driving prevention content CTp1 continues to be displayed until a predetermined time has elapsed since the start of the display or until the reverse driving prediction operation of the driver that caused the determination that it is the first reverse driving scene Sn1 is canceled.

[0057] The display generation unit 76 changes the content of the first reverse driving prevention content CTp1 (reverse driving prevention content CTp) according to the operation content of the reverse driving prediction operation indicated by the operation information. Specifically, the display generation unit 76 starts the display of the first reverse driving prevention content CTp1 shown in FIG. 4 based on the ON operation of the direction indicator (direction indicator switch 64) that becomes the reverse driving prediction operation. The first reverse driving prevention content CTp1 displayed at this time includes a virtual barrier CTb.

[0058] The virtual barrier CTb is superimposed on the road surface of the driving lane Lnc. The virtual barrier CTb is erected substantially vertically upward from the road surface of the driving lane Lnc and is drawn in a wall shape extending in the traveling direction of the host vehicle along the center line CL. With such a display shape, the virtual barrier CTb exerts a visual effect of preventing the host vehicle from changing lanes into the oncoming lane Lnw. The virtual barrier CTb is displayed as if it were fixed to the road surface, and moves rearward (lower side) within the viewing angle VA together with the road surface in the foreground as the host vehicle travels.

[0059] Despite the display of the virtual barrier CTb, when the driver performs a steering operation to bring the vehicle A close to the center line CL, the display generation unit 76 starts to display the first reverse prevention content CTp1 in the emphasized state shown in FIG. 5 based on the steering operation that is a reverse sign operation. The first reverse prevention content CTp1 displayed at this time includes a virtual oncoming vehicle CTc.

[0060] The virtual oncoming vehicle CTc is displayed in place of the virtual barrier CTb (see FIG. 4). The virtual oncoming vehicle CTc is superimposed on the road surface of the oncoming lane Lnw. The virtual oncoming vehicle CTc is a display object imitating a vehicle seen from the front side. By passing through the viewing angle VA faster than the road surface of the oncoming lane Lnw, the virtual oncoming vehicle CTc exerts a visual effect as if an oncoming vehicle is traveling in the oncoming lane Lnw. Due to the display that the virtual oncoming vehicle CTc moves faster than the virtual barrier CTb, the first reverse prevention content CTp1 displayed based on the steering operation becomes a more emphasized state than the first reverse prevention content CTp1 displayed based on the ON operation of the direction indicator. The animation of the virtual oncoming vehicle CTc passing through the viewing angle VA is repeatedly displayed at a predetermined cycle until the display of the first reverse prevention content CTp1 ends.

[0061] Here, the superimposed content CTs similar to the virtual barrier CTb shown in FIG. 4 may be displayed as driving assistance content associated with, for example, LDW. However, the driving assistance content associated with LDW is displayed only when the host vehicle is in a driving state where it is likely to cross the lane line, based on the relative distance and relative angle of the host vehicle with respect to the lane line of the host vehicle, regardless of whether there is an oncoming lane Lnw in the moving direction of the host vehicle. On the other hand, the first reverse prevention content CTp1 is displayed based on a reverse sign operation only when there is an oncoming lane Lnw in the moving direction of the host vehicle. At this time, the relative distance and relative angle of the host vehicle with respect to the center line CL of the host vehicle, in other words, whether the host vehicle is in a driving state where it is likely to cross the center line CL is not substantially considered. That is, while the driving assistance content associated with LDW is content that alerts based on the driving state, the first reverse prevention content CTp1 is content that alerts based on the driving operation. As described above, there is an essential difference in the display start conditions between the first reverse prevention content CTp1 and the driving assistance content associated with LDW and the like.

[0062] The second reverse prevention content CTp2 shown in FIG. 6 induces a lane change of the vehicle A to the driving lane Lnc in which the vehicle A should travel by making the driver recognize that the lane in which the host vehicle is traveling is the oncoming lane Lnw. The second reverse prevention content CTp2 starts to be displayed when it is determined that it is the second reverse scene Sn2 by the second scene determination. At least a part of the second reverse prevention content CTp2 is superimposed and displayed on the road surface of the driving lane Lnc in which the vehicle A should travel. The second reverse prevention content CTp2 continues to be displayed until the vehicle A returns to the correct driving lane Lnc.

[0063] When the driving scene of the vehicle A shifts from the first reverse scene Sn1 to the second reverse scene Sn2 after the display of the first reverse prevention content CTp1 (see FIG. 5), the display generation unit 76 changes the state of the reverse prevention content CTp. That is, the display generation unit 76 displays the second reverse prevention content CTp2 in a state different from that of the first reverse prevention content CTp1 displayed in the first reverse scene Sn1. The second reverse prevention content CTp2 includes the virtual guidance paint CTg.

[0064] The virtual guidance paint CTg has a shape that crosses the center line CL in an oblique direction and is superimposed and displayed across both the road surface on the host vehicle side of the oncoming lane Lnw and the road surface on the back side of the driving lane Lnc. The virtual guidance paint CTg has a drawing shape that makes the host vehicle remember the driving route when changing lanes from the oncoming lane Lnw in which it is traveling to the correct driving lane Lnc. The virtual guidance paint CTg preferably has a shape that is difficult to overlap with the distant oncoming vehicle TA traveling in the oncoming lane Lnw. The virtual guidance paint CTg is displayed in a display color that is more eye-catching than the virtual barrier CTb (see FIG. 4) and the virtual oncoming vehicle CTc (see FIG. 5). For example, the virtual guidance paint CTg is displayed with higher brightness or higher chroma than the virtual barrier CTb and the virtual oncoming vehicle CTc. The virtual guidance paint CTg is displayed as an animation that repeatedly extends from the host vehicle side (the lower edge of the viewing angle VA) toward the back side (the upper edge of the viewing angle VA). The animation in which the virtual guidance paint CTg extends in the traveling direction within the viewing angle VA is repeatedly displayed at a predetermined cycle until the display of the second reverse-travel prevention content CTp2 ends.

[0065] When the scene determination unit 73 determines that the partition object Ob exists, the display generation unit 76 interrupts the superimposed display of the reverse-travel prevention content CTp (the first reverse-travel prevention content CTp1) by the HUD 20 as shown in FIG. 7. However, even during the period when the display of the reverse-travel prevention content CTp is interrupted, the scene determination unit 73 continues to determine whether it is a predetermined reverse-travel scene SnX. Further, even during the period when the display of the reverse-travel prevention content CTp is interrupted, the display generation unit 76 continues to prepare the drawing data of the reverse-travel prevention content CTp. The preparation of the drawing data is a process of determining the drawing shape of the original image of the reverse-travel prevention content CTp. The display generation unit 76 temporarily interrupts the superimposed display of the reverse-travel prevention content CTp by generating the original image of the reverse-travel prevention content CTp and stopping the process of drawing the generated original image on the video data.

[0066] Next, the details of the display control method for displaying the reverse travel prevention content CTp will be described below with reference to FIGS. 1 to 7 based on the flowcharts shown in FIGS. 8 and 9. The mode switching process shown in FIG. 8 and the content display process shown in FIG. 9 are repeatedly started by the HCU 100 that has completed the startup process, etc., for example, by switching to the on state of the vehicle power supply.

[0067] In S11 of the mode switching process shown in FIG. 8, it is determined whether there is a partition object Ob. If it is determined in S11 that there is no partition object Ob, the process proceeds to S12. In S12, the display setting of the reverse travel prevention content CTp is set to the display permission mode in which the superimposed display of the reverse travel prevention content CTp is permitted, and the mode switching process ends.

[0068] On the other hand, if it is determined in S11 that there is a partition object Ob, the process proceeds to S13. In S13, the display setting of the reverse travel prevention content CTp is set to the display prohibition mode in which the superimposed display of the reverse travel prevention content CTp is prohibited, and the mode switching process ends. With such a setting in S13, the superimposed display of the reverse travel prevention content CTp (virtual barrier CTb) that overlaps the partition object Ob is interrupted. Note that regardless of the display setting of the reverse travel prevention content CTp by the mode switching process, the content display process described later is continuously executed.

[0069] In S101 of the content display process shown in FIG. 9, it is determined whether the current driving scene is the first reverse travel scene Sn1 (first scene determination). If it is determined in S101 that it is not the first reverse travel scene Sn1, the process proceeds to S104. On the other hand, if it is determined in S101 that it is the first reverse travel scene Sn1, the process proceeds to S102. In S102, display control for displaying the first reverse travel prevention content CTp1 is performed, and the process proceeds to S103.

[0070] In the display control of S102, the display setting of the reverse-travel prevention content CTp by the mode switching process is referred to. When the display setting is the display permission mode, the first reverse-travel prevention content CTp1 corresponding to the content of the reverse-travel prediction operation is displayed by S102. On the other hand, when the display setting is the display prohibition mode, in S102, up to the preparation of the drawing data of the first reverse-travel prevention content CTp1 corresponding to the content of the reverse-travel prediction operation is performed.

[0071] In S103, it is determined whether the display end condition of the first reverse-travel prevention content CTp1 is satisfied. As described above, the display end condition of the first reverse-travel prevention content CTp1 is that a predetermined time has elapsed since the start of display, or the reverse-travel prediction operation has been canceled, etc. In addition, when the driving scene of the own vehicle shifts from the first reverse-travel scene Sn1 to the second reverse-travel scene Sn2, the display end condition is also satisfied. As an example, when at least a part of vehicle A is located on the center line CL, or when a part of vehicle A protrudes from the driving lane Lnc into the oncoming lane Lnw, the result of the scene determination transitions from the first reverse-travel scene Sn1 to the second reverse-travel scene Sn2.

[0072] If it is determined in S103 that the display end condition of the first reverse-travel prevention content CTp1 is not satisfied, the process returns to S102. As a result, the display of the first reverse-travel prevention content CTp1 continues. On the other hand, if it is determined in S103 that the display end condition of the first reverse-travel prevention content CTp1 is satisfied, the process proceeds to S104.

[0073] In S104, it is determined whether the current driving scene is the second reverse-travel scene Sn2 (second scene determination). If it is determined in S104 that it is not the second reverse-travel scene Sn2, the process proceeds to S107. On the other hand, if it is determined in S104 that it is the second reverse-travel scene Sn2, the process proceeds to S105. In S105, display control for displaying the second reverse-travel prevention content CTp2 is performed, and the process proceeds to S106. In the display control of S105, the display setting of the reverse-travel prevention content CTp by the mode switching process is not referred to.

[0074] In S106, it is determined whether or not the display end condition of the second reverse prevention content CTp2 is satisfied. As described above, the display end condition of the second reverse prevention content CTp2 is that the vehicle A has returned to the correct driving lane Lnc. For example, when the entire vehicle A moves to the side of the driving lane Lnc with respect to the center line CL, the display end condition of the second reverse prevention content CTp2 is satisfied. If it is determined in S106 that the display end condition is not satisfied, the process returns to S105. As a result, the display of the second reverse prevention content CTp2 is continued. On the other hand, if it is determined in S106 that the display end condition of the second reverse prevention content CTp2 is satisfied, the process proceeds to S107. In S107, the display of the reverse prevention content CTp started in S102 or S105 is ended, and the content display process is ended.

[0075] In the first embodiment described so far, when it is determined that the driving scene of the vehicle A is a predetermined reverse driving scene SnX, the reverse prevention content CTp for guiding the vehicle A to drive on the correct driving lane Lnc is superimposed and displayed on the road surface in the foreground by the HUD20. Therefore, it becomes easier for the driver to grasp information such as which lane the vehicle is currently driving in and which lane the vehicle should drive in. In this way, by easily showing detailed information related to reverse driving by the superimposed display of the reverse prevention content CTp, it is possible to improve the convenience for the driver.

[0076] In addition, in the first embodiment, not only the second scene determination as to whether or not the vehicle A is in the second reverse driving scene Sn2 where the vehicle A is reverse driving, but also the first scene determination as to whether or not the vehicle A is in the first reverse driving scene Sn1 where the vehicle A is likely to reverse drive is included in the determination as to whether or not it is the predetermined reverse driving scene SnX. According to the above, before the reverse driving of the vehicle A actually occurs, the display of the first reverse prevention content CTp1 based on the first scene determination becomes possible. As a result, the occurrence of reverse driving can be prevented beforehand.

[0077] Also, in the first embodiment, it is determined whether it is the first reverse driving scene Sn1 based on the operation information related to the operation of the driver who drives the vehicle A. In this way, by basing on the driver's operation information, it becomes possible to early detect the sign of a driving operation that is erroneously about to head towards the oncoming lane Lnw. As a result, the effect of preventing the occurrence of reverse driving is more likely to be exerted.

[0078] Furthermore, in the first embodiment, when it is determined that it is the first reverse driving scene Sn1, the content of the reverse driving prevention content CTp (the first reverse driving prevention content CTp1) changes according to the operation content of the driver indicated by the operation information. In this way, by associating the operation content of the driver with the content of the reverse driving prevention content CTp, when the driver's erroneous operation continues, the reverse driving prevention content CTp can repeatedly alert the driver to the error of the input operation. As a result, the effect of preventing the occurrence of reverse driving is further improved.

[0079] Specifically, in the first embodiment, based on the ON operation of the direction indicator switch 64, the display of the first reverse driving prevention content CTp1 is started (see FIG. 4). Then, based on the steering operation of approaching the vehicle A to the center line CL that is the boundary between the traveling lane Lnc and the oncoming lane Lnw, the first reverse driving prevention content CTp1 changes to an emphasized state (see FIG. 5). As described above, if an emphasized change is caused in the first reverse driving prevention content CTp1 as the risk of reverse driving increases, the driver is more likely to notice that they are making a misrecognition that could lead to reverse driving.

[0080] Also, in the first embodiment, when shifting from the first reverse driving scene Sn1 to the second reverse driving scene Sn2, a second reverse driving prevention content CTp2 different from the first reverse driving prevention content CTp1 displayed in the first reverse driving scene Sn1 is displayed. In this way, if the display switching that changes the state of the reverse driving prevention content CTp is implemented in accordance with the transition of the predetermined reverse driving scene SnX, the driver is more likely to notice the reverse driving state of their own vehicle.

[0081] In addition, according to the first embodiment, the first reverse-prevention content CTp1 is displayed until a predetermined time has elapsed since the start of display or until the reverse omen operation of the driver that caused the determination that it is the first reverse scene Sn1 is canceled. According to the above, the first reverse-prevention content CTp1 displayed in the first reverse scene Sn1 becomes non-displayed before the driver feels bothered while appropriately alerting the driver.

[0082] On the other hand, when it is determined that it is the second reverse scene Sn2, the second reverse-prevention content CTp2 is continuously displayed until the vehicle A returns to the correct driving lane Lnc. In this way, the display end condition in the second reverse scene Sn2 is different from the display end condition in the first reverse scene Sn1, and is a condition where it is difficult to end the display. As a result, the second reverse-prevention content CTp2 is displayed indefinitely during the reverse period of the own vehicle, and can play a role of continuously notifying the driver of the correct driving lane Lnc until the own vehicle returns to the correct driving lane Lnc.

[0083] Furthermore, in the first embodiment, at least a part of the second reverse-prevention content CTp2 displayed in the second reverse scene Sn2 is superimposed on the road surface of the driving lane Lnc where the own vehicle should travel. According to such a display form, the second reverse-prevention content CTp2 can clearly inform the driver of the correct driving lane Lnc to which the own vehicle should return.

[0084] In addition, in the first embodiment, the presence or absence of the partition object Ob existing between the driving lane Lnc and the oncoming lane Lnw is determined, and when such a partition object Ob exists, the superimposed display of the reverse-prevention content CTp by the HUD20 is interrupted. According to such a display process, a situation where the reverse-prevention content CTp is displayed in a scene where reverse driving does not substantially occur will not occur. As a result, the reverse-prevention content CTp is less likely to be felt bothersome to the driver.

[0085] Also, in the first embodiment, even when the partition object mark Ob exists, the determination as to whether or not it is a predetermined reverse driving scene SnX is continued. According to the continuation of such scene determination, for example, it becomes possible to implement a reverse driving warning using an in-vehicle display device different from the HUD 20.

[0086] Furthermore, even when the partition object mark Ob exists, the display generation unit 76 in the first embodiment continues to prepare the drawing data of the reverse driving prevention content CTp during the period in which it is determined that it is a predetermined reverse driving scene SnX. As described above, according to the continuation of the drawing process in the background, it becomes difficult for the start of display of the reverse driving prevention content CTp to be delayed in the predetermined reverse driving scene SnX after the partition object mark Ob disappears.

[0087] Note that, in the first embodiment, the partition object mark Ob corresponds to an "obstacle", the display generation unit 76 corresponds to a "display control unit", and the HCU 100 corresponds to a "display control device".

[0088] (Second Embodiment) The second embodiment of the present disclosure shown in FIGS. 10 and 11 is a modification of the first embodiment. In the second embodiment, the states of the first reverse driving prevention content CTp1 and the second reverse driving prevention content CTp2 are different from those in the first embodiment. Hereinafter, the details of the first reverse driving prevention content CTp1 and the second reverse driving prevention content CTp2 in the second embodiment will be described with reference to FIGS. 10 and 11 and with reference to FIG. 3.

[0089] The first reverse driving prevention content CTp1 shown in FIG. 10 includes a route display paint CTk. The route display paint CTk is superimposed and displayed on the road surface of the driving lane Lnc in such a manner as to cover the entire road surface of the driving lane Lnc sandwiched between the left and right lane lines. The drawing shape of the route display paint CTk sequentially changes according to the shape of the driving lane Lnc. In the second embodiment, even if the operation content of the reverse driving prediction operation changes, the display content of the first reverse driving prevention content CTp1 does not substantially change. That is, regardless of the type of the reverse driving prediction operation, the display of the route display paint CTk is continued.

[0090] The route display paint CTk is, for example, set to a light green or light blue display color. The route display paint CTk has a drawing shape similar to or substantially the same as the route guidance content displayed based on navigation information. Therefore, the route display paint CTk becomes the overlapping content CTs that only differs from the route guidance content in the display timing. Specifically, the route guidance content starts to be displayed at the timing when vehicle A approaches a predetermined distance (e.g., 300 m) to the guidance area. On the other hand, the route display paint CTk starts to be displayed based on the detection of a reverse sign operation regardless of the distance to the guidance area. Furthermore, the route display paint CTk starts to be displayed based on the detection of a reverse sign operation even when no destination is set in the navigation device 52. As described above, even if there is a relationship in the display shape, there is an essential difference in the display start conditions between the route display paint CTk and the route guidance content.

[0091] The second reverse prevention content CTp2 shown in FIG. 11 includes a reverse warning paint CTa in addition to the route display paint CTk. After the route display paint CTk starts to be displayed in the first reverse scene Sn1, it continues to be displayed as the display object of the second reverse prevention content CTp2 even after the driving scene shifts to the second reverse scene Sn2. The route display paint CTk continues to be superimposed on the road surface of the correct driving lane Lnc and moves from the center to the side (upper left corner) within the viewing angle VA as vehicle A moves laterally. The route display paint CTk changes to an emphasized state as it shifts from the first reverse scene Sn1 to the second reverse scene Sn2. The emphasis of the route display paint CTk is mainly implemented by a change in the display color. Specifically, the route display paint CTk in the second reverse scene Sn2 is displayed in a display color with higher visibility (brightness or chroma) than the route display paint CTk in the first reverse scene Sn1. The route display paint CTk is, for example, set to a dark green or dark blue display color. Even in the second reverse scene Sn2, the route display paint CTk is displayed regardless of the presence or absence of the guidance area, unlike the route guidance content, and continues to be displayed until vehicle A returns to the correct driving lane Lnc.

[0092] The reverse-travel warning paint CTa is superimposed on the road surface of the oncoming lane Lnw so as not to overlap with the route display paint CTk. The reverse-travel warning paint CTa includes a warning message with characters such as "reverse travel" and a frame-shaped image surrounding the outer periphery of the warning message. Similar to the virtual guidance paint CTg (see FIG. 6) of the first embodiment, the reverse-travel warning paint CTa is also displayed so as not to overlap with the oncoming vehicle TA traveling far away in the oncoming lane Lnw. The reverse-travel warning paint CTa is displayed in a display color such as yellow or amber. The reverse-travel warning paint CTa may be continuously displayed a predetermined distance ahead from the own vehicle, or may repeatedly move backward (downward) within the viewing angle VA together with the road surface of the oncoming lane Lnw.

[0093] Even in the second embodiment described so far, the same effects as those of the first embodiment are achieved, and information such as which lane the vehicle A is currently traveling in and where it should travel is provided to the driver by the reverse-travel prevention content CTp. As a result, it becomes possible to improve the convenience of the driver.

[0094] In addition, the display generation unit 76 of the second embodiment continues to display the route display paint CTk started in the first reverse-travel scene Sn1 even when shifting from the first reverse-travel scene Sn1 to the second reverse-travel scene Sn2. According to such continuous display of the route display paint CTk, the correct driving lane Lnc in which the own vehicle should travel is continuously notified to the driver.

[0095] Also, in the second embodiment, the state of the route display paint CTk in the second reverse-travel scene Sn2 is emphasized more than that in the first reverse-travel scene Sn1. According to such a change in state, the function of the route display paint CTk for notifying the correct driving lane Lnc can be further improved. In addition, due to the movement of the emphasized route display paint CTk to the corners of the viewing angle VA, it becomes easier for the driver to recognize that they are mistakenly traveling in the oncoming lane Lnw in reverse.

[0096] (Third Embodiment) The third embodiment of the present disclosure shown in FIGS. 12 and 13 is another modification of the first embodiment. Also in the third embodiment, the states of the first reverse-prevention content CTp1 and the second reverse-prevention content CTp2 are different from those of the first embodiment. Hereinafter, the details of the first reverse-prevention content CTp1 and the second reverse-prevention content CTp2 of the third embodiment will be described with reference to FIGS. 12 and 13 and referring to FIG. 3.

[0097] Both the first reverse-prevention content CTp1 and the second reverse-prevention content CTp2 include a forward arrow CTf and a reverse arrow CTr. The forward arrow CTf and the reverse arrow CTr are both drawn in the shape of an arrow and indicate different directions from each other. The forward arrow CTf is superimposed so as to be attached to the road surface of the travel lane Lnc in a posture where the tip of the arrowhead is directed in the traveling direction so as to indicate the traveling direction of the travel lane Lnc. The reverse arrow CTr is superimposed so as to be attached to the road surface of the oncoming lane Lnw in a posture where the tip of the arrowhead is directed rearward of the own vehicle so as to indicate the traveling direction of the oncoming lane Lnw.

[0098] When it is determined that it is the first reverse scene Sn1, the display generation unit 76 alternately displays the reverse arrow CTr and the forward arrow CTf as the reverse-prevention content CTp. Specifically, the display generation unit 76 displays the reverse arrow CTr, then makes the reverse arrow CTr non-displayed, and then displays the forward arrow CTf. Further, the display generation unit 76 makes the forward arrow CTf non-displayed and then displays the reverse arrow CTr. The reverse arrow CTr is displayed as an animation that flows backward (to the lower corner of the viewing angle VA) one or more times together with the road surface of the oncoming lane Lnw. Similarly, the forward arrow CTf is displayed as an animation that flows backward (below the viewing angle VA) one or more times together with the road surface of the travel lane Lnc.

[0099] The reverse arrow CTr may also be a display object that continues to be stationary at a lateral position a certain distance away from the host vehicle in a drawing shape adapted to the oncoming lane Lnw. Similarly, the forward arrow CTf may be a display object that continues to be stationary at a forward position a certain distance away from the host vehicle in a drawing shape adapted to the driving lane Lnc.

[0100] Even when the driving scene transitions from the first reverse driving scene Sn1 to the second reverse driving scene Sn2, the display generation unit 76 continues to alternately display the reverse arrow CTr and the forward arrow CTf. In the second reverse driving scene Sn2, as the vehicle A moves into the oncoming lane Lnw, the reverse arrow CTr is displayed in front of the viewing angle VA. On the other hand, the forward arrow CTf is displayed at the upper corner of the viewing angle VA.

[0101] The display colors of the above forward arrow CTf and reverse arrow CTr may be the same as or different from each other. In addition, the display colors of the forward arrow CTf and the reverse arrow CTr may be the same as or different from each other between the first reverse driving scene Sn1 and the second reverse driving scene Sn2. As an example, the forward arrow CTf is displayed in light green or light blue in the first reverse driving scene Sn1 and in dark green or dark blue in the second reverse driving scene Sn2. On the other hand, the reverse arrow CTr is displayed in yellow or light amber in the first reverse driving scene Sn1 and in dark amber or red in the second reverse driving scene Sn2.

[0102] Even in the third embodiment described so far, the same effects as those of the first embodiment are achieved, and detailed information related to reverse driving is easily shown by the superimposed display of the reverse driving prevention content CTp. As a result, the convenience for the driver is improved.

[0103] In addition, when the scene determination unit 73 determines that it is a predetermined reverse driving scene SnX, the display generation unit 76 of the third embodiment displays the forward arrow CTf after displaying the reverse arrow CTr as the reverse driving prevention content CTp. In this way, the reverse arrow CTr and the forward arrow CTf are not displayed simultaneously, but are displayed in a predetermined order triggered by the occurrence of the predetermined reverse driving scene SnX. According to the above, by clearly indicating the driving direction of the oncoming lane Lnw with the reverse arrow CTr, the risk of reverse driving can be easily conveyed to the driver. Then, after the reverse arrow CTr is hidden, by clearly indicating the correct driving lane Lnc with the forward arrow CTf, the driver can accurately recognize the lane in which the vehicle should travel.

[0104] In the third embodiment, the reverse arrow CTr corresponds to the "reverse content", and the forward arrow CTf corresponds to the "forward content". Also, the scene determination unit 73 of the third embodiment does not necessarily need to distinguish between the first reverse driving scene Sn1 and the second reverse driving scene Sn2. In other words, the first reverse driving prevention content CTp1 and the second reverse driving prevention content CTp2 do not necessarily need to be distinguished.

[0105] (Fourth Embodiment) The fourth embodiment of the present disclosure shown in FIG. 14 is a modification of the second embodiment. In the fourth embodiment, the state of the first reverse driving prevention content CTp1 displayed in the first reverse driving scene Sn1 is different from that in the second embodiment. The first reverse driving prevention content CTp1 of the fourth embodiment includes a route display paint CTk and a virtual dividing line CTl.

[0106] The route display paint CTk is drawn in the shape of an arrow indicating the traveling direction of the travel lane Lnc, similar to the forward arrow CTf (see FIG. 11) of the third embodiment. Also in the fourth embodiment, the route display paint CTk has a drawing shape similar to or substantially the same as that of the route guidance content, similar to the second embodiment. That is, in the fourth embodiment, the route guidance content is in the shape of an arrow. The route display paint CTk may be the superimposed content CTs that is attached to the road surface a certain distance ahead from the own vehicle, or may be the superimposed content CTs that moves within the viewing angle VA together with the road surface of the travel lane Lnc.

[0107] The virtual lane line CTl is the superimposed content CTs that is respectively superimposed inside the left and right lane lines and extends in a strip shape along the adjacent lane lines. The pair of virtual lane lines CTl is arranged on both the left and right sides of the route display paint CTk, and together with the route display paint CTk, indicates that the travel lane Lnc currently being traveled is the lane to be traveled. The virtual lane line CTl may be displayed, for example, as an animation that repeatedly extends in the traveling direction. The virtual lane line CTl may have a drawing shape similar to or substantially the same as that of the content displayed as the route guidance content, similar to the route display paint CTk. Alternatively, the virtual lane line CTl may have a drawing shape similar to or substantially the same as that of the driving operation content associated with LDW or LTC.

[0108] Even in the fourth embodiment described so far, the reverse travel prevention content CTp including the route display paint CTk and the virtual lane line CTl clearly shows detailed information related to reverse travel. As a result, the same effects as those of the above-described embodiments and the like are achieved, and the convenience for the driver is improved.

[0109] (Fifth Embodiment) The fifth embodiment of the present disclosure shown in FIG. 15 is another modification of the second embodiment. Also in the fifth embodiment, the state of the first reverse travel prevention content CTp1 displayed in the first reverse travel scene Sn1 is different from that of the second embodiment. The first reverse travel prevention content CTp1 of the fifth embodiment includes the entry prohibition paint CTx.

[0110] The entry prohibition paint CTx is drawn in a cross shape in a display color such as yellow or amber. The entry prohibition paint CTx is superimposed on the road surface of the oncoming lane Lnw. A plurality of entry prohibition paints CTx are arranged in a row along the center line CL with a space therebetween, alerting the driver that movement to the oncoming lane Lnw across the center line CL is prohibited. The entry prohibition paint CTx may be superimposed content CTs that is stationary on the road surface a certain distance ahead of the host vehicle, or may be superimposed content CTs that moves to the lower corner within the viewing angle VA together with the road surface of the oncoming lane Lnw.

[0111] Even in the fifth embodiment described so far, detailed information related to reverse driving is clearly shown by the reverse driving prevention content CTp including the entry prohibition paint CTx. As a result, the same effects as those of the above-described embodiments and the like are achieved, and the convenience for the driver is improved.

[0112] (Sixth Embodiment) The sixth embodiment of the present disclosure shown in FIGS. 16 and 17 is still another modification of the first embodiment. The HCU 100 (see FIG. 3) in the sixth embodiment suspends the superimposed display of the reverse driving prevention content CTp in an overtaking scene Snp where the host vehicle overtakes the overtaking target TP. That is, in the overtaking scene Snp, even if a part or all of the host vehicle protrudes into the oncoming lane Lnw, the reverse driving prevention content CTp (second reverse driving prevention content CTp2, see FIG. 6 etc.) is not displayed. Hereinafter, based on FIGS. 16 and 17 and referring to FIGS. 1 to 3, the details of the scene determination unit 73 and the display generation unit 76 in the sixth embodiment will be described.

[0113] In addition to the above-described first scene determination and second scene determination, the scene determination unit 73 determines whether or not it is an overtaking scene Snp. In a scene where the host vehicle protrudes into the oncoming lane Lnw, the scene determination unit 73 combines the type information of the center line CL and the detection information around the host vehicle, etc., and discriminates whether it is a reverse driving scene (second reverse driving scene Sn2, see FIG. 6 etc.) or an overtaking scene Snp by a plurality of methods.

[0114] The scene determination unit 73 grasps the type information of the center line CL that divides the driving lane Lnc and the oncoming lane Lnw based on the high-precision map data or imaging data provided by the information acquisition unit 72. Specifically, the scene determination unit 73 grasps, as the type information of the center line CL, the color of the center line CL (white or yellow) and whether the center line CL is a solid line or a broken line. Based on the grasped type information of the center line CL, the scene determination unit 73 determines whether or not it is prohibited to protrude from the current driving lane Lnc into the oncoming lane Lnw. When the host vehicle protrudes into the oncoming lane Lnw where protrusion is not prohibited, the scene determination unit 73 determines that it is an overtaking scene Snp. On the other hand, when the host vehicle protrudes into the oncoming lane Lnw where protrusion is prohibited, the scene determination unit 73 determines that it is not an overtaking scene Snp but a second reverse driving scene Sn2.

[0115] The scene determination unit 73 may also be able to grasp information on whether or not overtaking is prohibited on the road during driving based on the recognition results of road signs on the side of the road and road markings laid on the road surface (so-called Traffic Sign Recognition). The recognition results of the road signs and road markings may be generated by the scene determination unit 73 using the imaging data of the front camera 31 provided to the information acquisition unit 72, or may be generated by the driving support ECU 50 and provided to the information acquisition unit 72.

[0116] The scene determination unit 73 determines whether or not there are other vehicles around the host vehicle using the detection information of the surrounding monitoring sensor 30 provided to the information acquisition unit 72. When there are no other vehicles around the host vehicle, the driver is likely to misunderstand the driving direction defined for each lane, and as a result, is likely to drive in reverse. Also, when there are no other vehicles, there is no need to overtake. Therefore, when there are no other vehicles around the host vehicle, the scene determination unit 73 prioritizes the first scene determination and the second scene determination over the determination of whether or not it is an overtaking scene Snp. That is, even on a road where protrusion into the oncoming lane Lnw is not prohibited, when the host vehicle protrudes into the oncoming lane Lnw, a warning by the second reverse driving prevention content CTp2 is implemented.

[0117] When there are other vehicles around the host vehicle, the scene determination unit 73 further grasps the type, relative position, size, moving state, etc. of the target object TP to be overtaken based on the detection information. The target object TP to be overtaken includes a vehicle ahead traveling in the same travel lane Lnc as the host vehicle, a motorcycle, a bicycle, a parked vehicle that has stopped with at least a part protruding from the travel lane Lnc, an obstacle, and the like. When the host vehicle protrudes into the oncoming lane Lnw in a state where there is no target object TP to be overtaken, the scene determination unit 73 determines that it is a reverse driving scene (second reverse driving scene Sn2). On the other hand, when a target object TP to be overtaken is detected ahead and the host vehicle is approaching the target object TP to be overtaken in a state where the traveling speed of the target object TP to be overtaken and the traveling speed of the host vehicle deviate (the relative speed is large), the scene determination unit 73 determines that it is an overtaking scene Snp.

[0118] When it is determined by the scene determination unit 73 that it is an overtaking scene Snp, the display generation unit 76 suspends the superimposed display of the reverse driving prevention content CTp by the HUD 20. Thus, the details of the content display process (see FIG. 17) of the sixth embodiment in which the presentation of the reverse driving prevention content CTp can be suspended in the overtaking scene Snp will be described below.

[0119] In S201, the scene determination unit 73 determines whether there are other vehicles around the host vehicle. In S201, both the travel lane Lnc and the oncoming lane Lnw are detection targets, and all other vehicles existing in front of, on the side of, and behind the host vehicle are grasped. If it is determined in S201 that there are no other vehicles around the host vehicle, the process proceeds to S202. In this case, the scene determination unit 73 preferentially performs the first scene determination rather than the determination of whether it is an overtaking scene Snp.

[0120] In S202, the scene determination unit 73 determines whether the current driving scene is the first reverse driving scene Sn1. If it is determined in S202 that it is not the first reverse driving scene Sn1, the process proceeds to S206. On the other hand, if it is determined in S202 that it is the first reverse driving scene Sn1, the process proceeds to S203. In S203, the display generation unit 76 performs display control of the first reverse driving prevention content CTp1 (see FIG. 4 etc.) according to the content of the reverse driving prediction operation, and the process proceeds to S204.

[0121] In S204, the display generation unit 76 determines whether the display end condition of the first reverse prevention content CTp1 is satisfied. When a predetermined time has elapsed since the start of display, when the reverse sign operation has been canceled, or when the driving scene of the host vehicle has shifted from the first reverse scene Sn1 to the second reverse scene Sn2, the display end condition is satisfied, and the process proceeds to S206.

[0122] In S206, the scene determination unit 73 determines whether the current driving scene is the second reverse scene Sn2. If it is determined in S206 that the scene is not the second reverse scene Sn2, the process proceeds to S212. On the other hand, if it is determined in S206 that the scene is the second reverse scene Sn2, the process proceeds to S210. In S210, display control for displaying the second reverse prevention content CTp2 (see FIG. 6 etc.) is performed, and the process proceeds to S211.

[0123] In S211, the scene determination unit 73 determines whether the display end condition of the second reverse prevention content CTp2 is satisfied. When the host vehicle has returned to the correct driving lane Lnc, the display end condition of the second reverse prevention content CTp2 is satisfied. If it is determined in S211 that the display end condition is not satisfied, the process returns to S210. In this case, the display generation unit 76 continues to display the second reverse prevention content CTp2. On the other hand, if it is determined in S211 that the display end condition is satisfied, the process proceeds to S212. In S212, the display generation unit 76 ends the display of the reverse prevention content CTp started in S203 or S210.

[0124] On the other hand, if it is determined in S201 that there is another vehicle around the host vehicle, the scene determination unit 73 proceeds to S205 and determines whether it is the overtaking scene Snp. In S205, the presence or absence of an overtaking target TP with a speed difference from the host vehicle is determined. If it is determined in S205 that there is no overtaking target TP with a speed difference, it is determined that it is not the overtaking scene Snp, and the process proceeds to S206. On the contrary, if it is determined in S205 that there is an overtaking target TP with a speed difference, the process proceeds to S207.

[0125] In S207, the scene determination unit 73 determines whether the host vehicle has protruded into the oncoming lane Lnw where protrusion is prohibited (hereinafter, the overtaking prohibited lane). If it is determined in S207 that the host vehicle has protruded into the overtaking prohibited lane, it is regarded as the second reverse driving scene Sn2 instead of the overtaking scene Snp, and the process proceeds to S210. On the other hand, if it is determined in S207 that the host vehicle has protruded into the oncoming lane Lnw where protrusion is not prohibited (hereinafter, the overtaking possible lane), it is determined that the current driving scene is the overtaking scene Snp, and the process proceeds to S208. Similarly, if it is determined that the host vehicle has not protruded from the driving lane Lnc, it is also determined that it is the overtaking scene Snp where overtaking is performed within the driving lane Lnc, and the process proceeds to S208.

[0126] In S208, the scene determination unit 73 determines whether the elapsed time after protruding into the overtaking possible lane has exceeded a predetermined time. The predetermined time may be a substantially constant time defined in advance, or may be adjusted according to the speed difference between the host vehicle and the overtaking target TP so that the smaller the speed difference, the longer the time. If it is determined in S208 that the elapsed time after protruding into the overtaking possible lane has not exceeded the predetermined time, the process proceeds to S209. Even when overtaking is being performed within the driving lane Lnc, the process proceeds to S209.

[0127] On the other hand, if it is determined in S208 that the predetermined time has elapsed after protruding into the overtaking possible lane, the determination result of the current driving scene is shifted from the overtaking scene Snp to the second reverse driving scene Sn2, and the process proceeds to S210. Incidentally, the scene determination unit 73 may determine in S208 whether the distance traveled while continuing to drive in the overtaking possible lane has exceeded a predetermined distance. In this case, if the vehicle continues to travel a predetermined distance after protruding into the overtaking possible lane, the determination result of the current driving scene is shifted from the overtaking scene Snp to the second reverse driving scene Sn2, and the process proceeds to S210.

[0128] In S209, the scene determination unit 73 determines whether there is a driving operation (hereinafter referred to as a return operation) to return the host vehicle to the traveling position before the start of overtaking based on the operation information provided by the information acquisition unit 72 from the steer ECU 61 and the body ECU 63. The return operation includes a steering operation and a turn signal operation by the driver. If it is determined in S209 that there is no return operation, the process returns to S208. Through such repeated processing of S208 and S209, the display of the second reverse travel prevention content CTp2 is suspended until a predetermined time elapses. If no steering information to return to the original traveling position is detected within the predetermined time, the scene determination unit 73 determines that the current traveling scene is the second reverse travel scene Sn2. In this case, based on the shift of the process from S208 to S210, the display of the second reverse travel prevention content CTp2 is started. On the other hand, if it is determined in S209 that a return operation has been input before the elapse of the predetermined time, the current content display process ends.

[0129] Even in the sixth embodiment described so far, the same effects as those of the first embodiment are achieved, and detailed information related to reverse travel can be presented to the driver in an easy-to-understand manner by the superimposed display of the reverse travel prevention content CTp. Therefore, it is possible to improve the convenience for the driver.

[0130] In addition, in the sixth embodiment, it is further determined whether the vehicle A is in an overtaking scene Snp in which the overtaking target TP is overtaken. If it is determined that it is the overtaking scene Snp, the superimposed display of the reverse travel prevention content CTp by the HUD 20 is suspended. Therefore, when the driver intentionally protrudes into the oncoming lane Lnw, the reverse travel prevention content CTp does not issue a warning about reverse travel. According to the above, in the overtaking scene Snp, it is less likely that the erroneously displayed reverse travel prevention content CTp will cause trouble to the driver. As a result, it is possible to further improve the convenience for the driver.

[0131] Also, in the sixth embodiment, when the host vehicle protrudes into the no-passing lane, even in a scene where an overtaking attempt is being made, it is determined as the second reverse driving scene Sn2. Therefore, when the driver misrecognizes the driving environment around the host vehicle and performs an incorrect driving action, it becomes possible to appropriately carry out a warning using the reverse driving prevention content CTp.

[0132] Furthermore, in the sixth embodiment, detection information of other vehicles around the host vehicle and detection information of the overtaking target TP are used for discriminating between the overtaking scene Snp and the second reverse driving scene Sn2. According to the above, the scene determination unit 73 can accurately distinguish whether the host vehicle's protrusion into the oncoming lane Lnw is an overtaking or a reverse driving. According to the above, since it becomes possible to appropriately display the reverse driving prevention content CTp, the convenience for the driver can be further improved.

[0133] (Seventh Embodiment) The seventh embodiment of the present disclosure shown in FIGS. 18 to 20 is still another modification of the first embodiment. The HCU 100 (see FIG. 3) of the seventh embodiment displays the reverse driving prevention content CTp (the first reverse driving prevention content CTp1) together with the route guidance content CTnv in a guidance area GA for displaying the route guidance content CTnv based on the navigation information. Hereinafter, based on FIGS. 18 and 19, while referring to FIGS. 1 to 3, the details of the information acquisition unit 72, the scene determination unit 73, and the display generation unit 76 of the seventh embodiment will be described.

[0134] The information acquisition unit 72 grasps a guidance area GA for performing route guidance based on navigation information including route information to a destination set in the navigation device 52. The guidance area GA is an intersection where a right or left turn is made, a branching point, a merging point, or the like. The information acquisition unit 72 refers to the high-precision map data provided from the locator 40 and grasps a prohibited entry area Axe existing in the guidance area GA.

[0135] The prohibited entry area Axe includes areas where the entry of the own vehicle is prohibited, areas where the own vehicle will drive in reverse, and non-road areas where the driving of vehicle A itself is prohibited. Specifically, in the route guidance scene SnN at an intersection, among the plurality of lanes connected to the intersection, the lane in which the specified driving direction is opposite to the planned driving direction of the own vehicle (see the dashed arrow in Fig. 18) becomes the prohibited entry area Axe (see the dotted range in Fig. 18). Furthermore, in the route guidance scene SnN at an intersection, the sidewalk near the intersection is also recognized as the prohibited entry area Axe. Also, in the route guidance scene SnN at an interchange and a junction, the exit lane and the entry lane in which the specified driving direction is opposite to the planned driving direction of the own vehicle become the prohibited entry area Axe.

[0136] When there is a guidance execution request from the navigation device 52 to the information acquisition unit 72, the scene determination unit 73 determines that it is the route guidance scene SnN. In addition, when the information acquisition unit 72 has grasped the prohibited entry area Axe related to the guidance area GA where route guidance is executed based on the navigation information, the scene determination unit 73 determines that it is the first reverse driving scene Sn1 in which vehicle A may drive in reverse.

[0137] When the scene determination unit 73 determines that it is the route guidance scene SnN, the display generation unit 76 determines whether the guidance area GA is located within the viewing angle VA. When the display generation unit 76 determines that the guidance area GA is located within the viewing angle VA, it superimposes and displays the route guidance content CTnv for performing route guidance on the road surface within the guidance area GA. As an example, when performing a right-turn route guidance at an intersection (crossroads), the display generation unit 76 displays an image indicating the right direction as the route guidance content CTnv (see Fig. 19). The route guidance content CTnv is drawn so as to be visually recognized in a posture perpendicular to the road surface.

[0138] When the scene determination unit 73 determines that the route guidance scene SnN is the first reverse scene Sn1, the display generation unit 76 further determines whether or not the entry prohibited area Axe grasped by the information acquisition unit 72 is located within the viewing angle VA. When the display generation unit 76 determines that the entry prohibited area Axe is located within the viewing angle VA, the entry prohibited paint CTx is superimposed and displayed in the foreground where the route guidance content CTnv is superimposed and displayed. The entry prohibited paint CTx is the superimposed content CTs corresponding to the reverse travel prevention content CTp and the first reverse travel prevention content CTp1. The entry prohibited paint CTx is drawn so as to be visually recognized in a posture along the road surface.

[0139] Before starting the superimposed display of the route guidance content CTnv due to the approach of the host vehicle to the guidance area GA, the display generation unit 76 starts the superimposed display of the entry prohibited paint CTx. In the guidance area GA where the route guidance for a right turn is performed, the entry prohibited paint CTx is superimposed and displayed on the right side of the intersection as viewed from the driver of the host vehicle. The entry prohibited paint CTx is displayed only on the turning side (right side) of the intersection and is not displayed on the non-turning side (left side). The display generation unit 76 arranges the entry prohibited paint CTx on the road surface at the entrance to the oncoming lane so as to prevent the host vehicle from entering the oncoming lane where reverse travel is to occur. As a result, the entry prohibited paint CTx is superimposed and displayed on the road surface in front of the superimposed position of the route guidance content CTnv as viewed from the driver.

[0140] After sequentially displaying the entry prohibited paint CTx and the route guidance content CTnv, when the host vehicle approaches the guidance area GA further, the display generation unit 76 makes the entry prohibited paint CTx invisible earlier than the route guidance content CTnv. Specifically, the display generation unit 76 temporarily terminates the display of the entry prohibited paint CTx at the timing when the road surface at the entrance to the oncoming lane goes out of the viewing angle VA.

[0141] Even after the display of the entry-prohibited paint CTx is interrupted, the display generation unit 76 continues the process of simulating the display layout of the entry-prohibited paint CTx in the virtual space by means of the above-described virtual layout function. As a result, when the host vehicle makes a right turn within the intersection according to the route guidance content CTnv and the entrance road surface of the oncoming lane comes within the painting angle VA again, the display generation unit 76 resumes the superimposed display of the entry-prohibited paint CTx.

[0142] In the guidance area GA where left-turn route guidance is performed, the display generation unit 76 suspends the superimposed display of the entry-prohibited paint CTx. When performing left-turn route guidance, from the driver's perspective, the entrance road surface of the oncoming lane is on the back side with respect to the superimposed position of the route guidance content CTnv. Therefore, if the entry-prohibited paint CTx is superimposed and displayed on the entrance road surface of the oncoming lane, the entry-prohibited paint CTx may overlap at least a part of the route guidance content CTnv. For this reason, in the guidance area GA where left-turn route guidance is performed, the display generation unit 76 preferentially performs the superimposed display of the route guidance content CTnv with respect to the entry-prohibited paint CTx.

[0143] Even in the seventh embodiment described so far, the same effects as those of the first embodiment are achieved, and the entry-prohibited paint CTx superimposed and displayed as the reverse-travel prevention content CTp can present detailed information related to reverse travel to the driver in an easily understandable manner. Therefore, it is possible to improve the convenience for the driver.

[0144] In addition, in the seventh embodiment, when there is an entry-prohibited area Axe in the foreground where the route guidance content CTnv is superimposed and displayed, the entry-prohibited paint CTx is superimposed and displayed on the road surface leading to the entry-prohibited area Axe. Therefore, in the route guidance scene SnN, a situation where a driver who has misrecognized the guidance by the route guidance content CTnv accidentally enters the entry-prohibited area Axe with the host vehicle is avoided. In this way, by displaying the entry-prohibited paint CTx together with the route guidance content CTnv, it becomes easier for the driver to recognize the correct route guided by the route guidance content CTnv.

[0145] Also, in the seventh embodiment, before the start of display of the route guidance content CTnv, an entry prohibition paint CTx is superimposed and displayed on the road surface in front of the superimposition position of the route guidance content CTnv. According to such sequential display of the superimposed contents, it becomes difficult for the driver to overlook the entry prohibition paint CTx. In addition, since the entry prohibition paint CTx is displayed first, the driver can determine the traveling direction of the own vehicle according to the route guidance content CTnv after grasping the existence of the entry prohibited area Axe. According to the above, the driver can more surely direct the own vehicle in the correct route.

[0146] Furthermore, in the seventh embodiment, after the start of turning at the intersection that becomes the guidance area GA, the entry prohibition paint CTx can be redisplayed. Therefore, when the driver makes a mistake in the driving operation of turning the steering wheel to the right and the own vehicle tries to go into the oncoming lane, the entry prohibition paint CTx is superimposed and displayed on the road surface in front of the driver. As a result, the entry prohibition paint CTx can clearly warn that the vehicle is going into the oncoming lane. As described above, the redisplay of the entry prohibition paint CTx can more surely exhibit the effect of stopping the reverse running of the own vehicle.

[0147] Also, the display generation unit 76 according to the seventh embodiment superimposes and displays the entry prohibition paint CTx together with the route guidance content CTnv even in the route guidance scene SnN at a multi-junction (6-junction) as shown in FIG. 20. The display generation unit 76 can also draw the route guidance content CTnv so as to be visually recognized in a posture along the road surface, similar to the entry prohibition paint CTx.

[0148] Specifically, when the planned travel route of the host vehicle (see the dashed arrow in FIG. 20) set in the navigation device 52 is directed to the road on the far right side connected to a multi-junction, the display generation unit 76 superimposes and displays the entry prohibition paint CTx on the entrance road surface of the road on the right front side. The entry prohibition paint CTx may be superimposed and displayed only on the entrance road surface leading to the entry prohibited area Axe of the road on the right front side, or may be superimposed and displayed on the entire entrance road surface of the road on the right front side. Even if the entry prohibited area Axe is recognized on the road on the far right side that is the planned travel route, the display generation unit 76 does not perform the superimposed display of the entry prohibition paint CTx on the road on the far right side. The entry prohibition paint CTx superimposed on the road on the right front side can exert an effect of guiding the driver to the correct lane of the road on the far right side in addition to the effect of preventing entry into the oncoming lane of the road.

[0149] In addition, in the seventh embodiment, the information acquisition unit 72 corresponds to the "area recognition unit".

[0150] (Other embodiments) As described above, a plurality of embodiments of the present disclosure have been described. However, the present disclosure is not construed as being limited to the above embodiments, and can be applied to various embodiments and combinations without departing from the gist of the present disclosure.

[0151] In Modification 1 of the above embodiment, the first reverse travel scene Sn1 and the second reverse travel scene Sn2 are not distinguished. The scene determination unit 73 determines that it is a predetermined reverse travel scene SnX when there is a reverse travel prediction operation or when the host vehicle is traveling in the oncoming lane Lnw. Also, in Modification 2 of the above embodiment, only one of the first reverse travel scene Sn1 and the second reverse travel scene Sn2 is assumed in advance as the predetermined reverse travel scene SnX. In addition, in Modifications 1 and 2, only one type of reverse travel prevention content CTp may be used.

[0152] In Modification 3 of the above embodiment, the display end condition of the first reverse travel prevention content CTp1 (FIG. 9 is different from the above-described embodiment (see S103). For example, in Modification 3, when a predetermined time has elapsed since the start of display of the first anti-backward travel content CTp1 and the sign of backward travel has been canceled, the display of the first anti-backward travel content CTp1 ends.

[0153] Also, in Modification 4 of the above-described embodiment, the display end condition of the second anti-backward travel content CTp2 (see FIG. 9 S106) is different from that of the above-described embodiment. For example, in Modification 4, when a predetermined time has elapsed since the start of display of the second anti-backward travel content CTp2, the display of the second anti-backward travel content CTp2 ends. Alternatively, when an oncoming vehicle TA is detected, the display of the second anti-backward travel content CTp2 may end so as not to obstruct the visibility of the oncoming vehicle TA.

[0154] In Modification 5 of the above-described embodiment, the process of the scene determination unit 73 that determines the presence or absence of the partition object mark Ob is omitted. As a result, regardless of the presence or absence of the partition object mark Ob, the display generation unit 76 displays the anti-backward travel content CTp based on the determination that it is a predetermined backward travel scene SnX. Also, in Modification 6 of the above-described embodiment, when the scene determination unit 73 grasps the presence of the partition object mark Ob, the display generation unit 76 not only interrupts the drawing of the drawing data of the anti-backward travel content CTp on the video data but also interrupts the preparation of the drawing data of the anti-backward travel content CTp.

[0155] In Modification 7 of the above-described sixth embodiment, the conditions for discriminating between an overtaking scene and a backward travel scene are different from those of the sixth embodiment. Specifically, in Modification 7, even if the host vehicle protrudes into the no-overtaking lane, when an overtaking target TP exists, the display of the anti-backward travel content CTp is suspended. In Modification 7, when protruding into the no-overtaking lane, the suspension time is set shorter than when protruding into the overtaking-possible lane. That is, in the overtaking scene Snp where the vehicle protrudes into the no-overtaking lane, the predetermined time (see FIG. 17 S208) for determining the elapsed time after the protrusion is changed to be shorter than that in the overtaking scene Snp where the vehicle protrudes into the overtaking-possible lane.

[0156] In Modifications 8 to 10 of the above-described Seventh Embodiment, the content of the display control of the route guidance content CTnv and the reverse-travel prevention content CTp (entry-prohibited paint CTx) is different from that of the Seventh Embodiment. Specifically, in Modification 8, the display generation unit 76 causes the route guidance content CTnv and the reverse-travel prevention content CTp to be displayed substantially simultaneously. That is, the display generation unit 76 starts the superimposed display of the route guidance content CTnv and the reverse-travel prevention content CTp at the timing when the superimposed position of the route guidance content CTnv is within the viewing angle VA.

[0157] The display generation unit 76 of Modification 9 also causes the reverse-travel prevention content CTp to be displayed at an intersection where the host vehicle makes a left turn. The display generation unit 76 superimposes and displays the reverse-travel prevention content CTp on the front side of the route guidance content CTnv in the guidance area GA where the host vehicle makes a right turn. On the other hand, the display generation unit 76 superimposes and displays the reverse-travel prevention content CTp on the rear side of the route guidance content CTnv in the guidance area GA where the host vehicle makes a left turn.

[0158] As in Modification 9 above, if the viewing angle VA of the HUD 20 is secured wide enough to avoid the overlap of the route guidance content CTnv and the reverse-travel prevention content CTp, the reverse-travel prevention content CTp may also be displayed in the guidance area GA where a left turn is made. Further, in a form where the viewing angle VA of the HUD 20 is not sufficient, in the guidance area GA where a left turn is made, icon-shaped non-superimposed content that alerts the driver to enter the entry-prohibited area Axe may be displayed within the viewing angle VA as the reverse-travel prevention content CTp.

[0159] The display generation unit 76 of Modification 10 refers to the steering information indicating the steering angle detected by the steering angle sensor 62, determines that it is the first reverse-travel scene Sn1 in which there is a possibility of reverse travel when the steering angle is equal to or greater than a predetermined angle, and superimposes and displays the reverse-travel prevention content CTp. Thereby, when the host vehicle is moving forward toward the correct driving lane Lnc within the intersection, the re-display of the reverse-travel prevention content CTp is stopped.

[0160] In the route guidance scene SnN, the superimposition position of the entry prohibition paint CTx displayed as the reverse travel prevention content CTp may be appropriately changed according to, for example, the viewing angle VA of the HUD20. As an example, if the viewing angle VA of the HUD20 is sufficiently wide, it is not limited to the entrance road surface of the entry prohibition area Axe, and the entry prohibition paint CTx may be superimposed and displayed at multiple locations in the entry prohibition area Axe. Furthermore, the form of the reverse travel prevention content CTp superimposed and displayed in the route guidance scene SnN is not limited to the entry prohibition paint CTx and can be appropriately changed. For example, a virtual barrier CTb (see FIG. 4), a virtual oncoming vehicle CTc (see FIG. 5), a virtual pedestrian, and a reverse arrow CTr (see FIG. 12) etc. may be displayed in the route guidance scene SnN as the reverse travel prevention content CTp.

[0161] In the above embodiment, a reverse travel scene where the host vehicle travels on the oncoming lane Lnw was exemplified, but the reverse travel prevention content CTp may be displayed in various reverse travel scenes. For example, when entering the wrong lane during a right or left turn at an intersection, when entering the exit side interchange mistakenly connected to a highway, and when entering an area that is not a lane such as a sidewalk and a railway etc., may be assumed in advance as a predetermined reverse travel scene SnX.

[0162] Furthermore, the display generation unit 76 may be able to change the form of the reverse travel prevention content CTp according to the difference in the area during reverse travel. As an example, the scene determination unit 73 grasps the type of the center line CL, specifically, the differences in the color and shape of the center line CL. The display generation unit 76 changes the method of attracting attention using the reverse travel prevention content CTp according to whether the center line CL is a white broken line, a white solid line, or a yellow (orange) solid line.

[0163] The form of the reverse travel prevention content CTp described in the above embodiment is an example. Specifically, static elements such as the content shape, display position, display color, and display brightness, as well as dynamic elements such as the presence or absence of blinking, the blinking period, the presence or absence of animation, and the animation operation, may be appropriately changed. Furthermore, for example, according to the driver's preference, the static or dynamic elements of the reverse travel prevention content CTp may be changeable.

[0164] The HCU of the above embodiment sequentially controlled the projection shape and projection position of the virtual image light imaged as the superimposed content CTs using the position information of the eye point detected by the DSM so that the superimposed content was superimposed on the superimposed target without deviation as seen from the driver. However, the HCU according to Modification Example 11 of the above embodiment controls the projection shape and projection position of the virtual image light imaged as the superimposed content using the set information centered on the preset reference eye point without using the detection information of the DSM.

[0165] The specific configuration of the HUD20 can be changed as appropriate. For example, in Modification Example 12, an EL (Electro Luminescence) panel is provided in the projector of the HUD instead of the LCD panel and the backlight. Further, instead of the EL panel, a projector using a display such as a plasma display panel, a cathode ray tube, and an LED can be adopted for the HUD.

[0166] In the HUD of Modification Example 13, a laser module (hereinafter, LSM) and a screen are provided instead of the LCD and the backlight. The LSM is configured to include, for example, a laser light source and a MEMS (Micro Electro Mechanical Systems) scanner. The screen is, for example, a micro mirror array or a micro lens array. In such a HUD, a display image is drawn on the screen by scanning the laser light emitted from the LSM. The HUD projects the display image drawn on the screen onto the windshield by an enlarged optical element to display a virtual image in the air.

[0167] The HUD of Modification Example 14 is provided with a DLP (Digital Light Processing, registered trademark) projector. The DLP projector includes a digital micromirror device (hereinafter referred to as DMD) provided with a large number of micromirrors, and a projection light source that projects light toward the DMD. The DLP projector draws a display image on the screen by controlling the DMD and the projection light source in cooperation. In the HUD of Modification Example 15, a projector using LCOS (Liquid Crystal On Silicon) is adopted. In the HUD of Modification Example 16, a holographic optical element is adopted as one of the optical systems for displaying a virtual image in the air.

[0168] In Modification Example 17 of the above embodiment, a camera image acquisition unit that acquires imaging data of the front camera 31 and that captures the foreground of the host vehicle is provided in the HCU 100. The display generation unit 76 generates video data obtained by superimposing the original image of the reverse driving prevention content CTp on the real image of the foreground based on the imaging data. Based on such video data, the HUD 20 projects, as a virtual image, a display in which the reverse driving prevention content CTp is superimposed on the real image in the foreground. As in Modification Example 17 above, when the viewing angle VA of the HUD 20 is not sufficient, a virtual image display in which the original image of the content etc. used for the AR display is superimposed on the real image may be implemented in a scene where the AR content is out of the viewing angle VA.

[0169] In Modification Example 18 of the above embodiment, the HCU and the HUD are integrally configured. That is, the processing function of the HCU is implemented in the control circuit of the HUD of Modification Example 18. In such a modification example, the HUD corresponds to the "display control device". Further, the processing function of the HCU may be implemented in the meter ECU, the navigation ECU, the display audio ECU, etc. In such a modification example, the meter device, the navigation device, and the display audio device each correspond to the "display control device".

[0170] In the above-described embodiment, each function provided by the HCU can also be provided by software and the hardware that executes it, software only, hardware only, or a combined combination thereof. Further, when such a function is provided by an electronic circuit as hardware, each function can also be provided by a digital circuit including a number of logic circuits or an analog circuit.

[0171] Also, the form of a storage medium (persistent tangible computer-readable medium, non-transitory tangible storage medium) that stores a program or the like capable of realizing the above-described display control method may be appropriately changed. For example, the storage medium is not limited to a configuration provided on a circuit board, and may be provided in the form of a memory card or the like, inserted into a slot portion, and electrically connected to the control circuit of the HCU. Further, the storage medium may be an optical disk and a hard disk drive or the like that serve as a copy source of the program to the HCU.

[0172] The vehicle equipped with the HMI system is not limited to a general passenger car for private use, and may be a vehicle for rental cars, a vehicle for manned taxis, a vehicle for ride-sharing, a freight vehicle, a bus, or the like.

[0173] The vehicle equipped with the HMI system may be a right-hand drive vehicle or a left-hand drive vehicle. Further, the traffic environment in which the vehicle travels may be a traffic environment based on left-hand traffic or a traffic environment based on right-hand traffic. The content display for the purpose of preventing reverse driving according to the present disclosure is appropriately optimized according to the road traffic laws of each country and region, and further according to the steering wheel position of the vehicle.

[0174] The control unit and its method described in the present disclosure may be implemented by a dedicated computer configured with a processor programmed to execute one or more functions embodied by a computer program. Alternatively, the device and its method described in the present disclosure may be implemented by dedicated hardware logic circuits. Or, the device and its method described in the present disclosure may be implemented by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by a computer.

Explanation of Signs

[0175] A Vehicle, Axe Prohibited Entry Area, CL Center Line, CTnv Route Guidance Content, CTp Anti-Returning Prevention Content, CTf Forward Arrow (Forward Content), CTr Reverse Arrow (Reverse Content), Lnc Driving Lane, Lnw Opposite Lane, Ob Partition Object (Obstacle), TP Overtaking Target, Snp Overtaking Scene, SnN Route Guidance Scene, SnX Predetermined Reverse Driving Scene, Sn1 First Reverse Driving Scene, Sn2 Second Reverse Driving Scene, 11 Processing Unit, 20 HUD (Head-Up Display), 64 Direction Indicator Switch (Direction Indicator), 72 Information Acquisition Unit (Area Grasping Unit), 73 Scene Determination Unit, 76 Display Generation Unit (Display Control Unit), 100 HCU (Display Control Device)

Claims

1. A display control device used in a vehicle (A) for controlling the display by a head-up display (20), comprising: a scene determination unit (73) for determining whether or not it is a predetermined reverse driving scene (SnX) assumed in advance in relation to reverse driving of the vehicle; a display control unit (76) for superimposing and displaying reverse driving prevention content (CTp) for guiding the vehicle to travel on a correct driving lane (Lnc) on the road surface in the foreground by the head-up display when the predetermined reverse driving scene occurs; The display control unit: starts displaying the reverse driving prevention content based on an ON operation of a direction indicator (64) of the vehicle; A display control device that changes the reverse driving prevention content displayed based on the ON operation to an emphasized state based on a steering operation that brings the vehicle closer to a center line (CL) that is a boundary between the driving lane and an oncoming lane (Lnw).

2. The scene determination unit further determines whether or not there is an obstacle (Ob) existing between the driving lane and an oncoming lane (Lnw); The display control unit interrupts the superimposed display of the reverse driving prevention content by the head-up display when the obstacle exists. The display control device according to claim 1.

3. A display control device used in a vehicle (A) for controlling the display by a head-up display (20), comprising: a scene determination unit (73) for determining whether or not it is a predetermined reverse driving scene (SnX) assumed in advance in relation to reverse driving of the vehicle; a display control unit (76) for superimposing and displaying reverse driving prevention content (CTp) for guiding the vehicle to travel on a correct driving lane (Lnc) on the road surface in the foreground by the head-up display when the predetermined reverse driving scene occurs; The scene determination unit further determines whether or not there is an obstacle (Ob) existing between the driving lane and an oncoming lane (Lnw); The display control unit interrupts the superimposed display of the reverse driving prevention content by the head-up display when the obstacle exists. The display control device.

4. The scene determination unit continues to determine whether or not it is the predetermined reverse driving scene even when the obstacle exists; The display control unit continues to prepare drawing data of the reverse driving prevention content during a period in which the scene determination unit determines that it is the predetermined reverse driving scene even when the obstacle exists. The display control device according to claim 2 or 3.

5. The scene determination unit includes a first scene determination for determining whether the vehicle is likely to be running in reverse (first reverse running scene (Sn1)), and a second scene determination for determining whether the vehicle is running in reverse (second reverse running scene (Sn2)), in the determination of whether it is the predetermined reverse running scene. The display control device according to any one of claims 1 to 4.

6. The scene determination unit determines whether it is the first reverse running scene based on operation information related to an operation of a driver driving the vehicle. The display control device according to claim 5.

7. When the scene determination unit determines that it is the first reverse running scene, the display control unit changes the content of the reverse running prevention content according to the operation content of the driver indicated by the operation information. The display control device according to claim 6.

8. When the scene determination unit determines that it is the first reverse running scene, the display control unit continues to display the reverse running prevention content until a predetermined time has elapsed since the start of the display of the reverse running prevention content, or until the operation of the driver that caused the determination that it is the first reverse running scene is canceled. The display control device according to claim 6 or 7.

9. After the display control unit displays the reverse running prevention content based on the determination that it is the first reverse running scene, when the running scene of the vehicle shifts to the second reverse running scene, the display control unit displays the reverse running prevention content different from the reverse running prevention content displayed in the first reverse running scene. The display control device according to any one of claims 5 to 8.

10. After the display control unit displays the reverse running prevention content based on the determination that it is the first reverse running scene, when the running scene of the vehicle shifts to the second reverse running scene, while continuing the display of the reverse running prevention content started in the first reverse running scene, the display control unit emphasizes the state of the reverse running prevention content more than in the first reverse running scene. The display control device according to any one of claims 5 to 8.

11. The display control unit superimposes and displays at least a part of the reverse running prevention content to be displayed in the second reverse running scene on the road surface of the driving lane on which the vehicle should travel. The display control device according to claim 9 or 10.

12. The display control unit according to any one of claims 5 to 11, which continues to display the reverse travel prevention content until the vehicle returns to the travel lane when the scene determination unit determines that it is the second reverse travel scene.

13. The scene determination unit further determines whether the vehicle is in an overtaking scene (Snp) in which the vehicle overtakes an overtaking target (TP), The display control unit according to any one of claims 1 to 12, which suspends the superimposed display of the reverse travel prevention content by the head-up display when the scene determination unit determines that it is the overtaking scene.

14. The vehicle further includes an area grasping unit (72) that grasps a prohibited entry area (Axe) where entry of the vehicle is prohibited, The display control unit according to any one of claims 1 to 13, which superimposes and displays the reverse travel prevention content on the road surface leading to the prohibited entry area when the prohibited entry area exists in the foreground where route guidance content (CTnv) for performing route guidance is superimposed and displayed.

15. The display control unit according to claim 14, which superimposes and displays the reverse travel prevention content on the road surface in front of the superimposed position of the route guidance content before the display of the route guidance content is started.

16. When the scene determination unit determines that it is the predetermined reverse travel scene, the display control unit displays reverse direction content (CTr) indicating the travel direction of the oncoming lane (Lnw) as the reverse travel prevention content, and then displays forward direction content (CTf) indicating the travel direction of the travel lane. The display control device according to any one of claims 1 to 15.

17. A display control program used in a vehicle (A) for controlling display by a head-up display (20), At least one processing unit (11), Determines whether it is a predetermined reverse travel scene (SnX) assumed in advance in relation to reverse travel of the vehicle (S101, S104, S202, S206), When it becomes the predetermined reverse travel scene, reverse travel prevention content (CTp) for guiding the vehicle to travel on the correct travel lane (Lnc) is superimposed and displayed on the road surface in the foreground by the head-up display (S102, S105, S203, S210), Performs a process including this, In the process of superimposing and displaying the reverse travel prevention content, Based on the ON operation of the direction indicator (64) of the vehicle, start the display of the reverse driving prevention content, A display control program that changes the reverse driving prevention content displayed based on the ON operation to an emphasized state based on a steering operation that brings the vehicle closer to the center line (CL) that is the boundary between the driving lane and the oncoming lane (Lnw).

18. A display control program used in a vehicle (A) for controlling the display by a head-up display (20), At least one processing unit (11), Determine whether it is a predetermined reverse driving scene (SnX) assumed in advance in relation to reverse driving of the vehicle (S101, S104, S202, S206), When it becomes the predetermined reverse driving scene, the reverse driving prevention content (CTp) that guides the vehicle to travel in the correct driving lane (Lnc) is superimposed and displayed on the road surface in the foreground by the head-up display (S102, S105, S203, S210), Further determine the presence or absence of an obstacle (Ob) existing between the driving lane and the oncoming lane (Lnw), When the obstacle exists, interrupt the superimposed display of the reverse driving prevention content by the head-up display, A display control program that performs processing including this.

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