JP2019056884A - Superimposed image display device - Google Patents

Abstract

To provide a superimposed image display device capable of displaying superimposed images with satisfactory visibility without giving any discomfort to a passenger.SOLUTION: The superimposed image display device is configured so as to, when allowing a passenger in a vehicle to recognize an image while overlapping with forward circumstances, perform the steps of: acquiring the position and the visual line direction of both eyes of a passenger; setting a reference line in a display area on the basis of an intersection point at which a center line which passes a middle point between the eyes of the passenger along a visual line direction crosses the image display area; and displaying an image to be displayed at the side corresponding to the left eye with respect to the reference line in the display area to display as the image to be recognized by the left eye, the image to be displayed in the side corresponding to the right eye with respect to the reference line as the image to be recognized by the right eye only from the images to be displayed.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a superimposed image display device that displays an image to be visually recognized by a vehicle occupant superimposed on a surrounding environment.

  Conventionally, various means have been used as information providing means for providing driving information such as route guidance and obstacle warnings to passengers of moving bodies such as vehicles. For example, display on a liquid crystal display installed on a moving body, sound output from a speaker, and the like. In recent years, as one of such information providing means, an image superimposed on the driver's surrounding environment such as a head-up display (hereinafter referred to as HUD) or a window shield display (hereinafter referred to as WSD) is displayed. There is a device that provides information.

  Here, HUD and WSD as described above are effective for an object (for example, a pedestrian or another vehicle) that the driver wants to recognize in the driver's field of view without deviating the driver's line of sight from the front. It is possible to perform guidance for guiding the gaze. Further, when an image superimposed on the surrounding environment is visually recognized by an occupant, in addition to the case where the image is visually recognized by both eyes, the image is also visually recognized only by one eye.

  For example, in Japanese Patent Application Laid-Open No. 2015-194709, when generating a virtual image to be visually recognized by a user, if the user's stereoscopic distance is less than 50 m, the virtual image is generated by visually recognizing the image with both eyes, When the stereoscopic viewing distance is 50 m or more, it is disclosed that a virtual image is generated by causing an image to be viewed with only one eye. Thereby, it is possible to reduce the burden on the user and generate a virtual image with good visibility.

JP2015-194709 (page 5)

  Here, Patent Document 1 discloses that a virtual image is generated by visually recognizing an image with only one eye instead of both eyes when a certain condition is satisfied. However, if the period for visually recognizing the image with only one eye continues, the eyes to be visually recognized become fatigued, which in turn burdens the user. Furthermore, if the burden on the user increases, the visibility of the virtual image may be reduced.

  The present invention has been made to solve the above-described conventional problems, and in particular, by appropriately selecting the occupant's eyes for visually recognizing the image according to the position where the image is displayed, it is possible to visually recognize the occupant without burdening the occupant. It is an object of the present invention to provide a superimposed image display device capable of displaying a superimposed image with good characteristics.

In order to achieve the above object, a superimposed image display device according to the present invention is mounted on a vehicle and superimposes an image on a surrounding environment in front of the line of sight of the occupant of the vehicle. Eye position acquisition means for acquiring the position of both eyes, line-of-sight direction acquisition means for acquiring the sight line direction of the occupant, and a center line passing through a midpoint between the eyes of the occupant along the line-of-sight direction displays the image. A reference line setting means for setting a reference line in the display area based on an intersection intersecting the display area to be displayed, and a side corresponding to a left eye from the reference line in an image displayed in the display area The image displayed on the left eye is an image visually recognized only by the left eye, and the image displayed on the side corresponding to the right eye with respect to the reference line is displayed as an image visually recognized only by the right eye.
The “side corresponding to the left eye” is the display direction of the image with respect to the reference line for displaying the image on the left eye side as viewed from the occupant, and the “side corresponding to the right eye” is on the right eye side when viewed from the occupant. This is the display direction of the image with respect to the reference line for displaying the image.

  According to the superimposed image display device according to the present invention having the above-described configuration, when the image superimposed on the surrounding environment in front of the line of sight of the vehicle occupant is visually recognized, the reference line set in the display area for displaying the image is used as a reference. Thus, it is possible to appropriately select the eyes of the occupant who visually recognizes the image according to the position where the image is displayed. In particular, since an image that is easy to visually recognize with the left eye is viewed with the left eye and an image that is easily visible with the right eye is visually recognized with the right eye, it is possible to display a superimposed image with good visibility without placing a burden on the occupant.

It is a schematic block diagram of the superimposed image display apparatus which concerns on this embodiment. It is the block diagram which showed the navigation apparatus which concerns on this embodiment. It is the figure which showed the internal structure of HUD which concerns on this embodiment. It is the figure which showed the structure of the liquid crystal display which concerns on this embodiment. It is a flowchart of the virtual image generation processing program which concerns on this embodiment. It is the figure which showed an example of the warning image used as a display target on a liquid crystal display. It is a figure explaining the setting method of a reference line. It is the figure which showed an example of the reference line set to an image display area. It is the figure which showed an example of the reference line set when the direction of a crew member's face changes. It is the figure which showed an example of the reference line set based on a passenger | crew's dominant eye. It is the figure which showed an example of the virtual image of the warning image visually recognized from a passenger | crew.

  DETAILED DESCRIPTION Hereinafter, a superimposed image display device according to an embodiment of the present invention will be described in detail with reference to the drawings based on an embodiment. First, a schematic configuration of the superimposed image display apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a superimposed image display apparatus 1 according to the present embodiment.

  As shown in FIG. 1, a superimposed image display device 1 includes a navigation device 3 mounted on a vehicle 2 and a head-up display device (hereinafter referred to as HUD) 4 that is also mounted on the vehicle 2 and connected to the navigation device 3. And basically.

  Here, the navigation device 3 searches for a recommended route to the destination, detects the current position of the vehicle 2, obtains it from the server, or based on map data stored in the memory, around the current position of the vehicle 2 The map image is displayed, and the movement guidance along the set guidance route and the warning guidance for obstacles are performed together with the HUD 4. Note that the navigation device 3 does not have to have all of the above functions, and the present invention is configured if it has at least a function of performing movement guidance along a set guidance route and warning guidance for obstacles. Is possible. Details of the structure of the navigation device 3 will be described later.

  On the other hand, the HUD 4 is installed inside the dashboard 5 of the vehicle 2 and has a liquid crystal display 6 that is an image display area in which an image is displayed. The image displayed on the liquid crystal display 6 is further reflected on the front window 8 in front of the driver's seat through the concave mirror 7 provided in the HUD 4 as will be described later, so that the passenger 9 of the vehicle 2 can visually recognize the image. ing. The image displayed on the liquid crystal display 6 includes information related to the vehicle 2 and various information used for assisting the driving of the occupant 9. For example, a warning for an object (another vehicle or a pedestrian) that is a warning target for the occupant 9, guidance information set by the navigation device 3, guidance information based on the guidance route (an arrow indicating a right / left turn direction, etc.), There are warnings to be displayed (such as rear-end collision warnings, speed limits, etc.), current vehicle speed, information signs, map images, traffic information, news, weather forecasts, times, connected smartphone screens, TV programs, and the like.

  Further, in the HUD 4 of the present embodiment, when the occupant 9 visually recognizes the image displayed on the liquid crystal display 6 by reflecting the front window 8, the occupant 9 is not at the position of the front window 8 but at the tip of the front window 8. The image displayed on the liquid crystal display 6 at a distant position is visually recognized as a virtual image 10. Further, the virtual image 10 is visually recognized by being superimposed on the surrounding environment in front of the line of sight of the occupant 9, and is visually recognized by being superimposed on, for example, an arbitrary object (such as an object to be warned) located in the field of view of the occupant 9. It is also possible to make it. The virtual image 10 that can be seen by the occupant 9 is an image displayed on the liquid crystal display 6, but the vertical direction and the horizontal direction may be reversed through the concave mirror 7 and other mirrors. Therefore, it is necessary to display an image on the liquid crystal display 6. In addition, the size is changed through the concave mirror 7.

  In the present embodiment, as will be described later, the liquid crystal display 6 is a liquid crystal display including a parallax barrier or a lenticular lens, and can display an image that is visible only to any one eye. That is, the HUD 4 according to the present embodiment can generate the virtual image 10 that is visible only with one eye.

  Here, regarding the position where the virtual image 10 is generated, more specifically, the distance L from the occupant 9 to the virtual image 10 (hereinafter referred to as the imaging distance) L, the curvature of the concave mirror 7 provided in the HUD 4, the liquid crystal display 6 and the concave mirror 7 It is possible to set as appropriate depending on the relative position of the. For example, if the curvature of the concave mirror 7 is fixed, the imaging distance L is determined by the distance (optical path length) along the optical path from the position where the image is displayed on the liquid crystal display 6 to the concave mirror 7. For example, the optical path length is set so that the imaging distance L is 25 m. Details of the structure of the HUD 4 will be described later.

  In this embodiment, the HUD 4 is used as a means for displaying an image to be superimposed on the field of view of the occupant 9, but other means may be used. For example, a window shield display (WSD) that displays an image on the front window 8 may be used. For example, an image may be displayed from a projector using the front window 8 as a screen, or the front window 8 may be a transmissive liquid crystal display. The image displayed on the front window 8 by the WSD is an image superimposed on the field of view of the occupant 9 as with the HUD 4.

  A front camera 11 is installed above the front bumper of the vehicle, behind the rearview mirror, and the like. The front camera 11 is an imaging device having a camera using a solid-state imaging device such as a CCD, for example, and is installed with the optical axis direction facing forward in the traveling direction of the vehicle. Then, by performing image processing on the captured image captured by the front camera 11, the situation of the front environment (that is, the environment in which the virtual image 10 is superimposed) that is visually recognized by the occupant 9 through the front window 8 is detected. Is done. A sensor such as a millimeter wave radar may be used instead of the front camera 11.

  An in-vehicle camera 12 is installed on the upper surface of the instrument panel of the vehicle. The in-vehicle camera 12 is an imaging device having a camera using a solid-state imaging device such as a CCD, for example, and is installed with the optical axis direction facing the driver's seat. Then, the face of the occupant 9 sitting in the driver's seat is imaged. Then, image processing is performed on the captured image captured by the in-vehicle camera 12, thereby detecting the eye position and line-of-sight direction of the occupant 9.

  Next, a schematic configuration of the navigation device 3 included in the superimposed image display device 1 will be described with reference to FIG. FIG. 2 is a block diagram showing the navigation device 3 according to the present embodiment.

  As shown in FIG. 2, the navigation device 3 according to the present embodiment includes a current position detection unit 13 that detects the current position of the vehicle 2 on which the navigation device 3 is mounted, and a data recording unit 14 that records various data. The navigation ECU 15 that performs various arithmetic processes based on the input information, the operation unit 16 that receives operations from the user, and the liquid crystal display 17 that displays facility information related to the map and facilities around the vehicle to the user. And a speaker 18 that outputs voice guidance related to route guidance, a DVD drive 19 that reads a DVD as a storage medium, and a communication that communicates with an information center such as a VICS (registered trademark: Vehicle Information and Communication System) center. And a module 20. The navigation device 3 is connected to the HUD 4, the front camera 11, the in-vehicle camera 12, and the like described above via an in-vehicle network such as CAN.

Below, each component which the navigation apparatus 3 has is demonstrated in order.
The current position detection unit 13 includes a GPS 21, a vehicle speed sensor 22, a steering sensor 23, a gyro sensor 24, and the like, and can detect the current vehicle position, direction, vehicle traveling speed, current time, and the like. . Here, in particular, the vehicle speed sensor 22 is a sensor for detecting a moving distance and a vehicle speed of the vehicle, generates a pulse according to the rotation of the driving wheel of the vehicle, and outputs a pulse signal to the navigation ECU 15. And navigation ECU15 calculates the rotational speed and moving distance of a driving wheel by counting the generated pulse. In addition, it is not necessary for the navigation device 3 to include all the four types of sensors, and the navigation device 3 may include only one or a plurality of types of sensors.

  The data recording unit 14 is also a hard disk (not shown) as an external storage device and a recording medium, and a driver for reading the map information DB 31 and a predetermined program recorded on the hard disk and writing predetermined data on the hard disk And a recording head (not shown). The data recording unit 14 may include a flash memory, a memory card, an optical disk such as a CD or a DVD, instead of the hard disk. The map information DB 31 may be stored in an external server, and the navigation device 3 may be configured to acquire by communication.

  Here, the map information DB 31 is, for example, link data 32 regarding roads (links), node data 33 regarding node points, point data 34 regarding points such as facilities, intersection data regarding each intersection, and map display data for displaying a map. The storage means stores search data for searching for routes, search data for searching for points, and the like.

  Here, as the link data 32, for example, a link ID for identifying the link, end node information for specifying a node located at the end of the link, a road type of a road formed by the link, and the like are stored. . The node data 33 stores a node ID for identifying the node, position coordinates of the node, connection destination node information for specifying a connection destination node to which the node is connected through a link, and the like. Further, as the point data 34, various types of information related to the facility to be set as the destination are stored. For example, an ID for specifying a facility, a facility name, position coordinates, a genre, an address, and the like are stored.

  On the other hand, the navigation ECU (Electronic Control Unit) 15 is an electronic control unit that controls the entire navigation device 3, and includes a CPU 41 as an arithmetic device and a control device, and a working memory when the CPU 41 performs various arithmetic processes. Read out from the ROM 43 and the ROM 43 in which the RAM 42 storing the route data when the route is searched, the control program, the virtual image generation processing program (FIG. 5) described later, and the like are recorded. An internal storage device such as a flash memory 44 for storing the program is provided. The navigation ECU 15 has various means as processing algorithms. For example, the eye position acquisition unit acquires the positions of both eyes of the occupant 9. The line-of-sight acquisition unit acquires the line-of-sight direction of the occupant 9. The reference line setting means sets a reference line in the display area of the liquid crystal display 6 based on the intersection point where the center line passing through the midpoint between the eyes of the occupant 9 along the line of sight intersects the display area of the liquid crystal display 6 To do.

  The operation unit 16 is operated when inputting a starting point as a travel start point and a destination as a travel end point, and has a plurality of operation switches (not shown) such as various keys and buttons. Then, the navigation ECU 15 performs control to execute various corresponding operations based on switch signals output by pressing the switches. The operation unit 16 may have a touch panel provided on the front surface of the liquid crystal display 17. Moreover, you may have a microphone and a speech recognition apparatus.

  The liquid crystal display 17 includes a map image including a road, traffic information, operation guidance, an operation menu, key guidance, a guidance route from the departure point to the destination, guidance information along the guidance route, news, weather forecast, Time, mail, TV program, etc. are displayed. In this embodiment, since the HUD 4 is provided as the information display means, the liquid crystal display 17 may be omitted if the map image or the like is displayed on the HUD 4.

  Further, the speaker 18 outputs voice guidance for guiding traveling along the guidance route and traffic information guidance based on an instruction from the navigation ECU 15.

  The DVD drive 19 is a drive that can read data recorded on a recording medium such as a DVD or a CD. Based on the read data, music and video are reproduced, the map information DB 31 is updated, and the like. A card slot for reading / writing a memory card may be provided in place of the DVD drive 19.

  The communication module 20 is a communication device for receiving traffic information composed of information such as traffic jam information, regulation information, traffic accident information transmitted from a traffic information center, for example, a VICS center or a probe center, For example, a mobile phone or DCM is applicable.

  Next, a schematic configuration of the HUD 4 included in the superimposed image display device 1 will be described with reference to FIG. FIG. 3 is a diagram showing an internal configuration of the HUD 4 according to the present embodiment.

  As shown in FIG. 3, the HUD 4 basically includes a liquid crystal display 6, a concave mirror 7, a cover glass 51, a control circuit unit 52, and a CAN interface 53.

  Here, the liquid crystal display 6 is an image display device that uses a backlight as a light source and has a function of displaying an image on an image display area provided on the front surface. As the backlight, for example, a CCFL (cold cathode tube) or a white LED is used. Further, the liquid crystal display 6 includes a parallax barrier or a lenticular lens, and in addition to an image that can be seen by both eyes of the occupant 9, an image that can be seen by only one of the eyes can be displayed. .

  For example, in the liquid crystal display 6 using a parallax barrier, as shown in FIG. 4, a parallax barrier (parallax barrier) 56 in which gaps are formed in a lattice shape is disposed in front of the image display area 55 of the liquid crystal display 6. Then, if an image is displayed only in an area that is visible from the left eye of the occupant 9 through the gap between the parallax barriers 56 in the image display area 55, the image becomes an image that is visible only to the left eye. On the other hand, if an image is displayed only in a region that is visible through the gap between the parallax barrier 56 from the right eye of the occupant 9 in the image display region 55, the image becomes an image that is visible only to the right eye. As a means for displaying an image, in addition to the liquid crystal display, an organic EL display, a combination of a projector and a screen, or the like may be used. However, it is desirable to be a means capable of displaying an image that is visible to only one eye. When a combination of a projector and a screen is used, the screen corresponds to an image display area where an image is displayed.

  On the other hand, the concave mirror 7 is a projection mirror that generates a virtual image of an image in front of the occupant 9 by enlarging and reflecting the image displayed on the liquid crystal display 6 and causing the occupant 9 to visually recognize the image. As the concave mirror 7, a spherical concave mirror, an aspherical concave mirror, or a free-form curved mirror for correcting distortion of a display image is used. Since the image displayed on the liquid crystal display 6 is reflected by the concave mirror 7, the generated virtual image 10 is an image that is upside down with respect to the image displayed on the liquid crystal display 6.

  The cover glass 51 is a transmissive plate-like member disposed on the upper surface of the HUD 4. The image displayed on the liquid crystal display 6 is reflected by the concave mirror 7 and is visually recognized by the occupant 9 through the cover glass 51. As the cover glass 51, a Fresnel lens may be used. Further, when a Fresnel lens is used as the cover glass 51, a flat mirror can be used instead of the concave mirror 7.

  The control circuit unit 52 is an electronic control unit that controls the entire HUD 4. Here, the control circuit unit 52 includes a CPU as an arithmetic device and a control device, a RAM used as a working memory when the CPU performs various arithmetic processes, a control program, and a control for generating a virtual image. An internal storage device such as a ROM in which programs are recorded is provided. The control circuit unit 52 is connected to the liquid crystal display 6 and performs drive control of the liquid crystal display 6.

  The CAN (controller area network) interface 53 is an interface for inputting / outputting data to / from CAN, which is a vehicle-mounted network standard that performs multiplex communication between various vehicle-mounted devices and control devices for vehicle equipment installed in the vehicle. It is. The HUD 4 is connected to various on-vehicle devices and vehicle equipment control devices (for example, the navigation device 3 and the AV device) via the CAN so as to communicate with each other. Accordingly, the HUD 4 is configured to be able to project information acquired from the navigation device 3 or the AV device.

  Next, a virtual image generation processing program executed in the navigation device 3 in the superimposed image display device 1 having the above configuration will be described with reference to FIG. FIG. 5 is a flowchart of the virtual image generation processing program according to the present embodiment. Here, the virtual image generation processing program is executed after the ACC power supply (accessory power supply) of the vehicle is turned on, and generates a superimposed image that is superimposed on the surrounding environment and visually recognized by the occupant 9 of the vehicle 2 using the HUD 4. It is a program to do. Note that the program shown in the flowchart of FIG. 5 below is stored in the RAM 42 or the ROM 43 provided in the navigation device 3 and is executed by the CPU 41.

  First, in step (hereinafter abbreviated as S) 1 in the virtual image generation processing program, the CPU 41 acquires a surrounding environment in front of the occupant's line of sight of the vehicle occupant based on the captured image captured by the front camera 11. For example, 3D data of the surrounding environment is created from the captured image of the front camera 11 and stored in the flash memory 44 or the like.

  Next, in S2, the CPU 41 determines whether there is an object to be warned to the vehicle occupant (hereinafter referred to as a warning object) ahead of the traveling direction of the vehicle based on the surrounding environment acquired in S1. judge. Here, the warning object is an object to be watched by a passenger who rides the vehicle, for example, another vehicle, a pedestrian, or a two-wheeled vehicle. It should be noted that other objects that should be watched by the passenger, such as signs and traffic lights, may be included in the warning object.

  Further, the presence or absence of a warning object in front of the traveling direction of the vehicle may be detected, for example, by performing image processing such as template matching on a captured image captured by the front camera 11, or created in S1. It may be detected from 3D data of the surrounding environment, or may be detected using a sensor such as a millimeter wave radar. Moreover, you may acquire by communication with a vehicle-to-vehicle communication or an external server.

  And when it determines with there being a warning target object ahead of the advancing direction of a vehicle (S2: YES), it transfers to S3. On the other hand, when it is determined that there is no warning object ahead in the traveling direction of the vehicle (S2: NO), the virtual image generation processing program is terminated.

  In S3, the CPU 41 obtains a specific position of the warning object that is determined to be ahead of the vehicle in the traveling direction. Note that the position of the warning object may be acquired, for example, by performing image processing on a captured image captured by the front camera 11, or may be detected from the 3D data of the surrounding environment created in S1. However, it may be acquired using a sensor such as a millimeter wave radar. Moreover, you may acquire by communication with a vehicle-to-vehicle communication or an external server. Further, the position of the warning object may be an absolute position, or a relative position with respect to an occupant (own vehicle). In addition, when there are a plurality of warning objects, the positions of the plurality of warning objects are acquired.

  Note that the CPU 41 continuously detects the position of the warning object ahead of the traveling direction of the vehicle until the virtual image generation processing program ends.

  Next, in S <b> 4, the CPU 41 detects the line-of-sight start point (eye position) and line-of-sight direction of the occupant 9 based on the captured image of the in-vehicle camera 12. For the eye position, the position of each eye of the right eye and the left eye is acquired. As described above, the in-vehicle camera 12 is installed on the instrument panel or the ceiling of the vehicle, and is installed with the imaging direction facing the driver's seat, and the captured image includes the face of the occupant 9. As a method of detecting the eye position and the line-of-sight direction, for example, there is a method of detecting using the center position of the pupil or the Purkinje image measured by the corneal reflection method. Since these methods are already known techniques, details are omitted.

  Thereafter, in S5, the CPU 41 generates an image to be displayed on the liquid crystal display 6 of the HUD 4 (hereinafter referred to as a warning image). In particular, in the present embodiment, the warning image is an image for warning a warning object, for example, a warning mark 61 as shown in FIG. 6 or a frame 62 surrounding the warning object. Further, in the present embodiment, the warning image is generated in two patterns, that is, an image for visualizing only to the right eye and an image for visualizing only to the left eye.

  Next, in S <b> 6, the CPU 41 sets a reference line in the display area based on an intersection where the center line passing through the midpoint between the eyes of the occupant intersects the display area displaying the warning image along the line-of-sight direction. . In the present embodiment, the display area for displaying the warning image is the image display area of the liquid crystal display 6 in the HUD 4.

The method for setting the reference line will be described in detail below.
First, as shown in FIG. 7, the CPU 41 extends a center line 63 passing through the midpoint X of the positions of both eyes of the occupant 9 detected in S <b> 4 along the line-of-sight direction Y, and displays the image display area 55 of the liquid crystal display 6. Identify the intersecting point Z. The line-of-sight direction Y is reflected by the front window 8 and the concave mirror 7 and the direction changes. Therefore, the center line 63 is similarly changed according to the line-of-sight direction Y.
Next, as shown in FIG. 8, the CPU 41 sets a line that passes through the intersection Z and is parallel to the vertical direction (or vertical direction) of the image display area 55 of the liquid crystal display 6 as the reference line 65. The reference line 65 is not necessarily a line parallel to the vertical direction of the image display area 55, and may be a line inclined with respect to the vertical direction. Furthermore, a curved line or a bent line can be used.

  The example shown in FIG. 8 is a reference line 65 that is set when the occupant 9 is facing the front. For example, when the occupant 9 turns to the left as shown in FIG. In addition, the position of the reference line 65 also moves to the left. On the other hand, when the occupant 9 turns to the right, the position of the intersection Z and the reference line 65 also moves to the right according to the angle of the face.

  Further, the CPU 41 acquires the dominant eye of the occupant 9 and passes a point farther away from the side corresponding to the dominant eye than the intersection Z, and a line parallel to the vertical direction of the image display area 55 is used as a reference line. good. For example, as shown in FIG. 10, if the dominant eye of the occupant 9 is the right eye, the position of the reference line 65 is moved from the intersection Z to the side opposite to the side corresponding to the dominant eye (ie, the left side) (for example, the image display area). It is good also as a line which passes the point which moved 10% of the width of 55). On the other hand, if the dominant eye of the occupant 9 is the left eye, the position of the reference line 65 may be a line that passes the point moved to the opposite side (ie, the right side) corresponding to the dominant eye. As a result, it is possible to make an image visible to a dominant eye over a non-dominant eye. The dominant eye of the occupant 9 may be detected using the in-vehicle camera 12 or may be input to the occupant 9 in advance.

  Subsequently, in S7, the CPU 41 displays the warning image to be displayed on the image display area 55 of the liquid crystal display 6 on the right side of the reference line 65 set in S6 (that is, the side corresponding to the right eye). It is determined whether to display on the left side (that is, the side corresponding to the left eye). Note that the position where the warning image is displayed is determined based on the position of the warning object acquired in S3, with the virtual image 10 of the warning image being superimposed on the warning object. Basically, in order to generate a virtual image 10 to be superimposed on a warning object located on the right side (right eye side) with respect to the occupant, a warning image is displayed on the right side of the reference line 65, and the left side ( In order to generate the virtual image 10 to be superimposed on the warning object located on the left eye side), the warning image is displayed on the left side of the reference line 65. However, when the image is reversed left and right by a mirror or the like arranged in the HUD 4, the left and right are reversed (that is, the left side of the reference line corresponds to the right eye and the right side of the reference line corresponds to the left eye). It may be the side to do.)

  If it is determined that the warning image to be displayed on the image display area 55 of the liquid crystal display 6 is displayed on the right side of the reference line 65 set in S6 (S7: YES), the process proceeds to S8. Transition. On the other hand, if it is determined that the warning image to be displayed on the image display area 55 of the liquid crystal display 6 is displayed on the left side of the reference line 65 set in S6 (S7: NO), the process proceeds to S9. Transition.

  In S <b> 8, the CPU 41 displays, on the image display area 55 of the liquid crystal display 6, an image to be viewed only by the right eye among the warning images generated in S <b> 5. As shown in FIG. 4, the liquid crystal display 6 of the present embodiment has a parallax barrier 56 formed with gaps in a lattice shape, for example, and displays a warning image for an area that is visible only to the right eye. Thus, it is possible to make the warning image visible only to the right eye. As a result, as shown in FIG. 11, the virtual image 10 superimposed on the warning object 71 ahead of the traveling direction of the vehicle is visually recognized at a position away from the occupant of the vehicle by the imaging distance L (for example, 25 m). Thereby, it is possible to guide the occupant's line of sight to the warning object 71 by the virtual image 10 and to make the warning object 71 visible to the user with certainty. Further, since the virtual image 10 that is seen in the right direction (right eye side) with respect to the occupant 9 is visually recognized by the right eye, it is possible to reduce the burden of visual recognition of the virtual image 10 as much as possible.

  In the present embodiment, the imaging distance L is a fixed value, but the imaging distance L can be arbitrarily changed by moving the liquid crystal display 6, for example. Further, when the imaging distance L can be changed, the CPU 41 acquires the imaging distance L of the currently displayed virtual image 10, and particularly when the imaging distance K is less than a threshold value (for example, less than 10 m), The warning image may be displayed on the liquid crystal display 6 as an image visually recognized by both eyes.

  On the other hand, in S <b> 9, the CPU 41 displays, on the image display area 55 of the liquid crystal display 6, an image for allowing only the left eye to be visually recognized among the warning images generated in S <b> 5. By displaying a warning image for a region that is visible only to the left eye, it is possible to make the warning image visible only to the left eye. Details are the same as in S8, and are omitted.

  In addition, when there are a plurality of warning objects and warning images are superimposed on each warning object, that is, when a plurality of warning images are displayed at the same time, each of the warning images to be displayed is S7 to S7. The process of S9 is executed. Therefore, a warning image that is visible only to the right eye and a warning image that is visible only to the left eye may be displayed at the same time. Further, when a plurality of warning images are displayed at the same time and a predetermined number or more (for example, 5 or more) of images are displayed only on one side with respect to the reference line 65, the distance from the reference line 65 is short. It is desirable to display a predetermined number (for example, 1/3 of the total display number) of images smaller than the predetermined number in order as images that are visible only to the eyes corresponding to the other side. For example, when six images are displayed only on the right side of the reference line 65, the two images in order of increasing distance from the reference line 65 are images that are visible only to the left eye, and other images are displayed. It is desirable to display it as an image that is visible only to the right eye.

  Further, since the display position of the warning image is a position where the virtual image 10 is superimposed on the warning object, if the position of the warning object (but not the absolute position but the relative position from the occupant) moves, the warning will be given accordingly. The display position of the image is also moved. Therefore, in S10, the CPU 41 determines whether or not the display position of the warning image has crossed the reference line 65 set in S6 as a result of moving the display position of the warning image.

  If it is determined that the display position of the warning image has crossed the reference line 65 set in S6 (S10: YES), the process proceeds to S11. On the other hand, when it is determined that the display position of the warning image does not cross the reference line 65 set in S6 (S11: NO), the current display of the warning image is maintained. Thereafter, the virtual image generation processing program is terminated when the warning object disappears.

  In S11, the CPU 41 determines whether or not the display position of the warning image has crossed the reference line 65 set in S6 a plurality of times within a predetermined interval (for example, 1 sec) as a result of moving the display position of the warning image.

  When it is determined that the display position of the warning image does not cross the reference line 65 set in S6 at a predetermined interval or less (S11: NO), the process proceeds to S12.

  In S <b> 12, the CPU 41 switches the warning image to an image that is visually recognized in the corresponding direction before and after the reference line 65 is crossed. That is, when the display position of the warning image moves from the right side to the left side of the reference line 65, the warning image that is visible only to the right eye at the timing across the reference line 65 is switched to the warning image that is visible only to the left eye.

  On the other hand, when it is determined that the display position of the warning object has crossed the reference line 65 set in S6 a plurality of times at a predetermined interval or less (S11: YES), the display of the current warning image is maintained. To do. That is, even if the display position of the warning image is moved from the right side to the left side of the reference line 65, the warning image is displayed as seen only by the right eye. Thereafter, the virtual image generation processing program is terminated when the warning object disappears.

  As described above in detail, the superimposed image display device 1 according to the present embodiment acquires the position and line-of-sight direction of both eyes of the occupant when the image superimposed on the surrounding environment in front of the line of sight of the vehicle occupant is visually recognized ( S4) A reference line is set in the display area based on the intersection where the center line passing through the midpoint between both eyes of the occupant along the line-of-sight direction intersects the display area of the image (S6), and is displayed in the display area. Of the images, the image displayed on the side corresponding to the left eye with respect to the reference line is displayed as an image to be viewed only by the left eye, and the image displayed on the side corresponding to the right eye with respect to the reference line is displayed as an image to be viewed only with the right eye. Thus (S8, S9), it is possible to appropriately select the eyes of the occupant who visually recognizes the image according to the position where the image is displayed with reference to the reference line set in the display area where the image is displayed. In particular, since an image that is easy to visually recognize with the left eye is viewed with the left eye and an image that is easily visible with the right eye is visually recognized with the right eye, it is possible to display a superimposed image with good visibility without placing a burden on the occupant.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the present embodiment, the virtual image is generated in front of the front window 8 of the vehicle 2 by the HUD 4, but the virtual image may be generated in front of a window other than the front window 8. In addition, the object to be reflected by the HUD 4 may be a visor (combiner) installed around the front window 8 instead of the front window 8 itself.

  In the present embodiment, the superimposed image display device 1 is installed on the vehicle 2. However, the superimposed image display device 1 may be installed on a moving body other than the vehicle 2. For example, it can be installed on a ship or an aircraft. Moreover, you may install in the ride type attraction installed in an amusement facility. In that case, a superimposed image can be generated around the ride so that the rider can visually recognize the superimposed image.

  In this embodiment, the HUD 4 is used as means for displaying an image to be superimposed on the surrounding environment. However, a window shield display (WSD) that displays an image on the front window 8 may be used. When WSD is used, the image display area is the front window 8 of the vehicle, and the reference line 65 is set for the front window 8. Further, it is necessary to arrange a parallax barrier 56 as shown in FIG. 4 with respect to the front surface of the front window 8.

  In the present embodiment, a warning image for warning a warning object is displayed as a superimposed image for guidance by being superimposed on the surrounding environment and visually recognized by the occupant 9, but the displayed image is another image. It is also good. For example, an arrow, a guide sign, a map image, traffic information, news, weather forecast, time, a connected smartphone screen, a television screen, or the like may be used.

  In the present embodiment, the image is superimposed on the warning object that is a warning target for the occupant. However, the target object on which the image is to be superimposed may be other than the warning target. For example, a road surface or a facility may be used.

  Further, in the present embodiment, the processing of the virtual image generation processing program (FIG. 4) is configured to be executed by the navigation ECU 15 of the navigation device 3, but the execution subject can be changed as appropriate. For example, it is good also as a structure which the control part of HUD4, ECU for vehicle control, and another onboard equipment perform. In addition, when the control part of HUD4 performs, the superimposed image display apparatus 1 which concerns on this invention can also be comprised only with HUD4.

  Further, although the embodiment embodying the superimposed image display device according to the present invention has been described above, the virtual image display device can also have the following configuration, and in that case, the following effects can be obtained.

For example, the first configuration is as follows.
A superimposed image display device (1) mounted on a vehicle (2) for superimposing an image on a surrounding environment in front of the line of sight of an occupant (9) of the vehicle, and acquiring an eye position of the occupant Position acquisition means (41), line-of-sight direction acquisition means (41) for acquiring the line-of-sight direction of the occupant, and a center line passing through a midpoint between both eyes of the occupant along the line-of-sight direction displays the image. Reference line setting means for setting a reference line (65) in the display area based on an intersection intersecting the display area (55), and the image displayed in the display area is more than the reference line. The image displayed on the side corresponding to the left eye is displayed as an image to be viewed only by the left eye, and the image displayed on the side corresponding to the right eye from the reference line is displayed as an image viewed only by the right eye.
According to the superimposed image display device having the above configuration, when an image to be superimposed on the surrounding environment in front of the line of sight of the vehicle occupant is visually recognized, the image is displayed with reference to the reference line set in the display area for displaying the image. It is possible to appropriately select an occupant's eye for visually recognizing the image according to the position to be performed. In particular, since an image that is easy to visually recognize with the left eye is viewed with the left eye and an image that is easily visible with the right eye is visually recognized with the right eye, it is possible to display a superimposed image with good visibility without placing a burden on the occupant.

The second configuration is as follows.
The reference line setting means (41) sets a line passing through the intersection and parallel to the vertical direction of the display area (55) as a reference line (65).
According to the superimposed image display device having the above-described configuration, an image display area is divided into right and left particularly with the sight line direction of the occupant as the center, the image displayed in the left area is the left eye, and the image displayed on the right is Since it is visually recognized by the right eye, it is possible to display a superimposed image with good visibility without placing a burden on the passenger.

The third configuration is as follows.
It has a dominant eye acquisition means (41) for acquiring the dominant eye of the occupant, and the reference line (65) passes through a point farther away from the side corresponding to the dominant eye than the intersection and the display A line parallel to the vertical direction of the region (55) is taken as a reference line.
According to the superimposed image display device having the above-described configuration, the image is preferentially visually recognized with respect to the dominant eyes of the occupant, so that it is possible to reduce the burden on the occupant related to the visual recognition of the image.

The fourth configuration is as follows.
When the display position of the image displayed in the display area (55) crosses the reference line (65), the display position is switched to an image that allows the image to be visually recognized in a corresponding direction before and after the crossing. When the display position of the image displayed in the display area crosses the reference line a plurality of times at a predetermined interval or less, the image is not switched before and after the crossing.
According to the superimposed image display device having the above configuration, it is possible to prevent frequent switching of the eyes that visually recognize the image, particularly when the display position of the image moves.

The fifth configuration is as follows.
In the case where a predetermined number or more images are displayed only on one side with respect to the reference line (65) in the display area (55), a predetermined number of images less than the predetermined number in order of increasing distance from the reference line. Is displayed as an image that is visible only to the eye corresponding to the other side.
According to the superimposed image display device having the above-described configuration, it is possible to display the image so that the burden is not biased to only one eye particularly when a large number of images are displayed.

The sixth configuration is as follows.
The occupant (9) of the vehicle visually recognizes the virtual image (10) displayed in the display area (55) superimposed on the surrounding environment, and changes the imaging distance from the occupant to the virtual image. An image distance changing means (41), and an imaging distance acquisition means (41) for acquiring the imaging distance of the currently displayed virtual image, and when the imaging distance is less than a threshold value, The image displayed in the display area is displayed as an image that can be viewed by both eyes.
According to the superimposed image display device having the above-described configuration, in the case where the virtual image of the image is visually recognized by the vehicle occupant, in a situation where it is possible to visually recognize a clear virtual image with less burden on the user when viewed with both eyes, By making an image displayed in the display area visible with both eyes, a more appropriate virtual image can be generated.

DESCRIPTION OF SYMBOLS 1 Superimposed image display apparatus 2 Vehicle 3 Navigation apparatus 4 HUD
6 Liquid crystal display 8 Front window 10 Virtual image 15 Navigation ECU
41 CPU
42 RAM
43 ROM
55 Image display area 61, 62 Warning image 71 Warning object

Claims (6)

A superimposed image display device that is mounted on a vehicle and superimposes an image on a surrounding environment ahead of the line of sight of the occupant of the vehicle,
Eye position acquisition means for acquiring the positions of both eyes of the occupant;
Gaze direction acquisition means for acquiring the occupant's gaze direction;
A reference line setting means for setting a reference line in the display area based on an intersection where a center line passing through a midpoint between both eyes of the occupant along the line-of-sight direction intersects the display area displaying the image; Have
Of the images displayed in the display area, an image displayed on the side corresponding to the left eye with respect to the reference line is an image to be viewed only by the left eye, and an image displayed on the side corresponding to the right eye with respect to the reference line is A superimposed image display device that displays an image that is visible only to the right eye.   The superimposed image display device according to claim 1, wherein the reference line setting unit uses a line passing through the intersection and parallel to the vertical direction of the display area as a reference line. A dominant eye acquisition means for acquiring the dominant eye of the occupant;
2. The superimposed image display according to claim 1, wherein the reference line passes through a point distant from a side corresponding to a dominant eye with respect to the intersection and is parallel to the vertical direction of the display area as a reference line. apparatus. When the display position of the image displayed in the display area crosses the reference line, while switching to an image that allows the image to be visually recognized in a corresponding direction before and after the crossing,
The image is not switched between before and after the display position when the display position of the image displayed in the display area crosses the reference line a plurality of times at a predetermined interval or less. Superimposed image display device.   In a case where a predetermined number or more images are displayed only on one side with respect to the reference line in the display area, a predetermined number of images that are smaller than the predetermined number correspond to the other side in order of increasing distance from the reference line. The superimposed image display device according to any one of claims 1 to 4, wherein the superimposed image display device displays an image that is visible only to the eyes. In the vehicle occupant, a virtual image of the image displayed in the display area is visually recognized superimposed on the surrounding environment,
Imaging distance changing means for changing the imaging distance from the occupant to the virtual image;
Imaging distance acquisition means for acquiring the imaging distance of the currently displayed virtual image,
The superimposed image display device according to any one of claims 1 to 5, wherein when the imaging distance is less than a threshold value, an image to be displayed in the display area is displayed as an image visually recognized by both eyes.

Images