Navigation device, head-up display, control method, program, and storage medium

Abstract

To provide a navigation device and a head-up display that enable a driver to visually recognize a route guidance image in good condition.SOLUTION: A head-up display 2 includes a light source unit 4 and a combiner 9. A control part 55 of the light source unit 4 controls a communication part 56 to acquire positional information on a vehicle Ve from a navigation device 1. The control part 55 then controls the combiner 9 to display a route guidance image and switches between a normal mode and a wide area mode. When a route distance Dtag in a display object area Atag in the normal mode becomes equal to or less than a first threshold Dth1, the control part 55 switches to the wide area mode.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a display technique for providing route guidance. [Background technology]

[0002] Conventionally, there has been known an in-vehicle display system that displays a route guidance image showing a route from a current position to a destination or a stop-off point. For example, Patent Document 1 discloses a head-up display that displays a route guidance image showing a route from a current position to a destination or a stop-off point in correspondence with the road surface included in the scenery in front of the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-79930 Summary of the Invention [Problem to be solved by the invention]

[0004] When approaching a curve with a large curvature or a turning point, the head-up display will make a large turn in the guided route, and the route guidance image will also make a similar turn, shortening the distance of the route shown in the route guidance image. In this case, the user can only grasp the immediate route from the route guidance image, which can make them feel uneasy because they do not know what the route beyond is.

[0005] The present invention has been made to solve the above-mentioned problems, and its main object is to provide a navigation device and a head-up display that can allow a user to view a route guidance image in a preferred manner. [Means for solving the problem]

[0006] The claimed invention is a control means for switching between a normal mode in which a route guidance image showing a route to be taken by the moving body is superimposed on a view ahead of the moving body or a view ahead of the moving body captured by a photograph of the view ahead, and a wide-area mode in which a route guidance image having a wider range than that of the normal mode is displayed on the display means; The control means displays a route guidance image corresponding to roads located in an area within a first angle range including the direction of travel of the moving body in the normal mode, and displays a route guidance image corresponding to roads located in an area within a second angle range wider than the first angle range in the wide area mode, and is a navigation device characterized by switching to the wide area mode when the length of the road corresponding to the route guidance image in the normal mode is less than a predetermined value.

[0007] The claimed invention also includes: A control method executed by a navigation device, comprising: a control step of switching between a normal mode in which a route guidance image showing a route to be taken by the moving body is superimposed on a view ahead of the moving body or a view ahead of the moving body captured by a photograph of the view ahead, and a wide-area mode in which a route guidance image having a wider range than that of the normal mode is displayed on the display means; In the control process, in the normal mode, a route guidance image corresponding to roads existing in an area within a first angle range including the direction of travel of the moving body is displayed, and in the wide area mode, a route guidance image corresponding to roads existing in an area within a second angle range wider than the first angle range is displayed, and when the length of the road corresponding to the route guidance image in the normal mode is less than a predetermined value, the mode is switched to the wide area mode.

[0008] The claimed invention also includes: A computer-executable program, a control means for switching between a normal mode in which a route guidance image showing a route to be taken by the mobile body is superimposed on a view ahead of the mobile body or a photographed view ahead of the mobile body, and a wide-area mode in which a route guidance image with a wider range than that in the normal mode is displayed on the display means; causing the computer to function as The control means is characterized in that in the normal mode, it displays a route guidance image corresponding to roads located in an area within a first angle range that includes the direction of travel of the moving body, and in the wide area mode, it displays a route guidance image corresponding to roads located in an area within a second angle range that is wider than the first angle range, and switches to the wide area mode when the length of the road corresponding to the route guidance image in the normal mode is less than a predetermined value. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows a schematic configuration of a display system. [Figure 2] 1 shows a schematic configuration of a navigation device. [Figure 3] 1 shows a schematic configuration of a head-up display. [Figure 4] 2 shows a schematic configuration of a light source unit. [Figure 5] (A) shows the set range of the display area within the map showing the area around the current position. (B) is an example of the view ahead as seen from the driver's seat in the example of (A). [Figure 6] This shows the state after the vehicle has traveled a predetermined distance from the example of FIG. [Figure 7] This shows the state after switching from the example in Figure 6 to wide-area mode. [Figure 8] FIG. 10 is a diagram for explaining a method for calculating a route distance. [Figure 9] FIG. 10 is a diagram for explaining a method for calculating a route distance. [Figure 10] 10 shows a flowchart illustrating a process in a normal mode. [Figure 11] 10 shows a flowchart illustrating processing in wide area mode. [Figure 12] 10 shows the configuration of a display system according to a modified example. [Figure 13] 10 shows a display example according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] In one preferred embodiment of the present invention, a navigation device comprises an acquisition means for acquiring the position of a moving body, and a control means for switching between a normal mode in which a route guidance image showing a route from the current position of the moving body to a destination or a stop-off point is displayed on a display means by superimposing the route guidance image on a scenery ahead of the moving body or a photographed forward image of the scenery, and in which the route guidance image is displayed on the display means in correspondence with a road surface corresponding to the route included in the scenery or the forward image, and a wide-area mode in which a route guidance image showing a route over a wider area than the route guidance image displayed in the normal mode is displayed on the display means, and the control means switches to the wide-area mode when the distance of the road surface corresponding to the route guidance image when the route guidance image is displayed in the normal mode becomes less than a predetermined value.

[0011] The navigation device includes an acquisition unit and a control unit. The acquisition unit acquires the position of the moving object. The control unit displays a route guidance image on the display unit and switches between a normal mode and a wide-area mode. Here, the route guidance image is superimposed on a scenery ahead of the moving object or a captured forward image of the scenery, showing a route from the moving object's current location to a destination or a stop-off point. The normal mode is a mode in which the display unit displays the route guidance image in correspondence with a road surface corresponding to the route included in the scenery or forward image. The wide-area mode is a mode in which the display unit displays a route guidance image showing a wider range of route than the route guidance image displayed in the normal mode. The control unit switches to the wide-area mode when the distance of the road surface corresponding to the route guidance image displayed in the normal mode is equal to or less than a predetermined value. In this aspect, the navigation device switches to a route guidance image showing a wider range of route when the distance of the road surface corresponding to the route guidance image is short. This allows the navigation device to make the user aware of an appropriate route range, even when approaching a curve with a large curvature or a point where the vehicle is to turn right or left, and gives the user a sense of security.

[0012] In one aspect of the above navigation device, the acquisition means acquires the position and traveling direction of a moving object, and the control means causes the display means to display a route guidance image that exists within a first angle range that includes the traveling direction in the normal mode, and causes the display means to display a route guidance image that exists within a second angle range that is wider than the first angle range in the wide-area mode. In this way, by displaying a route guidance image that exists within the second angle range that is wider than the first angle range in the wide-area mode, the navigation device can preferably display a wide range of the route in the route guidance image even when approaching a curve with a large curvature or a turning point.

[0013] In another aspect of the navigation device, the control means switches from the wide area mode to the normal mode when the distance of the road surface corresponding to the route guidance image displayed in the normal mode is greater than a second predetermined value that is longer than the predetermined value. In this way, the navigation device can preferably suppress frequent switching between the wide area mode and the normal mode by setting a stricter threshold value for switching from the wide area mode to the normal mode than a threshold value for switching from the normal mode to the wide area mode.

[0014] In another aspect of the navigation device, the control means displays, together with the route guidance image, mark images indicating facilities included in the scenery at positions corresponding to the facilities in the normal mode, and does not display the mark images in the wide-area mode. In the wide-area mode, by widening the route displayed in the route guidance image, the mark images may be displayed at positions that do not correspond to facilities in the actual scenery. Therefore, this aspect can effectively prevent the user from feeling uncomfortable due to misalignment of the mark images.

[0015] In another aspect of the navigation device, the control means increases the predetermined value as the moving speed of the moving object increases. Generally, when moving at high speed, the distance traveled per unit time is long, so it is presumed that the user wants to check the route further ahead. Therefore, with this aspect, the navigation device can accelerate the timing of switching to the wide-area mode when moving at high speed, thereby suitably reducing anxiety caused by not being able to understand the route ahead.

[0016] In another aspect of the navigation device, when the road surface shown in the route guidance image displayed in the normal mode is not continuous and the distance of the road surface excluding the road surface after the discontinuity is equal to or less than the predetermined value, the control means switches to the wide-area mode. With this aspect, the navigation device can suitably switch to the wide-area mode when, for example, the route has a large, dogleg-shaped curve and the near side of the route displayed in the route guidance image is short.

[0017] In another aspect of the navigation device, the control means causes the display means to display the route guidance image superimposed on a forward image acquired from a camera that captures a scene ahead of the vehicle. Even in this aspect, the present invention can be preferably implemented.

[0018] In another aspect of the navigation device, when the control means causes the display means to display a route guidance image that exists within a first angle range that includes the traveling direction in the normal mode and causes the control means to display a route guidance image that exists within a second angle range that is wider than the first angle range in the wide area mode, the control means makes the angle of view of the forward image displayed in the wide area mode wider than the angle of view of the forward image displayed in the normal mode. In this way, the navigation device can preferably display the route guidance image in association with the road surface displayed in the forward image even when switched to the wide area mode.

[0019] In another preferred embodiment of the present invention, a head-up display includes any one of the navigation devices described above and a display unit that reflects light constituting an image toward a driver of a vehicle to allow the driver to visually recognize the virtual image. The head-up display of the above aspect allows a user to recognize an appropriate range of the route even when approaching a curve with a large curvature or a turning point.

[0020] In yet another embodiment of the present invention, a control method executed by a navigation device includes an acquisition step of acquiring the position of a mobile body, and a control step of displaying, on a display means, a route guidance image showing a route from the current position of the mobile body to a destination or a stop-off point by superimposing the route guidance image on a scenery ahead of the mobile body or a captured forward image of the scenery, and switching between a normal mode in which the route guidance image is displayed on the display means in correspondence with a road surface corresponding to the route included in the scenery or the forward image, and a wide-area mode in which the display means displays a route guidance image showing a route that is wider than the route guidance image displayed in the normal mode, wherein the control step switches to the wide-area mode when the distance of the road surface corresponding to the route guidance image when displayed in the normal mode is equal to or less than a predetermined value. By executing this control method, the navigation device can make the user recognize an appropriate range of the route, even when approaching a curve with a large curvature or a turning point, and give the user a sense of security.

[0021] In yet another embodiment of the present invention, a computer-executable program causes the computer to function as an acquisition unit for acquiring the position of a mobile object; a control unit for displaying a route guidance image on a display unit, the route guidance image being superimposed on a scenery ahead of the mobile object or a captured forward image of the scenery, and indicating a route from the current position of the mobile object to a destination or a stop-off point; and a control unit for switching between a normal mode in which the route guidance image is displayed on the display unit in correspondence with a road surface corresponding to the route included in the scenery or the forward image, and a wide-area mode in which the display unit displays a route guidance image showing a wider area of ​​the route than the route guidance image displayed in the normal mode. The control unit switches to the wide-area mode when the distance of the road surface corresponding to the route guidance image displayed in the normal mode is less than a predetermined value. By executing this program, the computer can allow a user to recognize an appropriate route range, even when approaching a curve with a large curvature or a right or left turn, giving the user a sense of security. Preferably, the program is stored in a storage medium. [Example]

[0022] Preferred embodiments of the present invention will now be described with reference to the drawings.

[0023] [Schematic configuration] (1) System configuration Fig. 1 shows an example of the configuration of a display system 100 according to an embodiment. As shown in Fig. 1, the display system 100 is mounted on a vehicle Ve, and includes a navigation device 1 and a head-up display 2. Note that, instead of the configuration shown in Fig. 1, the head-up display 2 may incorporate a function equivalent to that of the navigation device 1.

[0024] The navigation device 1 has a function of providing route guidance from a departure point to a destination, etc. The navigation device 1 can be, for example, a stationary navigation device installed in a vehicle Ve, a PND (Portable Navigation Device), or a mobile terminal such as a smartphone.

[0025] The head-up display 2 is a device that generates an image (also called a "guide image") that displays map information including the current location, route guidance information, driving speed, and other information that assists driving, and allows the driver to view the guide image as a virtual image from the driver's eye position (eye point). Various information used in navigation processing, such as vehicle position information, information about the guide route, and map information including facility information, is supplied to the head-up display 2 from the navigation device 1. Note that instead of generating a guide image, the head-up display 2 may receive a guide image generated by the navigation device 1 and allow the driver to view the guide image as a virtual image.

[0026] If the navigation device 1 is a mobile terminal such as a smartphone, the navigation device 1 may be held by a cradle or the like. In this case, the navigation device 1 may exchange information with the head-up display 2 via the cradle or the like.

[0027] (2) Configuration of the navigation device Fig. 2 shows the configuration of the navigation device 1. As shown in Fig. 2, the navigation device 1 includes a stand-alone positioning device 10, a GPS receiver 18, a system controller 20, a disk drive 31, a data storage unit 36, a communication interface 37, a communication device 38, an interface 39, a display unit 40, an audio output unit 50, and an input device 60.

[0028] The stand-alone positioning device 10 includes an acceleration sensor 11, an angular velocity sensor 12, and a distance sensor 13. The acceleration sensor 11 is made of, for example, a piezoelectric element, detects the acceleration of the vehicle Ve, and outputs acceleration data. The angular velocity sensor 12 is made of, for example, a vibration gyroscope, detects the angular velocity of the vehicle Ve when the vehicle Ve changes direction, and outputs angular velocity data and relative direction data. The distance sensor 13 measures vehicle speed pulses, which are pulse signals generated in conjunction with the rotation of the wheels of the vehicle Ve.

[0029] The GPS receiver 18 receives radio waves 19 carrying downlink data including positioning data from multiple GPS satellites. The positioning data is used to detect the absolute position (also called the "current position") of the vehicle Ve from latitude and longitude information, etc.

[0030] The system controller 20 includes an interface 21, a CPU (Central Processing Unit) 22, a ROM (Read Only Memory) 23, and a RAM (Random Access Memory) 24, and controls the navigation device 1 as a whole.

[0031] The interface 21 acts as an interface with the acceleration sensor 11, angular velocity sensor 12, distance sensor 13, and GPS receiver 18. From these sensors, the interface 21 inputs vehicle speed pulses, acceleration data, relative direction data, angular velocity data, GPS positioning data, absolute direction data, etc. to the system controller 20. The CPU 22 controls the entire system controller 20. The ROM 23 includes a non-volatile memory (not shown) that stores a control program for controlling the system controller 20, etc. The RAM 24 readably stores various data, such as route data preset by the user via the input device 60, and provides a working area for the CPU 22.

[0032] The system controller 20, a disk drive 31 such as a CD-ROM drive or a DVD-ROM drive, a data storage unit 36, a communication interface 37, a display unit 40, an audio output unit 50 and an input device 60 are interconnected via a bus line 30.

[0033] The disc drive 31 reads and outputs content data such as music data and video data from a disc 33 such as a CD or DVD under the control of the system controller 20. The disc drive 31 may be either a CD-ROM drive or a DVD-ROM drive, or may be a CD and DVD compatible drive.

[0034] The data storage unit 36 ​​is configured, for example, with a HDD, and is a unit that stores various data used in navigation processing, such as map data. The map data includes road data represented by links corresponding to roads and nodes corresponding to road junctions (intersections), facility information on each facility, etc. The facility information includes, for example, information on a facility mark (mark image) to be displayed for each registered facility, and location information of the facility.

[0035] The communication device 38 is configured with, for example, an FM tuner, a beacon receiver, a mobile phone, or a dedicated communication module, and receives road traffic information such as congestion and traffic information distributed from a VICS (Vehicle Information Communication System, registered trademark) center, and other information, via the communication interface 37. The communication device 38 also transmits to the head-up display 2 various information used in navigation processing, such as current position information acquired from the GPS receiver 18, information such as vehicle speed pulses acquired from the standalone positioning device 10, and map data.

[0036] The display unit 40 displays various display data on a display device such as a monitor under the control of the system controller 20. Specifically, the system controller 20 reads map data from the data storage unit 36. The display unit 40 displays the map data and other data read from the data storage unit 36 ​​by the system controller 20 on a display screen. The display unit 40 includes a graphic controller 41 that controls the entire display unit 40 based on control data sent from the CPU 22 via the bus line 30, a buffer memory 42 such as a VRAM (Video RAM) that temporarily stores image information that can be displayed immediately, a display control unit 43 that controls the display 44, such as a liquid crystal display or a CRT (Cathode Ray Tube), based on image data output from the graphic controller 41, and a display 44. The display 44 functions as an image display unit and is, for example, a liquid crystal display device with a diagonal of approximately 5 to 10 inches, and is mounted near the front panel inside the vehicle.

[0037] The audio output unit 50 is configured to include a D / A converter 51 that performs D / A (Digital to Analog) conversion of audio digital data sent via the bus line 30 from the CD-ROM drive 31, DVD-ROM 32, RAM 24, etc. under the control of the system controller 20, an amplifier (AMP) 52 that amplifies the audio analog signal output from the D / A converter 51, and a speaker 53 that converts the amplified audio analog signal into audio and outputs it inside the vehicle.

[0038] The input device 60 is composed of keys, switches, buttons, a remote control, a voice input device, etc. for inputting various commands and data. The input device 60 is arranged on the front panel of the main body of the in-vehicle electronic system installed in the vehicle or around the display 44. In addition, if the display 44 is a touch panel type, the touch panel provided on the display screen of the display 44 also functions as the input device 60.

[0039] (3) Head-up display configuration Fig. 3 is a schematic configuration diagram of the head-up display 2. As shown in Fig. 3, the head-up display 2 according to this embodiment includes a light source unit 4 and a combiner 9, and is attached to a vehicle Ve that includes a windshield 25, a ceiling 27, a hood 28, a dashboard 29, etc.

[0040] The light source unit 4 is installed on the ceiling 27 inside the vehicle cabin via support members 5a and 5b, and emits light that constitutes a guide image showing information to assist driving toward the combiner 9, allowing the driver to see a virtual image "Iv" through the combiner 9.

[0041] The combiner 9 projects the display image emitted from the light source unit 4 and reflects the display image toward the driver's eye point "Pe" to display the display image as a virtual image Iv. The combiner 9 has a support shaft 8 installed on the ceiling portion 27 and rotates around the support shaft 8 as a support shaft. The support shaft 8 is installed on the ceiling portion 27 near the upper end of the windshield 25, for example, in the vicinity of a position where a sun visor (not shown) for the driver is installed. The support shaft 8 may be installed in place of the sun visor described above. The combiner 9 is an example of the "display means" in the present invention.

[0042] (4) Light source unit configuration 4 is a diagram schematically illustrating the configuration of the light source unit 4. As shown in FIG.

[0043] The light source 54 has, for example, red, blue, and green laser light sources, and emits light (also called "display light") that constitutes a display image to be irradiated onto the combiner 9 based on the control of the control unit 55.

[0044] The communication unit 56 receives various types of information used in navigation processing from the navigation device 1 under the control of the control unit 55. For example, when a destination is set, the communication unit 56 receives information about a guided route from the navigation device 1. The communication unit 56 also receives information about the current location measured by the GPS receiver 18 from the navigation device 1 at predetermined intervals. The communication unit 56 also receives information about facilities that serve as landmarks for route guidance, information about traffic regulations on the guided route and around the current location, and the like from the navigation device 1 as POI (Point of Interest) information.

[0045] The control unit 55 has a CPU, a ROM that stores control programs and data executed by the CPU, a RAM that serves as a work memory when the CPU is operating and into which various data is sequentially read and written, and performs overall control of the head-up display 2.

[0046] In this embodiment, the control unit 55 recognizes the position and traveling direction of the vehicle Ve based on measurement information of the GPS receiver 18 and measurement information of the autonomous positioning device 10 received from the navigation device 1. The control unit 55 then recognizes an area (also referred to as a "display target area Atag") that is within a predetermined angle (also referred to as an "angle θ") from the traveling direction of the vehicle Ve and within a predetermined distance (also referred to as a "distance r") from the vehicle Ve. The control unit 55 then generates, as guide images, a route guide image that shows a guide route within the display target area Atag and mark images that show facilities within the display target area Atag, and displays the guide images on the combiner 9 so that they are superimposed on the scenery ahead of the driver by emitting light that constitutes these guide images from the light source 54. The control unit 55 then functions as an "acquisition means," a "control means," and a computer that executes a program.

[0047] [Display guide image] Next, a method for displaying a guidance image executed by the control unit 55 will be described. In summary, when the length of the road surface that is the guidance route within the display target area Atag (also referred to as the "route distance Dtag") falls within a predetermined distance, the control unit 55 enlarges the display target area Atag by increasing the angle θ. In this way, the control unit 55 allows the driver to appropriately recognize the route to be taken even when approaching a right or left turn or a sharp curve.

[0048] Hereinafter, the display mode of the guide image before the angle θ is increased to enlarge the display target area Atag will be referred to as the "normal mode," and the display mode of the guide image when the angle θ is increased to enlarge the display target area Atag will also be referred to as the "wide-area mode." Additionally, the angle θ and distance r used in the normal mode will also be referred to as the "first angle θ1" and the "first distance r1," respectively, and the angle θ and distance r used in the wide-area mode will also be referred to as the "second angle θ2" and the "second distance r2," respectively.

[0049] (1) Display processing in normal mode First, the display process of the guide image in the normal mode will be specifically described with reference to FIGS.

[0050] Fig. 5(A) shows the set range of the display target area Atag within a map showing the area around the current position of the vehicle Ve. In Fig. 5(A), the guide route within the display target area Atag is shown by a solid line 84A, and the guide route outside the display target area Atag is shown by a dashed line 84B.

[0051] First, the control unit 55 recognizes the display target area Atag based on a first angle θ1 (e.g., 20 degrees) and a first distance r1 (e.g., 200 m). In the example of FIG. 5(A), the control unit 55 recognizes a sector-shaped area surrounded by a dashed line that is within the first angle θ1 from the traveling direction of the vehicle Ve and within the first distance r1 from the current position of the vehicle Ve as the display target area Atag. Note that the first angle θ1 and the first distance r1 are set to values ​​such that the range of scenery visible to the driver via the combiner 9 approximately matches the display target area Atag.

[0052] Then, the control unit 55 generates a route guidance image corresponding to the road 85A within the display target area Atag and a mark image (here, "A") for a facility that serves as a landmark on the route guidance, and displays these images superimposed on the scenery ahead on the combiner 9. This will be described with reference to FIG. 5(B).

[0053] Fig. 5(B) is an example of a view ahead viewed from the driver's seat in the example of Fig. 5(A). In Fig. 5(B), the control unit 55 displays a route guidance image 80 showing a road 85A, which is a guidance route within the display target area Atag, and also displays a mark image 81 of a facility 90, which is within the display target area Atag. Here, the control unit 55 displays the route guidance image 80 in a position above the road 85A, which is a guidance route within the display target area Atag, inverted upside down. The control unit 55 also displays the mark image 81 at a position corresponding to the facility 90, with a size according to the distance from the current location.

[0054] In addition to displaying the guidance image, the control unit 55 calculates the route distance Dtag within the display target area Atag and determines whether the route distance Dtag is longer than a threshold (also referred to as the "first threshold Dth1") for determining whether to switch from the normal mode to the wide-area mode. In the examples of Figures 5(A) and (B), the control unit 55 determines that the route distance Dtag is longer than the first threshold Dth1 (for example, 100 m), and continues the normal mode.

[0055] 6(A) shows the state after the vehicle Ve has traveled a predetermined distance from the example of FIG. 5(A). In this case, the control unit 55 again recognizes the display target area Atag based on the first angle θ1 and the first distance r1. Furthermore, the control unit 55 calculates the route distance Dtag within the display target area Atag, determines that the route distance Dtag is longer than the first threshold Dth1, and continues the normal mode. The control unit 55 then generates a guidance image for roads 85A and 85B, which are the guidance route within the display target area Atag, and facilities 90 present within the display target area Atag.

[0056] Fig. 6(B) is a display example of the combiner 9 superimposed on the landscape in the example of Fig. 6(A). Note that Fig. 6(B) shows only the display of the portion overlapping the combiner 9. In this case, as shown in Fig. 6(B), the control unit 55 displays a route guidance image 80 indicating roads 85A and 85B, which are the guidance route present within the display target area Atag, in association with each road, and also displays a mark image 81 of a facility 90 present within the display target area Atag at a position corresponding to the facility 90.

[0057] In the example of Fig. 6, road 85B, which is the route after turning left from road 85A, extends so as to pass through the left edge of combiner 9, and the route guidance image 80 corresponding to road 85B ends at the left edge of combiner 9. Therefore, in this case, the driver cannot yet grasp the route after turning left from road 85A to road 85B. To deal with this, control unit 55 immediately switches to wide-area mode, which will be described later.

[0058] (2) Display processing in wide mode Next, the display process in the wide-area mode will be described with reference to FIG.

[0059] Fig. 7(A) shows the range of the display target area Atag after the vehicle Ve has traveled a predetermined distance from the state shown in Fig. 6(A). In this example, the control unit 55 calculates the route distance Dtag within the display target area Atag recognized based on the first angle θ1 and the first distance r1, and determines that the route distance Dtag has become equal to or less than the first threshold Dth1, and switches from the normal mode to the wide-area mode.

[0060] 7A, in the wide-area mode, the control unit 55 sets the display target area Atag based on the second angle θ2, which is set to a value greater than the first angle θ1 (here, twice the first angle θ1), and the second distance r2, which is set to a value equal to or greater than the first distance r1. As a result, the set display target area Atag is set to be wider than the display target area Atag in the normal mode. The set display target area Atag then newly includes road 85C, which is the next road to be traveled after road 85B, and a facility corresponding to the facility mark "B" that is located near the intersection of roads 85B and 85C. The control unit 55 then generates a guidance image targeting roads 85A to 85C that are located within the display target area Atag based on the second angle θ2 and the second distance r2, and facility 90 and the facility corresponding to the facility mark "B" that are located within the display target area Atag.

[0061] Fig. 7(B) is a display example of the combiner 9 superimposed on the landscape in the example of Fig. 7(A). Note that Fig. 7(B) shows only the portion that overlaps with the combiner 9, similar to Fig. 6(B).

[0062] 7(B), in this case, the control unit 55 displays, on the combiner 9, a route guidance image 80 corresponding to a road 85C in the scenery that cannot be seen through the combiner 9, in addition to roads 85A and 85B. Similarly, the control unit 55 displays a facility mark 88 corresponding to a facility in the scenery that cannot be seen through the combiner 9, at a position relative to the route guidance image 80. The control unit 55 also displays a facility mark 81 corresponding to a facility 90 at a position relative to the route guidance image 80.

[0063] 7(B), the control unit 55 expands the range of the guidance route shown by the route guidance image 80 by setting the display target area Atag to a wider area than the area visible through the combiner 9. This allows the control unit 55 to allow the driver to preferably view the route after turning left from road 85A onto road 85B.

[0064] Furthermore, even in the wide-area mode, the control unit 55 calculates the route distance Dtag within the display target area Atag based on the first angle θ1 and the first distance r1, and if the route distance Dtag is longer than a threshold (also referred to as the "second threshold Dth2") for determining whether to switch from the wide-area mode to the normal mode, the control unit 55 switches back from the wide-area mode to the normal mode. The second threshold Dth2 may be the same as or different from the first threshold Dth1. Preferably, the control unit 55 sets the second threshold Dth2 to a distance longer than the first threshold Dth1. For example, if the first threshold Dth1 is set to 100 m, the control unit 55 sets the second threshold Dth2 to 150 m. This allows the control unit 55 to preferably prevent frequent switching between the normal mode and the wide-area mode.

[0065] (3) Calculation method of guide distance Next, a specific example of a method for calculating the route distance Dtag will be described with reference to FIGS.

[0066] FIG. 8 is a diagram showing a guide route represented by points (nodes) N1-N6 and lines (links) L1-L6 on map data, together with the display target area Atag. When calculating the route distance Dtag in the example of FIG. 8, the control unit 55 first recognizes the boundary of the display target area Atag based on the traveling direction and current position of the vehicle Ve, the first angle θ1, and the first distance r1. Next, the control unit 55 recognizes the intersection "α" between the lines L1-L6 indicating the guide route and the boundary of the display target area Atag, and recognizes that the point closest to the intersection α is point N4. The control unit 55 then calculates the sum of the lengths of the lines connecting the current position or point N2 closest to the current position on line L2 to point N4 closest to intersection α, and recognizes the sum multiplied by a coefficient corresponding to the scale of the map as the route distance Dtag. In this way, the control unit 55 can optimally calculate the route distance Dtag.

[0067] Note that, when the control unit 55 determines that the current position is off the guide route, it is not necessary to perform the calculation process of the route distance Dtag. In this case, the control unit 55 performs the display process of the guide image by fixing the display mode (normal mode or wide area mode) of the guide image before the current position deviates from the guide route.

[0068] Preferably, when the guide route exits the display target area Atag and then re-enters the display target area Atag, the control unit 55 does not include the portion of the guide route that re-enters the display target area Atag in the calculation of the route distance Dtag. This will be described with reference to FIG. 9.

[0069] 9 shows a specific example of a case where the guide route exits the display target area Atag and then re-enters the display target area Atag. On the road 89 shown in FIG. 9, a section 89B beyond section 89A is outside the display target area Atag, and a section 89C beyond section 89B is again within the display target area Atag.

[0070] In this case, the control unit 55 calculates the route distance Dtag using a section 89A from the current location to when the vehicle leaves the display target area Atag as the target, and does not include a section 89C that re-enters the display target area Atag from outside the display target area Atag as the target for calculation of the route distance Dtag. That is, if the guided route indicated by the route guidance image displayed in normal mode is not continuous, the control unit 55 calculates the route distance Dtag by excluding the portion of the guided route after the discontinuity. This allows the control unit 55 to suitably switch from normal mode to wide-area mode before approaching a curve, even when traveling on a road that bends in a dogleg shape, such as road 89 shown in FIG. 9.

[0071] (4) Processing flow Fig. 10 is an example of a flowchart showing a processing procedure in the normal mode. The control unit 55 repeatedly executes the processing of the flowchart shown in Fig. 10 when the display mode of the guide image is the normal mode.

[0072] First, the control unit 55 recognizes the display target area Atag based on the first angle θ1 and the first distance r1 (step S101). Next, the control unit 55 calculates the route distance Dtag within the display target area Atag recognized in step S101, and determines whether the route distance Dtag is equal to or less than a first threshold Dth1 (step S102). If the route distance Dtag is equal to or less than the first threshold Dth1 (step S102; Yes), the control unit 55 determines that the route indicated by the route guidance image in the normal mode is too short, and switches to the wide-area mode to perform display processing of the guidance image (step S103). The processing in the wide-area mode will be described later with reference to FIG. 11.

[0073] On the other hand, when the control unit 55 determines that the route distance Dtag is longer than the first threshold value Dth1 (step S102; No), it generates a guidance image based on the display target area Atag, which is based on the first angle θ1 and the first distance r1, and displays it on the combiner 9 (step S104). That is, in this case, the control unit 55 generates route guidance images, mark images, etc. corresponding to the guide route and facilities, etc., which are visible through the combiner 9, and displays these images on the combiner 9 in association with the actual roads and facilities.

[0074] Fig. 11 is an example of a flowchart showing a processing procedure in the wide area mode. The control unit 55 repeatedly executes the processing of the flowchart shown in Fig. 11 when the display mode of the guide image is the wide area mode.

[0075] First, the control unit 55 recognizes the display target area Atag based on the second angle θ2, which is greater than the first angle θ1, and the second distance r2, which is set to be equal to or greater than the first distance r1. Then, the control unit 55 generates a guidance image targeting the recognized display target area Atag and displays it using the combiner 9 (step S201). In this case, the angle θ is increased from the first angle θ1 to the second angle θ2, thereby expanding the range of the guidance route displayed as the route guidance image. Therefore, when approaching a right / left turn point or a point with a sharp curve, the control unit 55 can suitably alleviate the driver's anxiety caused by the short guidance route displayed as the route guidance image.

[0076] Next, the control unit 55 calculates the route distance Dtag within the display target area Atag based on the first angle θ1 and the first distance r1 (step S202). The control unit 55 then determines whether the route distance Dtag is longer than a second threshold Dth2 (step S203). If the control unit 55 determines that the route distance Dtag is longer than the second threshold Dth2 (step S203; Yes), it switches the display mode of the guidance image to the normal mode (step S204). Preferably, the control unit 55 sets the second threshold Dth2 to a value greater than the first threshold Dth1. This makes it possible to prevent the display mode of the guidance image from being frequently switched. On the other hand, if the control unit 55 determines that the route distance Dtag is equal to or less than the second threshold Dth2 (step S203; No), it returns the process to step S202.

[0077] As described above, the head-up display 2 according to this embodiment includes the light source unit 4 and the combiner 9. The control unit 55 of the light source unit 4 acquires position information of the vehicle Ve from the navigation device 1 via the communication unit 56. The control unit 55 then displays a route guidance image on the combiner 9 and switches between the normal mode and the wide-area mode. At this time, the control unit 55 switches to the wide-area mode when the route distance Dtag within the display target area Atag in the normal mode is equal to or less than the first threshold Dth1. This allows the head-up display 2 to allow the user to recognize an appropriate range of the route, even when approaching a curve with a large curvature or a turning point, thereby providing the user with a sense of security.

[0078] [Variations] Preferred modifications of the above-described embodiment will be described below. The following modifications may be applied to the above-described embodiment in any combination.

[0079] (Variation 1) Instead of displaying the guidance image on the head-up display 2 superimposed on the scenery, the display system 100 may display the guidance image on the display 44 of the navigation device 1 superimposed on an image taken by a camera capturing an image ahead of the vehicle Ve.

[0080] Fig. 12 shows an example of the configuration of a display system 100A according to this modified example. As shown in Fig. 12, the display system 100A includes a navigation device 1 such as a mobile terminal, as well as a camera 6 that captures an image of the area ahead of the vehicle Ve. The camera 6 supplies the captured image (also referred to as a "camera image") to the navigation device 1. The system controller 20 of the navigation device 1 then displays a guidance image, such as a route guidance image or a mark image, on the display 44, superimposed on the camera image.

[0081] 10 and 11, and switches between the normal mode and the wide-area mode according to the route distance Dtag. In this manner, the control unit 55 can also allow the user to recognize an appropriate route range even when approaching a curve with a large curvature or a turning point.

[0082] 10 and 11, the system controller 20 preferably switches the angle of view of the camera 6 in conjunction with switching the display mode of the guide image. This reduces the positional deviation between the route guide image and the mark image and the actual scenery in the wide area mode. This will be explained with reference to FIG. 13.

[0083] Figure 13(A) is an example of the display 44 in normal mode just before switching to wide-area mode when vehicle Ve is traveling on road 85A, and Figure 13(B) is an example of the display 44 just after switching to wide-area mode from the state of Figure 13(A).

[0084] 13(A) and 13(B), the system controller 20 widens the angle of view of the camera 6 in wide-area mode compared to normal mode. In other words, the system controller 20 widens the angle of view of the camera 6 by the amount that the angle θ increases from the first angle θ1 to the second angle θ2 when switching from normal mode to wide-area mode. In this case, for example, the system controller 20 changes the angle of view of the camera image between normal mode and wide-area mode by sending a control signal related to the setting of the angle of view to the camera 6. In another example, the angle of view of the camera 6 is fixed to the angle of view used in wide-area mode, and in normal mode, the system controller 20 crops both the left and right ends of the camera image and displays them full-screen on the display 44.

[0085] 13(B), the route guidance image 80 and mark images 81, 88 pointing to roads 85A-85C and facilities 90-91 in the camera image are associated with appropriate positions. In this way, by widening the angle of view of camera 6 in wide-area mode, system controller 20 can display the route guidance image and mark images in appropriate association with the positions of the guidance route and facilities on the camera image.

[0086] In this modification, the display 44 of the display unit 40 is an example of the "display means" of the present invention. The system controller 20 is an example of the "acquisition means," "control means," and "computer" of the present invention.

[0087] (Variation 2) Instead of setting the first threshold value Dth1 and the second threshold value Dth2 to fixed values, the control unit 55 may change them depending on the traveling speed of the vehicle Ve. Specifically, the control unit 55 may increase the first threshold value Dth1 and the second threshold value Dth2 as the traveling speed of the vehicle Ve increases.

[0088] Generally, when traveling at high speeds, the vehicle Ve travels a long distance per unit time, so the driver needs to check the route further ahead compared to when traveling at low speeds. Therefore, the control unit 55 makes it easier to switch to the wide-area mode when traveling at high speeds by setting the first threshold value Dth1 and the second threshold value Dth2 higher as the traveling speed of the vehicle Ve is higher, thereby allowing the driver to easily understand the recommended route.

[0089] Furthermore, in addition to or instead of increasing the first threshold value Dth1 and the second threshold value Dth2 as the traveling speed of the vehicle Ve increases, the control unit 55 may increase the second angle θ2 and / or the second distance r2 as the traveling speed of the vehicle Ve increases. This allows the control unit 55 to allow the driver to preferably view the guidance route further ahead when switching to the wide area mode while traveling at high speed.

[0090] (Variation 3) Instead of the display example in the wide area mode of FIG. 7(B), the control unit 55 may hide the mark image in the wide area mode.

[0091] 7(B), in the wide area mode, the angle θ is made larger than in the normal mode, resulting in a larger deviation between the display position of the mark image 81 and the position of the facility 90. In consideration of the above, in this modified example, the control unit 55 does not display the mark image in the wide area mode, thereby preventing the occurrence of an uncomfortable feeling caused by the deviation between the display position of the mark image 81 and the position of the facility 90.

[0092] (Variation 4) When switching the display mode from the normal mode to the wide-area mode, the control unit 55 may change the angle θ from the first angle θ1 to the second angle θ2 in a stepwise or continuous manner. For example, when the second angle θ2 is twice the first angle θ1, the control unit 55 gradually changes the angle θ from the first angle θ1 to 1.2×θ1, 1.4×θ1, 1.6×θ1, 1.8×θ1, and 2×θ1.

[0093] (Variation 5) In FIG. 3 , the head-up display 2 has a combiner 9, and allows the driver to view a virtual image Iv based on the light emitted from the light source unit 4 reflected by the combiner 9. However, the configuration to which the present invention is applicable is not limited to this. Alternatively, the head-up display 2 may not have a combiner 9, and may allow the driver to view a virtual image Iv based on the light emitted from the light source unit 4 reflected by a windshield 25. In this case, the windshield 25 is an example of the "display means" in the present invention.

[0094] Furthermore, the position of the light source unit 4 is not limited to being installed on the ceiling portion 27. Alternatively, the light source unit 4 may be installed on the dashboard 29 or inside the dashboard 29. If the light source unit 4 is installed on the dashboard 29, a combiner 9 is provided on the dashboard 29, or light from the light source unit 4 is reflected directly onto the windshield 25, allowing the driver to recognize a virtual image Iv. If the light source unit 4 is installed inside the dashboard, an opening is provided in the dashboard 29 to allow light to pass through the combiner 9 or the windshield 25.

[0095] (Variation 6) A part of the processing of the control unit 55 may be executed by the system controller 20. For example, a mode may be adopted in which the system controller 20 generates a guide image to be displayed by the head-up display 2, and the light source unit 4 of the head-up display 2 receives the guide image. In this case, the system controller 20 executes the processing of the flowcharts in Fig. 10 and Fig. 11 in place of the control unit 55. In this case, in steps S104 and S201 of Fig. 10, the system controller 20 transmits the generated guide image to the light source unit 4, thereby causing the guide image to be displayed on the head-up display 2.

[0096] In this modification, the system controller 20 is an example of the "acquisition means," "control means," and "computer" of the present invention. [Explanation of symbols]

[0097] 1. Navigation devices 2 Head-up display 4 Light source unit 9 Combiner 25 Windshield 28 Bonnet 29 Dashboard 100, 100A display system

Claims

1. a control means for switching between a normal mode in which a route guidance image showing a route to be taken by the moving body is superimposed on a view ahead of the moving body or a view ahead of the moving body captured by a photograph of the view ahead, and a wide-area mode in which a route guidance image having a wider range than that of the normal mode is displayed on the display means; a control means for displaying a route guidance image corresponding to roads in an area within a first angle range including the direction of travel of the moving body in the normal mode, and for displaying a route guidance image corresponding to roads in an area within a second angle range wider than the first angle range in the wide area mode; and for switching to the wide area mode when the length of the road corresponding to the route guidance image in the normal mode is equal to or less than a predetermined value.

2. 2. The navigation device according to claim 1, wherein the control means switches from the wide-area mode to the normal mode when the length of the road corresponding to the route guidance image in the normal mode is longer than a second predetermined value that is greater than the predetermined value.

3. The navigation device according to claim 1 or 2, characterized in that in the normal mode, the control means displays a mark image indicating a facility included in the scenery ahead together with the route guidance image at a position corresponding to the facility, and in the wide-area mode, the control means does not display the mark image.

4. 4. The navigation device according to claim 1, wherein the control means increases the predetermined value as the moving speed of the moving object increases.

5. The navigation device according to any one of claims 1 to 4, characterized in that the control means switches to the wide area mode when the roads indicated by the route guidance image displayed in the normal mode are not continuous in the area within the first angle range, and when the length of the roads excluding the roads after the discontinuity is less than the predetermined value.

6. The navigation device according to claim 1, characterized in that the control means causes the display means to display a route guidance image indicating a route along which the moving body should proceed superimposed on the forward image, and the angle of view of the forward image when displayed in the wide-area mode is wider than the angle of view of the forward image when displayed in the normal mode.

7. The navigation device according to claim 1; a display unit that reflects light that constitutes an image toward a driver of a vehicle, thereby allowing the driver to visually recognize a virtual image.

8. A control method executed by a navigation device, comprising: a control step of switching between a normal mode in which a route guidance image showing a route to be taken by the moving body is superimposed on a view ahead of the moving body or a forward image obtained by capturing the view ahead on a display means, and a wide-area mode in which a route guidance image having a wider range than that of the normal mode is displayed on the display means; The control method is characterized in that, in the control process, in the normal mode, a route guidance image corresponding to roads located in an area within a first angle range including the direction of travel of the moving body is displayed, and in the wide-area mode, a route guidance image corresponding to roads located in an area within a second angle range wider than the first angle range is displayed, and when the length of the road corresponding to the route guidance image in the normal mode becomes less than a predetermined value, the control method switches to the wide-area mode.

9. A computer-executable program, a control means for switching between a normal mode in which a route guidance image showing a route to be taken by the mobile body is superimposed on a view ahead of the mobile body or a photographed view ahead of the mobile body, and a wide-area mode in which a route guidance image with a wider range than that in the normal mode is displayed on the display means; causing the computer to function as The control means displays a route guidance image corresponding to roads located in an area within a first angle range including the direction of travel of the moving body in the normal mode, and displays a route guidance image corresponding to roads located in an area within a second angle range wider than the first angle range in the wide area mode, and switches to the wide area mode when the length of the road corresponding to the route guidance image in the normal mode is less than a predetermined value.

10. A storage medium storing the program according to claim 9.

Images