JP2015127170A - Head-up display, control method, program, and memory medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head-up display capable of properly suppressing degradation in visibility of a virtual image near an entrance of a tunnel.SOLUTION: A head-up display 2 includes a light source unit 4, and a combiner 9. A control section 55 of the light source unit 4 generates a guide image that is displayed by being superposed on a front scene. The control section 55 obtains a current position of a vehicle Ve from a navigation device 1. The control section 55, further, obtains the tunnel information including a position of a tunnel entrance by referencing a map data stored in the navigation device 1. Then, the control section 55 changes brightness of the guide image before the vehicle Ve passes the tunnel entrance.

Description

  The present invention relates to a display technology for a head-up display.

  2. Description of the Related Art Conventionally, a technology for switching the brightness of a screen display between when traveling inside a tunnel and when traveling outside a tunnel is known. For example, Patent Document 1 discloses a navigation that automatically switches the brightness and saturation of a display screen according to whether the road where the vehicle is located is a tunnel based on map data, and whether the current day is day or night. An apparatus is disclosed.

JP 2001-33257 A

  In the case of a head-up display, the virtual image is displayed superimposed on the front landscape, so the virtual image display position is the tunnel before the vehicle enters the tunnel, the virtual image display position overlaps with the scenery in the tunnel, or before entering the tunnel. It overlaps with the scenery outside. On the other hand, in the technology described in Patent Document 1, the brightness of the display screen is adjusted depending on whether the vehicle is inside or outside the tunnel, and when this is applied to a head-up display, The visibility of the virtual image may deteriorate.

  The present invention has been made in order to solve the above-described problems, and mainly provides a head-up display capable of suitably suppressing deterioration of the visibility of a virtual image near a tunnel entrance. Objective.

  The invention described in the claims is a head-up display that is mounted on a moving body and displays an image superimposed on a front scenery, and an image generation unit that generates the image, and a position that acquires a current position of the moving body Based on the acquisition means, the tunnel information acquisition means for acquiring the tunnel information including the position of the tunnel entrance, the position of the tunnel entrance / exit included in the tunnel information, and the current position of the mobile body, the mobile body enters and exits the tunnel Control means for changing the brightness of the image generated by the image generation means before passing through the image.

  Further, the invention described in claim is a control method executed by a head-up display that is mounted on a moving body and displays an image superimposed on a forward landscape, the image generating step for generating the image, and the moving body Based on the position acquisition step of acquiring the current position, the tunnel information acquisition step of acquiring tunnel information including the position of the tunnel entrance, the position of the tunnel entrance included in the tunnel information, and the current position of the mobile body, And a control step of changing brightness of an image generated by the image generation step before the moving body passes through a tunnel entrance.

  Further, the invention described in the claims is a program executed by a computer that controls a head-up display that is mounted on a moving body and displays an image superimposed on a front landscape, and that generates the image; and The position acquisition means for acquiring the current position of the mobile body, the tunnel information acquisition means for acquiring tunnel information including the position of the tunnel entrance, the position of the tunnel entrance / exit included in the tunnel information, and the current position of the mobile body Based on this, the computer is caused to function as control means for changing the brightness of the image generated by the image generation means before the moving body passes through the entrance of the tunnel.

1 shows a schematic configuration of a display system. 1 shows a schematic configuration of a navigation device. 1 shows a schematic configuration of a head-up display. The schematic structure of a light source unit is shown. It is an example of the front scenery visually recognized from the driver's seat when the vehicle is traveling on the road outside the tunnel during the daytime. The example of a display of the combiner before a vehicle approaches the entrance of a tunnel is shown. A display example of the combiner when the vehicle is traveling in the tunnel is shown. The example of a display of the combiner before a vehicle approaches the exit of a tunnel is shown. It is a flowchart which shows the brightness | luminance adjustment process of the guidance image in the tunnel vicinity.

  In one preferred embodiment of the present invention, a head-up display that is mounted on a moving body and displays an image superimposed on a front landscape, the image generating means for generating the image, and the current position of the moving body Based on the position acquisition means for acquiring, the tunnel information acquisition means for acquiring the tunnel information including the position of the tunnel entrance, the position of the tunnel entrance included in the tunnel information, and the current position of the mobile body, Control means for changing the brightness of an image generated by the image generation means before passing through a tunnel entrance.

  The head-up display includes image generation means, position acquisition means, tunnel information acquisition means, and control means. The image generation means generates an image to be displayed over the front landscape. The position acquisition unit acquires the current position of the moving body. The tunnel information acquisition means acquires tunnel information including the position of the tunnel entrance. The control means changes the brightness of the image generated by the image generation means before the moving body passes through the entrance of the tunnel.

  In general, since the head-up display displays an image superimposed on the front landscape, the display position of the image is displayed before the moving object enters the tunnel, before the image display position overlaps with the scenery in the tunnel or before entering the tunnel. Overlaps with the scenery outside the tunnel. Considering the above, the head-up display changes the brightness of the image before passing through the entrance of the tunnel. Thereby, the head-up display can adjust the brightness of an image suitably according to the brightness of the background of an image, and can suppress the deterioration of the visibility in the entrance / exit vicinity of a tunnel suitably.

  In one aspect of the head-up display, the control unit changes the brightness of the image when an area of the entrance / exit of the tunnel and the display position of the image overlap. According to this aspect, the head-up display allows the driver to visually recognize an image even when the brightness is different between the entrance / exit part of the tunnel and the other background part.

  In another aspect of the head-up display, the image generation unit generates the image for each piece of information to be displayed, and the control unit includes an entrance / exit of the tunnel among the images generated by the image generation unit. Change the brightness of the image that overlaps the region. According to this aspect, the head-up display can suitably adjust the brightness of the image overlapping the entrance / exit portion of the tunnel so that the visibility does not deteriorate.

  In another aspect of the head-up display, the control means darkens the image when the area of the entrance of the tunnel and the display position of the image overlap in a daytime period, and The image is brightened when the exit area and the display position of the image overlap. In general, during the daytime, the outside of the tunnel is brighter than the inside of the tunnel, so the head-up display can make the driver appropriately view the image by adjusting the brightness of the image in this way. .

  In another aspect of the head-up display, when the brightness of the image is changed, the control unit gradually changes the brightness of the image stepwise or continuously. With this aspect, the head-up display can reduce a sense of discomfort when changing the brightness of the image.

  In another aspect of the head-up display, the control means determines the brightness of the image whose brightness is changed based on the apparent size of the entrance / exit of the tunnel. By doing in this way, the head-up display can determine the brightness of an image suitably.

  In another preferred embodiment of the present invention, a control method executed by a head-up display that is mounted on a moving body and displays an image superimposed on a front landscape includes an image generation step of generating the image, Based on the position acquisition step of acquiring the current position, the tunnel information acquisition step of acquiring tunnel information including the position of the tunnel entrance, the position of the tunnel entrance included in the tunnel information, and the current position of the mobile body, And a control step of changing the brightness of the image generated by the image generation step before the moving body passes through the entrance / exit of the tunnel. By executing this control method, the head-up display can suitably adjust the brightness of the image according to the brightness of the background of the image, and it is preferable that the visibility of the image near the entrance / exit of the tunnel is deteriorated. Can be suppressed.

  In still another embodiment of the present invention, there is provided a program executed by a computer that controls a head-up display that is mounted on a moving body and displays an image superimposed on a front landscape, and the image generating unit that generates the image; The position acquisition means for acquiring the current position of the mobile body, the tunnel information acquisition means for acquiring tunnel information including the position of the tunnel entrance, the position of the tunnel entrance / exit included in the tunnel information, and the current position of the mobile body Based on this, the computer is caused to function as control means for changing the brightness of the image generated by the image generation means before the moving body passes through the entrance of the tunnel. By executing this program, the computer can suitably adjust the brightness of the image according to the brightness of the background of the image, and suitably suppress the deterioration of the visibility of the image near the entrance of the tunnel. be able to. Preferably, the program is stored in a storage medium.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Schematic configuration]
(1) System Configuration FIG. 1 shows a configuration example of a display system 100 according to the 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. Instead of the configuration shown in FIG. 1, the head-up display 2 may incorporate a function corresponding to the navigation device 1.

  The navigation device 1 has a function of performing route guidance from a departure place to a destination. The navigation device 1 can be, for example, a stationary navigation device installed in the vehicle Ve, a portable terminal such as a PND (Portable Navigation Device), or a smartphone.

  The head-up display 2 is an apparatus that generates an image (also referred to as a “guide image”) that displays information for assisting driving and visually recognizes the guide image as a virtual image from the position (eye point) of the driver's eyes. . The head-up display 2 displays, for example, an arrow indicating the direction of the guidance route, information on a guidance point such as a right / left turn point, information on traveling of the vehicle Ve such as a vehicle speed, information on traffic regulations, and the like as a guidance image. The head-up display 2 is supplied from the navigation device 1 with various information necessary for generating a guide image such as guide route information.

  When 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 a cradle or the like.

(2) Configuration of Navigation Device FIG. 2 shows the configuration of the navigation device 1. As shown in FIG. 2, the navigation device 1 includes a self-supporting 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, and a display unit 40. A voice output unit 50 and an input device 60.

  The autonomous 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 composed of, for example, a vibrating gyroscope, detects the angular velocity of the vehicle Ve when the direction of the vehicle Ve is changed, and outputs angular velocity data and relative azimuth data. The distance sensor 13 measures a vehicle speed pulse composed of a pulse signal generated with the rotation of the wheel of the vehicle Ve.

  The GPS receiver 18 receives radio waves 19 carrying downlink data including positioning data from a plurality of GPS satellites. The positioning data is used to detect the absolute position (also referred to as “current position”) of the vehicle Ve from latitude and longitude information.

  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 entire navigation apparatus 1.

  The interface 21 performs an interface operation with the acceleration sensor 11, the angular velocity sensor 12, the distance sensor 13, and the GPS receiver 18. From these, vehicle speed pulses, acceleration data, relative azimuth data, angular velocity data, GPS positioning data, absolute azimuth data, and the like are input to the system controller 20. The CPU 22 controls the entire system controller 20. The ROM 23 includes a nonvolatile memory (not shown) in which a control program for controlling the system controller 20 is stored. The RAM 24 stores various data such as route data preset by the user via the input device 60 so as to be readable, and provides a working area to the CPU 22.

  A 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 mutually connected via a bus line 30. It is connected to the.

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

  The data storage unit 36 is configured by, for example, an HDD and stores various data used for navigation processing such as map data. The map data includes road data represented by links corresponding to roads and nodes corresponding to road connecting portions, facility information about each facility, and the like. In addition, information regarding a tunnel (also referred to as “tunnel information”) is added to road data of a road having a tunnel section. The tunnel information includes position information on the entrance / exit of the tunnel, shape information on the entrance / exit of the tunnel, and the like. The shape information of the entrance / exit of the tunnel includes, for example, information indicating that the entrance / exit of the tunnel is semi-elliptical, and information on the major axis and minor axis of the ellipse.

  The communication device 38 includes, for example, an FM tuner, a beacon receiver, a portable terminal, a dedicated communication module, and the like. Receive road traffic information such as traffic information and other information. In addition, the communication device 38 transmits to the head-up display 2 various information used for navigation processing, such as current position information acquired from the GPS receiver 18, information such as vehicle speed pulses acquired from the autonomous positioning device 10, and map data. To do.

  The display unit 40 displays various display data on a display device such as a display 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 read from the data storage unit 36 by the system controller 20 on the 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 and a memory such as a VRAM (Video RAM), and can display image information that can be displayed immediately. A buffer memory 42 that temporarily stores, a display control unit 43 that controls display of a 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 are provided. . The display 44 functions as an image display unit, and includes, for example, a liquid crystal display device having a diagonal of about 5 to 10 inches and is mounted near the front panel in the vehicle.

  The audio output unit 50 performs D / A (Digital to Analog) conversion of audio digital data sent from the CD-ROM drive 31, DVD-ROM 32, RAM 24, or the like via the bus line 30 under the control of the system controller 20. A D / A converter 51 to perform, 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 sound and outputs the sound into the vehicle. It is prepared for.

  The input device 60 includes keys, switches, buttons, a remote controller, a voice input device, and the like for inputting various commands and data. The input device 60 is disposed around the front panel and the display 44 of the main body of the in-vehicle electronic system mounted in the vehicle. When the display 44 is a touch panel system, the touch panel provided on the display screen of the display 44 also functions as the input device 60.

(3) Configuration of Head-Up Display 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 the present embodiment includes a light source unit 4 and a combiner 9. The vehicle Ve includes a front window 25, a ceiling portion 27, a hood 28, a dashboard 29, and the like. It is attached.

  The light source unit 4 is installed on the ceiling portion 27 in the passenger compartment via the support members 5a and 5b, and emits light constituting a guide image indicating information for assisting driving toward the combiner 9 so that the combiner 9 The driver is caused to visually recognize the virtual image “Iv”.

  The combiner 9 projects the display image emitted from the light source unit 4 and reflects the display image to the driver's eye point “Pe” to display the display image as a virtual image Iv. And the combiner 9 has the support shaft part 8 installed in the ceiling part 27, and rotates the support shaft part 8 as a spindle. The support shaft portion 8 is installed, for example, in the vicinity of the ceiling portion 27 in the vicinity of the upper end of the front window 25, in other words, the position where a sun visor (not shown) for the driver is installed. The support shaft portion 8 may be installed instead of the above-described sun visor.

(4) Configuration of Light Source Unit FIG. 4 is a diagram schematically showing the configuration of the light source unit 4. As illustrated in FIG. 4, the light source unit 3 includes a light source 54, a control unit 55, and a communication unit 56.

  The light source 54 includes, for example, red, blue, and green laser light sources, and emits light (also referred to as “display light”) that constitutes a display image to be irradiated to the combiner 9 based on the control of the control unit 55. .

  The communication unit 56 receives various types of information used for navigation processing from the navigation device 1 based on the control of the control unit 55. For example, the communication unit 56 receives information necessary for generating a guidance image such as guidance route information and current position information from the navigation device 1.

  The control unit 55 includes a CPU, a ROM that stores a control program executed by the CPU, data, and the like, and a RAM that sequentially reads and writes various data as a work memory when the CPU operates. Control.

  In the present embodiment, the control unit 55 generates a guide image based on information transmitted from the navigation device 1 and causes the light source 54 to emit display light constituting the guide image. At this time, the control unit 55 appropriately increases the brightness of the guidance image in the daytime period when the external light is relatively strong compared to the night time period when the external light is relatively weak, thereby appropriately displaying the guidance image to the driver. Make it visible. Further, the control unit 55 changes the brightness of the guide image displayed as the virtual image Iv at the timing before passing through the entrance of the tunnel in the daytime period. This will be explained in detail in the section [Brightness adjustment near the tunnel]. The control unit 55 functions as an “image generation unit”, “position acquisition unit”, “tunnel information acquisition unit”, “control unit”, and a computer that executes a program.

[Brightness adjustment near the tunnel]
Next, a guide image brightness adjustment method executed by the control unit 55 will be described. Schematically, the control unit 55, even before the vehicle Ve passes through the entrance / exit of the tunnel, if the display position of the virtual image Iv indicating the guide image overlaps the area of the entrance / exit of the tunnel, The brightness is changed according to the brightness of the overlapping area. Thereby, the deterioration of the visibility of the virtual image Iv in the vicinity of the tunnel is suitably suppressed.

(1) Display Example First, a display example of a guidance image according to the present embodiment will be described with reference to FIGS.

  FIG. 5 is an example of a front view viewed from the driver's seat when the vehicle Ve is traveling on a road outside the tunnel during the daytime. In FIG. 5, the control unit 55 displays an arrow image 80 indicating the direction in which the vehicle Ve should travel based on the guidance route along the road that is the guidance route, and the speed of the vehicle Ve (here 66 km / h). Is displayed on the combiner 9. In this case, the control unit 55 preferably sets the brightness of the arrow image 80 and the speed image 81 higher than the night time zone because the daylight time zone is relatively strong outside. Thereby, the control part 55 suppresses suitably that it becomes difficult to see a guide image relatively with external light.

  FIG. 6 shows a display example of the combiner 9 before the vehicle Ve reaches the entrance of the tunnel. In FIG. 6, the arrow image 80 exists at a position overlapping the area indicating the entrance portion of the tunnel on the combiner 9 (also referred to as “tunnel entrance area Ain”). In this case, as shown in FIG. 6, the controller 55 reduces the brightness of the arrow image 80 because the tunnel entrance area Ain is darker than the other background portions. As a result, the brightness of the arrow image 80 is lower than the brightness of the speed image 81.

  Thus, before reaching the tunnel entrance, the control unit 55 reduces the brightness of the guide image (here, the arrow image 80) that overlaps the tunnel entrance area Ain, so that the guide image is suitable according to the brightness of the background. Can be displayed. Here, the control unit 55 may gradually decrease the brightness of the arrow image 80 stepwise or continuously in accordance with a predetermined time constant instead of decreasing it at once. Thereby, a user's uncomfortable feeling by the brightness change of a guidance image can be controlled suitably. Moreover, the control part 55 may reduce the brightness | luminance of the arrow image 80 according to the apparent magnitude | size of the tunnel entrance area | region Ain. In other words, the control unit 55 may lower the ratio according to the ratio of the area of the tunnel entrance region Ain to the area of the display surface of the combiner 9. In this case, the brightness of the arrow image 80 decreases as the vehicle Ve approaches the entrance of the tunnel, and becomes the lowest value when the vehicle Ve enters the tunnel.

  FIG. 7 shows a display example of the combiner 9 when the vehicle Ve is traveling in the tunnel. In this example, both the arrow image 80 and the velocity image 81 are displayed at a position overlapping the area in the tunnel where sunlight does not enter. Therefore, in this case, the control unit 55 lowers the brightness of the arrow image 80 and the speed image 81 both lower than the brightness when displaying outside the tunnel (see FIG. 5).

  FIG. 8 shows a display example of the combiner 9 before the vehicle Ve reaches the exit of the tunnel. In the example of FIG. 8, the arrow image 80 exists at a position that overlaps an area (also referred to as “tunnel exit area Aout”) indicating the exit part of the tunnel on the combiner 9. In this case, as shown in FIG. 8, the control unit 55 increases the brightness of the arrow image 80 because the tunnel exit area Aout is brighter than the other background portions in the tunnel. As a result, the brightness of the arrow image 80 is higher than the brightness of the speed image 81.

  Thus, before reaching the tunnel exit, the controller 55 increases the brightness of the guide image (here, the arrow image 80) that overlaps the tunnel exit area Aout, so that the guide image is suitable according to the brightness of the background. Can be displayed. Here, the control unit 55 may increase the brightness of the arrow image 80 at once as in the description with reference to FIG. 6, or may gradually increase it stepwise or continuously according to a predetermined time constant. Further, the control unit 55 may increase the luminance of the arrow image 80 according to the apparent size of the tunnel exit area Aout.

(2) Processing Flow Next, the processing procedure relating to the brightness adjustment of the guide image near the tunnel will be described in detail with reference to FIG. FIG. 9 is a flowchart showing the brightness adjustment processing of the guide image near the tunnel. The control unit 55 repeatedly executes the process of the flowchart shown in FIG.

  First, the control unit 55 determines whether or not the current daytime is a time zone, that is, whether the outside of the tunnel is a relatively bright time zone due to sunlight (step S101). For example, the control unit 55 may set the above-mentioned daytime time zone to be a time zone from sunrise to sunset according to the current date and time information, position information, and the like. It may be set. In another example, the control unit 55 acquires information indicating the state of the headlight of the vehicle Ve from the vehicle Ve, and determines that the current time is the daytime time zone when the headlight is turned off. May be. When the control unit 55 determines that the current time is the daytime time zone (step S101; Yes), the control unit 55 advances the process to step S102. On the other hand, if the control unit 55 determines that the current time is not a daytime zone (step S101; No), that is, if it is determined that the current time is a nighttime zone, the process of the flowchart ends.

  Next, the control unit 55 determines whether or not the vehicle Ve is traveling outside the tunnel (step S102). For example, the control unit 55 determines whether or not the current position is outside the tunnel based on the current position specified based on the output of the autonomous positioning device 10 of the navigation device 1 and / or the GPS receiver 18 and the map data. To do. When the control unit 55 determines that the vehicle Ve is traveling outside the tunnel (step S102; Yes), the process proceeds to step S103. On the other hand, when the control unit 55 determines that the vehicle Ve is traveling in the tunnel (step S102; No), the process proceeds to step S107.

  In the following, the brightness adjustment of the guidance image when traveling outside the tunnel will be described in steps S103 to S106.

  First, the control unit 55 is traveling based on the position information of the entrance of the tunnel obtained by referring to the map data and the current position specified based on the output of the autonomous positioning device 10 and / or the GPS receiver 18. It is determined whether or not there is a tunnel entrance within a predetermined distance in the traveling direction along the road (step S103). Here, the “predetermined distance” is set in advance to a distance at which the entrance of the tunnel can be visually recognized via the combiner 9, for example. Then, when the control unit 55 determines that there is a tunnel entrance within a predetermined distance (step S103; Yes), the control unit 55 executes the process of step S104. On the other hand, when determining that there is no tunnel entrance within a predetermined distance (step S103; No), the control unit 55 determines that there is no possibility that the guide image overlaps the tunnel entrance area Ain, and returns the process to step S101.

  Next, in step S104, the control unit 55 recognizes the tunnel entrance area Ain on the combiner 9 based on the position information of the tunnel entrance included in the tunnel information and the shape information of the tunnel entrance (step S104). For example, the control unit 55 models the entrance portion of the tunnel on the three-dimensional coordinate space based on the above-described position information and shape information, and then projects the generated three-dimensional coordinate space on the combiner 9 from the position of the eye point Pe. By generating the raster image, the position of the tunnel entrance area Ain is recognized.

  Next, the control unit 55 determines whether or not each guide image is displayed in the tunnel entrance area Ain (step S105). In this case, for example, the control unit 55 determines the overlap between the center position of each guide image and the tunnel entrance area Ain, and the guide image whose center position overlaps the tunnel entrance area Ain is displayed in the tunnel entrance area Ain. It is determined that it is a guide image. In the example of FIG. 6, the control unit 55 determines whether or not the center position of each of the guide images of the arrow image 80 and the velocity image 81 overlaps the tunnel entrance area Ain, and the arrow image 80 where the center positions overlap is the tunnel entrance area. It is determined that it is displayed in Ain.

  When the control unit 55 determines that there is a guide image displayed in the tunnel entrance area Ain (step S105; Yes), the control unit 55 decreases the brightness of the guide image (step S106). Thereby, the control part 55 can adjust the guidance image which overlaps with the tunnel entrance area | region Ain to appropriate brightness | luminance according to the brightness | luminance of a background, and can make a driver | operator visually recognize it suitably. On the other hand, when there is no guide image displayed in the tunnel entrance area Ain (step S105; No), the control unit 55 determines that it is not necessary to adjust the brightness of the guide image at this time, and returns the process to step S101.

  Next, the brightness adjustment of the guide image when traveling in the tunnel will be described in steps S107 to S110.

  First, the control unit 55 determines the direction of travel along the traveling road based on the position information of the tunnel exit obtained by referring to the map data and the current position specified based on the output of the autonomous positioning device 10. It is determined whether there is a tunnel exit within a predetermined distance (step S107). Here, the “predetermined distance” is determined to be a distance at which the exit of the tunnel can be visually recognized via the combiner 9, for example. If the control unit 55 determines that there is a tunnel exit within a predetermined distance (step S107; Yes), the control unit 55 executes the process of step S108. On the other hand, when determining that there is no tunnel exit within the predetermined distance (step S107; No), the control unit 55 determines that there is no possibility that the guide image overlaps the tunnel exit area Aout, and returns the process to step S101.

  Next, in step S108, the control unit 55 recognizes the tunnel exit area Aout on the combiner 9 based on the position information of the tunnel exit included in the tunnel information and the shape information of the tunnel exit (step S104). For example, the control unit 55 models the exit portion of the tunnel on the three-dimensional coordinate space based on the above-described position information and shape information, and then projects the generated three-dimensional coordinate space on the combiner 9 from the position of the eye point Pe. By generating the raster image, the position of the tunnel exit area Aout is recognized.

  Next, the control unit 55 determines whether or not each guide image is displayed in the tunnel exit area Aout (step S109). In this case, for example, the control unit 55 determines the overlap between the center position of each guide image and the tunnel exit area Aout, and the guide image whose center position overlaps the tunnel exit area Aout is displayed in the tunnel exit area Aout. It is determined that it is a guide image.

  When the control unit 55 determines that there is a guide image displayed in the tunnel exit area Aout (step S109; Yes), the control unit 55 increases the brightness of the guide image (step S110). Thereby, the control part 55 can adjust the guidance image which overlaps with the tunnel exit area | region Aout to appropriate brightness | luminance according to the brightness | luminance of a background, and can make a driver | operator visually recognize it suitably. On the other hand, when there is no guide image displayed in the tunnel exit area Aout (step S109; No), the control unit 55 determines that it is not necessary to adjust the brightness of the guide image at this time, and returns the process to step S101.

  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 generates a guide image to be displayed over the front scenery. In addition, the control unit 55 acquires the current position of the vehicle Ve from the navigation device 1. Furthermore, the control unit 55 acquires the tunnel information including the position of the tunnel entrance by referring to the map data stored in the navigation device 1. And the control part 55 changes the brightness of a guidance image, before the vehicle Ve passes the entrance and exit of a tunnel. Thereby, the head-up display 2 can suitably adjust the brightness of the guide image according to the brightness of the background of the guide image, and suitably suppress the deterioration of the visibility near the entrance of the tunnel. it can.

  At this time, the controller 55 recognizes the tunnel entrance area Ain and the tunnel exit area Aout on the combiner 9 on the basis of the tunnel information and the current position information without using a camera, and guides these areas. Determine overlap with image. Therefore, the display system 100 according to the present embodiment can be configured at a relatively low cost because it does not require a camera.

[Modification]
Hereinafter, modified examples suitable for the above-described embodiments will be described. The following modifications may be applied in any combination to the above-described embodiments.

(Modification 1)
The map data stored in the data storage unit 36 includes the shape information of the entrance / exit of the tunnel. Instead of this, the map data may not include the shape information of the entrance and exit of the tunnel.

  For example, when executing step S104 or step S108 of FIG. 9, the control unit 55 acquires information on the width of the road passing through the target tunnel from the map data. Then, the control unit 55 estimates that the shape of the entrance / exit of the target tunnel is a semi-elliptical or semi-circular shape having a major axis and a minor axis corresponding to the acquired width. Thereby, the control part 55 can recognize suitably the tunnel entrance area | region Ain and the tunnel exit area | region Aout on the combiner 9, even if it is a case where the shape information of the entrance / exit of a tunnel is not contained in map data. . In another example, the control unit 55 may regard the shape of the entrance / exit of the tunnel as having a common shape and size in each tunnel.

(Modification 2)
In the example of FIGS. 6 and 8, the control unit 55 individually adjusts the brightness of the guide image (that is, the arrow image 80) overlapping the tunnel entrance area Ain or the tunnel exit area Aout. However, the brightness adjustment method to which the present invention is applicable is not limited to this.

  For example, when it is determined that all the guide images are displayed so as to overlap the tunnel entrance area Ain or the tunnel exit area Aout, the control unit 55 may adjust the brightness of all the guide images. In this case, in the example of FIGS. 6 and 8, the control unit 55 does not adjust the brightness of the arrow image 80 at the time shown in FIGS. 6 and 8, and both the arrow image 80 and the velocity image 81 are in the tunnel entrance area Ain. Alternatively, the brightness adjustment of the arrow image 80 and the speed image 81 is performed when displayed overlapping the tunnel exit area Aout.

  In another example, when it is determined that one guide image is displayed so as to overlap the tunnel entrance area Ain or the tunnel exit area Aout, the control unit 55 may adjust the brightness of all the guide images. In this case, in the example of FIGS. 6 and 8, the control unit 55 performs the same brightness adjustment on the velocity image 81 as well as the arrow image 80 at the same time.

  In still another example, when the control unit 55 determines that a part of a certain guide image is displayed so as to overlap the tunnel entrance area Ain or the tunnel exit area Aout, only the overlapped part of the guide image is targeted. Brightness adjustment may be performed. For example, immediately before the example of FIG. 6, in a state where the upper half of the arrow image 80 overlaps with the tunnel entrance area Ain, the control unit 55 performs brightness adjustment only for the upper half of the arrow image 80 that overlaps the tunnel entrance area Ain.

  Further, instead of determining that the guide image having the center position in the tunnel entrance area Ain or the tunnel exit area Aout overlaps the tunnel entrance area Ain or the tunnel exit area Aout, the control unit 55 A guide image that overlaps the tunnel exit area Aout by a predetermined ratio (for example, 50%) or more may be determined to overlap the tunnel entrance area Ain or the tunnel exit area Aout.

(Modification 3)
A server device that can communicate with the navigation device 1 or the head-up display 2 may have all or part of the map data that the data storage unit 36 has. For example, when the map data stored in the data storage unit 36 does not include the shape information of the entrance / exit of the tunnel, the control unit 55 obtains the shape information of the tunnel to be passed from the server device that stores the shape information of each tunnel. You may get it.

(Modification 4)
In FIG. 3, the head-up display 2 has a combiner 9 and makes the driver visually recognize the virtual image Iv based on the emitted light of 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. Instead of this, the head-up display 2 may not have the combiner 9 and may allow the driver to visually recognize the virtual image Iv based on the emitted light of the light source unit 4 reflected by the windshield 25.

  Further, the position of the light source unit 4 is not limited to the case where it is installed on the ceiling portion 27. Instead of this, the light source unit 4 may be installed on the dashboard 29 or installed inside the dashboard 29. When installed on the dashboard 29, the combiner 9 is provided on the dashboard 29, or light is directly reflected from the light source unit 4 on the windshield 25 to allow the driver to recognize the virtual image Iv. When installed in the dashboard, the dashboard 29 is provided with an opening for allowing light to pass through the combiner 9 or the windshield 25.

(Modification 5)
The system controller 20 may execute part of the processing of the control unit 55. For example, the system controller 20 may generate a guide image for the head-up display 2 to display, and the light source unit 4 of the head-up display 2 may receive the guide image. In this case, the system controller 20 executes the process of the flowchart of FIG. 9 instead of the control unit 55. Then, in step S106 and step S110 of FIG. 9, the system controller 20 transmits the guide image after the brightness adjustment to the light source unit 4 so that the guide image after the brightness adjustment is displayed on the head-up display 2.

  In this modification, the system controller 20 functions as an “image generation unit”, “position acquisition unit”, “tunnel information acquisition unit”, “control unit”, and a computer that executes a program in the present invention.

  In another example, the head-up display 2 may have a part or all of the functions of the navigation device 1. In this case, the light source unit 4 may include, for example, a memory that stores map data, sensors such as a GPS receiver, and the like.

(Modification 6)
The controller 55 may adjust the brightness of the guide image that overlaps the tunnel entrance area Ain or the tunnel exit area Aout even when it is determined in step S101 that the current time is the night time zone.

  Generally, in the night time zone, the inside of the tunnel is brighter than the outside of the tunnel due to the light of the light installed in the tunnel. Therefore, in this case, the control unit 55 preferably increases the brightness of the guide image that overlaps the tunnel entrance area Ain and decreases the brightness of the guide image that overlaps the tunnel exit area Aout in the night time zone.

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 2 Head-up display 4 Light source unit 9 Combiner 25 Windshield 28 Bonnet 29 Dashboard 100 Display system

Claims (9)

A head-up display that is mounted on a moving object and displays an image superimposed on the front landscape.
Image generating means for generating the image;
Position acquisition means for acquiring a current position of the moving body;
Tunnel information acquisition means for acquiring tunnel information including the position of the tunnel entrance;
Control for changing the brightness of the image generated by the image generating means before the mobile body passes through the entrance of the tunnel based on the position of the tunnel entrance and the current position of the mobile body included in the tunnel information Means,
A head-up display comprising:   2. The head-up display according to claim 1, wherein the control unit changes the brightness of the image when the area of the entrance / exit of the tunnel and the display position of the image overlap each other. The image generation means generates the image for each piece of information to be displayed,
3. The head-up display according to claim 1, wherein the control unit changes a brightness of an image that overlaps a region of the entrance / exit of the tunnel among the images generated by the image generation unit. In the daytime time period, the control means
If the tunnel entrance area and the display position of the image overlap, darken the image,
4. The head-up display according to claim 1, wherein the image is brightened when an exit area of the tunnel overlaps with a display position of the image. 5.   5. The head-up according to claim 1, wherein when the brightness of the image is changed, the control unit gradually changes the brightness of the image stepwise or continuously. 6. display.   6. The head-up according to claim 1, wherein the control unit determines the brightness of an image whose brightness is changed based on an apparent size of an entrance / exit of the tunnel. display. A control method executed by a head-up display that is mounted on a moving object and displays an image superimposed on a front landscape,
An image generating step for generating the image;
A position acquisition step of acquiring a current position of the moving body;
Tunnel information acquisition step for acquiring tunnel information including the position of the tunnel entrance,
Control that changes the brightness of the image generated by the image generation step before the mobile body passes through the entrance of the tunnel based on the position of the tunnel entrance and the current position of the mobile body included in the tunnel information Process,
A control method characterized by comprising: A program executed by a computer that controls a head-up display that is mounted on a moving object and displays an image superimposed on a front landscape,
Image generating means for generating the image;
Position acquisition means for acquiring a current position of the moving body;
Tunnel information acquisition means for acquiring tunnel information including the position of the tunnel entrance;
Control for changing the brightness of the image generated by the image generating means before the mobile body passes through the entrance of the tunnel based on the position of the tunnel entrance and the current position of the mobile body included in the tunnel information A program for causing the computer to function as means.   A storage medium storing the program according to claim 8.