Display system and display method

Abstract

Provided is a more suitable display device or display technology. The present invention contributes to the sustainable development goal "3. Ensure healthy lives and promote well-being for all at all ages".　The display system comprises an acquisition device, a storage device, and a control device. The acquisition device acquires information about the location of a vehicle. The storage device stores information representing one or a plurality of set locations set in advance on a specific route on which the vehicle moves, and display information associated with the set locations. When it is determined that the vehicle has reached a set location, the control device performs a control to display, on a display device, display information corresponding to the set location the vehicle is determined to have reached. The set location is a desired location designated by a user, and the display information corresponding to the set location is desired display information set by the user.

Description

Display system and display method

[0001] The present invention relates to a display device, a virtual image display device, display technology, and a vehicle equipped with the display device.

[0002] A display device or a virtual image display device that projects video light onto a windshield or a front glass of a vehicle such as an automobile to display a virtual image, and displays driving information such as vehicle speed and engine speed, traffic information from navigation, and vehicle information such as remaining fuel and coolant temperature is known.

[0003] Japanese Patent Laid-Open No. 3-169752

[0004] The display device is disposed, for example, on or inside a dashboard of a vehicle. When the display device is used, a driver can obtain information necessary for driving without moving his or her line of sight to an instrument panel incorporated in the dashboard, that is, a so-called instrument panel. On the other hand, sufficient consideration has not been given to the arrangement, brightness, influence from external light, information display, etc. of the display device.

[0005] An object of the present invention is to provide a more suitable display device or display technology.

[0006] According to an aspect of the present invention, the following display system is provided. The display system is a display system using a display device mounted on a vehicle, and includes an acquisition device that acquires information on the position of the vehicle, information representing one or more set positions preset on a specific route along which the vehicle moves, and display information associated with the set position. A storage device that stores the information, and a control device that controls the display device to display the display information corresponding to the set position determined to have been reached by the vehicle when it is determined that the vehicle has reached the set position. The set position is a desired position designated by a user, and the display information corresponding to the set position is desired display information set by the user.

[0007] According to an aspect of the present invention, the following display system is provided. The display system is a display system using a display device mounted on a vehicle, and comprises: a storage device that stores display IDs and display information in association with each other; a signal receiving device that receives signals including display IDs set in one or more signal transmitting devices pre-installed on a specific route along which the vehicle travels; and a control device that controls the display and erasure of display information corresponding to the display IDs included in the received signals on the display device.

[0008] According to an aspect of the present invention, the following display method is provided. The display method is a display method in a display system using a display device mounted on a vehicle, and comprises the steps of: storing information of one or more pre-set locations on a specific route to which the vehicle travels, and display information associated with the set locations, in a storage device; setting a desired location specified by a user as the set location; setting desired display information set by the user as display information corresponding to the set location; acquiring information representing the location of the vehicle; and, when it is determined that the vehicle has reached the set location, displaying the display information corresponding to the set location to which the vehicle has been determined to have reached on the display device.

[0009] According to an aspect of the present invention, the following display method is provided. The display method is a display method in a display system using a display device mounted on a vehicle, and comprises the steps of: storing a display ID and display information in association with each other in a storage device; receiving a signal including a display ID set in one or more signal transmitting devices pre-installed on a specific route on which the vehicle travels; displaying the display information corresponding to the display ID included in the received signal on the display device; and erasing the display information displayed on the display device.

[0010] According to the present invention, a more suitable display device or display technology can be provided. Other problems, configurations, and effects not mentioned above will be clarified by the following description of the embodiments.

[0011] This figure shows an example of an in-vehicle system including a display device. This figure shows an example of a device used to acquire vehicle information. This is a block diagram showing an example of a display device. This figure shows an example of a configuration in which a display device is mounted on a vehicle. This figure shows an example of a configuration in which a display device is mounted on a vehicle. This figure shows an example of a light source structure for a display device. This figure shows an example of a specific route and event occurrence location in the first embodiment. This figure illustrates an example of event occurrence conditions and display clearing conditions in the first embodiment. This figure shows a first example of event display in the first embodiment. This figure shows a second example of event display in the first embodiment. This figure shows the processing flow in the in-vehicle system according to the first embodiment. This figure shows an example of a specific route and event occurrence location in the second embodiment. This figure illustrates an example of event occurrence conditions and display clearing conditions in the second embodiment. This figure shows a first example of event display in the second embodiment. This figure shows a second example of event display in the second embodiment. This figure shows the processing flow in the in-vehicle system according to the second embodiment.

[0012] Embodiments of the present invention will be described below with reference to the drawings. The embodiments are illustrative examples for explaining the present invention, and have been omitted and simplified as appropriate for clarity of explanation. The present invention can also be implemented in various other forms. Unless otherwise specified, each component may be singular or plural. The position, size, shape, and range of each component shown in the drawings may not represent the actual position, size, shape, and range in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, and range disclosed in the drawings. When there are multiple components that have the same or similar function, they may be described using the same reference numeral with different subscripts. Also, when it is not necessary to distinguish between these multiple components, the subscripts may be omitted in the description.

[0013] In explanations, when describing program-based processing, the focus may sometimes be on the program, functions, or processing units. However, the main hardware component is the processor, or a controller, device, computer, or system composed of such a processor. The computer, using its processor, executes processing according to the program read into memory, utilizing resources such as memory and communication interfaces as appropriate. This realizes the specified functions and processing units. The processor is composed of semiconductor devices such as a CPU / MPU or GPU. Processing is not limited to software program processing; it can also be implemented using dedicated circuits. Applicable dedicated circuits include FPGAs, ASICs, CPLDs, etc.

[0014] The program may be pre-installed as data on the target computer, or it may be distributed as data to the target computer from the program source. The program source may be a program distribution server on a communication network, or a non-transient computer-readable storage medium, such as a memory card or disk. The program may consist of multiple modules. The computer system may consist of multiple devices. The computer system may consist of a client-server system, a cloud computing system, an IoT system, etc. Various types of data and information are composed of structures such as tables and lists, but are not limited to these. Representations such as identification information, identifiers, IDs, names, and numbers are interchangeable.

[0015] Figure 1 shows an example configuration of an in-vehicle system including a display device or virtual image display device 1. With respect to the vehicle or ride 2 and the driver, the horizontal direction X is the left-right direction, the lateral direction of the vehicle or ride 2, or the width direction of the vehicle or ride 2; the vertical direction Z is the up-down direction, or vertical direction of the vehicle; and the horizontal direction Y, perpendicular to the lateral direction of the vehicle or ride 2, is the front-rear direction of the vehicle or ride 2, or the direction of travel of the vehicle. The display device 1 may also be called a virtual image display device. The following explanation will use the term "display device". The vehicle or ride 2 is typically an automobile or a truck, but is not limited to these; it may also be a railway vehicle or an aircraft. The following explanation will use the term "vehicle".

[0016] The display device 1 acquires vehicle information 4 from cameras and various sensors installed in various parts of the vehicle 2. The display device 1 may also be called a virtual image display device. The various sensors, for example, detect various events that occur in the vehicle 2 and periodically detect the values ​​of various parameters related to driving conditions. It can also acquire road information from a navigation device 6 (car navigation system), external devices 400, terminal devices (e.g., mobile terminals) 410, and GPS (Global Positioning System) information. The GPS may be installed in the vehicle 2, or it may be installed in the external devices 400 or terminal devices 410.

[0017] Vehicle information 4 includes, for example, vehicle 2's speed information, gear information, steering angle information, lamp illumination information, ambient light information, distance information, infrared information, engine ON / OFF information, camera image information, accelerometer / gyro information, GPS (Global Positioning System) information, navigation information, vehicle-to-vehicle communication information, and vehicle-to-infrastructure communication information. Camera image information includes in-vehicle camera image information and exterior camera image information. GPS information includes latitude and longitude as well as current time information. Vehicle information 4 also includes input information from the driver.

[0018] The display device 1 is connected to the controller 100 of the vehicle 2 via an information transmission path, and the display device 1 and the controller 100 are able to communicate with each other. The controller 100 of the vehicle 2 is an ECU (Electronic Control Unit). The display device 1 and the controller 100 of the vehicle 2 communicate via the information transmission path using, for example, a CAN (Controller Area Network) or LIN (Local Interconnect Network) interface. Alternatively, the display device 1 and the controller 100 of the vehicle 2 may communicate via the information transmission path using an in-vehicle Ethernet or the like. Other connection configurations may also be adopted. For example, when transmitting all information, including video information, through a single information transmission path, the connection between the controller 100 on the vehicle 2 side (source of video information, etc.) and the display device 1 (in other words, the connection configuration of the information transmission path) may be FPD-Link III, GMSL (Gigabit Multimedia Serial Link), etc.

[0019] The in-vehicle system is configured such that the controller 100 controls the vehicle 2 based on data input and output and is connected to the display device 1. The in-vehicle system can communicate with the outside of the vehicle 2 via a communication device or network. Examples of communication with the outside of the vehicle 2 include direct communication and indirect communication. Direct communication is used internationally as ITS (Intelligent Transport System) communication, while indirect communication is performed, for example, via a server to an external device 400 or terminal device 410. The in-vehicle system can send and receive data or information to, for example, a server 700 connected to the network 500 via a relay station 600 on the network 500. The in-vehicle system may also communicate with infrastructure such as external devices and terminals installed on the road on which the vehicle 2 travels.

[0020] Figure 2 shows an example of a device used to acquire vehicle information. As shown in Figure 2, vehicle information 4 is acquired using devices such as a camera and various sensors connected to the controller 100 or control device 100. Note that the various devices in Figure 2 can be deleted, other types of devices added, or replaced with other types of devices as appropriate. Also, as an example, the controller 100 of the vehicle 2 may also have the function of controlling the display device 1.

[0021] The vehicle speed sensor 901 detects the speed of the vehicle 2 and is used to generate speed information as a result of the detection. The shift position sensor 902 detects the current gear and is used to generate gear information as a result of the detection. The steering angle sensor 903 detects the current steering angle and is used to generate steering angle information as a result of the detection. The headlight sensor 904 detects whether the headlights are ON or OFF and is used to generate lamp illumination information as a result of the detection.

[0022] The illuminance sensor 905 and the chromaticity sensor 906 detect ambient light from the vehicle 2 and are used to generate ambient light information as detection results. The distance measuring sensor 907 detects the distance between the vehicle 2 and an external object, or the distance between external objects, and is used to generate distance information as detection results. The infrared sensor 908 detects the presence and distance of objects in the vicinity of the vehicle 2 and is used to generate infrared information as detection results. The engine start sensor 909 detects the ON / OFF status of the engine and is used to generate ON / OFF information as detection results. The acceleration sensor 912 and the gyro sensor 913 detect the acceleration and angular velocity of the vehicle 2 and are used to generate acceleration gyro information representing the attitude and behavior of the vehicle 2.

[0023] The temperature sensor 914 detects the temperature inside and outside the vehicle and is used to generate temperature information as the detection result. For example, if the display device 1 is located inside the dashboard of the vehicle 2, the temperature sensor 914 may be used to detect the temperature inside the dashboard. If a temperature that may affect the operation of the display device 1 is detected, the display device 1 may stop operating. The temperature sensor 914 may also be located in other places that may reach temperatures similar to those inside the dashboard.

[0024] Furthermore, if the display device 1 is installed on the dashboard or elsewhere, the temperature sensor 914 may be used to detect the temperature in the vicinity where the display device 1 is installed. If a temperature is detected that may affect the operation of the display device 1 due to direct sunlight or the like, the display device 1 may stop operating. Here, the temperature sensor 914 may be placed on the dashboard as an example. The temperature sensor 914 may also be placed outside the vehicle, assuming that the temperature near the display device 1 and the temperature outside the vehicle are similar.

[0025] The vehicle-to-infrastructure wireless transceiver 915 generates vehicle-to-infrastructure communication information through vehicle-to-infrastructure communication between the vehicle 2 and roads, signs, signals, etc. The vehicle-to-vehicle wireless transceiver 916 generates vehicle-to-vehicle communication information through vehicle-to-vehicle communication between the vehicle 2 and other surrounding vehicles. The wired wireless communication unit 917 for mobile terminal-to-vehicle communication is a device that acquires information via wired or wireless communication from devices connected to an LTE (Long Term Evolution) network (e.g., Wi-Fi devices). The controller 100 or control device can acquire information transmitted and received on the LTE network via the wired wireless communication unit 917 for mobile terminal-to-vehicle communication.

[0026] The in-vehicle camera 919 and the exterior camera 920 capture images of the interior and exterior of the vehicle and are used to generate in-vehicle and exterior camera image information. Specifically, the in-vehicle camera 919 is, for example, a camera for a Driver Monitoring System (DMS) that captures the driver's posture, eye position, and movement. In this case, by analyzing the captured images, the driver's fatigue level and gaze position can be determined.

[0027] On the other hand, the external camera 920 captures images of the surroundings, such as the front and rear of the vehicle 2. In this case, by analyzing the captured images, it becomes possible to determine the presence or absence of obstacles such as other vehicles or people in the vicinity, buildings and terrain, road surface conditions such as rain, snow, ice, and unevenness, and road signs. The external camera 920 may also include, for example, a drive recorder that records the situation while driving.

[0028] The GPS receiver 921 generates GPS information obtained by receiving GPS signals from GPS satellites. For example, the GPS receiver 921 can obtain the current time, latitude, and longitude. The VICS (Vehicle Information and Communication System, registered trademark) receiver 922 generates VICS information obtained by receiving VICS signals. The GPS receiver 921 and the VICS receiver 922 may be provided as part of a navigation system.

[0029] The voice input device 918 receives the driver's voice and is used to generate voice information. The driver can input operation details via the voice input device 918 by speaking. The vehicle operation switches 911 are used to generate driver operation information for steering wheel switches, etc.

[0030] Furthermore, the video generation unit 910 generates video information based on vehicle information 4 acquired by the controller 100 of the vehicle 2. It can also generate video information based on external information.

[0031] Figure 3 is a block diagram of the display device 1. It is mainly used to control the display of projected images (virtual images) on the display device 1.

[0032] In Figure 3, the display device 1 includes, for example, a control unit 1010, a non-volatile memory 1011, a volatile memory 1012, a storage unit 1013, a display driver 1021, and a light source drive unit 1022, all of which are mounted on a wiring board or the like. The display device 1 also includes a communication unit 1014, a wireless communication unit 1015, a video processing unit 1016, an operation input unit 1017, an external power input unit 1018, a speaker 1019, and a light-emitting indicator 1020.

[0033] The control unit 1010 is specifically a microcontroller unit (MCU), a CPU (Central Processing Unit), etc. Each block other than the control unit 1010 may be mounted within the control unit 1010 as appropriate. Furthermore, the display device 1 is not limited to implementation using the control unit 1010, but may also be implemented using an ECU (Electronic Control Unit) or other semiconductor devices. The configuration shown in Figure 3 may, for example, be a control unit mounted inside the housing of the display device 1, or a control unit mounted outside the housing. Also, the display device 1 can be controlled by a controller in the vehicle 2 or an external device without implementing the control unit 1010 in the display device 1.

[0034] The non-volatile memory 1011 primarily stores programs executed within the control unit 1010, setting parameters used in the processing of each part within the control unit 1010, and predefined audio and video data. The non-volatile memory 1011 may also store information other than programs, such as video, audio, and video.

[0035] The volatile memory 1012 operates by unpacking the program stored in the non-volatile memory 1011. The volatile memory 1012 primarily processes acquired information and various data used in the processing of each part within the control unit 1010 as appropriate.

[0036] The storage unit 1013 stores video data, video data, or audio data for output to the speaker 1019, etc. The video data, video data, or audio data to be stored in the storage unit 1013 may be stored in the storage unit 1013 in advance. Alternatively, the video data, video data, or audio data to be stored in the storage unit 1013 may be received from an external device via the communication unit 1014.

[0037] In Figure 3, the communication unit 1014 transmits and receives information such as vehicle information 4 to and from the controller 100 of the vehicle 2 or various devices such as sensors of the vehicle 2, using a mechanism such as CAN or an in-vehicle Ethernet. The communication unit 1014 may also receive video information using a mechanism such as FPD-Link III or GMSL. The hardware of the communication interface that receives vehicle information 4 and the hardware of the communication interface that receives video information in the communication unit 1014 may be separate or integrated. The communication unit 1014 may also function as the control unit of the display device 1.

[0038] The wireless communication unit 1015 may be configured with a Wi-Fi communication interface, a Bluetooth® communication interface, a mobile communication interface such as 4G or 5G, etc. As shown in Figure 1, the wireless communication unit 1015 may communicate with external devices via a network 500 connected through a router or relay station 600. An example of an external device is a server 700 connected via the network 500. Alternatively, the wireless communication unit 1015 may communicate directly with a terminal device 410, etc. An example of a terminal device 410 is a smartphone, tablet, wireless earphones, headphones, or beacon.

[0039] The video processing unit 1016 may perform distortion correction, conversion, and other processing on the received video information. The video processing unit 1016 may generate video data for the video display unit 200 using acquired vehicle information, external information, etc. Specifically, the distortion correction here corrects the distortion of the video caused by the curvature of the windshield 3 when the video from the display device 1 is projected onto the display area 5, as shown in Figure 1. The video processing unit 1016 may also be implemented by the control unit 1010 reading and executing a program stored in the non-volatile memory 1011 or the volatile memory 1012.

[0040] That is, the video processing unit 1016 processes video data related to the display video projected onto the display area 5 in FIG. 1 or the like based on the information acquired from the outside or the vehicle 2. On the other hand, it is not necessarily required to have the video processing unit 1016. In such a case, the control unit 1010 can process video information from the vehicle 2 or an external terminal via the communication unit 1014. Also, the video information may be processed by the controller 100 of the vehicle 2.

[0041] The operation input unit 1017 is, for example, an operation button, a reception unit such as a remote controller, or an infrared light receiving unit, and inputs the user's operation. The operation input unit 1017 may be used, for example, for a driver to operate the display device 1.

[0042] The external power input unit 1018 inputs power from the outside and supplies the necessary power to each unit of the display device 1 in FIG. 3.

[0043] The speaker 1019 emits sound based on the audio data stored in the volatile memory 1012, the non-volatile memory 1011, or the storage unit 1013.

[0044] The light-emitting indicator 1020 emits light by a light-emitting element or the like, and can notify the user of the state of the display device 1 by the light-emitting timing or the light-emitting color of the light-emitting element.

[0045] The display driver 1021 drives each display element (pixel) included in the display panel 11 based on the video data. Thereby, the video display unit or the video display unit 200 creates and displays a video for projection onto the display area 5 based on the video data.

[0046] The light source driver 1022 drives the light source 20 to generate light source light. Based on the drive from the light source driver 1022, the light source 20 generates light source light and supplies it to the display panel 11. The light source 20 is adjusted or controlled using the light source driver 1022, which is a driver used for driving the light source 20, based on the vehicle information 4 received via the communication unit 1014 or information from a terminal device or the like.

[0047] In addition, the display device 1 may protect the display panel 11 based on external light information from the illuminance sensor 905 or the like. That is, in order to prevent sunlight from hitting the display panel 11 and burning the display panel 11, the display device 1 may perform an operation of protecting the display panel 11 from sunlight according to the value of the illuminance sensor 905. More specifically, when the intensity of the external light or sunlight acquired by the illuminance sensor 905 is strong and there is a risk that the display panel 11 may be burned out, the brightness of the light source 20 is reduced, and the amount of light from the light source 20 incident on the display panel 11 is suppressed, thereby suppressing the temperature rise of the display panel 11.

[0048] Each part of FIG. 3 may be implemented by a dedicated circuit such as an FPGA (Field Programmable Gate Array) as appropriate. In the present embodiment, the configuration has a non-volatile memory 1011, a volatile memory 1012, a storage unit 1013, and a video processing unit 1016, but the above processing may be made to function by one memory.

[0049] Next, the video display unit 200 will be specifically described. The video display unit (video display unit) 200 projects the video light of the video formed on the display panel 11 using the light emitted from the light source 20 (in other words, the light source light) based on the video data. The video display unit 200 may be referred to as a projection type video display device or a projector. The video display unit 200 includes a light source 20 and a display panel 11 such as a liquid crystal panel LCD (Liquid Crystal Display) having a video display element.

[0050] The light source 20 functions as a backlight source of the display panel 11. The light source 20 is configured using, for example, a semiconductor light source element, generates predetermined light source light, and supplies it to the display panel 11. Typically, an LED (Light Emitting Diode) element is used as the semiconductor light source element. The light source 20 may have a configuration in which a plurality of light sources are arranged. The backlight unit is configured using the light source 20 or the like.

[0051] The display panel 11 generates and emits modulated video light based on the light source. In other words, the display panel 11 forms and displays an image on the display screen based on video data, and generates and emits video light corresponding to the image based on the light from the light source 20. The video data in this embodiment will be described as video data input from the video processing unit 1016. The display panel 11 forms an image to be projected onto the display area 5 by modulating the light from the light source 20 pixel by pixel according to the video data, and projects it as video light (in other words, projected light).

[0052] Furthermore, the display panel 11 is not limited to a liquid crystal panel; it may also be a screen plate with a diffusion function. As a means of projecting an image onto the screen plate with a diffusion function, a means of projecting an image from a DMD (Digital Micromirror Device) or a liquid crystal panel in combination with a projection lens may be used, or a means of using a micro-electromechanical system may be used.

[0053] Figures 4 and 5 show examples of configurations in which the display device 1 is projected onto a vehicle 2. Figure 4 shows an example of projecting the display device 1 onto a passenger car. Passenger cars include sports cars, sedans, SUVs (Sport Utility Vehicles), and minivans, where the angle of the windshield 3 is 20° to 45° with respect to the Y-axis (the longitudinal direction or direction of travel of the vehicle 2). Figure 5 shows an example of projecting the display device 1 onto some passenger cars and commercial vehicles, in other words, the windshield or windshield 3 in Figure 5 is in an upright position. Specifically, these include light super-height wagons, trucks, and buses, where the angle of the windshield 3 is 45° to 90° with respect to the Y-axis (the longitudinal direction or direction of travel of the vehicle 2). As shown in Figures 4 and 5, the display device 1 is positioned on the dashboard 7 of the vehicle 2. The display device 1 may also be implemented so as to be embedded within the dashboard 7. Dashboard 7 also includes an instrument panel, such as the meter cluster, located in front of the steering wheel.

[0054] As shown in Figures 4 and 5, the image light 13 in Figure 4 is emitted toward the driver, and the image light 13 in Figure 5 is emitted toward the windshield 3. The image light 13 emitted from the display device 1 is reflected when it is irradiated onto the windshield or windshield 3. The reflected image light 13 is incident on the driver's viewpoint 14. From the driver's viewpoint 14, a virtual image 10 corresponding to the image light 13 is formed and visible at a position visible through the display area 5 (Figure 1) of the display device 1 corresponding to the irradiation area of ​​the image light 13. In this embodiment, the projection of image light onto the display area 5 of the windshield 3 is described, but the projection unit that projects the image light may be a projection member other than the windshield 3.

[0055] Figure 6 shows the video display unit 200 of the display device 1. The light source unit 12 may also be called the backlight unit. The light source unit 12 includes a light source 20, a reflective mirror 21, a polarization conversion element 22, and a light guide unit 23, and may also include a diffuser plate 24. The reflective mirror 21 is used to reflect light from the light source 20 and adjust it to parallel light. The reflective surface of the reflective mirror 21 is a parabolic surface and may be asymmetrical with respect to the optical axis of the light emitted from the light source 20. The reflective mirror 21 may also be positioned eccentrically with respect to the light source 20. The reflective mirror 21 may also be called a reflector.

[0056] The polarization conversion element 22 is composed of a polarizing beam splitter (PBS) and a phase difference film (1 / 2λ). It separates incident light into S-polarized and P-polarized light, and then uses the phase difference film (1 / 2λ) to polarize either the separated S-polarized or P-polarized light, so that the randomly polarized light incident on the polarization conversion element 22 is emitted as linearly polarized light.

[0057] The light guide section 23 may also be called an optical transmission section. The light guide section 23 is configured to adjust the angle of incidence of light rays to the display panel 11, and in this example, it is configured using an optical reflecting section 23a having a prism shape (a jagged shape). The light guide section 23 may also be a prism sheet as an example. In this example, the light rays incident on the optical reflecting section 23a of the light guide section 23 are adjusted to a predetermined light distribution and reflected toward the display panel 11. The distribution of light incident on the display panel 11 can be adjusted by the shape of the reflective surface of the optical reflecting section 23a, the inclination of the reflective surface, the surface roughness, etc. In this structure, the optical axis of the light source 20 and the optical axis of the light incident on the display panel 11 are parallel or approximately parallel.

[0058] The light guide 23 is, for example, a resin member having a prism shape, and the prism-shaped portion that becomes the reflective surface is coated with an Al reflective film or the like. The light reflective portion 23a of the light guide 23 may be configured to have multiple inclinations on one surface in order to achieve more precise adjustment of reflected light. Furthermore, the reflective surface may be composed of multiple or multifaceted surfaces, or it may be composed of curved surfaces. When a large number of reflective surfaces and connecting surfaces are alternately formed in a sawtooth pattern on the light reflective portion 23a, the light incident on the light guide 23 is reflected on each reflective surface and directed toward the display panel 11, and further adjusted to a predetermined light distribution characteristic via the diffuser plate 24 before incident on the display panel 11. The diffuser plate 24 uniformly disperses the incident light from the light guide 23. The diffuser plate 24 has the effect of improving the brightness uniformity within the virtual image plane.

[0059] Furthermore, the video display unit 200 may have a configuration other than that shown in Figure 6, and may, for example, include a light source, an illumination optical system, a PBS or polarization separation element, and a reflective liquid crystal panel or LCOS.

[0060] (First Embodiment) The first embodiment of the present invention will now be described.

[0061] <Summary of the First Embodiment> The in-vehicle system according to the first embodiment functions as a display system using a display device mounted on a vehicle. The display system comprises an acquisition device, a storage device, and a control device. The acquisition device, storage device, and control device may all be provided by the display device 1, the vehicle 2, an external device 400, or a terminal device 410. The acquisition device acquires information representing the location of the vehicle. The storage device stores information representing one or more pre-set locations on a specific route the vehicle travels, and display information associated with the set locations. When the control device determines that the vehicle has reached a set location, it causes the display device to display the display information corresponding to the set location that the vehicle has reached. The set location is a desired location specified by the user, and the display information corresponding to the set location is desired display information set by the user.

[0062] The first embodiment will be explained in more detail. In the first embodiment, vehicle 2 travels along a specific route. One or more event occurrence points (set locations) are set on the specific route and registered in the in-vehicle system according to the first embodiment. The in-vehicle system acquires vehicle position information sequentially while vehicle 2 is traveling along the specific route. Based on at least the acquired vehicle position information, the in-vehicle system determines whether vehicle 2 is approaching an event occurrence point and whether an event has occurred. If the in-vehicle system determines that an event has occurred, it operates to display information corresponding to the event that occurred, or the event occurrence point of that event.

[0063] The event occurrence location is a desired location specified by the user, and the display information corresponding to the event occurrence location is the desired display information set by the user. The display information corresponding to the event occurrence location is set, for example, by the user selecting from a plurality of display information pre-stored in a storage device such as the storage unit 1013.

[0064] Vehicle 2 could be a commercial vehicle, such as a route bus, tour bus, shuttle bus, or freight vehicle. The displayed information could include information not found on typical signs, information different from signs, or information not found on maps. Specific examples of displayed information could include speed limits, warnings, and messages for tourists based on regulations within the organization or company managing and operating Vehicle 2.

[0065] The operation of the in-vehicle system according to the first embodiment is specifically as follows: The GPS receiver 921 (acquisition device) receives GPS signals from GPS satellites. Based on the received GPS signals, the GPS receiver 921 sequentially generates information representing the vehicle position, which is the position of the vehicle 2. The GPS receiver 921 also sequentially generates information representing the vehicle direction of travel, which is the direction of travel of the vehicle, from the history of the vehicle position, i.e., changes over time. Here, the vehicle position is represented by vehicle latitude and longitude, which expresses the position of the vehicle in terms of latitude and longitude. The vehicle direction of travel is represented by vehicle azimuth, which expresses the direction of travel of the vehicle in terms of azimuth. The vehicle azimuth is defined as an angle that represents the direction by taking a positive (+) angle clockwise, with north being 0 degrees. In addition, instead of the vehicle direction of travel, the vehicle entry direction, which is the direction in which the vehicle enters the road as viewed from the road, may be used.

[0066] The storage device (memory device) such as the storage unit 1013 stores a correspondence table for each event, which shows the relationship between the event ID, registered latitude and longitude, registered azimuth angle (set direction), display ID, and display information (mark / character). The storage device also stores display information for each display ID. Here, the registered latitude and longitude are the latitude and longitude of the location registered as the event occurrence point. The registered azimuth angle is the azimuth angle of the vehicle registered as a parameter of the event occurrence condition at the event occurrence point. Note that the vehicle's azimuth angle will vary depending on the GPS accuracy and the driving route, so it is advisable to set an error tolerance range of ±30° to ±60° for the registered azimuth angle.

[0067] In this embodiment, the control device will be described using the controller 100 of the vehicle 2. The controller 100 acquires the generated vehicle latitude and longitude and vehicle azimuth angle from the GPS receiver 921. The controller 100 refers to the above correspondence table and determines whether or not an event has occurred based on the comparison result between the acquired vehicle latitude and longitude and the registered latitude and longitude, and the comparison result between the vehicle azimuth angle and the registered azimuth angle. If the controller 100 determines that an event has occurred, it refers to the above correspondence table and identifies the display ID corresponding to the event that occurred. The controller 100 controls each part so that the display information corresponding to the identified display ID is displayed by the display device 1.

[0068] <Example of a specific route and event occurrence point in the first embodiment> Figure 7 shows an example of a specific route and event occurrence point in the first embodiment. As shown in Figure 7, a specific route RT1 is predetermined on which the vehicle 2 travels from the starting point (P11) to the goal point (P16). One or more different event occurrence points are set on the specific route RT1. Here, for example, as shown in Figure 7, event occurrence points E11, E12, E13, E14, E15, and E16 are set. Furthermore, registered latitude and longitude P11, P12, P13, P14, P15, and P16 are associated with event occurrence points E11 to E16, respectively. Furthermore, registered azimuth angles θ12, θ13, θ14, θ15, and θ16 are associated with each event occurrence point E12 to E16 as parameters for the event occurrence condition.

[0069] <Example of Event Occurrence Conditions and Display Clearing Conditions in the First Embodiment> Figure 8 is a diagram illustrating an example of event occurrence conditions and display clearing conditions in the first embodiment. Here, the event occurrence conditions and display clearing conditions will be explained using event occurrence point E12 as an example.

[0070] As shown in Figure 8, the event occurrence point E12 on the specific route RT1 is associated with the registered latitude and longitude P12. The event occurrence point E12 is also associated with the registered azimuth angle θ12. In the in-vehicle system, the conditions for an event to occur and for the display of corresponding information to begin are that the vehicle position PV, i.e., the vehicle latitude and longitude, falls within a predetermined region C1 (first region) based on the registered latitude and longitude P12 corresponding to the event occurrence point E12, and the vehicle azimuth angle θV falls within a predetermined angle θR (first angle) that includes the registered azimuth angle θ12 corresponding to the event occurrence point E12. As a result, when vehicle 2 travels along the specific route RT1 in the correct direction and approaches the event occurrence point E12 beyond a certain distance, the corresponding display information is displayed.

[0071] Here, the predetermined region C1 is, for example, a circular region with radius r1 centered on the registered latitude and longitude P12. The predetermined angle θR is an angle of ±Δθ centered on the registered azimuth angle θ12. Δθ is, for example, about 30 to 60 degrees. The event occurrence condition may be simply that the vehicle position PV, i.e., the vehicle latitude and longitude, falls within the range of the predetermined region C1 based on the registered latitude and longitude P12 corresponding to the event occurrence point E12.

[0072] On the other hand, the condition for clearing the display information after it has been displayed is that the vehicle's latitude and longitude, as the vehicle position PV, has moved outside the range of a predetermined area C2 (second area) based on the registered latitude and longitude P12 corresponding to the event occurrence point E12. As a result, when vehicle 2 moves beyond a certain distance from the event occurrence point E12, the display information is cleared.

[0073] Here, the predetermined region C2 is defined as a circular region with radius r2 centered on the registered latitude and longitude P12. The radius r1 defining the circular region as the predetermined region C1 related to the event occurrence condition and the radius r2 defining the circular region as the predetermined region C2 related to the display clearing condition may be the same. However, it is sometimes preferable to set the radius r2 to be larger than the radius r1, thereby creating hysteresis between the size of the predetermined region C1 related to the event occurrence condition and the size of the predetermined region C2 related to the display clearing condition. When hysteresis is created, for example, even if the vehicle latitude and longitude as the vehicle position PV fluctuate slightly due to measurement errors, or if the vehicle 2 temporarily moves slightly backward due to traffic circumstances, it is possible to prevent the display of the display information, once started, from flashing or flickering. The predetermined region C1 may also be called the predetermined range C1. The predetermined region C2 may also be called the predetermined range C2.

[0074] <First Example of Event Display in the First Embodiment> Figure 9 shows a first example of event display in the first embodiment. Figure 9 shows an example of display information suitable for a commercial vehicle traveling on a specific route RT1, such as a cargo truck. In the first embodiment, each event ID is associated with registered latitude and longitude, registered direction of travel (azimuth angle), and display ID. In addition, each display ID is associated with display information to be displayed. One or more display IDs are associated with a single event ID. Data for a correspondence table representing the correspondence between registered latitude and longitude, registered azimuth angle, and display ID, and the correspondence between display ID and display information, as well as data for display information, are stored in advance in a storage device such as a storage unit 1013 or a non-volatile memory 1011.

[0075] Furthermore, users can customize the above correspondence table. Display IDs and their display information can also be added, edited, and deleted. These points are also applicable to the second example of the first embodiment, and the first and second examples of the second embodiment, which will be described later.

[0076] An example of event display shown in Figure 9 will be explained. For example, event ID "1" corresponding to event occurrence point E11 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle corresponding to event occurrence point E11 "Undefined (regardless of entry direction)", and the display ID "00". Display ID "00" is associated with display information representing a start mark that informs the vehicle driver that they are at the starting point. In this case, the event type is "Starting Point". The vehicle's latitude, longitude and azimuth are compared with the registered latitude, longitude and registered azimuth angle corresponding to event occurrence point E11, and if the event occurrence conditions are met, the display information representing the start mark corresponding to this display ID "00" is displayed. The reason why the registered azimuth angle corresponding to event occurrence point E11 is "Undefined (regardless of entry direction)" is because the event type of this event is "Starting Point".

[0077] For example, as shown in Figure 9, the event ID "2" corresponding to event location E12 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "45 degrees", and the display ID "13". Display ID "13" is associated with display information that combines a warning mark to alert the driver and a pedestrian mark that mimics the appearance of a pedestrian. In this case, the event type is "Pedestrian Warning". The vehicle's latitude and longitude and vehicle azimuth are compared with the registered latitude and longitude and registered azimuth angle corresponding to event location E12, and if the event conditions are met, the display information that combines the warning mark and pedestrian mark, corresponding to display ID "13", is displayed.

[0078] For example, as shown in Figure 9, event ID "3" corresponding to event location E13 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "90 degrees", and the display ID "20". Display ID "20" is associated with display information that combines a warning mark to alert the driver and a vehicle exit mark indicating the exit of another vehicle. In this case, the event type is "Caution: Vehicle Exit". The vehicle latitude and longitude and vehicle azimuth are compared with the registered latitude and longitude and registered azimuth angle corresponding to event location E13, and if the event conditions are met, display information that combines a warning mark and a pedestrian mark, corresponding to display ID "20", is displayed.

[0079] For example, as shown in Figure 9, event ID "4" corresponding to event location E14 is associated with the registered latitude and longitude "N:XX, E:XX", the registered direction of travel "140 degrees", and the display ID "23". Display ID "23" is associated with display information that combines a warning mark to alert the driver and a width reduction mark to indicate a decrease in road width. In this case, the event type is "Wide width reduction warning". The vehicle's latitude and longitude and vehicle azimuth are compared with the registered latitude and longitude and registered azimuth corresponding to event location E14, and if the event conditions are met, the display information that combines the warning mark and the width reduction mark, corresponding to display ID "23", is displayed.

[0080] For example, as shown in Figure 9, event ID "5" corresponding to event location E15 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "200 degrees", and the display ID "06". Display ID "06" is associated with display information that combines a warning mark to alert the driver and a speed mark to indicate speed. In this case, the event type is "Speeding Warning". The vehicle's latitude and longitude and vehicle azimuth are compared with the registered latitude and longitude and registered azimuth angle corresponding to event location E15, and if the event conditions are met, the display information that combines a warning mark and a speed mark, corresponding to display ID "06", is displayed.

[0081] For example, as shown in Figure 9, event ID "6" corresponding to event location E16 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "200 degrees", and the display ID "99". Display ID "99" is associated with display information representing a finish marker that informs the driver that they are at the finish line. In this case, the event type is "Finish Line". The vehicle's latitude and longitude and vehicle azimuth are compared with the registered latitude and longitude and registered azimuth angle corresponding to event location E16, and if the event conditions are met, display information representing a start marker, corresponding to display ID "99", is displayed.

[0082] The driver of vehicle 2, for example, upon seeing the displayed "Caution: Vehicle Exit" mark, can take action to avoid a collision with another vehicle, such as slowing down or carefully checking the area around the exit, taking into consideration the possibility of another vehicle coming out of the exit. Also, the driver can take action to ensure that their vehicle speed does not exceed the speed limit upon seeing the displayed "Caution: Speeding" mark, for example, in places where vehicle speeds tend to be high, such as straight roads with little congestion or downhill roads.

[0083] <Second Example of Event Display in the First Embodiment> Figure 10 shows a second example of event display in the first embodiment. Figure 10 shows an example of display information suitable for tourist vehicles at tourist attractions.

[0084] An example of event display shown in Figure 10 will be explained. For example, event ID "1" corresponding to event occurrence point E11 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle corresponding to event occurrence point E11 as "Undefined (direction of entry irrelevant)", and the display ID "101". Display ID "101" is associated with the display information "Welcome!", which represents a welcome mark that informs the driver, guide, or passengers of vehicle 2 that they are at the starting point. In this case, the event type is "Starting Point". The vehicle latitude and longitude and vehicle azimuth angle are compared with the registered latitude and longitude and registered azimuth angle corresponding to event occurrence point E11, and if the event occurrence conditions are met, the display information representing the welcome mark corresponding to display ID "101" is displayed. The reason why the registered azimuth angle corresponding to event location E11 is set to "Undefined (direction of entry irrelevant)" is because the event type for this event is "Starting Point".

[0085] For example, as shown in Figure 10, event ID "2" corresponding to event location E12 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "45 degrees", and display IDs "104" and "121". Display ID "104" is associated with the text display information that conveys the message to the passenger, "Look Left!". Display ID "121" is associated with the display information of an object that the passenger should look at, in this case a mountain mark (Figure) that resembles a mountain. In this case, the event type is "Look Left / Mountain". The vehicle's latitude, longitude, and azimuth are compared with the registered latitude, longitude, and azimuth corresponding to event location E12. If the event conditions are met, display information is shown that combines "Look Left!" corresponding to display ID "104" and a mountain mark corresponding to display ID "121".

[0086] For example, as shown in Figure 10, event ID "3" corresponding to event location E13 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "90 degrees", and display IDs "102" and "123". Display ID "102" is associated with the text display information that conveys the message to the passenger, "Look Front!". Display ID "123" is associated with the display information of an object that the passenger should look at, in this case an island mark resembling an island. In this case, the event type is "Look Front / Island". The vehicle's latitude, longitude, and azimuth are compared with the registered latitude, longitude, and azimuth corresponding to event location E13. If the event conditions are met, display information is shown that combines "Look Left!" corresponding to display ID "104" and a mountain mark corresponding to display ID "121".

[0087] For example, as shown in Figure 10, event ID "4" corresponding to event location E14 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "140 degrees", and display IDs "106" and "134". Display ID "106" is associated with the text display information that conveys the message to the passenger, "Look Right!". Display ID "134" is associated with the display information of an object that the passenger should look at, in this case a building mark resembling a building. In this case, the event type is "Look Right / Building". The vehicle's latitude, longitude, and azimuth are compared with the registered latitude, longitude, and azimuth corresponding to event location E14. If the event conditions are met, display information is shown that combines "Look Right!" corresponding to display ID "106" and a building mark corresponding to display ID "134".

[0088] For example, as shown in Figure 10, event ID "5" corresponding to event location E15 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "200 degrees", and display IDs "106" and "138". Display ID "106" is associated with the text display information that conveys the message to the passenger, "Look Right!". Display ID "138" is associated with the display information of an object that the passenger should look at, in this case a temple mark resembling a temple. In this case, the event type is "Look Right / Temple". The vehicle's latitude, longitude, and azimuth are compared with the registered latitude, longitude, and azimuth corresponding to event location E15. If the event conditions are met, display information is shown that combines "Look Right!" corresponding to display ID "106" and a temple mark corresponding to display ID "138".

[0089] For example, as shown in Figure 10, event ID "6" corresponding to event location E16 is associated with the registered latitude and longitude "N:XX, E:XX", the registered azimuth angle "200 degrees", and the display ID "199". Display ID "199" is associated with the display information "See You Again!", which represents a farewell mark that informs the driver, guide, or passengers of vehicle 2 that they have reached the goal. In this case, the event type is "Goal". The vehicle's latitude and longitude and vehicle azimuth are compared with the registered latitude and longitude and registered azimuth angle corresponding to event location E16, and if the event occurrence conditions are met, the display information representing the farewell mark corresponding to display ID "199" is displayed.

[0090] The driver or guide of vehicle 2 can, for example, see the displayed "Look Left!" and mountain symbol and announce useful information to passengers, such as, "Look to the left! You can see the famous ** mountain!" Alternatively, by displaying this information in a location visible to passengers, useful information can be directly provided to passengers, encouraging them to take action, such as looking to the left to see the mountain.

[0091] Furthermore, if vehicle 2 is operating autonomously, or if the location where the display information is shown is visible to passengers, the following display methods may be adopted. For example, when displaying "Look Left!", it may be displayed slightly to the left when facing forward, and when displaying "Look Right!", it may be displayed slightly to the right when facing forward. This would encourage passengers to naturally turn in the direction indicated by focusing their attention on where the display information is shown.

[0092] <Processing flow in the in-vehicle system according to the first embodiment> Here, we will explain the processing flow in the in-vehicle system according to the first embodiment.

[0093] Figure 11 is a diagram showing the processing flow in an in-vehicle system according to the first embodiment. The processing flow shown in Figure 11 consists of steps S11 to S15. Note that this processing flow is intended to give a general overview of the processing flow, and detailed processing or processing that is performed as a matter of course has been omitted.

[0094] As shown in Figure 11, in step S11, information representing the vehicle's position and direction of travel is acquired. Specifically, the GPS receiver 921 in the in-vehicle system receives GPS signals from GPS satellites. Based on the received GPS signals, the GPS receiver 921 determines the vehicle's latitude and longitude as the vehicle's position. The GPS receiver 921 also determines the vehicle's azimuth angle as the direction of travel from the history of the determined vehicle's position, i.e., its change over time.

[0095] In step S12, an event occurrence is determined. Specifically, the controller 100 in the in-vehicle system determines whether the event occurrence conditions are met based on the vehicle latitude and longitude and vehicle azimuth angle obtained in step S11, and the registered latitude and longitude and registered azimuth angle corresponding to the event occurrence location. For example, the controller 100 determines that an event corresponding to the event occurrence location has occurred if the vehicle latitude and longitude as the vehicle position are within a predetermined area range based on the event occurrence location, and the vehicle azimuth angle as the direction of vehicle travel is within a predetermined angular range including the registered azimuth angle. The predetermined area here is, for example, a circular area with radius r1 centered on the event occurrence location, as described above. If it is determined in this determination that the event occurrence conditions are met, the processing step proceeds to step S13. On the other hand, if it is determined that the event occurrence conditions are not met, the processing step proceeds to step S11.

[0096] Furthermore, after the controller 100 determines that an event has occurred, it may perform processing to prevent the event from being switched until a predetermined event retention time TKE has elapsed.

[0097] In step S13, a determination is made as to whether or not the information needs to be displayed. Basically, the controller 100 displays the information according to the display ID associated with the event ID of the event that occurred. However, depending on the situation or conditions, it may be preferable not to display the information. Therefore, the controller 100 makes a determination as to whether or not the information needs to be displayed.

[0098] Specifically, for example, the controller 100 determines whether the same event that occurred previously (most recently) has occurred again. In other words, the controller 100 determines whether an event with the same event ID has occurred repeatedly in succession. This determination means determining whether the corresponding display information will be displayed repeatedly based on the same event ID.

[0099] If the controller 100 determines that the same event that occurred previously has occurred, it determines that it is not necessary to display information corresponding to the currently occurring event. In this case, the processing steps return to step S11. On the other hand, if it determines that the same event that occurred previously has not occurred, it determines that it is necessary to display information corresponding to the currently occurring event. In this case, the processing steps proceed to step S14.

[0100] In step S14, display information (marks / characters) is displayed. Specifically, if the controller 100 determines in step S13 that it is necessary to display display information, it refers to a correspondence table stored in a storage device such as the storage unit 1013 based on the event ID currently occurring, and identifies the corresponding display ID. Then, the controller 100 executes a process to display the display information corresponding to the identified display ID on the display device 1.

[0101] In step S15, the display information (marks / characters) is cleared. Specifically, the controller 100 determines whether the vehicle position has moved outside a predetermined area based on the event location of the event determined to have occurred in step S12. If the controller 100 determines that the vehicle position has moved outside the predetermined area, it clears the display information at the time. The predetermined area here is, for example, a circular area with radius r2 centered on the event location, as described above.

[0102] In step S15, the controller 100 may continue displaying the current display information until a predetermined time, called the display hold time TKD, has elapsed, and then erase the display of the current display information after the display hold time TKD has elapsed. In this case, the time from when the vehicle enters the predetermined area C1 until it leaves the predetermined area C2 varies depending on the vehicle's speed, preventing variations in the display time of the display information. Furthermore, it prevents the display of the display information from being erased midway due to changes in the GPS signal reception environment, such as external noise from radio waves, which may prevent the GPS signal from being received accurately. The display hold time TKD may be set based on the vehicle's speed. For example, if the vehicle is moving relatively fast and moves out of the predetermined area C2 in a short time, the display hold time TKD is set to be short, and if the vehicle is moving relatively slow due to traffic congestion, etc., and it takes a long time to move out of the predetermined area C2, the display hold time TKD is set to be long. This ensures a stable display time suitable for allowing viewers to recognize the display information.

[0103] Furthermore, in step S15, the controller 100 may prioritize continuing the display until the display holding time TKD has elapsed, and then erase the display information if the vehicle position moves outside the range of a defined predetermined area.

[0104] According to the first embodiment described above, useful information specific to commercial vehicles traveling on a particular route, which cannot be obtained from road signs, car navigation systems, maps, etc., can be conveyed to the occupants of the vehicle. For example, when a commercial vehicle traveling on a particular route approaches a place where attention specific to that job should be paid, the content of that attention can be conveyed to the observers inside the vehicle through the display of information. As a result, the occupants of the vehicle, such as the driver, guide, and passengers, can take appropriate actions, preferential actions, or obtain useful information more reliably and safely.

[0105] Furthermore, users can register or combine their desired locations and display information, such as event locations and corresponding display information. This is a feature not found in car navigation systems, allowing users to provide useful information to vehicle passengers, leveraging their skills and experience. For example, it can be used for educating vehicle passengers.

[0106] In the first embodiment, the controller 100 may be connected to a terminal device 410 equipped with GPS functionality in a communicative manner, and obtain GPS information from the terminal device 410 to obtain the vehicle's latitude and longitude as the vehicle's position PV. Alternatively, the controller 100 may obtain GPS information from the car navigation system 6 to obtain the vehicle's latitude and longitude as the vehicle's position PV.

[0107] (Second Embodiment) A second embodiment of the present invention will now be described.

[0108] <Outline of Operation of the In-Vehicle System According to the Second Embodiment> The in-vehicle system according to the second embodiment functions as a display system using a display device mounted on a vehicle. The display system comprises a storage device, a signal receiving device, and a control device. The storage device, the signal receiving device, and the control device may all be provided by the display device 1, the vehicle 2, an external device 400, or a terminal device 410. The storage device stores display IDs and display information in association. The signal receiving device receives signals containing display IDs unique to one or more signal transmitting devices pre-installed along a specific route on which the vehicle travels. The control device causes the display device to display the display information corresponding to the display IDs contained in the received signals.

[0109] The second embodiment will now be described in more detail. The in-vehicle system according to the second embodiment receives beacon signals from roads on a specific route that the vehicle (vehicle) 2 is traveling on. Based on the received beacon signals, the in-vehicle system detects when the vehicle is approaching an event location and operates to display information corresponding to that event location. The assumed vehicle and displayed information are the same as in the first embodiment.

[0110] The operation of the in-vehicle system according to the second embodiment is specifically as follows: One or more event occurrence points are set on the road of a specific route traveled by the vehicle. A signal transmitting device (signal transmitter) that emits a beacon signal is installed at or near the event occurrence point. The beacon signal includes information representing the signal transmitting device ID and display ID, or information representing the display ID.

[0111] The vehicle-to-infrastructure wireless transceiver 915 (signal receiving device) receives a beacon signal from a signal transmitting device and acquires information representing the signal transmitting device ID and display ID unique to the signal transmitting device, which are included in the received beacon signal. A storage device (memory device) such as the storage unit 1013 stores a correspondence table for each event, which represents the correspondence between the display ID and the display information. The controller 100 (control device) acquires information representing the signal transmitting device ID and display ID from the vehicle-to-infrastructure wireless transceiver 915. The controller 100 refers to the correspondence table and identifies the display information corresponding to the acquired display ID. The controller 100 controls each part so that the identified display information is displayed by the display device 1.

[0112] <Example of a specific route and event occurrence points for a vehicle in the second embodiment> Figure 12 shows an example of a specific route and event occurrence points in the second embodiment. As shown in Figure 12, a specific route RT2 is predetermined on which the vehicle travels from the starting point to the goal point. One or more different event occurrence points are set on the specific route RT2. In addition, a signal transmitting device that emits a beacon signal is installed at each of the one or more event occurrence points. Here, for example, as shown in Figure 12, event occurrence points E21, E22, and E23 are set. In addition, signal transmitting devices DV21, DV22, and DV23 are installed at event occurrence points E21, E22, and E23, respectively.

[0113] The signal transmitting devices transmit beacon signals periodically (for example, once per second) or almost continuously. The beacon signals contain information representing the signal transmitting device ID and display ID unique to the transmitting signal transmitting device. Here, signal transmitting device DV21 transmits a beacon signal that includes signal transmitting device ID information representing "1" as the signal transmitting device ID, and display ID information associated with the signal transmitting device ID "1". Similarly, signal transmitting device DV22 transmits a beacon signal that includes signal transmitting device ID information representing "2" as the signal transmitting device ID, and display ID information associated with the signal transmitting device ID "2". Likewise, signal transmitting device DV23 transmits a beacon signal that includes signal transmitting device ID information representing "3" as the signal transmitting device ID, and display ID information associated with the signal transmitting device ID "3".

[0114] <Examples of Event Occurrence Conditions and Display Clearing Conditions in the Second Embodiment> Figure 13 is a diagram illustrating an example of event occurrence conditions and display clearing conditions in the second embodiment. Here, the event occurrence conditions and display clearing conditions will be explained using event occurrence point E21 as an example. The event occurrence condition is the condition for determining whether or not an event corresponding to the event occurrence point has occurred. In this embodiment, as will be described later, it means the condition for determining (determining) the priority device, which is a priority signal transmitting device. The display clearing condition means the condition for clearing the display information displayed due to the determination of the priority device.

[0115] Here, we will explain using the example shown in Figure 13, where vehicle 2 travels along a road on a specific route RT2 and sequentially passes through event occurrence points E21 and E22. A beacon signal BS21 is transmitted from signal transmitting device DV21 installed at event occurrence point E21. The signal strength of beacon signal BS21 weakens as the distance from signal transmitting device DV21 increases. Similarly, a beacon signal BS22 is transmitted from signal transmitting device DV22 installed at event occurrence point E22. The signal strength of beacon signal BS22 weakens as the spatial distance from signal transmitting device DV22 increases.

[0116] On the other hand, the determination of whether or not an event has occurred, i.e., the determination of a priority device, is made based on the magnitude of the signal strength of the received beacon signal. Specifically, a threshold strength STH is pre-set for each beacon signal. In an in-vehicle system, when a beacon signal is received, if its signal strength is equal to or greater than the threshold strength STH, the beacon signal with the greatest signal strength is identified as the priority beacon signal. The signal generating device that transmits the priority beacon signal is then determined to be the priority device. In other words, it is determined that an event corresponding to the priority device has occurred.

[0117] Assuming that, as shown in Figure 13, vehicle 2 approaches event location E21 and vehicle position PV reaches position PV1, the in-vehicle system receives a beacon signal BS21 from signal transmitting device DV21 installed at event location E21, but its signal strength does not reach the threshold strength STH or higher. Therefore, when vehicle position PV is position PV1, the in-vehicle system does not determine the priority device, meaning no event occurs.

[0118] Next, let's assume that vehicle 2 approaches the event occurrence point E21 further, and the vehicle position PV reaches position PV22. At this time, the signal strength of the beacon signal BS21 received by the in-vehicle system becomes equal to or greater than the threshold strength STH. Therefore, the in-vehicle system determines that the signal transmitting device DV21 is the priority device and identifies the signal transmitting device ID "1" corresponding to the priority device, signal transmitting device DV21. In other words, it is determined that an event corresponding to the event occurrence point E21 has occurred. The in-vehicle system then displays the display information of the display ID corresponding to this signal transmitting device ID "1". Note that if multiple beacon signals with a threshold strength of STH or higher are received simultaneously with the same signal strength, the determination of the priority device may be delayed until there is one beacon signal with a threshold strength of STH or higher and the highest signal strength.

[0119] Furthermore, when the in-vehicle system displays information for a display ID corresponding to a certain signal-emitting device ID, it will generally erase the display after a predetermined time has elapsed since the start of displaying the information. Also, when the in-vehicle system displays information for a display ID corresponding to a certain signal-emitting device ID and erases the display after a predetermined time has elapsed, if the same signal-emitting device ID that was the basis for the most recent display is identified, the display will not be shown again. In other words, based on the occurrence of the same event as before, the system will not display the information corresponding to that event consecutively.

[0120] In the example shown in Figure 13, the in-vehicle system operates as follows while the vehicle position PV changes from position PV2 to position PV3. The in-vehicle system displays display information for the display ID corresponding to the signal transmitting device ID "1", and erases the display after a predetermined time ΔT has elapsed since the start of the display. Subsequently, even if the beacon signal BS21, which is again above the threshold strength STH, is received at the strongest signal strength, the in-vehicle system does not display the same display information corresponding to the signal transmitting device ID "1" as before.

[0121] Assume that vehicle 2 continues from location PV2 and reaches location PV3. At location PV3, the in-vehicle system receives a beacon signal BS21 from signal transmitting device DV21, whose signal strength is equal to or greater than the threshold strength STH. At location VP3, the in-vehicle system also receives a beacon signal BS22 from signal transmitting device DV22, whose signal strength is equal to or greater than the threshold strength STH. However, at location PV3, the signal strength of beacon signal BS22 is greater than the signal strength of beacon signal BS21. Therefore, the in-vehicle system determines that signal transmitting device DV22, which is transmitting the strongest beacon signal with a signal strength equal to or greater than the threshold strength STH, is the priority device. The in-vehicle system identifies the signal transmitting device ID "2" corresponding to the priority device, signal transmitting device DV22. The in-vehicle system then displays the display information of the display ID corresponding to this signal transmitting device ID "2".

[0122] In the example shown in Figure 13, the in-vehicle system operates as follows while the vehicle position PV changes from position PV3 to the next position PV4. The in-vehicle system displays display information corresponding to signal transmitting device ID "2", and then erases the display after a predetermined time ΔT has elapsed since the start of the display. Subsequently, even if the beacon signal BS22, which is above the threshold strength STH, is received again at the strongest signal strength, the in-vehicle system does not display the same display information corresponding to signal transmitting device ID "2" as before. On the other hand, if the vehicle changes direction of travel without the vehicle position PV progressing from position PV3 to the next position PV4, there is a predetermined period during which the system periodically or continuously detects either the beacon signal of signal transmitting device DV21 or signal transmitting device DV22. In such cases, the display information corresponding to the signal transmitting device ID is not displayed until the stronger signal strength is continuously detected.

[0123] With this operation of the in-vehicle system, when vehicle 2 approaches the event location sufficiently, display information corresponding to that location can be displayed. Furthermore, by preventing the display information from being based on the same event that occurred previously, inappropriate displays such as flashing, flickering, or displaying information for an unnecessarily long time can be prevented.

[0124] <First Example of Event Display in the Second Embodiment> Figure 14 shows a first example of event display in the second embodiment. Figure 14 shows an example of display information suitable for a commercial vehicle traveling on a specific route RT2, such as a route bus. In the second embodiment, a display ID representing the type of display information to be displayed is associated with each signal transmission device ID. In addition, display information to be displayed is associated with each display ID. One or more display IDs are associated with a single signal transmission device ID. Data in the correspondence table representing the correspondence between signal transmission device IDs and display IDs, and the correspondence between display IDs and display information, as well as data for the display information, are stored in advance in a storage device such as a storage unit 1013 or a non-volatile memory 1011. The same applies to the second embodiment described later.

[0125] Let's explain an example of an event display shown in Figure 14. For example, signal transmitting device ID "1" is associated with display ID "56". Display ID "56" is associated with display information that combines a warning mark to alert the driver or passenger and a right-turn mark that resembles a right-curving arrow. In this case, the event type is "Right Turn Warning". If the beacon signal transmitted from the priority device contains information for signal transmitting device ID "1", then display information that combines the warning mark and the right-turn mark, corresponding to display ID "56", will be displayed.

[0126] For example, as shown in Figure 14, the signal transmitting device ID "2" is associated with the display ID "60". Display ID "60" is associated with display information that combines a warning mark to alert the driver or passenger and a pedestrian mark that resembles the figure of a pedestrian. In this case, the event type is "Pedestrian Warning". If the beacon signal transmitted from the priority device contains information for signal transmitting device ID "2", the display information that combines the warning mark and the pedestrian mark, corresponding to this display ID "60", will be displayed.

[0127] For example, as shown in Figure 14, the signal transmitting device ID "3" is associated with the display ID "78". Display ID "78" is associated with display information that combines a warning mark to alert the driver or passenger and a merging mark that mimics a road where lanes merge. In this case, the event type is "Merging Warning". If the beacon signal transmitted from the priority device contains information for signal transmitting device ID "3", then the display information that combines the warning mark and the merging mark, corresponding to this display ID "78", will be displayed.

[0128] The driver or guide of vehicle 2 can, for example, see the displayed "Caution: Right Turn" mark to confirm points to be aware of while driving. In particular, in places where road signs cannot be installed or are not installed for some reason, or in places where there are special precautions unique to commercial vehicles, if a signal-emitting device is installed and a warning display like the one described above is shown, the driver, guide, or passenger of the vehicle can obtain useful information.

[0129] <Second Example of Event Display in the Second Embodiment> Figure 15 shows a second example of event display in the second embodiment. Figure 15 shows an example of display information suitable for tourist vehicles (tour buses) in zoos / zoo / nature parks.

[0130] Let's explain an example of event display shown in Figure 15. For example, signal transmitting device ID "1" is associated with display IDs "102" and "181". Display ID "102" is associated with the display information of text (characters) that represents the message to be conveyed to the passenger, "Look Front!". Display ID "181" is associated with the display information of a mark (figure) that resembles the shape of a lion, an animal that the passenger should look at. In this case, the event type is "Look Front / Lion". If the beacon signal transmitted from the priority device contains information for signal transmitting device ID "1", the text information "Look Front!" corresponding to display ID "102" and the lion mark corresponding to display ID "181" will be displayed.

[0131] For example, as shown in Figure 15, the signal transmitting device ID "2" is associated with display IDs "104" and "188". Display ID "104" is associated with the text display information that conveys the message to the passenger, "Look Left!". Display ID "188" is associated with the display information of a mark resembling an object that the passenger should look at, in this case an animal, a camel. In this case, the event type is "Look Left / Camel". If the beacon signal transmitted from the priority device contains information for signal transmitting device ID "2", the text information "Look Left!" corresponding to display ID "104" and the camel mark corresponding to display ID "188" will be displayed.

[0132] For example, as shown in Figure 15, the signal transmitting device ID "3" is associated with display IDs "102" and "185". Display ID "102" is associated with the text display information that conveys the message to the passenger, "Look Front!". Display ID "185" is associated with the display information of a mark resembling an object that the passenger should look at, in this case an animal, a giraffe. In this case, the event type is "Look Front / Giraffe". If the beacon signal transmitted from the priority device contains the information of signal transmitting device ID "3", the text information "Look Front!" corresponding to display ID "102" and the giraffe mark corresponding to display ID "185" will be displayed.

[0133] The vehicle driver or guide can, for example, see the displayed "Look Front!" and lion symbol and announce useful information to passengers, such as "Look straight ahead! There's a lion!" Alternatively, by displaying this information in a location visible to passengers, useful information can be provided, encouraging passengers to take action, such as focusing their eyes straight ahead to see the lion.

[0134] <Processing flow in the in-vehicle system according to the second embodiment> Here, we will explain the processing flow in the in-vehicle system according to the second embodiment.

[0135] Figure 16 is a diagram showing the processing flow in an in-vehicle system according to the second embodiment. The processing flow shown in Figure 16 consists of steps S21 to S25. Note that this processing flow is intended to give a general overview of the processing flow, and detailed processing or processing that is performed as a matter of course has been omitted.

[0136] As shown in Figure 16, first, in step S21, the signal transmitting device ID is received. Specifically, the vehicle-to-infrastructure communication wireless transceiver 915 in the in-vehicle system receives a beacon signal from a signal transmitting device installed at the event occurrence point. It is also possible that the vehicle-to-infrastructure communication wireless transceiver 915 receives beacon signals from multiple signal transmitting devices. The beacon signal contains information representing the signal transmitting device ID unique to the transmitting signal transmitting device, and information representing the display ID associated with that signal transmitting device ID. Therefore, receiving a beacon signal is equivalent to receiving the signal transmitting device ID and its corresponding display ID.

[0137] In step S22, the priority device is determined. Specifically, the controller 100 in the in-vehicle system determines (determines) the signal transmitting device that is the source of the beacon signal with the highest signal strength among the beacon signals received in step S21 as the priority device. Incidentally, determining the priority device means determining a signal transmitting device ID that is unique to the signal transmitting device corresponding to the priority device.

[0138] In this case, the controller 100 may process the data so as not to determine a priority device unless the signal strength of any of the received beacon signals exceeds a predetermined first threshold strength STH1. In other words, the controller 100 may determine the signal transmitting device that is the source of the beacon signal whose signal strength is equal to or greater than the first threshold strength STH1 and has the highest signal strength among the received beacon signals as the priority device.

[0139] Furthermore, after determining the priority device, the controller 100 may perform a process that prevents it from switching the priority device until a predetermined priority device holding time TKP has elapsed.

[0140] In step S23, a determination is made as to whether or not to display the information. Basically, the controller 100 displays the display information according to the display ID received from the priority device. However, in some cases, it may be preferable not to display the information. Therefore, the controller 100 makes a determination as to whether or not to display the information.

[0141] Specifically, the controller 100 determines whether the same signal-emitting device that was previously (most recently) determined to be a priority device has been determined (judged) again as a priority device. In other words, the controller 100 determines whether the same signal-emitting device ID has been repeatedly determined as the signal-emitting device ID of a priority device consecutively. This determination means determining whether the corresponding display information will be repeatedly displayed based on the beacon signal from the same signal-emitting device.

[0142] If the controller 100 determines that the same signal transmitting device that was previously determined to be the priority device has been determined to be the priority device again, it determines that it is not necessary to display the display information corresponding to the current priority device. In this case, the processing steps return to step S21. On the other hand, if the controller 100 determines that the same signal transmitting device that was previously determined to be the priority device has not been determined to be the priority device again, it determines that it is necessary to display the display information corresponding to the current priority device. In this case, the processing steps proceed to step S24.

[0143] In step S24, display information (marks / characters) is displayed. Specifically, if the controller 100 determines in step S23 that it is necessary to display display information, it refers to the correspondence table stored in the storage unit 1013 based on the signal transmitting device ID of the currently prioritized device and identifies the corresponding display ID. Then, the controller 100 executes a process to display the display information corresponding to the identified display ID on the display device 1.

[0144] In step S25, the display information (marks / characters) is cleared. Specifically, the controller 100 clears the display information when the signal strength of the beacon signal from the priority device falls below a predetermined second threshold strength STH2. In this case, even if the vehicle's speed is low due to traffic congestion or other reasons, the display information can be kept displayed as long as the vehicle is in a location where it should be displayed. This allows observers to pay attention to the display information while they are in a location where they should be aware of its contents.

[0145] The second threshold intensity STH2 may be the same as the first threshold intensity STH1. Alternatively, the second threshold intensity STH2 may be made smaller (weaker) than the first threshold intensity STH1 to introduce hysteresis between the signal intensity of the beacon signal at which display can be initiated and the signal intensity of the beacon signal at which display is erased.

[0146] Furthermore, in step S25, the controller 100 may continue displaying the current display information until a predetermined time, known as the display hold time TKD, has elapsed, and then erase the display of the current display information after the display hold time TKD has elapsed. In this case, the time variation of the signal strength of the received beacon signal fluctuates according to the vehicle's speed, preventing variations in the display time of the display information. Also, the signal strength of the received beacon signal may fluctuate in response to changes in the beacon signal reception environment, such as external noise from radio waves, preventing the display of the display information from being erased midway. This ensures a stable display time suitable for allowing viewers to recognize the display information. The display hold time TKD may be set based on the vehicle's speed. For example, if the vehicle's speed is relatively fast and it moves away from the beacon in a short time, the display hold time TKD may be set to be short. Conversely, if the vehicle's speed is relatively slow due to traffic congestion, and it takes a long time to move away from the beacon, the display hold time TKD may be set to be long.

[0147] Furthermore, in step S25, the controller 100 may prioritize continuing the display until the display hold time TKD has elapsed, and then, if the signal strength of the beacon signal from the priority device falls below the second threshold strength STH2, it may erase the display of the display information.

[0148] According to the second embodiment described above, the same effects as the first embodiment can be obtained. That is, useful information specific to commercial vehicles traveling on a particular route, which cannot be obtained from road signs, car navigation systems, maps, etc., can be conveyed to the occupants of the vehicle. For example, when a commercial vehicle traveling on a particular route approaches a place where attention specific to that job should be paid, the content of that attention can be conveyed to the observer inside the vehicle through the display of information. As a result, the occupants of the vehicle, such as the driver, guide, and passengers, can take appropriate actions, preferential actions, or obtain useful information more reliably and safely. Furthermore, even if there is no GPS receiver inside the vehicle, the occurrence of an event can be determined if there is a signal receiving device.

[0149] Furthermore, users can register or combine their desired locations and display information, such as event locations and corresponding display information. This is a feature not found in car navigation systems, allowing users to provide useful information to vehicle passengers, leveraging their skills and experience. For example, it can be used for educating vehicle passengers.

[0150] In the second embodiment, the signal receiving device for receiving the beacon signal is not limited to one connected to the controller 100, for example, a vehicle-to-infrastructure wireless transceiver 915, but may be built into the display device 1 or be externally connected to the display device 1.

[0151] Furthermore, in the second embodiment, the beacon signal may include only the display ID among the signal transmitting device ID and display ID. In this case, it is not possible to determine the type of event, but it is possible to identify the display information to be displayed.

[0152] Furthermore, in the second embodiment, the transmission and reception of beacon signals is performed, for example, based on the BLE (Bluetooth® Low Energy) standard, but is not limited to transmission and reception based on this standard. Also, the transmission and reception of signals between the signal transmitting device and the signal receiving device in the in-vehicle system is not limited to the transmission and reception of beacon signals, but may be the transmission and reception of other types of signals.

[0153] As described above, each embodiment of the present invention provides the aforementioned effects, thereby offering more suitable display technologies, such as display devices, display systems, and display methods.

[0154] (Regarding modifications, etc.) The vehicle on which the display device 1 is installed is not limited to automobiles, but may be other vehicles such as trams, monorails, railway trains, ships, and aircraft. Furthermore, the vehicle is preferably for commercial use, and may be for tourism, shuttle service, or transportation.

[0155] Furthermore, the vehicle is not limited to those driven by a driver; it may also be a type that operates autonomously.

[0156] Furthermore, the display device 1 is not limited to a virtual image display device, but may be a type of display device that displays information on a liquid crystal panel or an organic EL panel, allowing the viewer to directly see it. Also, the display device 1 is not limited to a type in which its main body is installed on the dashboard of a vehicle or on the interior of a vehicle, but may be a type in which it is built into the interior of a vehicle. The display device 1 may display information in a manner that can be seen by passengers of a vehicle.

[0157] Furthermore, a display method for displaying information on a display device in an in-vehicle system according to the first or second embodiment is one embodiment of the present invention.

[0158] Furthermore, the technology described in the above embodiment makes it possible to prevent traffic accidents by providing an information display device (head-up display device) that can display a good virtual image and reduce the driver's eye movement, thereby contributing to safe driving support. This contributes to "Goal 3: Good Health and Well-being" of the United Nations' Sustainable Development Goals (SDGs).

[0159] 1 Display device (virtual image display device) 2 Vehicle 11 Display panel 20 Light source 100 Controller 410 Terminal device 915 Wireless transceiver for vehicle-to-infrastructure communication (signal receiving device) 921 GPS receiver 1013 Storage unit (memory device) DV21-DV23 Signal transmitting device E11-E16, E21-E23 Event occurrence point (set location) RT1, RT2 Specific route

Claims

1. A display system using a display device mounted on a vehicle, comprising: an acquisition device that acquires information on the location of the vehicle; a storage device that stores information representing one or more pre-set locations on a specific route the vehicle travels; and display information associated with the set locations; and a control device that, when it is determined that the vehicle has reached one of the set locations, controls the display device to display the display information corresponding to the set location that the vehicle has reached, wherein the set locations are desired locations specified by a user, and the display information corresponding to the set locations is desired display information set by the user.

2. A display system according to claim 1, wherein the storage device stores a plurality of predetermined display information, and the display information corresponding to the setting position is set by the user selecting from the plurality of display information.

3. A display system according to claim 1, wherein the control device determines that the vehicle has reached the set position when the position of the vehicle is within the range of a first region based on the set position.

4. A display system according to claim 3, wherein the control device makes it a condition for clearing the display of the display information that the vehicle has moved outside the range of a second region based on the set position.

5. A display system according to claim 4, wherein the range of the second area is set to be wider than the range of the first area.

6. A display system according to claim 3, wherein the control device further determines that the vehicle has reached the set position when the direction of travel of the vehicle is within a range of a first angle that includes the set direction associated with the set position.

7. A display system according to claim 1, wherein an event ID is set at the setting position, and the control device, after clearing the display of the display information, when the same event ID is set again at the setting position, controls the display device not to display the display information associated with the event ID.

8. A display system according to claim 1, wherein the control device performs control to erase the display of the display information after a predetermined time has elapsed.

9. A display system according to claim 8, wherein the predetermined time is set based on the speed of the vehicle.

10. A display system according to claim 1, wherein the display device is a virtual image display device that projects image light onto the windshield or windshield of the vehicle to display a virtual image.

11. A display system according to claim 1, wherein the display device displays the display information in a manner that can be seen by passengers of the vehicle.

12. A display system according to claim 1, wherein the vehicle is for sightseeing, picking up or dropping off passengers, or transporting passengers.

13. A display system using a display device mounted on a vehicle, comprising: a storage device that stores display IDs and display information in association; a signal receiving device that receives signals including display IDs set in one or more signal transmitting devices pre-installed on a specific route along which the vehicle travels; and a control device that controls the display and erasure of display information corresponding to the display IDs included in the received signals on the display device.

14. A display system according to claim 13, wherein the control device causes the display device to display display information corresponding to a display ID included in the signal whose signal strength is greater than or equal to a first threshold strength and has the maximum strength among the received signals.

15. A display system according to claim 14, wherein the control device has a control condition for erasing the display of the display information, wherein the intensity of a signal including a display ID corresponding to the display information displayed on the display device falls below a second threshold intensity.

16. A display system according to claim 15, wherein the second threshold intensity is set to an intensity smaller than the first threshold intensity.

17. A display system according to claim 13, wherein the storage device stores a signal transmitting device ID unique to the signal transmitting device and a display ID corresponding to the signal transmitting device ID in association; the signal transmitting device transmits a signal including a signal transmitting device ID unique to the signal transmitting device and a display ID corresponding to the signal transmitting device ID; and the control device identifies display information to be displayed based on the signal transmitting device ID and display ID included in the received signal, and causes the display device to display the identified display information.

18. A display system according to claim 17, wherein the control device, after erasing the display of the display information, receives the same signal transmitter ID again, controls the display device so that the display information associated with the signal transmitter ID is not displayed on the display device.

19. A display system according to claim 13, wherein the control device performs control to erase the display of the display information after a predetermined time has elapsed.

20. A display system according to claim 19, wherein the predetermined time is set based on the speed of movement of the vehicle.

21. A display system according to claim 13, wherein the display device is a virtual image display device that projects image light onto the windshield or windshield of the vehicle to display a virtual image.

22. A display system according to claim 13, wherein the display device displays the display information in a manner that can be seen by passengers of the vehicle.

23. A display system according to claim 13, wherein the vehicle is for sightseeing, picking up or dropping off passengers, or transporting passengers.

24. A display method in a display system using a display device mounted on a vehicle, comprising: storing in a storage device information information of one or more pre-set locations on a specific route the vehicle travels, and display information associated with the set locations; setting a desired location specified by a user as the set location; setting the desired display information set by the user as display information corresponding to the set location; acquiring information representing the location of the vehicle; and, when it is determined that the vehicle has reached the set location, displaying the display information corresponding to the set location that the vehicle has been determined to have reached on the display device.

25. A display method in a display system using a display device mounted on a vehicle, comprising: the steps of: storing a display ID and display information in association with each other in a storage device; receiving a signal including a display ID set in one or more signal transmitting devices pre-installed on a specific route along which the vehicle travels; displaying the display information corresponding to the display ID included in the received signal on the display device; and erasing the display information displayed on the display device.

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