Information projecting method and information projecting device

Abstract

To provide an information projecting method and an information projecting device that can display a video for a driver and a video for a person around a vehicle more properly, which can contribute to achieving "3 good health and welfare to everyone" which is a sustainable development goal.SOLUTION: In an information projecting method, a processor obtains data or information and a projecting device mounted on a vehicle is controlled, so that information is displayed on a road surface. The method includes: a display preparing step of determining whether the projecting device can display information or not, on the basis of a starting condition for the projecting device; a display adjusting step of determining whether it is necessary to adjust display or not on the basis of a display adjustment condition for the projecting device, after it is determined whether the projecting device can display or not in the display preparing step; and a step of making the projecting device start to display a video, after the display is adjusted in the display adjusting step.SELECTED DRAWING: Figure 14A

Description

[Technical Field]

[0001] The present invention relates to an information projection method and an information projection device. [Background technology]

[0002] As disclosed in Patent Document 1 and Patent Document 2, techniques for projecting information onto a road surface are known.

[0003] Patent Document 1 discloses a projection device for a vehicle that projects a route guidance image onto a road surface ahead of the vehicle. This projection device for a vehicle includes a route search means that searches for the current position of the vehicle and a route from the current position to a set destination, and a projection means that, when the vehicle approaches a branch point on the route to a visible extent for a passenger, projects a route guidance image onto the road surface ahead of the vehicle based on the route information searched by the route search means, guiding the vehicle in the branch direction.

[0004] Patent Document 2 discloses a technology that can clearly alert moving objects such as pedestrians, and as an example, discloses a road surface projection method. This road surface projection method includes the steps of pre-storing image data of an image to be projected onto the road surface, monitoring the area around the vehicle, identifying a moving object based on the monitoring results, setting a discrimination area in the monitored area, and when the identified moving object is present in the discrimination area, reading out the pre-stored image data and projecting the image onto a road surface position near the moving object. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-247369 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-7079 Summary of the Invention [Problem to be solved by the invention]

[0006] There is a need to provide a technology that can more appropriately display images for the driver and images for vehicles and people around the vehicle. [Means for solving the problem]

[0007] According to a first aspect of the present invention, there is provided an information projection method as follows. This information projection method is a method in which a processor acquires data or information and controls a projection device mounted on a vehicle to display information on a road surface. This information projection method includes a display preparation step of determining whether the projection device can display based on a startup condition of the projection device, a display adjustment step of determining whether the projection device can display in the display preparation step and determining whether display adjustment is necessary based on a display adjustment condition of the projection device, and a step of performing display adjustment in the display adjustment step and starting image display by the projection device.

[0008] According to a second aspect of the present invention, there is provided an information projection device as follows. This information projection device is a device mounted on a vehicle. This information projection device includes a projection unit that displays an image including information, an adjustment unit that can adjust the display of the projected image, and a control unit that controls the projection of the projection unit. The control unit determines whether to display the image based on data or information acquired from the vehicle, and the adjustment unit adjusts the display of the image based on display adjustment conditions if the image is to be displayed. [Effects of the Invention]

[0009] According to the present invention, a technology is provided that enables more appropriate display of an image for a driver and an image for vehicles and people around the vehicle. Note that problems, configurations, and effects other than those described above will become clear from the following description of the embodiment of the invention. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of an outline of a vehicle equipped with an information projection device. [Figure 2A] FIG. 2 is a diagram illustrating an example of a configuration provided in a vehicle. [Figure 2B] FIG. 2 is a diagram illustrating an example of a configuration provided in a vehicle. [Figure 2C] FIG. 2 is a diagram illustrating an example of a configuration provided in a vehicle. [Figure 3A] FIG. 10 is a diagram showing an example of an image display when information is projected onto the road surface ahead of the vehicle. [Figure 3B] 10A and 10B are diagrams showing an example of an image display when information is projected onto a road surface behind a vehicle. [Figure 4A] FIG. 1 is a diagram illustrating an example of the configuration of a projection device. [Figure 4B] FIG. 1 is a diagram illustrating an example of the configuration of a projection device. [Figure 4C] FIG. 1 is a diagram illustrating an example of the configuration of a projection device. [Figure 5A] 10A and 10B are diagrams for explaining examples of arrangements of optical components and the like. [Figure 5B] 10A and 10B are diagrams for explaining examples of arrangements of optical components and the like. [Figure 5C] 10A and 10B are diagrams for explaining examples of arrangements of optical components and the like. [Figure 6] FIG. 2 is a diagram showing an example of a display area of ​​an image seen by a driver. [Figure 7] 10A and 10B are diagrams illustrating an example of a display area onto which image light is projected. [Figure 8A] FIG. 10 is a diagram for explaining an example of how an image appears. [Figure 8B] FIG. 10 is a diagram for explaining an example of how an image appears. [Figure 8C] FIG. 10 is a diagram for explaining an example of how an image appears in more detail. [Figure 8D] FIG. 10 is a diagram for explaining an example of how an image appears in more detail. [Figure 9] 1 is a diagram illustrating an example of an image seen by a driver and vehicles and people around the driver's vehicle; [Figure 10A] FIG. 2 is a diagram illustrating an example of polarization of image light incident on a road surface. [Figure 10B]FIG. 2 is a diagram illustrating an example of polarization of image light incident on a road surface. [Figure 11] FIG. 10 is a diagram for explaining the influence of polarization on image display. [Figure 12A] FIG. 10 is a diagram illustrating an example of the arrangement of optical components used for polarization. [Figure 12B] FIG. 10 is a diagram illustrating an example of the arrangement of optical components used for polarization. [Figure 12C] FIG. 10 is a diagram illustrating an example of the arrangement of optical components used for polarization. [Figure 13A] 10A and 10B are diagrams for explaining an example of the type of video to be displayed to the driver. [Figure 13B] 10A and 10B are diagrams for explaining examples of types of images to be displayed to vehicles and people around the vehicle; [Figure 14A] 10 is a flowchart illustrating an example of a video display process. [Figure 14B] 10 is a flowchart illustrating an example of a video display process. [Figure 15] 10 is a diagram for explaining a specific example of the start-up determination (S11) of the projection device. FIG. [Figure 16A] FIG. 10 is a diagram for explaining a specific example of display start condition determination 1 (S12). [Figure 16B] FIG. 16B is a continuation of FIG. 16A and is a diagram for explaining a specific example of the display start condition determination 1 (S12). [Figure 17] FIG. 10 is a diagram for explaining a specific example of the display start condition determination 2 (S13). [Figure 18A] FIG. 10 is a diagram for explaining a specific example of selection of a display adjustment condition (S4). [Figure 18B] FIG. 10 is a diagram for explaining a specific example of selection of a display adjustment condition (S4). [Figure 18C] FIG. 10 is a diagram for explaining a specific example of selection of a display adjustment condition (S4). [Figure 19] FIG. 10 is a diagram for explaining a specific example of the display start operation (S5). [Figure 20]FIG. 10 is a diagram for explaining a specific example of the display termination condition determination (S6). [Figure 21] FIG. 10 is a diagram for explaining a specific example of the display ending operation (S7). DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment is an example for explaining the present invention, and for clarity of explanation, appropriate omissions and simplifications have been made. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0012] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0013] Examples of various types of information may be described using expressions such as "table," "list," and "queue," but the various types of information may also be expressed using data structures other than these. For example, various types of information such as "XX table," "XX list," and "XX queue" may also be expressed as "XX information." When describing identification information, expressions such as "identification information," "identifier," "name," "ID," and "number" are used, but these are interchangeable.

[0014] When there are multiple components with the same or similar functions, they may be described using the same reference numeral with different subscripts. When there is no need to distinguish between these multiple components, the subscripts may be omitted.

[0015] In the embodiments, processing performed by executing a program may be described. Here, a computer executes the program using a processor (e.g., a CPU or a GPU) and performs processing defined by the program using storage resources (e.g., a memory) and interface devices (e.g., a communication port). Therefore, the entity performing the processing by executing the program may be the processor. Similarly, the entity performing the processing by executing the program may be a controller, device, system, computer, or node having a processor. The entity performing the processing by executing the program may be any computing unit, and may include a dedicated circuit that performs specific processing. Here, the dedicated circuit may be, for example, an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a CPLD (Complex Programmable Logic Device).

[0016] A program may be installed on a computer from a program source. The program source may be, for example, a program distribution server or a computer-readable storage medium. When the program source is a program distribution server, the program distribution server may include a processor and storage resources for storing the program to be distributed, and the processor of the program distribution server may distribute the program to be distributed to other computers. In addition, in an embodiment, two or more programs may be realized as one program, or one program may be realized as two or more programs.

[0017] In the embodiment, an example of a technology for displaying information on a road surface using a projection device mounted on a vehicle will be described. Note that in the embodiment, with respect to the vehicle and the driver, the horizontal direction is the left-right direction, the lateral direction of the vehicle, or the width direction of the vehicle, the vertical direction is the up-down direction or longitudinal direction of the vehicle, and the vertical direction perpendicular to the lateral direction of the vehicle is the front-rear direction of the vehicle or the direction of travel of the vehicle.

[0018] Fig. 1 is a diagram showing an overview of a vehicle. As shown in Fig. 1, the vehicle 2 includes, for example, a projection device 11 (information projection device), an in-vehicle image display device 12, a car navigation system 150, headlamps 13 (i.e., headlights 13), tail lamps (not shown), turn signals 14, and a controller 100. The vehicle 2 also includes an in-vehicle system 300 including these components. An in-vehicle network is implemented in the in-vehicle system 300, and the controller 100 can transmit and receive data or information to and from these components, components described below, and the like. The in-vehicle system 300 includes, for example, a controller area network (CAN), an in-vehicle Ethernet, a local interconnect network (LIN), and the like.

[0019] The in-vehicle system 300 can also communicate with the outside of the vehicle via a communication device. Examples of communication with the outside of the vehicle include a dedicated direct communication system and an indirect communication system. The direct communication system uses bands such as the 760 MHz band and the 5.9 GHz band, which are internationally used for ITS (Intelligent Transport System) communication, to directly communicate between vehicles, between vehicles, between roads and vehicles, and between pedestrians. In contrast, the indirect communication system uses bands for mobile phones other than 5.9 GHz to indirectly communicate via a mobile carrier network. The in-vehicle system 300 can transmit and receive data or information to, for example, a server 24 connected to the network 21 via, for example, an access point 22 or a relay station 23 on the network 21. The in-vehicle system 300 may communicate with information terminals carried by other vehicles or pedestrians, or with infrastructure such as terminals installed on the road where the vehicle is traveling. An example of road-to-vehicle communication is receiving traffic congestion information and weather information using radio beacons or optical beacons.

[0020] Vehicle information 4, which is an example of data or information acquired by the in-vehicle system 300, includes, for example, speed information, gear information, steering wheel angle information, lamp illumination information, external light information, distance information, infrared information, engine ON / OFF information, camera image information, acceleration gyro information, GPS information, navigation information, vehicle-to-vehicle communication information, road-to-vehicle communication information, pedestrian-to-vehicle communication information, and in-vehicle sensor information such as Lidar (Light Detection and Ranging). The camera image information includes in-vehicle camera image information and in-vehicle camera image information. The GPS information includes current time information, latitude and longitude information. This vehicle information can be acquired, for example, from sensors described below.

[0021] The vehicle information 4 also includes information input by the driver. The driver can input the information using an appropriate device used for inputting information. This device may be a device that is pre-installed in the vehicle. Alternatively, this device may be an external device that can be connected to the in-vehicle system 300 via a wired or wireless connection, such as an input device, a tablet, a smartphone, a wearable device such as AR (Augmented Reality) glasses or an HMD (Head Mounted Display), or a personal computer.

[0022] The in-vehicle system 300 can execute various controls such as driving control and display control using the acquired data or information.

[0023] The projection device 11 projects image light for displaying information. A specific configuration example of the projection device 11 will be described later. The image projected by the projection device 11 can be seen by the driver and people around the vehicle 2, i.e., pedestrians walking near the vehicle, and drivers and passengers of other vehicles traveling near the vehicle.

[0024] The in-vehicle image display device 12 generates image light for displaying information and projects the image light toward a predetermined display area 5 on the windshield 3. As a result, the in-vehicle image display device 12 superimposes a virtual image corresponding to the displayed image on the scenery, for example, so that the driver of the vehicle (from the driver's viewpoint) can view it. Note that in this example, the image light is projected onto the display area 5 on the windshield 3, but the projection unit that projects the image light may be a projection member such as a combiner. The in-vehicle image display device 12 may be, for example, a known HUD (Head-Up Display) that includes a light source, a display panel that forms a display image, a control unit, etc.

[0025] The car navigation system 150 is an electronic device called a car navigation system. The car navigation system 150 is a device that uses, for example, map information and location information from a GPS to display the current position and route to the destination. The car navigation system 150 can use traffic information such as VICS (Vehicle Information and Communication System, registered trademark) to present an efficient route to the destination.

[0026] In this example, a pair of headlights 13 are provided on the left and right at the front of the vehicle. A lamp, which is an illuminant, is built into the headlights 13. The turn indicators 14 are devices that indicate the direction to those around when turning right or left, changing lanes, etc., and are provided in pairs on the left and right at the front of the vehicle, just like the headlights 13.

[0027] The controller 100 is an electronic control unit (ECU) mounted in the vehicle 2, and includes, for example, a processing device (e.g., a central processing unit), a storage device, and an input / output device (I / O unit). The storage device can be configured using, for example, a main storage device and an auxiliary storage device. The main storage device is a work area for the processing device, and the processing device stores data in the main storage device and executes data processing. The main storage device is, for example, a RAM (Random Access Memory). The auxiliary storage device is a non-volatile storage device that stores data in a non-volatile manner. The auxiliary storage device is, for example, a ROM (Read Only Memory).

[0028] Data or information is input to the controller 100 via an input / output device and an in-vehicle network 300. The controller 100 can also control various devices connected to the in-vehicle network via the input / output device and the in-vehicle network.

[0029] Vehicle information 4 and information acquired from the server 24 are input to the controller 100 via an input / output device, for example. Then, the controller 100 may control the driving of the headlights 13, the driving of the turn signals 14, the operation of the projection device 11, the operation of the in-vehicle image display device 12, the operation of the car navigation system 150, and the like, based on the acquired information.

[0030] The projection device 11 may be connected to various sensors mounted on the vehicle 2, devices mounted on the vehicle 2 (for example, the car navigation system 150), communication devices used for communication with the outside of the vehicle, and the like, to acquire data or information. Then, the projection device 11 may use the acquired data or information to generate image light for displaying information and project the image light.

[0031] The projection device 11 can omit communication with the controller 100. Here, the projection device 11 can acquire data or information from a configuration different from that of the controller 100, for example, through communication based on CAN, in-vehicle Ethernet, etc. The same can be said for the in-vehicle image display device 12.

[0032] Alternatively, the controller 100 may generate video data using the acquired data or information and transmit the generated video data to the projection device 11. The projection device 11 may generate video light for displaying information based on the video data generated by the controller 100 and project the video light. Alternatively, the controller 100 may not generate video data, but rather an image generation unit may generate the video data and transmit the generated video data to the projection device 11. Here, the controller 100 and the projection device 11 may communicate based on, for example, FPD-Link III or GMSL (Gigabit Multimedia Serial Link), and the projection device 11 may acquire the video data from the controller 100. The projection device 11 may perform image processing on the acquired video data, where the image processing includes image distortion correction, color correction, brightness correction, contrast correction, conversion (e.g., decoding), and the like. The video data may be stored in advance in a storage device of the controller or the projection device, or may be processed in real time without being stored in a storage device. When the video data is stored in advance in a storage device of the controller or the projection device, the stored video data may be successively changed by a system update or a user operation, by wired or wireless means, etc. As described above, the projection device 11 may be connected to various sensors mounted on the vehicle, devices mounted on the vehicle 2 (e.g., the car navigation system 150), and communication devices used for communication with the outside of the vehicle, and may acquire data or information through communication based on CAN, in-vehicle Ethernet, etc. Then, the projection device 11 may generate video light for displaying information based on the acquired information and project the video light. The same can be done for the in-vehicle video display device 12.

[0033] Furthermore, the controller 100 may control the headlights 13 and the projection device 11 in a coordinated manner. For example, the controller 100 may turn on the headlights 13 and cause the projection device 11 to project image light ahead of the vehicle. For example, the controller 100 may turn off the headlights 13 and cause the projection device 11 to generate an image of information to be displayed and project the image light ahead of the vehicle. In other words, the headlights 13 and the projection device 11 may operate in a coordinated manner via the controller 100.

[0034] On the other hand, the headlights 13 and the projection device 11 may operate without the intervention of the controller 100. For example, the headlights 13 and the projection device 11 may be connected, and the operation of the headlights 13 may be controlled by the projection device 11 (more specifically, a control unit of the projection device 11). The projection device 11 may, for example, turn on the headlights 13, generate an image of the information to be displayed, and project the image light in front of the vehicle. Alternatively, the projection device 11 may, for example, turn off the headlights 13, generate an image of the information to be displayed, and project the image light in front of the vehicle.

[0035] As an example, the projection device 11 may be mounted on the front of the vehicle body, and the image light from the projection device 11 may be projected onto the road surface in front of the vehicle. The projection device 11 may be mounted, for example, near the roof of the vehicle body 2. The projection device 11 may also be mounted, for example, in the side mirror area, on the roof, or on the side or bottom of the vehicle body 2. However, the present invention is not limited to these.

[0036] One or more projection devices 11 may be mounted. For example, a pair of projection devices 11 may be mounted at the front end of the vehicle 2. Furthermore, the projection device 11 may be integrated into the headlight 13, for example. When the projection device 11 is integrated into the headlight 13, the light source of the headlight 13 can also be used as a light source for projection.

[0037] For example, the projection device 11 may be mounted on the rear of the vehicle body, and the image light from the projection device 11 may be projected onto the road surface behind the vehicle. Alternatively, a pair of projection devices 11 may be mounted, for example, at the rear end of the vehicle 2. Alternatively, the projection device 11 may be integrated into, for example, a tail lamp. When the projection device 11 is integrated into, the tail lamp's light source can also be used as a light source for projection. The above-described tail lamp may be a stop lamp or a backup lamp, and hereinafter, the term "tail lamp" may be replaced with "stop lamp" or "back lamp."

[0038] Furthermore, the controller 100 may control the tail lamps and the projection device 11 in a coordinated manner. For example, the controller 100 may turn on the tail lamps and cause the projection device 11 to generate an image of the information to be displayed and project the image light toward the rear of the vehicle. For example, the controller 100 may turn off the tail lamps and cause the projection device 11 to generate an image of the information to be displayed and project the image light toward the rear of the vehicle. In other words, the tail lamps and the projection device 11 may operate in a coordinated manner via the controller 100.

[0039] On the other hand, the tail lamps and the projection device 11 may operate without the intervention of the controller 100. For example, the tail lamps and the projection device 11 may be connected, and the operation of the tail lamps may be controlled by the projection device 11 (more specifically, a control unit of the projection device 11). The projection device 11 may, for example, turn on the tail lamps, generate an image of the information to be displayed, and project the image light toward the rear of the vehicle. Alternatively, the projection device 11 may, for example, turn off the tail lamps, generate an image of the information to be displayed, and project the image light toward the rear of the vehicle.

[0040] The controller 100 may also control the turn indicators and the projection device 11 in a coordinated manner. For example, the controller 100 may turn on the turn indicators, cause the projection device 11 to generate an image of the information to be displayed, and project the image light forward or backward on the side of the vehicle. For example, the controller 100 may turn off the turn indicators, cause the projection device 11 to generate an image of the information to be displayed, and project the image light forward or backward on the side of the vehicle. That is, the turn indicators and the projection device 11 may operate in a coordinated manner via the controller 100. The turning on and off of the turn indicators may also be controlled by the driver's operation. For example, the projection device may be configured to project the image light toward the road surface on the side of the vehicle 2.

[0041] Information such as vehicle information 4 is acquired using devices such as cameras and various sensors. FIG. 2A shows an example in which various devices are connected to a controller 100. The controller 100 is configured to generate images. FIG. 2B shows an example in which various devices are connected to the controller 100. FIG. 2B includes an image generation unit that generates images. FIG. 2C shows an example in which various devices are connected to the controller 100. The controller 100 acquires signals from the various devices and transmits them to a projection device 11. However, control units such as the projection device 11, the in-vehicle image display device 12, and the car navigation system 150 can be connected to the devices shown in FIGS. 2A and 2B and acquire information directly without going through the controller 100. The various devices shown in FIGS. 2A, 2B, and 2C can be deleted, or other types of devices can be added or replaced with other types of devices, as appropriate.

[0042] The vehicle speed sensor 501 detects the speed of the vehicle 2 and is used to generate speed information as the detection result. The shift position sensor 502 detects the current gear and is used to generate gear information as the detection result. The steering wheel angle sensor 503 detects the current steering wheel angle and is used to generate steering wheel angle information as the detection result.

[0043] The headlight sensor 504 detects, for example, whether the headlights 13 are on or off. The headlight sensor 504 may also detect the luminance of the headlights 13 when they are on. The headlight sensor 504 is used to generate lamp lighting information, which is the detection result. The vehicle 2 may also be provided with a high / low sensor that detects the high beam or low beam state of the headlights 13, and the high / low sensor is used to generate information indicating the high beam or low beam. The vehicle 2 may also be provided with a tail lamp sensor (not shown). The tail lamp sensor detects, for example, whether the tail lamps are on or off. The tail lamp sensor may also detect the luminance of the tail lamps when they are on. The tail lamp sensor is used to generate lamp lighting information, which is the detection result. Similarly, although not shown, sensors that detect the on / off and lighting luminance of stop lamps, backup lamps, hazard lamps, and turn signals may also be provided.

[0044] The illuminance sensor 505 and the chromaticity sensor 506 detect external light from the vehicle 2 and are used to generate external light information, which is the detection result. The chromaticity sensor 506 may also be used to detect the color of the road surface around the vehicle 2 and generate projection surface color information, which is the detection result. The distance measurement sensor 507 detects the distance between the vehicle 2 and an external object or the distance between external objects and is used to generate distance information, which is the detection result. The infrared sensor 508 detects the presence or absence of an object in the vicinity of the vehicle and the distance, etc., and is used to generate infrared information, which is the detection result. The engine start sensor 509 detects whether the engine is on or off and is used to generate on / off information, which is the detection result.

[0045] The vehicle operation switches 510 are various switches operated by the driver or the like, and are used to generate operation information such as ON / OFF of these switches. The vehicle operation switches 510 relate to steering switches, switches on the dashboard, vehicle door switches, switches on the armrest, switches on the center console, etc.

[0046] Communication unit 511 is a component used for communication, and includes, for example, first communication unit 5111, second communication unit 5112, third communication unit 5113, in-vehicle wireless communication unit 5114, and out-vehicle wireless communication unit 5115.

[0047] The first communication unit 5111 is configured to perform communication according to, for example, FPD-Link III, and includes a communication line and a communication device used for communication according to FPD-Link III.

[0048] The second communication unit 5112 implements a communication protocol (CAN communication protocol) and includes a communication line and a communication device used for communication by the CAN.

[0049] The third communication unit 5113 is configured to perform communication via in-vehicle Ethernet, has an in-vehicle Ethernet communication protocol implemented, and includes a communication line and a communication device used for communication via in-vehicle Ethernet. The third communication unit 5113 may include a USB (Universal Serial Bus) port, and the driver or the like may connect a device (e.g., a USB memory or a device having computer functions) to the port as appropriate. The third communication unit 5113 may then perform communication via in-vehicle Ethernet between the device connected to the port and the connected configuration.

[0050] The in-vehicle wireless communication unit 5114 is configured to communicate with information devices in the vehicle, has a communication protocol implemented, and includes a wireless device. The in-vehicle wireless communication unit 5114 performs wireless communication using, for example, Wifi (registered trademark) or Bluetooth (registered trademark). Note that the in-vehicle wireless communication unit 5114 may also perform short-range wireless communication such as NFC (Near Field Communication).

[0051] The exterior-vehicle wireless communication unit 5115 is configured to communicate with the outside of the vehicle 2, has a communication protocol implemented, and includes a wireless device. The exterior-vehicle wireless communication unit 5115 performs wireless communication using, for example, LTE (Long Term Evolution), 5G, or Wi-Fi.

[0052] The configuration of the communication unit 511 may be changed as appropriate. The communication unit 511 may be configured to be able to perform communication using LIN, for example. The communication unit 511 may also be configured to be able to perform communication using GMSL, for example.

[0053] The acceleration sensor 512 and the gyro sensor 513 detect the acceleration and angular velocity of the vehicle 2 and are used to generate acceleration gyro information that indicates the attitude and behavior of the vehicle 2. The temperature sensor 514 detects the temperatures inside and outside the vehicle and on the road surface, and is used to generate temperature information that is the detection result.

[0054] The wireless transceiver 515 for road-to-vehicle communication generates road-to-vehicle communication information through road-to-vehicle communication between the vehicle 2 and roads, signs, traffic lights, etc. The wireless transceiver 516 for vehicle-to-vehicle communication generates vehicle-to-vehicle communication information through vehicle-to-vehicle communication between the vehicle 2 and other surrounding vehicles. The wired and wireless communication unit 517 for terminal-to-vehicle communication is a device that acquires information through wired communication or wireless communication from a device connected to the LTE network (e.g., a WiFi device). The controller 100 or the control unit can acquire information to be transmitted and received over the LTE network via the wired and wireless communication unit 517 for terminal-to-vehicle communication.

[0055] The GPS receiver 518 generates GPS information by receiving GPS signals from GPS satellites. For example, the current time, latitude, and longitude can be acquired by the GPS receiver 518. The VICS receiver 519 generates VICS information by receiving VICS signals. The VICS signals here include traffic congestion information and weather information from radio beacons and optical beacons. The GPS receiver 518 and the VICS receiver 519 may be provided as part of a navigation system.

[0056] In-vehicle camera 520 and exterior camera 521 capture images of the interior and exterior of the vehicle, and are used to generate in-vehicle camera image information and exterior camera image information. Specifically, in-vehicle camera 520 is, for example, a camera for a DMS (Driver Monitoring System) that captures the driver's posture, eye position, movement, etc. In this case, the driver's fatigue level, eye position, etc. can be determined by analyzing the captured images.

[0057] The voice of the driver is input to the voice input device 522, which is used to generate voice information. By emitting voice, the driver can input operation details via the voice input device 522. The voice output device 523 is, for example, a device that outputs voice processed by the controller 100 or the control unit.

[0058] The humidity sensor 524 detects humidity and is used to generate humidity information. The humidity sensor 524 may detect humidity outside the vehicle 2 or on the road surface, and humidity information about the outside of the vehicle 2 may be generated. The humidity sensor 524 may also detect humidity inside the vehicle 2, and humidity information about the interior of the vehicle may be generated.

[0059] A rain sensor 525 detects raindrops and is used to generate rainfall information. A wiper switch 526 detects whether the wipers are on or off and is used to generate wiper on / off information. A turn signal switch (not shown) detects whether the driver operates the turn signal and is used to generate turn signal information.

[0060] The image generating unit 527 may generate image information based on information acquired from each sensor, information from a mobile terminal, information from the Internet, or the like, or may generate image information based on information acquired by the controller 100. Information other than that related to the vehicle includes information from a mobile terminal, information from the Internet, and the like.

[0061] The controller 100 or the processor may, for example, transmit and receive data or information via wireless communication and acquire information necessary for driving. The controller 100 or the processor may also acquire information necessary for autonomous driving. The controller 100 or the processor may also, for example, transmit and receive data or information via wireless communication and perform update processing of the data or information. The controller 100 or the processor may, for example, update various data or information (map data, data used for video processing, software, etc.) as update processing. Such technology is sometimes called OTA (Over the Air) technology.

[0062] Next, an example of information projection by a projection device will be described with reference to FIG. 3. As shown in FIG. 3A, image light is projected from the projection device onto the road surface ahead. The figure shows a projection area 14a projected from the projection device 11 through a window 13a on the front right side of the vehicle 2, and a projection area 14b projected from the projection device 11 through a window 13b on the front left side of the vehicle. The projection images of the respective projection areas (14a, 14b) are combined to project an image (in this example, an arrow 15 indicating that the vehicle 2 is moving straight ahead) onto the road surface ahead of the vehicle 2. Note that in this example, the projection areas (14a, 14b) are divided into left and right, but the projection areas may also be divided into areas near and far from the vehicle. Furthermore, only one of the projection devices 11 installed on the left and right sides of the vehicle may be used to project image light. In this example, the projection device 11 is incorporated inside the headlight 13, and the light source of the headlight 13 is used as the light source for projection. However, as described above, the location of the projection device 11 can be changed as appropriate. The projection device 11 may have a light-emitting structure different from that of the headlight 13, and may project image light using the light emitted by this structure.

[0063] As shown in FIG. 3B, the projection device 11 projects image light onto the road surface behind the vehicle. The figure shows a projection area 17a projected from the projection device 11 on the rear right side of the vehicle and a projection area 17b projected from the projection device 11 on the rear left side of the vehicle. The projection images of the respective projection areas (17a, 17b) are combined to project an image (in this example, an arrow 18 indicating that the vehicle is reversing and moving straight backward) onto the road surface behind the vehicle. While the projection areas (17a, 17b) are divided into left and right sides in this example, the projection areas may be divided into areas near and far from the vehicle. Furthermore, only one of the projection devices 11 installed on the left and right sides of the vehicle may be used to project image light. In this example, the projection device 11 is installed so that the light source of the tail lamp can be used as the light source for projection. However, as described above, the location of the projection device 11 can be changed as appropriate. The projection device 11 may have a light-emitting structure different from a tail lamp, and may project image light by utilizing the light emitted from this structure.

[0064] An example configuration of the projection device 11 will be described with reference to FIG. 4. The projection device 11 generates an image of information to be displayed using, for example, data or information acquired via various sensors and a communication unit, and projects image light. Note that, for example, data or information may be input to the projection device 11 from the controller 100. For example, signal data, video data, etc. may be input to the projection device 11 from the controller 100. The projection device 11 may then perform processing using the input information. Also, for example, the controller 100 may control the projection device 11 instead of the control unit of the projection device 11. Also, the control unit of the projection device 11 and the controller 100 may share processing responsibilities. For example, the controller 100 may control adjustment of the brightness of the headlights 13 and the brightness of the taillights, and the control unit of the projection device 11 may control adjustment of the brightness of the projected image.

[0065] As shown in FIG. 4A , the projection device 11 includes a projection optical system 701 and a light source device 702. The projection device 11 also includes a power supply 703, a cooling unit 704, an operation input unit 705, a video signal input unit 706, an audio signal input unit 707, an audio output unit 708, a communication unit 709, a non-volatile memory 710, a memory 711, a storage unit 712, an adjustment unit 713, and a control unit 714. The control unit 714 may be configured as a processing device. The control unit 714 can control the operation of the projection device 11. On the other hand, if the projection device 11 does not include a control unit, the controller 100 can also control the projection device 11.

[0066] The projection optical system 701 is a configuration used for projecting light, and includes optical components such as lenses and / or mirrors.

[0067] The light source device 702 is a device capable of generating image light. The light source device may use, for example, a high-pressure mercury lamp, a xenon lamp, an LED light source, a laser light source, etc. The light source device may also include an optical element used for condensing and homogenizing light.

[0068] The power supply 703 supplies power to, for example, the light source, and also supplies the necessary power to each of the other components.

[0069] The cooling unit 704 cools down the various components that reach high temperatures, such as the light source, the power supply 703, or the light source device 702, by air cooling or liquid cooling as needed.

[0070] The operation input unit 705 is, for example, an operation button or a light receiving unit of a remote control, and receives an operation signal from the user. The input of the operation signal from the user switches on / off a switch (operation switch) that activates the projection device 11.

[0071] The video signal input unit 706 is an interface device that acquires video data from the outside. The audio signal input unit 707 is an interface device that acquires audio data from the outside. The audio output unit 708 can output audio based on the audio data input to the audio signal input unit 707, for example. The audio output unit 708 may output, for example, an operation sound or an error warning sound.

[0072] The communication unit 709 is an interface device used for communication with the outside. The communication unit 709 is connected to, for example, an external information processing device (for example, the controller 100) and inputs and outputs various control signals. The communication unit 710 may be connected to various sensors, communication devices provided in the vehicle 2, etc. and inputs and outputs various data or information.

[0073] The nonvolatile memory 710 stores various data used in the projector function, for example. The data stored in the nonvolatile memory 710 includes image data and video data prepared in advance for projecting video.

[0074] The memory 711 stores image data to be projected, control parameters for each part of the device, and the like.

[0075] The storage unit 712 is a device that records video, images, audio, various data, etc. For example, video, images, audio, various data, etc. may be recorded in advance at the time of product shipment, or video, images, audio, various data, etc. obtained from an external device or external server via the communication unit 709 may be recorded. The control unit 714 may also obtain updated data or information from the outside via the communication unit 709 and update the recorded data or information with new data or information. Furthermore, a portion or all of the recorded data or information may be updated with new data or information at the user's discretion. The video, images, various data, etc. recorded in the storage unit 712 may be output as projected video. The audio recorded in the storage unit 712 may be output as audio from the audio output unit 708.

[0076] The adjustment unit 713 can adjust the image light and includes, for example, an image adjustment unit and a polarization adjustment unit. The image adjustment unit performs image processing on the image data input by the image signal input unit, the image data stored in the nonvolatile memory 710, and the image data. Examples of the image processing include image distortion correction, scaling processing for enlarging, reducing, or transforming the image, brightness adjustment processing for changing the image brightness, contrast adjustment processing for changing the image contrast curve (including adjustment of the brightness gradation linearity characteristics), color correction processing for changing the image chromaticity, and Retinex processing for decomposing the image into light components (illumination light component, reflected light component, and ambient light component) and changing the weighting of each component. The image adjustment unit is realized by the control unit 714 storing data in the memory 711 and executing image processing.

[0077] The polarization adjustment unit adjusts the degree of polarization of the image light to be projected. Here, the degree of polarization refers to the ratio of P-polarized light components to S-polarized light components contained in the light (P-polarized light components and S-polarized light components are defined relative to the projection surface). For example, the projection device 11 is provided with a configuration capable of adjusting the degree of polarization of the emitted light, such as a polarization separation element and a polarization conversion element described below, and the control unit 714 adjusts the degree of polarization of the image light by controlling this configuration. The polarization control unit is realized by the control unit 714 storing data (parameters used for control, etc.) in the memory 711 and controlling this configuration. Alternatively, multiple projection devices 11 with different degrees of polarization may be provided and switched between.

[0078] In the example of FIG. 4B , the light source device 702a includes a light source 7021, a display element 7022, an optical element 7023, a polarization separation element 7024, and a polarization conversion element 7025. The light source 7021 generates light for image projection. The optical element 7023 is used for condensing and homogenizing the light. Note that descriptions similar to those above may be omitted. The polarization separation element 7024 is an element that separates incident light into S-polarized light and P-polarized light. For example, the polarization separation element 7024 may be a polarizing beam splitter, which separates light by reflecting or transmitting light of a specific polarization state. The polarization conversion element 7025 is an element that converts the degree of polarization. For example, the polarization conversion element 7025 may be a waveplate, which changes the polarization state by delaying the phase of the light. Here, for example, the polarization conversion element 7025 may be connected to an actuator (e.g., a motor) used to control the incident angle of transmission, and the adjustment unit 713 or the polarization adjustment unit 722 may adjust the polarization degree of the incident light according to the incident angle.

[0079] The projection device 11 also includes a display element, a display element driver, and the like. The display element is an element that generates an image by modulating transmitted or reflected light, and may be, for example, a transmissive LCD (Liquid Crystal Display) panel, a reflective LCD panel, or a DMD (Digital Micromirror Device) (registered trademark) panel. The display element driver sends a drive signal to the display element, causing the display element to generate an image. Display elements include those that can display multiple images using control signals, such as DMDs and LCDs, as well as those that can only display a fixed image, such as mask types.

[0080] 4C, light source device 702b does not have a light source that serves as a backlight for the display element. In this example, the display element itself emits light. Note that the same description as above may be omitted.

[0081] The light source device 702b includes a display light-emitting element 7026, an optical element 7023, a polarization separation element 7024, and a polarization conversion element 7025. The display light-emitting element 7026 is configured as a self-luminous display such as an LED array or an OLED (Organic Light Emitting Diode) display. The optical element 7023 is an optical system used for collecting and homogenizing light. The optical element 7023, the polarization separation element 7024, and the polarization conversion element 7025 are the same as those described in FIG. 4B.

[0082] Next, an example of the arrangement of optical components and the like will be described with reference to FIG. 5. FIG. 5A shows an example using a reflective display element, in which an image is projected using the DMD method. A first optical element 901 is an optical element that collects light generated by a light source 900, such as a collimator. A second optical element 902 is a mirror that projects the collected light onto a display element 907. In this example, the display element 907 is configured as a DMD panel, and light projection is adjusted or controlled for each display pixel. A third optical element 903 is configured to project image light and is configured using optical components such as lenses and mirrors. A reflective LCD panel may also be used as the reflective display element.

[0083] 5B shows an example in which the display light-emitting element 908 itself emits light and projects an image. The display light-emitting element 908 is configured as an LED array panel or an LED matrix panel, and an image is generated by combining the lighting positions and lighting colors of the LEDs on the panel. The fourth optical element 904 is configured to project image light, and is configured using optical components such as lenses and mirrors. In addition to the above panels, an OLED display may also be used as the display light-emitting element.

[0084] FIG. 5C shows an example in which light is transmitted through a display element 909 to display an image. The fifth optical element 905 is similar to the first optical element 901 described above. The display element 909 is, for example, a transmissive LCD panel, and an image is generated on the display element 909. The sixth optical element 906 projects image light and is configured using optical components such as lenses and mirrors. The display element 909 may be configured such that a mask having a predetermined pattern is disposed on the light source side. In this case, a fixed image based on the pattern formed on the mask can be displayed by light that is not blocked by the mask serving as the display element and that passes through the mask. The display element 909 may also be configured such that a lens having a predetermined pattern is disposed on the light source side. In this case, the display element 909 can display a fixed image based on the pattern formed on the lens. The predetermined pattern formed on the lens is formed on the lens surface or inside the lens, and the formed pattern partially blocks or partially transmits light. The lens used in the display element 909 may be a microlens array. In this case, the pattern formed on each lens is different.

[0085] 5A and 5C can be configured by the light source of the projection device 11, but may also be the light source of the headlight 13 or a tail lamp. In this case, the light source of the projection device 11 may be omitted. On the other hand, the light source shown in FIGS. 5A and 5C may be configured by combining the light source of the projection device 11 and the light source of the headlight 13 or a tail lamp. Furthermore, the projection device 11 may be configured with one light source or multiple light sources. Similarly, the display element corresponding to the light source may be one or multiple.

[0086] Next, an example of the display area of ​​an image viewed by the driver will be described with reference to FIG. 6. FIG. 6 shows the illumination area A1 of the high beam of the headlight 13, the illumination area A2 of the low beam of the headlight 13, and the image area A3 for the road surface image projected by the projection device 11. The illumination area above the high beam is illuminated with a high beam positioned higher. That is, this illumination area can be illuminated with a high beam that brightly illuminates a distant area. The illumination area below the high beam is illuminated with a low beam positioned lower. Since this overlaps with the projection area of ​​the low beam, the low beam may be formed by shading a portion of the illumination area of ​​the headlight 13 that can project the high beam. Furthermore, the image area A3 projected by the projection device 11 is included in the illumination area below the low beam illumination area A2 and the high beam illumination area A1. Therefore, the projection device 11 can project an image using the low beam and high beam of the headlight 13, or the projection device 11 may be provided separately from the headlight 13.

[0087] An example of a projection area around a vehicle will be described with reference to FIG. 7. FIG. 7 shows a road surface display area A11 in front of the vehicle, a road surface display area A12 behind the vehicle, and a road surface display area A13 on the left and right sides of the vehicle. The road surface display area A11 in front of the vehicle is a display area formed on the road surface in front of the vehicle based on the position of the vehicle. For example, the projection device 11 may be provided to project image light onto this area to display information. The road surface display area A12 behind the vehicle is a display area formed on the road surface behind the vehicle based on the position of the vehicle. For example, the projection device 11 may be provided to project image light onto this area to display information. The road surface display area A13 on the left and / or right sides of the vehicle is a display area formed on the road surface on the left and / or right sides of the vehicle based on the position of the vehicle. For example, the projection device 11 may be provided to project image light onto this area to display information. This area A13 can be set as an area where information displayed by vehicles and people (pedestrians, etc.) around the vehicle can be seen, for example.

[0088] Next, an example of how an image appears will be described with reference to FIGS. 8 and 9. Because the projection device 11 and the image display area (the road surface in this example) are not directly facing each other, the distance between the projection device 11 and the image on the display area differs between near and far from the vehicle. When the projection device 11 projects an undistorted image (an arrow image in this example), as shown in FIG. 8A, the scenery seen by the driver appears smaller as the distance increases because the viewing angle decreases. The viewing angle here refers to the angle between the driver's eyes and the object seen by the driver. In contrast, the emission angle of the image light projected from the projection device 11 does not depend on the distance of the display area, so even an image displayed in the distance does not appear small from the driver's perspective. However, because the distance between the projection device 11 and the display area increases when the vehicle is farther away, the size of the image projected on the display area appears larger, which may cause the image to deviate from the driving lane, which is the original projection area. 8B shows how the near end (the side closer to the vehicle), midpoint, and far end (the side farther from the vehicle) of the image are displayed in the display area when an image divided into two equal parts horizontally and vertically is projected. As shown in FIG. 8B, because the distance between the projection device 11 and the display area is different between the near end and the far end of the image, the image displayed in the display area becomes larger as it gets farther away, which can cause a discrepancy between the size of the displayed information and how it appears to be real objects, including the surrounding road surface.

[0089] Furthermore, as shown in FIG. 8B, because the projection device 11 and the display area are not directly facing each other and the display area is not directly facing the object viewing the displayed information, distortion occurs in the image depending on the viewpoint position of the person viewing the information displayed in the display area. The driver and projection device 11 are located in the same vehicle, and the difference in angle and direction between the displayed information, the driver's viewpoint, and the projection device 11 is small. Therefore, image distortion from the driver's viewpoint does not occur very often. On the other hand, when viewed from the viewpoint of a nearby pedestrian or another vehicle, the difference in angle and direction between the image displayed by the projection device 11, the projection device 11, and the viewpoint position is large, resulting in significant image distortion.

[0090] A more detailed description will be given with reference to FIGS. 8C and 8D. FIG. 8C is a diagram for explaining vertical distortion when an image is projected onto a road surface. In this example, when an image bisected in the vertical direction is projected onto the road surface, the relationship between the angles and lengths formed by the respective points of the near end side A (the side closer to the vehicle), the midpoint C, and the far end side B (the side farther from the vehicle) of the image and the viewpoint position is shown. Here, the midpoint C does not represent the midpoint of the image on the road surface, but the midpoint of the image projected from the projection device 11. As shown in (a) of FIG. 8C, image light is projected toward the road surface from the same position as the headlight 13. The driver can see the image projected onto the road surface. In addition, vehicles and people (e.g., pedestrians) around the host vehicle can also see the image projected onto the road surface.

[0091] Here, image light is projected onto the road surface under the conditions shown in (b) of FIG. 8C. That is, as shown in (b) of FIG. 8C, the angles θ1 and θ2 are the angles formed by the road surface on which the image is displayed and the projection axis. The angle θ1 is the angle formed by the near end side A of the image and the midpoint C with respect to the projection device 11, and the angle θ2 is the angle formed by the far end side B of the image and the midpoint C with respect to the projection device 11. Here, the line connecting the projection device 11 and the midpoint C of the image is called the projection axis. When viewing the image projected onto the road surface from the image light emission position of the projection device 11, the angles θ1 and θ2 correspond to the viewing angles, and an image of a size corresponding to these angles can be visually recognized. The lengths M1 and M2 are the lengths indicating the range of the projection light on the straight line passing through the near end of the road surface and perpendicular to the projection axis, and are lengths depending on the angles θ1 and θ2. The lengths L1 and L2 are the lengths indicating the range of the road surface on which the image is displayed. The length of the display range (from A to C) on the near side of the vehicle is L1, and the length of the display range (from C to B) on the far side of the vehicle is L2. And when θ1 = θ2 and M1 = M2, since the display on the far side of the vehicle with respect to the near side of the vehicle on the road surface becomes larger, the condition of L1 << L2 is satisfied.

[0092] Here, the driver views the image under the conditions shown in (c) of FIG. 8C. That is, as shown in (c) of FIG. 8C, angles θ3 and θ4 are the angles between the road surface on which the image is displayed and the driver's viewpoint. Angle θ3 is the angle between the near end A of the image and the midpoint C and the driver's viewpoint, and angle θ2 is the angle between the far end B of the image and the midpoint C and the driver's viewpoint. The driver can see an image of a size corresponding to angles θ3 and θ4. Lengths M3 and M4 are lengths that indicate the field of view of the road surface on which the image is displayed, on a line that passes through the near end A of the image and is perpendicular to the line connecting the driver's viewpoint and the midpoint C, and are lengths that depend on angles θ3 and θ4. Lengths L1 and L2 are the lengths of the display range on the road surface, as described above. Since the image projection device 11 and the driver are in the same vehicle, with the driver positioned approximately behind the image projection device, the difference between the angle between the road surface on which the image is displayed and the image light output position of the image projection device and the angle between the road surface on which the image is displayed and the driver's viewpoint is small. As a result, the conditions θ1 ≒ θ3 and θ2 ≒ θ4 are met, so the driver sees an image that is approximately the same as the input image with little vertical distortion. In other words, the driver can correctly recognize the information displayed in the display area.

[0093] The condition shown in (d) of FIG. 8C is an example in which a person nearby other than the driver is viewing the video. In this example, a pedestrian is viewing the video displayed on the road surface from the opposite side of the vehicle being driven by the driver. As shown in (d) of FIG. 8C, angles θ5 and θ6 are the angles between the road surface on which the video is displayed and the pedestrian's viewpoint. Angle θ5 is the angle between the near end A of the video and the midpoint C and the pedestrian's viewpoint, and angle θ6 is the angle between the far end B of the video and the midpoint C and the pedestrian's viewpoint. Lengths M5 and M6 are lengths that indicate the field of view of the road surface on which the video is displayed, on the side of a line that passes through the far end B of the video and is perpendicular to the line connecting the pedestrian's viewpoint and the midpoint C, and are lengths that depend on angles θ3 and θ4. Lengths L1 and L2 are the lengths of the display range on the road surface, as described above. As shown in the figure, the relationship between the angle formed by the display range A to C on the road surface and the angle formed by the display range C to B is θ1 = θ2 when based on the projection device position, but θ5 << θ6 when based on the pedestrian's viewpoint. As a result, from the pedestrian's viewpoint, the image seen will have the midpoint C positioned significantly off-center, meaning that the information displayed in the display area cannot be correctly recognized.

[0094] FIG. 8D is a diagram for explaining distortion in the horizontal direction. This example shows the relationship between the angle of view of the near end (the side closer to the vehicle) and the far end (the side farther from the vehicle) of an image when an image divided into two equal parts horizontally is projected onto a road surface. As shown in (a) of FIG. 8D, image light is projected onto the road surface from a position similar to that of headlight 13. For simplicity's sake, this example shows an example in which image light is projected from a light on one side, but it may be projected from lights on both sides. Here, the angle of view of the image displayed on the road surface on the near end side of the vehicle is indicated by angle θ7, and the angle of view of the image displayed on the road surface on the far end side of the vehicle is indicated by angle θ8. Here, when an image with the same width is projected at the top and bottom, the condition θ7 = θ8 is met. The driver can then see the image projected onto the road surface. Note that vehicles and people (e.g., pedestrians) around the vehicle can also see the image projected onto the road surface.

[0095] FIG. 8D (b) shows an example of the driver's field of view. The viewing angle for the image displayed on the road surface near the vehicle's end is indicated by angle θ9, and the viewing angle for the image displayed on the road surface far from the vehicle is indicated by angle θ10. Because the driver's viewpoint position and the position of the projection device 11 are offset in the horizontal and vertical directions, θ7 and θ9, and θ8 and θ10 are different, but the difference is small, and the condition θ9 ≒ θ10 is established. Therefore, the amount of horizontal distortion that occurs in the image seen by the driver is small, and the image seen by the driver is substantially the same as the input image. In other words, the information displayed in the display area can be correctly recognized.

[0096] FIG. 8D (c) shows an example of the field of view of a person around a vehicle. In this example, a pedestrian is viewing an image displayed on the road surface from the opposite side of the vehicle being driven. The person's viewing angle to the near side of the image displayed on the road surface is indicated by angle θ11, and the person's viewing angle to the far side of the image displayed on the road surface is indicated by angle θ12. Here, from the person's viewpoint, the condition θ11 >> θ12 holds. Therefore, the person sees a distorted image with a large difference in horizontal width between the top and bottom of the image. In other words, the person is unable to correctly recognize the information displayed in the display area.

[0097] An example of an image seen by the driver and people around the vehicle will be described with reference to Fig. 9. The projection device 11 projects image light of an image showing "F" onto the road surface as shown in Fig. 8C(a) and Fig. 8D(a).

[0098] Here, when the image of the "F" is projected as is, i.e., when it is projected without image correction, the driver sees an image of the "F" with less distortion compared to the original image, as explained in (b) of FIG. 8C and (b) of FIG. 8D. However, as shown in (b) of FIG. 8D, the width of the projection area increases for images farther from the projection device 11, which results in the image deviating from the road surface and superimposing the image on objects around the road surface, which may prevent the information from being correctly recognized. As information is displayed on the road surface, it is desirable for the projected image to become smaller as it gets farther away, just like a landscape. This achieves a similar visibility effect to road signs painted on the road surface. On the other hand, when a person around the vehicle (e.g., a pedestrian roughly opposite the vehicle) looks at the projected "F," the person sees an "F" that is distorted vertically and horizontally due to the oblique projection, as explained in (d) of FIG. 8C. In this example, the image is magnified as it moves further away from the driver. Furthermore, as explained in (c) of FIG. 8D, horizontal distortion occurs (Case 1). This distortion becomes more pronounced as the image moves away from the projection device 11 that projects the image.

[0099] In order to superimpose information displayed by the projection device 11 onto the actual road surface from the driver's viewpoint, if the projection device 11 projects an image in which the original image of the "F" has been horizontally corrected, the driver can view the information without departing from the road surface, which is the display area, and therefore can see the "F" without being obstructed by surrounding objects outside the road surface. However, as described in (d) of FIG. 8C and (c) of FIG. 8D, people around the vehicle will see an "F" that has horizontal and vertical distortion (Case 2). Also, if the projection device 11 projects an image in which the original image of the "F" has been horizontally and vertically corrected so that the image is visible from the viewpoint of a person around the vehicle (e.g., a person approximately opposite the vehicle), this person will see an "F" that is free from horizontal and vertical distortion. However, the driver will see a distorted "F" compared to the original image of the "F" (Case 3). As explained above, the shape of the image suitable for viewing differs depending on the person observing the information and the position of the vehicle equipped with the projection device 11. Therefore, in order to properly convey information, it is desirable to adjust the image to be projected to match the target of the information to be conveyed.

[0100] Next, with reference to FIGS. 10 and 11, the effect of polarization of image light when an image is projected onto a road surface as a display area will be described. As shown in FIG. 10A, image light oscillating in a plane parallel to the road surface is incident on the road surface as S-polarized light. Also, as shown in FIG. 10B, image light oscillating in a plane perpendicular to the road surface is incident on the road surface as P-polarized light. Here, as shown in FIG. 11, when the refractive index is approximately 1.33, the reflectance of S-polarized light on the road surface tends to be higher than the reflectance of P-polarized light within the range of light incidence angles to the road surface from 0° to 90°. Therefore, for example, by projecting image light with a high S-polarized component, the reflectance increases, improving the visibility of images of surrounding people.

[0101] Next, an example of the arrangement of optical components used for polarization will be described with reference to Fig. 12. As shown in Fig. 12A, in the DMD system, as an example, a polarization separation element 7024 and a polarization conversion element 7025 are arranged in the light emission direction of a first optical element 901, and specifically, the polarization separation element 7024 and the polarization conversion element 7025 are arranged between the first optical element 901 and the second optical element 902 in the light emission direction. As shown in Fig. 12B, in a system in which a display light-emitting element 908 itself emits light and projects an image, as an example, the polarization separation element 7024 and the polarization conversion element 7025 are arranged in the emission direction of the display light-emitting element 908, and specifically, the polarization separation element 7024 and the polarization conversion element 7025 are arranged between the display light-emitting element 908 and the fourth optical element 904 in the light emission direction. As shown in Figure 12C, in a method of transmitting light through a display element 909 to display an image, as an example, a polarization separation element 7024 and a polarization conversion element 7025 are arranged in the light emission direction of the fifth optical element 905, and specifically, the polarization separation element 7024 and the polarization conversion element 7025 are arranged between the fifth optical element 905 and the display light-emitting element 909 in the light emission direction.

[0102] Next, an example of the type of image projected by the projection device 11 will be described with reference to Fig. 13. The projection device 11 of this example can project an image for the driver and an image for vehicles and people around the vehicle.

[0103] FIG. 13A shows an example of types of images (information) for the driver. The projection device 11 projects images such as a frozen road warning display, an excessive speed warning display, a lane departure warning display, a wrong-way driving warning display, a collision risk warning display, a driving speed display, a navigation display, a vehicle width display, and a predicted trajectory display. Here, the frozen road warning display is information informing the driver that the road surface is frozen. The excessive speed warning display is information informing the driver that the driving speed is exceeding the speed limit. The lane departure warning display is information informing the driver that the vehicle is driving outside its lane. The wrong-way driving warning display is information informing the driver that the vehicle is driving the wrong way on a road where the vehicle's direction of travel is restricted. The collision risk warning display is information informing the driver of the risk of collision with surrounding objects such as vehicles or people such as pedestrians. The driving speed display is information informing the driver of the vehicle's driving speed. The navigation display is information informing the driver of navigation information such as a destination set for the vehicle. The vehicle width display is information informing the driver of the vehicle's width. The predicted trajectory display is information informing the driver of the predicted trajectory of the vehicle. The display format is not particularly limited as long as it can properly convey the information, and it is possible to display using symbols, letters, etc.

[0104] FIG. 13B shows an example of the types of video information for nearby people. The projection device 11 projects images such as a right turn indication, a left turn indication, a hazard indication, a reversing indication, a lane change indication, a parking / stopping indication, a departure indication, a door opening / closing indication, and a crossing indication. Here, the right turn indication is information informing a vehicle of a right turn. The left turn indication is information informing a vehicle of a left turn. The hazard information is information informing an emergency stop of the vehicle. The reversing indication is information informing a vehicle of a reversing indication. The lane change indication is information informing a change in driving lane. The parking / stopping indication is information informing a vehicle of a parking / stopping indication. The departure indication is information informing a vehicle of a departure. The door opening / closing indication is information informing a vehicle of a door opening / closing indication. The crossing indication is information informing nearby people that they can cross the road (such as a pedestrian crossing indication). The display format is not particularly limited as long as it can appropriately convey information, and displays using symbols, letters, etc. are possible.

[0105] Images for people in the vicinity can be displayed in front, on the left and right sides, or behind the vehicle. Images for the driver can be displayed, for example, in front or behind the vehicle. Projected images may be classified into images aimed at the driver and images aimed at the area around the vehicle, or may be classified into two or more categories. The classified images are then adjusted for display position, polarization, geometric processing, etc.

[0106] An example of the image display process will be described with reference to FIG. 14. In the image display process of the present invention, the projection device 11 may be controlled by a processor, or the projection device 11 may determine the projection image based on information from the vehicle or an external device, or the process may be shared between the vehicle and the projection device 11. For example, when the image display process is controlled by a processor, image information based on information from a sensor is sent to the projection device 11. If the image information needs to be adjusted, image adjustment information is also sent to the projection device 11, and a projection signal for the adjusted image information is sent to the projection device 11 to project the image. Alternatively, control related to the process may be performed by the processor, and the projection device 11 only performs projection and does not perform any other control. In the following embodiments, the control method for the image display process is not particularly limited. As shown in FIG. 14A, step S1 is a display preparation step in which it is determined whether to start the projection device 11 and start display. Step S1 includes a projection device start determination (S11), a display start condition determination 1 (S12), and a display start condition determination 2 (S13). Each of these steps may be processed individually, or they may be combined into one process. When performing the processes individually, the order of the processes in S11, S12, and S13 is not limited, and the processes may be performed.

[0107] The order of these determination processes (S11, S12, S13) may be determined as appropriate depending on the projection situation, etc. Alternatively, the processes may be performed in a predetermined order. As shown in FIG. 14B, for example, the processes may be performed in the order of startup determination of the projection device 11 (S11), display start condition determination 1 (S12), and display start condition determination 2 (S13).

[0108] Step S4 is a display adjustment step, in which it is determined or selected whether display adjustment is necessary based on the display adjustment conditions of the image projected by the projection device 11. Then, the display of the image is adjusted based on the display adjustment conditions (S4). Step S5 is an image display step, in which the display of the adjusted image is started.

[0109] Thereafter, a step S6 determines whether to end the display, and then, depending on the result of the determination in the display end condition determination S6, the display is ended in accordance with the display end operation (S7).

[0110] The process of FIG. 14A is configured to directly or indirectly control the projection device 11. The process may be based on the controller 100, the control unit 714 of the projection device 11, another processing device provided in the vehicle, or a processing device outside the vehicle. Here, the process may be performed by one of these components, or may be performed in a distributed manner by multiple components. That is, the process of FIG. 14A may be configured by one of these components, or may be configured by multiple components. In controlling the projection device 11, the controller 100 may send a signal to the projection device 11 to control the projection device 11. Furthermore, the control unit 714 of the projection device 11 may control the display of the projection device 11 based on information acquired from the vehicle.

[0111] 15, a specific example of the startup determination (S11) of the projection device 11 will be described. In S11, the startup of the projection device 11 is determined according to preset information on whether the projection device 11 is in use or not.

[0112] In Example 1-1, whether or not to start the projection device 11 is determined based on the installation of the projection device 11. For example, if the installation of the projection device 11 is confirmed, it is determined to start the projection device 11, and if the installation of the projection device 11 is not confirmed, it is determined not to start the projection device 11.

[0113] In Example 1-2, whether to start the projection device 11 is determined based on the setting for use of the projection device 11. For example, if the use of the projection device 11 is set, it is determined to start the projection device 11, and if the use of the projection device 11 is not set, it is determined not to start the projection device 11. However, even if the use of the projection device 11 is not set, if it is determined that there is a risk of danger to the driver or surrounding vehicles and people, the projection device 11 displays an image. For example, if a risk of collision with surrounding vehicles or people is detected, a collision risk warning display may be displayed even if the use of the projection device 11 is not set.

[0114] In Example 1-3, whether to start the projection device 11 is determined based on the reception status of a fault signal for the projection device 11. For example, if a fault signal for the projection device 11 is not received, or if the projection device 11 has not acquired a fault signal from another source, it is determined to start the projection device 11. If a fault signal for the projection device 11 is received, it is determined not to start the projection device 11. In other words, it is determined that the projection device 11 is not faulty, and then it is started. On the other hand, if a fault signal is not received, or if no signal is received within a predetermined time, it is determined not to start the projection device 11.

[0115] In Example 1-4, when a failure signal is received for the projection device 11, whether or not to start the projection device 11 is determined by checking whether or not there is an area on the display element where normal display is possible. For example, even when a failure signal for the projection device 11 is received, if it is confirmed that there is an area on the display element where normal display is possible, it is possible to display using the normal portion, and therefore it is determined that the projection device 11 should be started.

[0116] In Example 1-5, a failure signal for the projection device 11 is received, and whether or not to start the projection device 11 is determined by checking whether another alternative projection device 11 is installed. Even if a failure signal for the projection device 11 is received, if it is confirmed that an alternative projection device 11 is installed, the alternative projection device 11 is started. For example, if a projection device 11 is incorporated in each of the left and right headlights, and only one of the projection devices 11 is broken, the other projection device is started.

[0117] In Example 1-6, whether or not to start the projection device 11 is determined depending on whether or not the projection device 11 is set to be unused. For example, if the projection device 11 is not set to be unused, it is determined to start the projection device 11, and if the projection device is set to be unused, it is determined not to start the projection device 11. However, even if the projection device 11 is set to be unused, if it is determined that there is a risk of danger to the driver or surrounding vehicles and people, the projection device 11 can display an image.

[0118] In Example 1-7, it is determined whether the projection device 11 is started based on the reception status of an activation signal from the activation switch or operation switch of the projection device 11. For example, it is determined that the projection device is started when there is an activation signal from the operation switch of the projection device 11. For example, when the user uses the activation switch or operation switch to set the projection device 11 to ON / OFF, and it is confirmed that the operation switch of the projection device 11 is ON, it is determined that the projection device 11 is started.

[0119] Example 1-8 determines whether or not a voice input is to activate the projection device 11. If there is data or information indicating that a voice input is to activate the projection device 11, it is determined that the projection device 11 is to be activated.

[0120] In Example 1-9, the activation of the projection device 11 is determined based on whether or not a signal indicating activation of the projection device 11 by an information terminal has been received. When a signal or information indicating activation of the projection device 11 is received from the information terminal, the determination is made to activate the projection device 11. For example, when an activation signal is received from a smartphone or wearable device operated by a driver or passenger, the determination is made to activate the projection device 11. Also, as shown in FIG. 15, the conditions in each example may occur simultaneously. For example, even if the projection device 11 is set to be unused in Example 1-6, activation of the projection device 11 by voice input in Example 1-8 may be received. In such a case, the determination is made based on the priority of the determination conditions for activation of the projection device. Alternatively, as shown in FIG. 15, the projection device 11 may be activated when multiple conditions in each example are met simultaneously.

[0121] 16A and 16B, a specific example of the display start condition determination 1 (S12) will be described. Fig. 16A relates to an image display for the driver. Fig. 16B relates to an image display for vehicles and people around the host vehicle.

[0122] When one or more of the following conditions (2-1A) to (2-1D) are met, the projection device 11 determines whether to display a frozen road warning (Example 2-1). Here, the condition (2-1A) determines whether to display a frozen road warning based on temperature information. For example, when a temperature detection unit or sensor detects or senses that the temperature is below a set temperature, the frozen road warning display is initiated. It is believed that roads freeze when the temperature outside the vehicle drops below 3 to 5 degrees Celsius, and this temperature may be set as the set temperature. Alternatively, the road temperature lower than the temperature outside the vehicle may be set as the set temperature, and whether the road temperature is below freezing may be detected. Furthermore, humidity conditions may be set similarly to the set temperature. The condition (2-1B) determines whether to display a frozen road warning based on frozen road information. For example, if frozen roads are determined based on road surface information captured by a camera, the frozen road warning display is initiated. Frozen roads may be determined based on changes in the amount of light reflected, or by capturing images using a polarizing filter attached to a camera. Furthermore, when information about frozen roads is received via communication from outside the vehicle, the display of a frozen road warning may be initiated. The condition (2-1C) determines whether or not to display a frozen road warning based on the operation of the anti-lock brake system. For example, when a signal or information indicating that the anti-lock brake system has been activated is detected, the display of a frozen road warning is initiated. The condition (2-1D) determines whether or not to display a frozen road warning based on the operation of the vehicle's anti-skid system. For example, when a signal or information indicating that the vehicle's anti-skid system has been activated is detected, the display of a frozen road warning is initiated. The operation of the anti-lock brake system or the vehicle's anti-skid system indicates a decrease in friction between the vehicle and the road surface, such as wheel spin, and indicates the possibility of frozen roads.

[0123] When one or more of the following conditions (2-2A) to (2-2B) are satisfied, the projection device 11 determines whether to display a speeding warning (Example 2-2). Here, the condition (2-2A) determines whether to display a speeding warning based on the vehicle's traveling speed. When the vehicle speed sensor 501 detects a signal or information indicating that the vehicle's current traveling speed exceeds the maximum speed sign, the speeding warning is displayed. Note that the speed information may be acquired from the acceleration sensor 512, the gyro sensor 513, the GPS receiver 518, or the like. The maximum speed sign may also be acquired by an appropriate method. For example, information on the speed set by the maximum speed sign may be acquired based on an image acquired by the external camera 521. The condition (2-2B) determines whether to display a speeding warning when the vehicle speed sensor 501 detects a signal or information indicating that the vehicle's current traveling speed exceeds the maximum speed indicated on the map information for the current location. The maximum speed on the map information at the current location may be obtained from a device such as the car navigation system 150, based on the speed limit sign on the road on which the vehicle is traveling.

[0124] If the following conditions (2-3A) and one or more of (2-3B) to (2-3C) are satisfied, the projection device 11 determines to display a lane departure warning (Example 2-3). Here, condition (2-3A) indicates that a lane departure warning is to be displayed when a sensor installed in the vehicle detects lane departure. For example, the system determines whether the host vehicle is traveling within the driving lane based on lane information in an image acquired by the exterior camera 521. If it is detected that the vehicle is deviating from the lane, the system displays the lane departure warning. Condition (2-3B) indicates that a lane departure warning is to be displayed when it is not possible to detect that the turn signal is on. Also, a driver may deviate from a lane intentionally in order to change lanes. To determine whether the lane departure is intentional, the system checks whether the turn signal is on. The exterior camera 521 may also check whether there are multiple lanes into which the lane can be changed and then determine whether the lane change is intentional. In the condition (2-3C), if the driving lane cannot be detected on either side of the vehicle, a lane departure warning is displayed. The driving lane may be detected by the external camera 521, for example.

[0125] When one or more of the conditions (2-4A) to (2-4C) are satisfied, it is determined that the projection device 11 should display a wrong-way driving warning (Example 2-4). Here, the condition (2-4A) is that the wrong-way driving warning is displayed when a no entry sign is detected in the lane in which the vehicle is traveling. The condition (2-4B) is that the wrong-way driving warning is displayed when a one-way sign is detected in the lane in which the vehicle is traveling. The condition (2-4C) is that the wrong-way driving warning is displayed when wrong-way driving is detected based on map information and sensors (GPS receiver 518, gyro sensor 513, acceleration sensor 512, vehicle speed sensor 501, etc.).

[0126] If one or more of the conditions (2-5A) to (2-5C) are met, the projection device 11 is determined to display a collision risk warning (Example 2-5). Here, the condition (2-5A) determines whether or not to display a collision risk warning based on the inter-vehicle distance. If the inter-vehicle distance between the host vehicle and a vehicle traveling ahead is less than a set distance, a collision risk warning is displayed. For example, a collision mitigation braking system is required to avoid collision when approaching a stopped vehicle ahead at a predetermined speed, e.g., 50 km / h. The stopping distance at 50 km / h is said to be approximately 24 m. However, if no human intervention is involved in the stopping operation, no free-running distance is generated, so only the braking distance may be considered. In this case, the stopping distance is approximately 14 m. Furthermore, a warning is issued to the driver at least a predetermined time before the collision mitigation braking system is activated, e.g., 0.8 seconds before activation, and the free-running distance during 0.8 seconds traveling at 50 km / h is approximately 11 m. It is desirable that the collision risk warning be displayed before the collision mitigation brake alarm is activated. Therefore, for example, assuming that there is no free-travel distance when traveling at 50 km / h, the collision risk warning should be displayed at least when the inter-vehicle distance is between 25 m and 30 m. The free-travel distance is the distance traveled before a person recognizes, judges, and takes action against danger, and the braking distance is the distance from when the brakes are activated until the vehicle stops. Furthermore, since the free-travel distance is proportional to the traveling speed and the braking distance is proportional to the square of the traveling speed, the inter-vehicle distance setting at which the display starts may be changed according to the traveling speed of the vehicle, or the display may start at a greater distance to alert the driver. Furthermore, since the stopping distance varies depending on the road surface condition in inverse proportion to the coefficient of friction of the road surface, the inter-vehicle distance setting at which the display starts may be changed according to the road surface condition. The collision risk warning can also be displayed when the inter-vehicle distance between the host vehicle and the vehicle traveling behind the host vehicle is equal to or less than the set distance.

[0127] The condition (2-5B) determines whether or not to display a collision risk warning based on the relative speed. A collision risk warning is displayed when the relative speed between the host vehicle and a vehicle traveling ahead of the host vehicle is equal to or greater than a set speed. A collision risk warning can also be displayed when the relative speed between the host vehicle and a vehicle traveling behind the host vehicle is equal to or greater than a set speed. If the vehicle traveling ahead of the host vehicle is traveling at a higher speed than the host vehicle, a collision will not occur. However, if the vehicle traveling ahead of the host vehicle is traveling at a lower speed than the host vehicle, there is a risk of a collision. However, since the vehicle traveling ahead is moving forward, the distance at which a collision with the vehicle traveling ahead occurs is shorter than when the vehicle traveling ahead is stopped. Therefore, the distance required to start displaying the collision risk warning described in (2-5A) must be set shorter than when the vehicle traveling ahead is stopped. For example, collision mitigation braking is required to avoid a collision when the vehicle traveling ahead is traveling at 20 km / h and the host vehicle is traveling at 50 km / h. In this case, assuming there is no free-running distance when the collision mitigation brake is applied, the vehicle will travel approximately 14 meters before stopping, requiring approximately 2 seconds. During this time, the vehicle in front will travel approximately 11 meters. Therefore, a 3-meter inter-vehicle distance will allow the vehicle to avoid a collision and stop. Even in this case, an alarm is issued to the driver at least 0.8 seconds before the collision mitigation brake is applied. Since the host vehicle travels 11 meters between the time the alarm is issued and the time the collision mitigation brake is applied, the collision danger warning should be displayed when the inter-vehicle distance is between 11 and 15 meters. As mentioned above, the inter-vehicle distance required to avoid a collision varies depending not only on the vehicle's speed but also on the relative speed with respect to surrounding vehicles. Therefore, the relative speed must also be taken into consideration when displaying the collision danger warning. Furthermore, the collision danger warning can be displayed even when the relative speed between the host vehicle and the vehicle behind it is below a set speed.

[0128] The condition (2-5C) is that a collision danger warning is displayed when the predicted time until a collision between the host vehicle and a vehicle traveling ahead is less than or equal to a set time. Also, when the predicted time until a collision between the host vehicle and a vehicle traveling behind the host vehicle is less than or equal to a set time. The stopping distance during braking can be calculated from the vehicle speed and the friction coefficient of the road surface. The speeds of the vehicles traveling ahead and behind the host vehicle may be obtained, for example, via appropriate communication, or may be calculated from the host vehicle's traveling speed and the relative position of surrounding vehicles captured by the external camera 521. The friction coefficient of the road surface may be calculated from the brake pedal depression amount and the vehicle speed deceleration amount or the time required for deceleration during braking. Furthermore, a collision danger warning may be displayed in front of or behind the vehicle in conjunction with activation of the collision mitigation brake. Alternatively, the collision danger warning may be displayed in conjunction with a collision mitigation brake warning, a predetermined time before activation of the collision mitigation brake, for example, 0.8 seconds or more, or may be displayed before the collision mitigation brake warning. Furthermore, when the vehicle's sensors detect a risk of collision at the current driving speed without linking with the collision mitigation brake warning, a collision risk warning can be displayed at least a specified time before the expected time of collision. For example, if the vehicle is traveling at 50 km / h, displaying the warning 5 to 10 seconds before the expected time of collision can prompt the driver to apply the brakes and prevent a collision. This specified or set time can also be changed according to the speed and road conditions.

[0129] In Example 2-6, when a predetermined condition is satisfied, the projection device 11 determines whether to display the driving speed. The condition (2-6) is that if the driving speed display setting of the projection device 11 is ON, the driving speed is displayed. Also, if the driving speed display setting of the projection device 11 is OFF, the driving speed is not displayed. The vehicle's current driving speed is detected by the vehicle speed sensor 501. The color and size of the displayed speed may be changed according to the vehicle's driving speed, or a speed range for the displayed speed may be preset. By displaying the speed only when the speed limit of the road being traveled is approached, it is possible to maintain a safe driving speed while preventing distraction during driving due to a constant display. For example, the display is displayed when the driving speed exceeds 90% of the speed limit or when the speed is within a predetermined speed, e.g., 5 km / h, of the speed limit. Note that if the driving speed changes rapidly, the display will be turned ON / OFF continuously. Therefore, the display may be determined based on the time average of the driving speed, or hysteresis may be added to the display start speed condition and the display end speed condition. In addition, the color and size can be adjusted to make the display less noticeable unless necessary.

[0130] Example 2-7 determines whether to display navigation information on the projection device 11 if a predetermined condition is met. Regarding condition (2-7), navigation information is enabled when the navigation display setting of the projection device 11 is ON. When the navigation display setting of the projection device 11 is OFF, navigation information is not displayed. The navigation display may be limited to content that can be overlaid on the road to improve recognition. For example, information such as right and left turns included in navigation information to a destination can be displayed on the actual road rather than on the navigation screen to prevent misrecognition. Furthermore, a portion of the HUD display may be displayed, or only content that does not overlap with the HUD may be displayed. For example, an image of the vehicle's lane may be displayed on the HUD, while information about adjacent lanes, sidewalks, and other areas outside the lane is displayed by the projection device. To display a wide-angle image in a HUD, the optical system installed in the device must be large, which poses a problem when installing it in a vehicle. The projection device can display images outside the HUD display area and can supplement the display area, thereby avoiding installation issues in the vehicle and displaying information to the driver and objects around the vehicle over a wide area. Furthermore, since the HUD display position is adjusted according to the driver's seating position, the projection device's display position can also be adjusted to match the driver's seating position. The display position of the image displayed by the projection device may be adjusted in conjunction with the HUD display position, or the HUD display position and the display position of the image displayed by the projection device may be adjusted independently. This prevents the images from the HUD and the projection device from overlapping.

[0131] In Example 2-8, when one or more conditions from (2-8A) to (2-8C) are satisfied, it is determined whether or not to cause the projection device 11 to display the host vehicle width. The condition (2-8A) is that when the display setting for the host vehicle width display is ON, the host vehicle width is displayed. The display setting for the host vehicle width display may be set by a user operation or may be set by default. For example, when traveling on a road with a narrow roadway width or a road that has been narrowed due to construction or the like, the host vehicle width may be displayed by a user operation to visually confirm whether the host vehicle is passable.

[0132] The condition (2-8B) requires that the vehicle's width be displayed if the lane width is less than the set value. For example, if the lane width is close to the vehicle's width, driving off the center of the lane can result in the vehicle's wheels skidding or contact with obstacles such as walls or road signs. Displaying the vehicle's width allows the driver to confirm the vehicle's position within the lane and avoid danger. While vehicle width generally refers to the width excluding the door mirrors, the vehicle's width display can display the vehicle's maximum width including the door mirrors. For example, the vehicle's width is displayed offset by 25 cm to the left and right of the vehicle's width. Furthermore, if a pedestrian is present, the vehicle's width is displayed offset by 50 cm to the left and right of the vehicle's width to avoid contact with the pedestrian. The required vehicle width for passing vehicles relative to the road width is (roadway width - 0.5 m) ÷ 2 on general urban roads, and (roadway width - 1.5 m) ÷ 2 on roads with many pedestrians and no sidewalks. The displayed vehicle width may be changed depending on the width of the surrounding roads and the presence of other vehicles.

[0133] The condition (2-8C) is that if the lane on which the vehicle is traveling cannot be detected, the vehicle width is displayed. Alternatively, a value slightly larger than the vehicle width may be displayed. For example, if there are no lanes on the road, or if the lanes are partially or completely missing and cannot be detected, the vehicle width is displayed. This may also be displayed if there are obstacles such as walls on the left and right sides of the vehicle, or if pedestrians are detected. In such cases, only the vehicle width on the side where the obstacles or pedestrians are present may be displayed.

[0134] In Example 2-9, when one or more conditions from (2-9A) to (2-9C) are satisfied, it is determined whether or not to cause the projection device 11 to display a predicted trajectory. Here, the condition (2-9A) is that when the display setting for the predicted trajectory display is ON, the predicted trajectory is displayed. The display setting for the predicted trajectory display may be set by a user operation, or the setting information from the previous driving may be displayed. For example, the predicted trajectory indicates the trajectory that the vehicle will travel in the future, and the driving trajectory may be displayed based on information from the steering angle sensor 503, or may be displayed based on map information or navigation information to the destination.

[0135] Regarding the condition (2-9B), if the turn signal is detected to be on, the predicted trajectory is displayed. If the turn signal is not on for a predetermined period of time or longer, the display of the predicted trajectory disappears. On the other hand, if the turn signal is detected to be on for a predetermined period of time or longer, the predicted trajectory may be displayed. Alternatively, if the steering angle of the steering wheel is detected, the predicted trajectory may be displayed. Regarding the condition (2-9C), if the inter-vehicle distance is less than a predetermined value, the predicted trajectory is displayed. By displaying the predicted trajectory to the driver, the driver can visually recognize that the predicted trajectory is interfering with surrounding vehicles, thereby drawing their attention. Note that the inter-vehicle distance may be acquired, for example, from the exterior camera 521 and the distance measurement sensor 507. Note that, similar to the vehicle width display described above, the maximum width of the vehicle, including the door mirrors, may also be displayed in the predicted trajectory display. For example, the predicted trajectory is displayed at a position offset by a predetermined distance, for example, 25 cm, to the left and right of the vehicle width. Furthermore, if a pedestrian is present, the predicted trajectory is displayed at a position offset by a predetermined distance, for example, 50 cm, to the left and right of the vehicle width to avoid contact with the pedestrian.

[0136] In Example 2-10, when one or more of the conditions (2-10A), or (2-10A) and (2-10B) to (2-10C) are satisfied, the projection device 11 determines whether to display a right turn. Here, the condition (2-10A) is that when the ON of the right turn indicator is detected, a right turn indication is displayed. Also, because of possible driver error, if the time the indicator is ON is longer than a predetermined time, a right turn indication is displayed, and if the time the indicator is ON is shorter than the predetermined time, a right turn indication is not displayed. Note that the state of the turn indicator may be acquired from the turn indicator switch, for example. The condition (2-10B) is that when a signal or information indicating a right turn of the steering wheel is detected, a right turn indication is displayed. The right turn indication may also be determined based on the steering angle of the steering wheel. For example, if the steering angle of the steering wheel is greater than a predetermined angle, a right turn indication is displayed. Note that steering wheel turning information may be acquired from the steering wheel angle sensor 503. Furthermore, there is a difference between the steering angle of the steering wheel and the resulting actual steering angle of the tires. Therefore, the total steering angle of the steering wheel can be converted and displayed as the actual steering angle of the tires. Alternatively, the actual steering angle of the tires can be sensed and displayed instead of the total steering angle of the road. The condition for (2-10C) is that a right turn is displayed when the right turn signal is ON and the accelerator is ON or the brake is OFF. For example, when the vehicle is stopped at an intersection waiting for a traffic light, the driver turns the accelerator ON or the brake is OFF in order to enter the intersection and turn right. By starting the display when the accelerator is ON or the brake is OFF, it is possible to display information linked to the vehicle's behavior.

[0137] In Example 2-11, when one or more conditions (2-11A), or (2-11A) and one or more of (2-11B) to (2-11C) are satisfied, the projection device 11 determines whether to display a left turn. Here, the condition (2-11A) is to display a left turn when the left turn indicator is detected to be ON. Also, because of possible driver error, if the indicator is ON for a predetermined time or longer, a left turn display is displayed, and if the indicator is ON for less than the predetermined time, a left turn display is not displayed. Note that the state of the indicator may be acquired from the indicator switch, for example. The condition (2-11B) is to display a left turn when a signal or information indicating a left turn of the steering wheel is detected. The left turn display may also be determined based on the steering angle of the steering wheel. For example, if the steering angle is equal to or greater than a predetermined angle, a left turn display is displayed. The condition for (2-11C) is that if the left turn signal is ON and the accelerator is ON or the brake is OFF, a left turn display is performed. This allows the display to be linked to the vehicle's behavior. For example, when the vehicle is stopped at an intersection waiting for a traffic light, the driver turns the accelerator ON or the brake OFF in order to enter the intersection and turn left. By starting the display when the accelerator is ON or the brake is OFF, it is possible to display the message linked to the vehicle's behavior.

[0138] In Example 2-12, when one or more of the conditions (2-12A) or (2-12A) and (2-12B) to (2-12C) are satisfied, the projection device 11 determines whether to display hazard warning lights. Here, the condition (2-12A) is that the hazard warning lights are displayed when the hazard warning light switch is detected as being ON. The condition (2-12B) is that the hazard warning lights are displayed when the brake is detected as being ON. Alternatively, the brake may be determined to be ON if the brake is applied for a predetermined period of time or longer, or information from the vehicle speed sensor 501 may be used instead of detecting the brake as being ON. The condition (2-12C) is that the hazard warning lights are displayed when the handbrake is detected as being ON. Hazard lights are primarily used to inform surrounding vehicles of the vehicle's actions when parking or stopping, but they are also used to inform following vehicles of traffic congestion ahead or to express gratitude when someone gives way to you. By considering the conditions (2-12B) to (2-12C), it is possible to determine whether the vehicle is parked or stopped and switch whether or not to display the information.

[0139] In Example 2-13, when one or more conditions (2-13A), or (2-13A) and (2-13B) to (2-13D), are satisfied, the projection device 11 determines whether to display a reverse display. Here, the condition (2-13A) is that when reverse gear is detected as being ON, the reverse display is displayed. Note that reverse gear information may be acquired, for example, from the shift position sensor 502. The condition (2-13B) is that when reverse gear is ON and the accelerator is ON or the brake is OFF, it is determined that the vehicle has started to reverse, and the reverse display is displayed. Also, instead of detecting the accelerator is ON or the brake is OFF, information from the vehicle speed sensor 501 may be used to determine the vehicle's reverse operation. The condition (2-13C) is that when reverse gear is ON and no obstacle is detected behind the vehicle, the reverse display is displayed. When an obstacle is present behind the vehicle, it is determined that there is no display area or no area for the vehicle to reverse into, and the reverse display is not displayed. Note that information about obstacles behind the vehicle may be acquired from, for example, the exterior camera 521, the distance measurement sensor 507, the infrared sensor 508, etc. The condition (2-13D) is that when the reverse gear is on and no obstacle is detected within a specified distance behind the vehicle, a reverse display is performed. An obstacle is an object that affects the display of the vehicle and its surroundings.

[0140] In Example 2-14, when one or more conditions (2-14A), or (2-14A) and one or more of (2-14B) to (2-14C) are satisfied, the projection device 11 determines whether to display a lane change. Here, the condition (2-14A) is that when a turn signal is detected to be ON, a lane change display is performed. Also, because there may be cases of driver error, a lane change display is performed when the turn signal is ON for a predetermined time or longer, and a lane change display is not performed when the turn signal is ON for less than the predetermined time. The condition (2-14B) is that when a turn signal is ON and the approach of a following vehicle in an adjacent lane is detected, a lane change display is performed. Note that this information about the approach of a vehicle may be acquired, for example, from the external camera 521, the distance measurement sensor 507, the infrared sensor 508, etc. The condition (2-14C) is that when the turn signal is ON and a person or a vehicle is detected around the vehicle, a lane change display is performed. Note that information on the presence of a person or a vehicle may be acquired from, for example, the external camera 521, the distance measurement sensor 507, the infrared sensor 508, etc.

[0141] In Example 2-15, when the conditions (2-15A) and (2-15B) are met, the processor determines whether to cause the projection device 11 to display a parking / stopping display. Here, when it is detected that the vehicle's drive source (engine, motor, etc.) is ON and that the parking brake is ON, the parking / stopping display is displayed. Also, instead of detecting that the parking brake is ON, it may be determined that the vehicle is stopped using information from the vehicle speed sensor 501.

[0142] In Example 2-16, when the conditions (2-16A) and (2-16B) are met, it is determined whether or not to make the projection device 11 display a start display. Here, when it is detected that the brake is off and the accelerator is on, the start display is performed. Also, instead of detecting that the brake is off and the accelerator is on, it is also possible to use information from the vehicle speed sensor 501 to determine whether the vehicle has started moving.

[0143] In Example 2-17, when the condition (2-17A) is satisfied, it is determined whether or not to make the projection device 11 display an open / closed door display. Here, the condition (2-17A) is that when a door unlock signal is detected, the door open / closed door display is made. For example, when a door lock signal is detected, the door closed door display may be made. Also, when a door lock signal is not detected within a predetermined time after the vehicle starts, the door unlocked door display may be set.

[0144] In Example 2-18, if the conditions (2-18A) and (2-18B) are met, it is determined whether or not to have the projection device 11 display a crossing indication. If the vehicle is stopped and a person is detected near the lane, the crossing indication is displayed. However, there are cases where the detected person has no intention of crossing the road. For this reason, the indication is displayed for a certain period of time, and if it is not confirmed that the detected person is crossing within that period, the indication may be terminated.

[0145] Next, a specific example of the display start condition determination 2 (S13) will be described with reference to Fig. 17. Here, even if the conditions of Fig. 16a and Fig. 16b are satisfied, it is possible that the display permission or not may be determined based on other conditions. A specific example is shown below.

[0146] In Example 3-1, if the condition (3A) is satisfied, it is determined whether or not to allow the projection device 11 to project an image. For example, when the ambient illuminance is high, such as during the day, it is difficult to increase the difference in brightness between the image light projected by the projection device 11 and the ambient light. As a result, the contrast of the image light decreases, making it impossible to distinguish the projected image. Therefore, in order to recognize the image, the ambient illuminance condition must be below a specified value. Here, the condition (3A) determines that the image can be displayed if the illuminance around the vehicle is below a specified value. As a result, the driver, surrounding vehicles, and people can recognize the projected image. Note that information about the illuminance around the vehicle may be acquired, for example, from the illuminance sensor 505.

[0147] In Example 3-2, if the condition (3B) is satisfied, it is determined whether or not to cause the projection device 11 to project an image. Here, the condition (3B) is that if the headlights are ON, it is determined that an image can be displayed. The headlights are required to automatically turn on within 2 seconds when the illuminance around the vehicle is 1000 lux or less, and to turn off within 5 to 300 seconds when the illuminance is 7000 lux or more. Therefore, the ON / OFF information of the headlights 13 reflects the illuminance around the vehicle, and by linking this with the ON information of the headlights 13, unnecessary display can be prevented and the image projected by the projection device 11 can be recognized. The ON / OFF information of the headlights 13 may be acquired, for example, from the headlight sensor 504.

[0148] In Example 3-3, if the condition (3C) is satisfied, it is determined whether or not to cause the projection device 11 to project an image. Here, the condition (3C) is that if the vehicle speed is equal to or greater than a set predetermined speed (in the figure, display lower limit speed 1), it is determined that the image can be displayed. The image for the driver contains information intended for the driver and contains information that is unnecessary for surrounding vehicles and people. Therefore, it is desirable that only the target of the image to be displayed is visible. For example, if the vehicle speed decreases, the relative speed with respect to objects other than the vehicle decreases, and the number of objects that can recognize the image projected by the vehicle increases. Therefore, by displaying the image only when the vehicle is traveling at a certain speed or above, distraction by others is prevented.

[0149] In Example 3-4, if the condition (3D) is met, it is determined whether or not to have the projection device 11 project an image. Here, the condition (3D) is that if the vehicle speed is equal to or less than a set predetermined speed (in the figure, upper display speed limit 1), it is determined that the image can be displayed. Images for the surroundings are information that should be recognized by surrounding objects, and a small relative speed with respect to surrounding objects is necessary for recognition of the image projected by the vehicle itself. Therefore, by displaying the image only when the vehicle is traveling at a certain speed or less, it is possible to encourage others to recognize the image.

[0150] In Example 3-5, if condition (3E) is met, it is determined whether to have the projection device 11 project an image. Here, condition (3E) determines that an image can be displayed if it is detected that the wipers are not operating continuously. On the other hand, the wipers may operate continuously for a short period of time, for example, when cleaning the windshield or front glass, and the wipers may operate continuously for a certain period of time. Therefore, if it is determined that the wipers are not operating continuously for a predetermined period of time or longer, it may be determined that an image should be displayed. When it rains, the reflective characteristics of the road surface change, and the direction of the reflected light changes. In some directions, light is strongly reflected, causing glare, while in other directions, light reflection is weaker, resulting in a dark image. Furthermore, when the vehicle's windshield 3 or projection device 11 gets wet, it becomes difficult to see the surroundings, and water droplets refract light, potentially preventing the intended image from being displayed and causing erroneous recognition. Therefore, it may be set not to project an image during rainy weather, etc. The wiper operation information may be acquired from, for example, the wiper switch 526. If the rain sensor 525 does not detect raindrops, it may be determined that the wipers are not operating continuously. If the amount of raindrops is small or the rain is light, it may be determined that the wipers are not operating continuously. For example, if the number of times the wipers move is less than a preset number, it may be determined that the wipers are not operating. While an example of linking the wiper operation with the rain sensor has been described here, it may also be linked with the rain sensor. A typical rain sensor detects the amount of rainfall by detecting changes in the intensity of infrared reflection caused by raindrops adhering to the windshield. Depending on the detection level of the rain sensor, if the detection level is low, it may be determined that the amount of rainfall is small and will not affect the image display of the projection device, and if the detection level is high, it may be determined that the amount of rainfall is large and will not affect the image display of the projection device.

[0151] In Example 3-6, if the condition (3F) is met, it is determined whether or not to allow the projection device 11 to project an image. Here, the condition (3F) is that if a specified level of wetness or more is not detected on the road surface, it is determined that an image can be displayed. Even if it is not currently raining, it may have rained in the past and the road surface may be wet. Even in such a case, the reflective characteristics of the road surface may change, and the directionality of the reflected light may change, which may change the appearance of the image. Therefore, it may be set not to project an image when the road surface is highly wet. Note that information about the wetness of the road surface may be obtained, for example, from an external camera. Furthermore, the information about the wetness of the road surface may be information obtained via communication and provided from an external system.

[0152] In Example 3-7, if the condition (3G) is satisfied, the processor determines to have the projection device 11 project an image. Here, the condition (3G) is that if it is detected that an image is not being projected onto the windshield 3, it is determined that an image can be displayed. When an image is displayed on the windshield 3 by an image display device such as a HUD, the image of the road surface displayed by the projection device 11 in the driver's field of view may overlap with the image displayed on the windshield 3, causing the image to be incorrectly recognized. Furthermore, there is a risk that the image will occupy the driver's field of view, obscuring information about the real space. Therefore, when an image is displayed on the windshield 3, the projection device 11 does not project an image. Alternatively, it is desirable to project an image onto the area where the image on the windshield 3 is displayed so that the image from the projection device 11 does not overlap with the area in the driver's field of view. Note that whether or not an image is being projected onto the windshield 3 may be acquired, for example, from the in-vehicle image display device 12.

[0153] In Example 3-8, if the condition (3H) is met, the processor determines whether to make the projection device 11 project an image. Here, the condition (3H) is determined to not display an image if the information display setting established in S12 is set to OFF beforehand. The information display may be set to OFF by the user. The user may set it on the operation screen, the setting screen, or by using an operation switch. It may also be set using voice input.

[0154] In Example 3-9, if the condition (3J) is satisfied, it is determined whether to allow the projection device 11 to project an image. Here, the condition (3J) is that it is determined that an image can be displayed if the inter-vehicle distance from the surrounding vehicle is equal to or greater than a specified value. If the inter-vehicle distance from the surrounding vehicle is not sufficiently secured, part or all of the image may interfere with the surrounding vehicle, preventing proper recognition. Therefore, it is determined whether there is a sufficient inter-vehicle distance to secure the necessary display area for the image, and whether to display it is determined accordingly. The required inter-vehicle distance may vary depending on the image. For example, an image displayed for the driver cannot be seen unless a predetermined inter-vehicle distance, e.g., 5 m or more, is secured on the road surface in front of the vehicle due to blind spots caused by the vehicle body. Furthermore, an image displayed for the surroundings does not require driver visibility, so it can be displayed if there is an inter-vehicle distance of approximately the size of the image display. Here, the inter-vehicle distance from the surrounding vehicle is used, but the distance from surrounding walls or obstacles may also be determined to be equal to or greater than a specified value.

[0155] In Example 3-10, if the condition (3K) is met, it is determined whether or not to cause the projection device 11 to project an image. Here, the condition (3K) is that if it is detected that no other vehicles are present in the display area of ​​the road surface, it is determined that an image can be displayed. If there are no surrounding vehicles, it is determined that there is a sufficient area to display the image, and the image can be displayed. Note that the presence of other vehicles may be obtained from, for example, the exterior camera 521, the distance measurement sensor 507, the infrared sensor 508, etc. Furthermore, if no surrounding vehicles or people are detected, the projection of the image toward the surroundings may be stopped.

[0156] Next, specific examples of the selection of display adjustment conditions (S4) will be described with reference to Figures 18A to 18C. In the figures, "Category 1" relates to images aimed at the driver. "Category 2" relates to images aimed at vehicles and people around the vehicle.

[0157] In the process of selecting the display adjustment condition (S4), one of the correction conditions shown in FIG. 18A is selected for adjusting the degree of polarization of the image light. The degree of polarization of the image light changes the state of reflection on the road surface. This change varies depending on the condition of the road surface, but when light is irradiated onto the road surface so that it is P-polarized, the amount of specularly reflected light on the road surface can be reduced compared to when light is projected onto the road surface so that it is S-polarized. It is desirable to adjust the degree of polarization of the image light depending on the condition of the road surface on which the image is displayed and the position of the target to whom information is to be conveyed via the image. For example, when conveying information via image light to the driver, it is desirable to suppress specularly reflected light, and when conveying information via image light to a person in front of the vehicle, it is desirable to strengthen specularly reflected light. Adjusting the degree of polarization in this way enables the target to correctly recognize the information provided by the image light.

[0158] Furthermore, if the line connecting the object to which the image is being transmitted and the projection device includes a vector component in the direction of the light emitted from the projection device, the object is considered to exist in a direction away from the projection device and the image. In this case, the amount of light that reaches the object can be increased by emitting light with a higher proportion of S-polarized light. Conversely, if the line connecting the object to which the image is being transmitted and the projection device does not include a vector component in the direction of the light emitted from the projection device, the object is considered to exist in a direction returning to the projection device as viewed from the image. In this case, the amount of light that reaches the object can be increased by emitting light with a higher proportion of P-polarized light. In this way, the degree of polarization can be adjusted depending on the relative positions of the projection device, the image, and the object to be transmitted.

[0159] In Example 4-1, when displaying an image, if there is an initial polarization control setting, it is possible to select a correction condition that does not adjust the degree of polarization. On unpaved roads, for example, the road surface is very uneven, making it difficult to define the polarization direction of the image light relative to the road surface. Therefore, the degree of polarization is not adjusted, and projection is performed under the initial setting conditions. The initial setting may be a state in which there is more P-polarized light or more S-polarized light. The initial setting may also be a non-polarized state.

[0160] In Example 4-2, for example, a correction condition can be selected that adjusts the polarization degree of the video light displaying the image for the driver and does not adjust the polarization degree of the video light displaying the image for vehicles and people around the vehicle. When the adjustment of Example 4-2 is performed, the polarization degree of the video light displayed for the driver is adjusted to increase the proportion of P-polarized light. When the image for the driver is reflected from the road surface, it is required that the light returns toward the driver's viewpoint. In particular, as the smoothness of the road surface increases, the proportion of specularly reflected light in the reflected light increases. Even on a general road surface, it is known that light is strongly reflected in a direction away from the light source (specular reflection direction). In particular, when the road surface is wet or icy, the smoothness of the road surface increases. In addition, road surfaces with painted road signs and crosswalks also become smoother due to the paint. Therefore, it is desirable to adjust the proportion of P-polarized light in the video light displayed for the driver. In this example, when displaying the image for the driver, the polarization setting is adjusted to polarization setting A, which is preset to have a high proportion of P-polarized light, thereby displaying a brighter, more visible image to the driver. Polarization setting A increases the proportion of P-polarized light in the image light compared to the initial setting. For example, polarization adjustment is performed by rotating the polarization conversion element 7025, which is positioned on the optical axis of the projection device, using an actuator. The polarization conversion element is made of birefringent crystal, and because the refractive index differs on each of the orthogonal axes, a phase difference can be added when light passes through the crystal. Taking advantage of this effect, a half-wave plate is used as the polarization conversion element, and by rotating it by π / 4, the phase of the light after passing through the polarization conversion element can be shifted, converting S-polarized light to P-polarized light and vice versa. Rotating it by any angle also allows the ratio of S-polarized light to P-polarized light to be controlled. Furthermore, even if light with a relatively high S-polarized component is incident on the polarization conversion element rather than linearly polarized light, it can be converted into light with a relatively high P-polarized component. A liquid crystal panel may also be used as the polarization conversion element. In this case, the adjusted polarized light can be output by not installing a polarizer on the output side of the liquid crystal panel. If the polarized light incident on the liquid crystal panel is not unpolarized, a polarizer on the input side is not necessary. By using a liquid crystal panel, it is possible to change the polarization of only a part of the image display area.

[0161] In Example 4-3, for example, a correction condition can be selected that adjusts the polarization degree of video light displaying video for vehicles and people around the host vehicle without adjusting the polarization degree of video light displaying video for the driver. When the adjustment of Example 4-3 is performed, the polarization degree of video light displayed for vehicles and people around the host vehicle is adjusted to increase the proportion of S-polarized light. Video for vehicles and people around the host vehicle is often displayed for objects that exist in the extension direction of the video displayed on the road surface. Therefore, it is desirable to adjust the video light so that the proportion of P-polarized light in the video light is reduced. In this example, when displaying video for vehicles and people around the host vehicle, the polarization setting is adjusted to polarization setting B, which is preset to a lower proportion of P-polarized light, so that brighter, more visible images can be displayed for vehicles and people around the host vehicle. Polarization setting B is set to a lower proportion of P-polarized light in the video light compared to the initial setting.

[0162] In Example 4-4, for example, a correction condition can be selected that adjusts the degree of polarization of video light displaying video for the driver and depolarizes video light displaying video for vehicles and people around the vehicle. When the adjustment of Example 4-4 is performed, the degree of polarization of video light displayed for the driver is adjusted so that the ratio of P-polarized light is higher than in the depolarized state. Vehicles and people around the vehicle may exist in all directions around the vehicle other than the direction of travel of the vehicle, or may exist in multiple directions simultaneously. Therefore, it may be desirable to irradiate the light without intentionally adjusting the polarization. In this example, when displaying video for vehicles and people around the vehicle, a non-polarized setting without polarization adjustment can be used to display highly visible video regardless of the locations of vehicles and people around the vehicle. Furthermore, when displaying video for the driver, the polarization setting is adjusted to polarization setting A, which is preset to a higher ratio of P-polarized light, so that a brighter, more visible video can be displayed to the driver. Polarization setting A has a higher ratio of P-polarized light in the video light than the depolarized setting. Furthermore, the depolarized setting may be adjusted from the initial setting or polarization setting B, or the initial setting may be the depolarized setting.

[0163] In Example 4-5, for example, a correction condition can be selected in which the image light displayed for the driver is unpolarized and the polarization degree of the image light displayed for vehicles and people around the vehicle is adjusted. When the adjustment of Example 4-5 is performed, the polarization degree of the image light displayed for vehicles and people around the vehicle is adjusted to increase the proportion of S-polarized light so that it is higher than the unpolarized state. If the driver wears polarized sunglasses to suppress reflection of external light and the image light from the projection device 11 is polarization-adjusted light, the polarized sunglasses may absorb or reflect light in a specific polarization state, making it difficult for the driver to see the image displayed on the road surface. Therefore, when wearing polarized sunglasses, or when the windshield and the film or interlayer formed on the windshield have the function of reflecting or absorbing specific polarized light, it is desirable to project unpolarized light as the image light. Furthermore, regarding the polarization degree of the image light displayed for vehicles and people around the vehicle, polarization setting B, which has a low proportion of P-polarized light, can display brighter, more visible images. Although not shown in Fig. 18A, in Example 4-5, polarization setting B may be set as the initial setting. In that case, it is desirable that the initial setting has a lower ratio of P polarization than the non-polarization setting.

[0164] In Example 4-6, for example, correction conditions can be selected to adjust the polarization degree of the video light displaying the video for the driver and the polarization degree of the video light displaying the video for vehicles and people around the vehicle. When the adjustment of Example 4-6 is performed, the adjustment is performed so that the ratio of P-polarized light in the video light displaying the video for the driver is higher than the ratio of P-polarized light in the video light displaying the video for vehicles and people around the vehicle. For example, the polarization setting of the projection device 11, which is initially set to the initial setting or non-polarized setting, is adjusted to polarization setting A, in which the polarization degree of the video light displaying the video for the driver is higher, and to polarization setting B, in which the polarization degree of the video light displaying the video for vehicles and people around the vehicle is lower. This allows the video for the driver to be displayed as a brighter, more visible image for the driver, and the video for vehicles and people around the vehicle to be displayed as a brighter, more visible image for the vehicles and people around the vehicle. In this example, by performing polarization adjustment, the polarization degree of the video light displaying images for the driver is adjusted to polarization setting A, which has a high proportion of P polarization, and the polarization degree of the video light displaying images for vehicles and people around the vehicle is adjusted to polarization setting B, which has a low proportion of P polarization, but these may also be set in advance.

[0165] Furthermore, in the process of selecting the display adjustment conditions (S4), one of the conditions shown in FIG. 18B is selected for the projection device 11 used to project the image. Here, projection device A and projection device B in the figure are projection devices 11 that project image light onto the same display area on the road surface, and are configured to project image light with different degrees of polarization. The ratio of P-polarized light in the image light projected by projection device A is set to be higher than the ratio of P-polarized light in the image light projected by projection device B. Either projection device A or projection device B may be set to a non-polarized state. Alternatively, the polarization state of each projection device 11 may be adjusted independently. Furthermore, two or more projection devices 11 may be prepared, and one of the multiple projection devices 11 may be selected according to the polarization state. Note that if there are not multiple projection devices 11 that project image light onto the same display area on the road surface, this selection may be omitted.

[0166] For example, a selection may be made to project an image for the driver and an image for vehicles and people around the host vehicle using the same projection device A (Example 4-7). For example, a selection may be made to project an image for the driver using projection device A, and an image for vehicles and people around the host vehicle using projection device B (Example 4-8). Or, a selection may be made to project an image for the driver and an image for vehicles and people around the host vehicle using the same projection device B (Example 4-9). In this example, taking into consideration the positions of the driver and the vehicles and people around the host vehicle, projection devices 11 set to the same polarization state may be used, or projection devices 11 set to different polarization states may be used.

[0167] Furthermore, in the process of selecting the display adjustment condition (S4), one of the correction conditions shown in Fig. 18C is selected for the geometric correction of the image. Also, the combination of the correction conditions "Category 1" for the image for the driver and "Category 2" for the image for the vehicles and people around the host vehicle may be different.

[0168] For example, a correction condition that does not perform geometric correction can be selected (Example 4-10). Depending on the location of the target onto which the image is projected, the image may be recognizable without performing geometric correction, or geometric correction may have little effect. For example, as described above, the angle between the driver's viewpoint and the projector 11 is very close, so the geometric distortion occurring in the perceived image is small. Also, even when projecting images onto vehicles and people around the vehicle, if information is displayed for multiple targets, performing geometric correction on a specific target may result in excessive geometric distortion occurring for other targets, making it impossible to correctly recognize the information. If this is determined to be the case, geometric correction may not be necessary.

[0169] For example, without geometrically correcting the image for the driver, it is possible to select correction conditions for geometrically correcting the image for vehicles and people around the vehicle so that the image is displayed without or with minimal distortion when the viewing direction is different from the light output direction of the image display device (Example 4-11). In this correction, when there are objects to be viewed in multiple directions around the vehicle, correction is performed to display an image with minimal distortion for the viewpoint position from directly above, which is the normal direction of the road surface of the image. This averages out the geometric distortion when the image is viewed from multiple directions, thereby preventing overcorrection due to geometric correction. This correction is sometimes referred to as directly above image viewpoint correction.

[0170] For example, without performing geometric correction on the image intended for the driver, it is possible to select the geometric correction conditions for the image intended for vehicles and people around the vehicle so that the image is displayed with little or no distortion from the viewpoint of the vehicle and people detected by the sensor (Example 4-12). This correction is sometimes referred to as sensing target viewpoint correction. In this example, the correction direction may be set arbitrarily to match the viewpoint of the detected object. However, the correction is performed so that the geometric distortion correction is suppressed after adjustment compared to before geometric correction. If the line connecting the object transmitting the image and the projection device includes a vector component in the direction of the light emitted from the projection device, the object is considered to exist in a direction away from the projection device and the image. Conversely, if the line connecting the object transmitting the image and the projection device does not include a vector component in the direction of the light emitted from the projection device, the object is considered to exist in a direction returning to the projection device as viewed from the image. Therefore, geometric correction may be adjusted depending on the positional relationship between the projection device, the image, and the transmitting object. As sensors for detecting people, for example, an exterior camera 521, a distance measurement sensor 507, and an infrared sensor 508 are used.

[0171] For example, without geometrically correcting the image for the driver, it is possible to select correction conditions for geometric correction so that the image for people around the vehicle is displayed as a distortion-free image from a viewpoint fixed at a predetermined position in real space (Example 4-13). In this example, the correction direction may be divided into multiple directions in advance around the image center, and any direction may be selected from among them and geometric correction may be performed according to that viewpoint. For example, the 360-degree perimeter of the image may be divided into eight regions (in 45-degree increments), and geometric correction may be set for each region in a direction away from the image center, and the region to which the geometric correction is to be performed may be selected. Alternatively, multiple arbitrary positions around the vehicle may be set in advance, and geometric correction conditions may be set according to the viewpoint from the set fixed position. By setting in this way, when turning right or left at an intersection, for example, correction may be performed from the viewpoint from the center of the vehicle's turning radius, thereby displaying an image with less distortion for objects located closer to the vehicle at the intersection. This correction is sometimes referred to as fixed viewpoint correction.

[0172] For example, a correction condition can be selected in which the image for the driver is geometrically corrected to produce a distortion-free display image, while the image for vehicles and people around the vehicle is not geometrically corrected (Example 4-14). As described above, even if the image projected from the projection device 11 has the same width from the driver's viewpoint, the image is displayed larger on the road surface compared to the road, which is the display area, in the vehicle's distant view. This can cause the image to be displayed outside the road, making it difficult to correctly recognize the image. Therefore, geometric correction can be performed to make the image displayed far from the vehicle smaller than the image displayed near the vehicle. In other words, the magnification of the image displayed far from the vehicle is changed so that it is smaller than the image displayed near the vehicle. In this case, the magnification can be changed in both the horizontal and vertical directions, or just one of them. From the driver's viewpoint, reducing the magnification of the image only in the horizontal direction can prevent the difficulty in viewing due to the high spatial frequency of the image in the vertical direction. In particular, the vertical spatial frequency of an image displayed by a projection device tends to increase the farther away the vehicle is, so when adjusting the image, it is desirable to make the vertical magnification smaller than the horizontal magnification. Note that this correction for images intended for the driver is sometimes referred to as driver's viewpoint correction.

[0173] For example, it is possible to select a correction condition that performs driver viewpoint correction for video for the driver and performs directly above viewpoint correction for video for people around the vehicle (Example 4-15).For example, it is possible to select a correction condition that performs driver viewpoint correction for video for the driver and performs directly above viewpoint correction, sensing target viewpoint correction, or fixed viewpoint correction for video for people around the vehicle (Example 4-15, Example 4-16, Example 4-17).

[0174] Next, a specific example of the display start operation (S5) will be described with reference to Fig. 19. For example, video display starts with one of the following operations S51 to S58.

[0175] Based on the results of S12, S13, and S4, the projection device 11 may display an image (S51). The time until the display starts and the time for which the display continues may use preset values ​​or may be changed depending on the content of the display. The driver or another user may also change the settings.

[0176] Based on the results of S12, S13, and S4, the projection device 11 may display an image. In S52, image display is started at a brightness set for the ambient illuminance. Alternatively, the image display is adjusted so that the image to be displayed has a brightness set for the ambient illuminance. If the brightness of one projection device 11 is insufficient, the necessary brightness may be adjusted by superimposing images from multiple projection devices 11. Furthermore, brightness adjustment may be performed by adjusting the current of the light source, by adjusting the lighting time ratio of the light source, or by adjusting the image display element. Furthermore, when the projection device starts displaying an image, the brightness may be set high and then decreased, or the brightness may be gradually decreased until the display is turned off.

[0177] The projection device 11 may display an image based on the results of S12, S13, and S4. Here, the projection device 11 displays an image so that image display starts at a specified cycle (S53). For example, the lighting cycle is set to between 60 and 120 times per minute, similar to that of a turn signal. Furthermore, if it is determined that there is a danger around the vehicle based on detection information from a sensor or the like, the lighting cycle may be shortened to call attention. The lighting cycle may also be changed depending on the distance to the object detected by the sensor. This makes it possible to make the driver and vehicles and people around the vehicle aware of an approaching danger.

[0178] The projection device 11 may display an image based on the results of S12, S13, and S4. In S54, the image color is corrected to match the color of the display area, and image display is started. Alternatively, the image display of the projection device 11 is adjusted so that the image color is corrected to match the color of the road surface display area. The color of the image displayed on the road surface is determined by both the color of the image light and the color of the road surface. Therefore, even if the color of the image light is the same for asphalt-paved roads, concrete-paved roads, and unpaved roads, the color of the image displayed on the road surface will differ. When the road surface color is close to black, it has a strong tendency to absorb image light, and when the road surface color is close to white, it has a strong tendency to reflect image light. Therefore, when the road surface color is close to black, the image may be corrected to an achromatic color and projected, and when the road surface color is white or gray, the image may be corrected to a chromatic color and projected.

[0179] This allows the effects of light absorption to be mitigated on roads with high light absorption, and enables color-enhanced display on roads with high light reflectivity. If the image permitted for display is achromatic, the number of gradations of the image to be displayed may be reduced on roads with high light absorption, and the number of gradations of the image may be displayed in the state of the image before adjustment or increased on roads with high light reflectivity. Furthermore, if the road surface is a specific color, the spectral reflectivity characteristics of the road surface may cause the specific color to be strongly reflected, making it impossible to display the image in the intended color. In such a case, the image may be adjusted to a state where the luminance of the specific color is reduced, and then projected. This enables image projection that takes into account the spectral reflectivity characteristics of the road surface. In addition, corrections such as increasing the line width or size of letters, symbols, etc. in the image may be performed on road surfaces with low reflectivity.

[0180] Based on the results of S12, S13, and S4, the projection device 11 may display an image. In S55, the image contrast is corrected to match the brightness around the display image, and image display is initiated. Alternatively, the image display of the projection device 11 is adjusted to correct the image contrast to match the brightness around the display area. The brightness around the display image may be the ambient illuminance around the vehicle, or it may be road surface illuminance, which is affected by the ambient illuminance, lighting from the vehicle itself and surrounding vehicles, and the reflectivity of the road surface. If the brightness of the image displayed by the projection device 11 is equivalent to the brightness around the display image, the contrast between the displayed image and the road surface background may be insufficient, and information may not be correctly recognized. For example, contrast correction may be performed by increasing the luminance of the outline of the image. Furthermore, it is known that human visual perception requires a higher frequency for recognition of images with high spatial frequencies than images with low spatial frequencies. Therefore, to lower the spatial frequency of the image, corrections such as increasing the line width of characters, symbols, etc. in the image or enlarging part or all of the image size may be performed.

[0181] The projection device 11 may display an image based on the results of S12, S13, and S4. In S56, the display image is edged in black, and then image display is started. Alternatively, the image display of the projection device 11 is adjusted so that the image is edged in black. For example, if the projection device 11 is integrally incorporated inside the headlight 13, the projection device 11 can project an image edged in black. This emphasizes the image portion, making it easier to recognize the information. Furthermore, if the projection device 11 is not incorporated inside the headlight 13, the headlight 13 may display an image in which the area corresponding to the outer edge of the image displayed by the projection device 11 is shaded.

[0182] Based on the results of S12, S13, and S4, the projection device 11 may display an image. Here, in S57, the brightness level of the display image is inverted, and then the image display is initiated. That is, the image display of the projection device 11 is adjusted so as to invert the brightness level of the display image. In a typical information display, the area displaying the information is small relative to the background area. In such a display in which the information display area is small relative to the background area, the image is small, and therefore the information may not be correctly recognized due to the influence of factors such as the brightness around the displayed image and the reflective characteristics of the road surface. In this example, by inverting the information display area and the background area, i.e., by inverting the brightness level, the image is enlarged, allowing the information to be correctly recognized. Furthermore, the brightness level of the display image may be inverted for the entire display image or for only a portion of the image.

[0183] The projection device 11 may display an image based on the results of S12, S13, and S4. In S58, the brightness of the headlights 13 that illuminate the area overlapping with the display image is partially dimmed, and then image display is started. In this example, only the headlights 13 are described, but lighting other than the headlights provided on the vehicle may also be dimmed in the same manner. For example, if lighting provided on the vehicle, such as the headlights 13, overlaps with the display area of ​​the projection device 11, the contrast of the displayed image can be ensured by dimming the luminance of all lighting on the vehicle other than the projection device 11, or by dimming or blocking the luminance of a portion of the area overlapping with the display area. It is desirable that the contrast between the background and the image displayed by the projection device be 30% or more.

[0184] Next, a specific example of the display termination condition determination (S6) will be described.

[0185] When the projection device 11 is displaying an image and the ambient illuminance is equal to or greater than a specified value according to the illuminance conditions from the illuminance sensor, it is determined that the projection device 11 should end the image display (Example 6-1). Although not shown in the figure in this example, it is also possible to return to the display start operation determination (S5) and determine whether it is possible to reduce the ambient illuminance to a specified value or less by dimming the vehicle's lights as in S58, and consider continuing the display.

[0186] When the projection device 11 detects that the headlights are turned off while the projection device 11 is displaying an image, it determines to end the image display on the projection device 11 (Example 6-2). When the headlights are turned off, it is considered that the ambient illuminance is equal to or greater than a specified value, or that the driver has stopped driving. Therefore, when the headlights are turned off and the ambient illuminance is equal to or less than a specified value, it is possible to end only the image for the driver.

[0187] When the projection device 11 is displaying an image and the vehicle speed is equal to or lower than the display lower limit speed 2, which is slower than the display lower limit speed 1, the projection device 11 determines to end the image display (Example 6-3). In the display start condition determination 2 (S13), it was explained that the illumination start condition is equal to or higher than the display lower limit speed 1. However, there are cases where the illumination speed falls below the display lower limit speed 1 during image display. In such cases, the display lower limit speed 2 may be set as the illumination end speed during image display, and hysteresis may be provided between the speed conditions for illumination start and illumination end. This allows the display to continue up to the display lower limit speed 2 after the display start even if the vehicle speed falls below the display lower limit speed 1. This prevents flicker caused by repeated image display and image end when the vehicle is traveling near the display lower limit speed 1. Although not described in this example, flicker caused by repeated image display and image end can also be prevented by ending the display when the vehicle speed falls below the display lower limit speed 1 and setting a pause period until the next illumination.

[0188] When the projection device 11 is displaying an image and the vehicle speed is equal to or greater than the display upper limit speed 2, which is faster than the display upper limit speed 1, the projection device 11 determines to end the image display (Example 6-4). In the display start condition determination 2 (S13), the lighting start condition is described as being equal to or less than the display upper limit speed 1. However, there are cases where the lighting start condition exceeds the display upper limit speed 1 during image display. In such cases, the display upper limit speed 2 may be set as the lighting end speed during image display, and hysteresis may be provided between the speed conditions for lighting start and lighting end. This allows the display to continue up to the display upper limit speed 2 after the display start even if the vehicle speed exceeds the display upper limit speed 1. This prevents flicker caused by repeated image display and image end when the vehicle is traveling near the display upper limit speed 1. Furthermore, although not shown in this example, flicker caused by repeated image display and image end can also be prevented by ending the display when the display upper limit speed 1 is exceeded and setting a pause period until the next lighting.

[0189] If the projection device 11 detects continuous operation of the wipers while displaying an image, it determines to end the image display on the projection device 11 (Example 6-5). Continuous operation of the wipers indirectly indicates rainy or snowy weather. In such a state, the image displayed on the road surface may not be properly recognized due to rain or snow adhering to the windshield, and changes in road surface conditions may prevent the image from being displayed properly, so the image display is ended. Also, although not shown in this example, even if continuous operation of the wipers is detected while displaying an image, if the operation is intermittent, the image display does not have to be ended.

[0190] When the projection device 11 is displaying an image and detects that the road surface is wetter than a specified level, it is determined that the projection device 11 should end the image display (Example 6-6). When the road surface is wetter than a specified level, the light from the projection device 11 may be totally reflected depending on the angle of incidence to the road surface. Therefore, when the road surface is wetter than a specified level, it is possible to end the image display.

[0191] When the projection device 11 is displaying an image and detects that an in-vehicle image display device is displaying information, the projection device 11 determines to end the image display (Examples 6-7). For example, if an image display device such as a HUD starts displaying an image on the windshield 3 while the projection device 11 is displaying an image, the image from the projection device 11 and the image from the image display device may overlap from the driver's viewpoint. In this case, the respective pieces of information cannot be correctly recognized. Therefore, when the projection device 11 is displaying an image and detects that an in-vehicle image display device is displaying information, it is possible to end either display. In this example, the image display from the projection device 11 is ended. Although not shown in this example, if the image from the projection device 11 and the image from the image display device do not overlap from the driver's viewpoint, the projection device 11 may continue displaying the image. Alternatively, even if the image from the projection device 11 and the image from the image display device overlap from the driver's viewpoint, and the display position of the image from the projection device 11 or the image from the image display device can be changed, the image display from the projection device 11 may be continued.

[0192] The image display position may be adjusted by the driver, or by the projection device without the driver's intervention. Furthermore, when the driver adjusts the display position of the image displayed by the projection device, it is desirable that the adjustment be made when the vehicle is stopped. The vehicle's stop may be determined by a speed sensor or by the on / off status of the parking brake. It may also be determined by the image displayed by the projection device. For example, displays intended for surrounding people or vehicles are often displayed in positions that are not visible from the driver's viewpoint because they are not designed to be visible to the driver. In such cases, there is no problem with simultaneously displaying information by the in-vehicle image display device and information by the projection device, since there is no risk of interference in the driver's field of view.

[0193] Furthermore, if the respective conditions in S12 are not met, it is determined whether to cause the projection device 11 to end the image display (Example 6-8).

[0194] Furthermore, when the projection device 11 that is displaying an image outputs a failure signal and this failure signal is acquired, it is determined that the projection device 11 should end the image display (Example 6-9). Note that while an image is being displayed based on the determination result based on the above (Example 1-4), if the processor cannot confirm that the area of ​​the display element used for image display is operating normally, it is determined that the projection device 11 should end the image display.

[0195] Furthermore, when a signal to turn off the display of the projection device 11 is received, the projection device 11 is controlled to end the image display (Example 6-10). For example, when the projection device 11 is turned off by a user operation, it is determined that the projection device 11 should end the image display. If the driver does not need the image display by the projection device 11 while the vehicle is running, the image display is ended while the image is being displayed. However, if the conditions set on the device side are set to take priority over the user's operation, the image display continues. For example, if there is a risk of collision with a nearby vehicle or person, a collision risk warning display is displayed. While this display is being displayed, the image display continues even if the projection device 11 is turned off by a user operation.

[0196] Furthermore, when the presence of another vehicle is detected in the display area of ​​the road surface, it is determined that the projection device 11 should end the image display (Example 6-11). When another vehicle intrudes into the display area of ​​the road surface, the image of the road surface may not be displayed correctly. The area into which the other vehicle has intruded is compared with the image display position to determine whether the image display overlaps with the other vehicle, and if it is determined that they overlap, the image display is ended. Alternatively, when it is determined that the image display overlaps with the other vehicle, if it is determined that the image display position can be changed, the display position is adjusted and the image display continues, but if it is determined that the image display position cannot be changed, the image display is ended. Note that the driver cannot change the image display position while driving.

[0197] Furthermore, when it is detected that the distance to the surrounding vehicles is equal to or less than a specified value, it is determined that the projection device 11 should terminate the image display (Example 6-12). If the distance between the vehicle and the surrounding vehicles is short, the image of the road surface may not be displayed correctly. Therefore, the distance between the vehicle and the surrounding vehicles is compared with a specified value, and if it is determined that the distance is equal to or less than the specified value, the image display is terminated. At this time, the required distance between the vehicles may be specified for each image displayed by the projection device. For example, since a blind spot exists due to the vehicle body, an image displayed for the driver cannot be seen unless a predetermined distance, for example, 5 meters, is maintained on the road surface in front of the vehicle. Furthermore, an image displayed for the surrounding vehicles does not require driver visibility, so it can be displayed if there is a distance between the vehicles of approximately the size of the image display.

[0198] Next, a specific example of the display termination operation (S7) will be described. For example, the operation of the projection device 11 at the time of display termination is determined based on one of the following (S71 to S74), and control is performed to cause the projection device 11 to terminate the display.

[0199] By stopping the image display on the projection device 11, control is performed to cause the projection device 11 to end the display (S71). In this example, the image display from the projection device 11 is immediately stopped.

[0200] The control unit 10 causes the projection device 11 to execute one cycle of image display, and then stops the image display of the projection device 11, thereby controlling the projection device 11 to end the display (S72). When the projection device 11 displays an image, it may display an image of the road surface that changes over time. For example, this may be the case when the direction of travel is displayed by sequentially displaying multiple images. When such a display is performed, if the display ends midway, there is a possibility that the image information will be misinterpreted. In this way, to prevent the image from stopping midway through the image display from the projection device 11, the image display may be stopped after executing one cycle of image display when a display end signal from the projection device is received.

[0201] The projection device 11 is caused to display an image for a specified time, and then the image display on the projection device 11 is stopped, thereby controlling the projection device 11 to end the display (S73).

[0202] The brightness of the image display is lowered for a specified time, thereby controlling the projection device 11 to end the display (S74). Note that the brightness of the image display may also be controlled to be gradually lowered.

[0203] Based on the above explanation, the following information projection method is provided as an example. This information projection method displays information by adjusting the display of an image on a projection device mounted on a vehicle based on acquired information. This information projection method includes a step (S1 or S11 to S13) of determining the activation conditions of the projection device, the type of information to be displayed on the road surface using the projection device, and the start of display, a step (S4) of determining correction conditions for the image to be displayed, and a step (S5) of controlling the start of image display by the projection device based on the result of the determination and the determined correction conditions.

[0204] Furthermore, based on the above description, the following information projection device is provided as an example. This information projection device is mounted on a vehicle and displays information. This information projection device includes a projection unit capable of generating image light and an adjustment unit capable of adjusting the projected image light. The projection unit includes a display element that receives light from a light source and projects the image light, or a display light-emitting element that emits light and projects the image light. The control unit determines whether to display information based on data or information acquired from the vehicle, and the adjustment unit adjusts the projected image light if information is to be displayed.

[0205] According to this information projection method and information projection device, as an example, by performing appropriate display correction depending on the image intended for the driver and the image intended for people around the vehicle, it is possible to provide road surface displays that are highly visible to the driver or the people around the vehicle.

[0206] Although the embodiments have been described above, the present invention is not limited to the above-described embodiments and includes various modifications and equivalent configurations within the spirit of the appended claims. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, for example, other configurations may be added, deleted, or replaced with part of the configuration of the embodiment.

[0207] For example, the processor may perform processing that takes into account standby time management, such as determining that the signal is ON when the signal continues for a certain period of time and OFF when the signal no longer continues for a certain period of time, and then performing processing accordingly.

[0208] Furthermore, by using the technology according to the above-described embodiment, it is possible to appropriately display necessary information, such as images for the driver and images for people around the vehicle. This makes it possible to provide an information projection device that contributes to safe driving, etc., and thereby to reduce traffic accidents. Furthermore, it is possible to contribute to "Good health and well-being" - goal 3 of the Sustainable Development Goals (SDGs) advocated by the United Nations. [Explanation of symbols]

[0209] 2 vehicles 11 Projection device 13 Headlamp 14 Turn signal 100 Controllers

Claims

1. An information projection method in which a projection device mounted on a vehicle displays information, comprising: a display preparation step of determining whether or not the projection device is capable of displaying based on a startup condition of the projection device; a display adjustment step of determining whether display adjustment is necessary based on a display adjustment condition of the image projected by the projection device, based on a result of the determination of whether display is possible or not of the projection device in the display preparation step; an image display step of performing the display adjustment in the display adjustment step and starting image display by the projection device, 1. An information projection method comprising:

2. 2. The information projection method according to claim 1, determining whether to activate the projection device according to preset information indicating whether the projection device is in use or not; 1. An information projection method comprising:

3. 2. The information projection method according to claim 1, determining whether to activate the projection device in response to information about the failure signal of the projection device; 1. An information projection method comprising:

4. 2. The information projection method according to claim 1, determining whether to start the projection device in accordance with startup switch information of the projection device input by a user; 1. An information projection method comprising:

5. 2. The information projection method according to claim 1, determining whether to start displaying the image on the projection device in accordance with the illumination condition detected by the illumination sensor; 1. An information projection method comprising:

6. 2. The information projection method according to claim 1, When the display adjustment condition adjusts the polarization of the image, the polarization of the image aimed at the driver is adjusted so that the ratio of P polarization is higher than that of the image aimed at the surroundings of the vehicle.

1. An information projection method comprising:

7. 2. The information projection method according to claim 1, When the display adjustment condition is to adjust the polarization of the image, the polarization of the image targeting the surroundings of the vehicle is adjusted so that the ratio of S-polarized light is higher than that of the image targeting the driver.

1. An information projection method comprising:

8. 2. The information projection method according to claim 1, determining correction conditions for the degree of polarization of the image light to be projected by selecting a projection device that will actually project the image light from a plurality of projection devices each capable of projecting image light with a different degree of polarization; 1. An information projection method comprising:

9. 2. The information projection method according to claim 1, determining correction conditions for geometric correction of the image to be displayed; 1. An information projection method comprising:

10. 10. The information projection method according to claim 9, The geometric correction is adjusted so that the image width at a distance from the vehicle is smaller than the image width at a distance from the vehicle.

1. An information projection method comprising:

11. 2. The information projection method according to claim 1, a display termination step of determining whether to terminate the display based on a display termination condition of the projection device; 1. An information projection method comprising:

12. The information projection method according to claim 11, Determine whether to end the display depending on the illuminance conditions from the illuminance sensor.

1. An information projection method comprising:

13. The information projection method according to claim 11, determining whether the display is to end based on the traveling speed of the vehicle; 1. An information projection method comprising:

14. The information projection method according to claim 11, determining whether to end the display based on the distance between the vehicle and surrounding obstacles; 1. An information projection method comprising:

15. An information projection device mounted on a vehicle, a projection unit that displays an image including information; an adjustment unit capable of adjusting the display of the image to be projected; a control unit that controls the projection of the projection unit; Equipped with The control unit determining whether to display the image based on data or information acquired from the vehicle; The adjustment unit When displaying the image, adjusting the display of the image based on a display adjustment condition.

1. An information projection device comprising:

Images