Vehicle

Abstract

The image projection device of the present application is capable of projecting information onto a road surface or the like based on information about a vehicle. The image projection device that projects an image includes an acquisition unit that acquires information to be displayed, and an image projection unit that projects an image based on the information to be displayed acquired by the acquisition unit.

Description

Technical Field

[0001] This invention relates to vehicles. Background Technology

[0002] As devices used to magnify and project desired images, image projection devices, represented by projectors, have been used in a wide range of fields, and in recent years they have been widely used as display devices for personal computers and mobile phones.

[0003] Regarding such image projection devices, especially those used in vehicles, the following technologies are known in the prior art.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 8-43781

[0007] Patent Document 2: Japanese Patent Application Publication No. 2004-136838

[0008] Patent Document 3: Japanese Patent Application Publication No. 2010-26759

[0009] Patent Document 4: Japanese Patent Application Publication No. 2012-247369

[0010] Patent Document 5: Japanese Patent Application Publication No. 2014-153868 Summary of the Invention

[0011] The technical problem that the invention aims to solve

[0012] That is, Patent Document 1 discloses a projection-type display device in which a portable LCD projector without a built-in light source is installed in front of the headlights of a vehicle, which serve as an external light source, thereby using the headlights as an external light source. Patent Document 2, in order to solve its problems, realizes a first state in which the projector is pre-assembled in front of the headlights and inside the vehicle, and a second state in which the projector or the headlight is moved so that the beam of light from the headlights directly illuminates the outside of the vehicle. Furthermore, it also provides an implementation method for displaying images on the road.

[0013] In addition, Patent Document 3 discloses a technology that, as a driving assistance device for a vehicle, effectively alerts the driver of the vehicle when it is determined to have deviated from the driving lane by displaying information to attract attention using an illumination unit (laser) mounted on the headlight portion in front of the vehicle on the road ahead.

[0014] Furthermore, Patent Document 4 discloses a technology in which a projector, serving as a projection unit, is installed at the front of the vehicle. Based on route information retrieved by a navigation system, a route guidance image for guiding towards a fork in the road is projected onto the road surface in front of the vehicle, along with a set projection angle. Additionally, Patent Document 5 discloses a vehicle driving assistance device that projects a depiction pattern consisting of target markers and tracking lines onto the road surface in front of the vehicle based on its driving status, thereby enabling the vehicle's destination to be identified and allowing for appropriate driving.

[0015] However, the aforementioned existing technologies may not all effectively display the various information required for the vehicle's operation.

[0016] Therefore, the present invention was made in view of the problems of the prior art mentioned above, and its object is to provide an image projection device that can project various information onto the road surface, wall surface, vehicle surface, etc. (hereinafter referred to as the road surface, etc.) based on information about the vehicle, such as the driving status of the vehicle (a moving body represented by a car, etc.).

[0017] Technical solutions to the problem

[0018] To solve the above problems, for example, the solutions described in the claimed claims can be used. This application includes various technical solutions to solve the above problems, such as the following: an image projection apparatus for projecting images, comprising an acquisition unit for acquiring information to be displayed, and an image projection unit for projecting images based on the information to be displayed acquired by the acquisition unit.

[0019] Invention Effects

[0020] According to the present invention, an image projection device is provided that can project information onto a road surface or the like for display based on information about a vehicle. Attached Figure Description

[0021] Figure 1 This is a perspective view of a vehicle viewed from the front, which is equipped with an image projection device according to one embodiment of the present invention and projects images onto a road surface or the like.

[0022] Figure 2 This is a perspective view of a vehicle viewed from the rear, which is equipped with an image projection device according to one embodiment of the present invention and projects images onto a road surface or the like.

[0023] Figure 3 This is a diagram showing the overall structure of the light distribution control ECU included in the image projection device.

[0024] Figure 4 This is a block diagram showing a more detailed structural example of the light distribution control ECU and its surrounding elements.

[0025] Figure 5 This is a diagram illustrating an example of the structure of an image projection device according to one embodiment of the present invention.

[0026] Figure 6 It is a ray diagram that includes the image plane of the projector.

[0027] Figure 7 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0028] Figure 8 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0029] Figure 9 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0030] Figure 10 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0031] Figure 11 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0032] Figure 12 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0033] Figure 13 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0034] Figure 14 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0035] Figure 15 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0036] Figure 16 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0037] Figure 17 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0038] Figure 18 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0039] Figure 19 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0040] Figure 20 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0041] Figure 21 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0042] Figure 22 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0043] Figure 23 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0044] Figure 24 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0045] Figure 25 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0046] Figure 26 This diagram illustrates specific examples of various images projected onto the road surface from a projector based on information about the vehicle.

[0047] Figure 27 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0048] Figure 28 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0049] Figure 29 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0050] Figure 30 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0051] Figure 31 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0052] Figure 32 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0053] Figure 33 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0054] Figure 34 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0055] Figure 35 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0056] Figure 36 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information.

[0057] Figure 37 This is a diagram showing more detailed examples of various images projected onto the road surface from the projector based on their relationship with vehicle information. Detailed Implementation

[0058] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0059] <Configuration of Image Projection Device>

[0060] First of all, Figure 1 In (A) and (B) of the figures, a passenger car is shown as an example of a vehicle 10 equipped with an image projection device according to one embodiment of the present invention. As shown in these figures, a pair of left and right headlights 11 are provided at the front of the main body of the passenger car 10.

[0061] exist Figure 1 In example (A), a lamp, which serves as a light-emitting element, is installed inside the pair of headlights 11, although it is not shown in detail here. Additionally, in Figure 1 In example (A), the image projection devices, detailed below, are mounted in pairs on the left and right sides of the vehicle (passenger car) 10. Image light from these image projection devices is projected, for example, through a transparent window onto the front of the vehicle (passenger car) 10. In this example, the image projected onto the road surface is used to display the current or future direction of travel to pedestrians walking near the vehicle (passenger car) 10, thereby enhancing safety.

[0062] Figure 1(B) illustrates an example where only one image projection device is mounted at the front end of the vehicle body. In this case, image light from the image projection device is projected onto the front of the vehicle (passenger car) 10 through a transparent window 12 located at the front end of the vehicle body.

[0063] In addition, such as Figure 1 As shown in (A), an image projection device is also mounted on the bottom and sides of the vehicle (passenger car) 10, thereby enabling the projection of desired images onto the road surface or other surfaces adjacent to the two sides of the vehicle (passenger car) 10.

[0064] then, Figure 2 Figures (A) and (B) show the rear of the aforementioned vehicle (passenger car) 10, which is equipped with an image projection device according to one embodiment of the present invention. As shown in these figures, red taillights 13 and 13' are provided at the rear of the vehicle body. Figure 2 In example (A), a lamp serving as a light source is installed inside the taillights 13 and 13', but this is not illustrated in detail here either. Additionally, in Figure 2 In example (A), the image projection device is mounted in a pair on the left and right, and the image light from the image projection device is projected to the rear of the vehicle (passenger car) 10 through a transparent window, for example.

[0065] in addition, Figure 2 (B) illustrates an example of mounting an image projection device, for instance, near the roof of a vehicle. Figure 2 In example (B), as mentioned above Figure 1 Similarly, in (B), the image light is projected onto the rear of the vehicle 10 through a transparent window located at the rear of the vehicle body.

[0066] In addition, such as Figure 2 As shown in (A), an image projection device is also installed inside the side mirror 14, thereby enabling the projection of desired images onto the road surface or other surfaces adjacent to the two sides of the vehicle 10.

[0067] The above description illustrates an example where one or more (e.g., a pair) image projection devices are mounted on the front, rear, left, and right sides of the vehicle 10. However, the present invention is not limited to this; the image projection device can be mounted at any location on the vehicle 10 (e.g., on the roof). Alternatively, the image projection device can be integrally integrated into the headlight or taillight. In other words, in the present invention, any method that allows the desired image to be projected onto the road surface is acceptable. Furthermore, when the image projection device is integrally integrated into the headlight or taillight, the light source of the headlight or taillight can be used as the projection light source.

[0068] <Structure of the Light Distribution Control ECU>

[0069] then, Figure 3 This figure illustrates one example of the structure of an electronic control unit (light distribution control ECU) installed in the aforementioned vehicle (passenger car) 10. As shown in the figure, the light distribution control ECU 40 includes a CPU (central processing unit) 41, RAM 42 and ROM 43 as storage units, and an input / output unit (I / O unit) 44. Furthermore, information from various information acquisition units or communication units is input to the light distribution control ECU via the I / O unit 44 to control the driving of the headlights 11 and the image projection of the image projection device 500.

[0070] Here, the information obtained from the various information acquisition units mentioned above includes, for example, a speed signal indicating the driving speed of the vehicle 10, a signal indicating the engine status (ON / OFF), gear shift information indicating the gear position, a hazard warning signal informing surrounding drivers of the presence of danger, a steering wheel angle signal indicating the steering wheel angle, a turn signal indicating the presence or absence of a turn signal (or also called a "turn light") or indicating which of the left or right turn lights is illuminated / flashing, and indicator light information indicating the illumination / flashing status of the aforementioned lights.

[0071] In addition, the information from the various information acquisition units mentioned above also includes, for example, information from an external light sensor (illuminance signal, chromaticity signal, etc.) that detects light outside the vehicle, image information from a camera installed on the vehicle, signals from a distance sensor that detects the distance between the vehicle 10 and surrounding objects such as vehicles moving in front of the vehicle, and signals from an infrared sensor that detects the external condition of the vehicle at night.

[0072] In addition, the information from the communications department includes, for example, GPS (Global Positioning System) signals used to calculate the position of the vehicle 10, information from navigation devices that provide route guidance, also known as navigation information, as well as information on vehicle-to-vehicle communication between the vehicle and other vehicles and road-to-vehicle communication between the road and the vehicle.

[0073] Figure 4 This describes a more detailed structure of the aforementioned light distribution control ECU 40 and its surrounding elements. That is, Figure 4In this system, signals from the direction indicator sensor 51, the steering wheel angle sensor 52 (detecting the steering wheel's operating angle), the gear shift position sensor 53, the vehicle speed sensor 54, the accelerator operation sensor 55, the brake operation sensor 56, the illuminance sensor 57, the color sensor 58, the engine start sensor 59, and the hazard warning light sensor 60 are input to the aforementioned light distribution control ECU 40. Additionally, the system includes a door handle sensor 68 for detecting when the driver or passenger is holding the door handle, a door lock sensor 69 for detecting the door's open / closed state (including when the door is not fully closed), a human body sensor 70 for detecting vacancy based on the weight on the seat, and a transmission sensor 71 for detecting the gear shift position. Signals from the camera 61 are input to the ECU 40 via the image processing unit 62, while signals from the GPS signal receiver 63 and the map information output unit 64 are input to the ECU 40 via the calculation unit 65.

[0074] In addition, the control signal from the aforementioned light distribution control ECU40 and the signal from the projection signal output unit 110 (the image signal to be projected onto the road surface, etc.) are input to the projector 100 constituting the aforementioned image projection device 500 through the control unit 120, thereby performing the image projection onto the road surface, etc. as described below.

[0075] Furthermore, the aforementioned light distribution control ECU40 also receives signals from the headlight sensor 66 and the high / low sensor 67.

[0076] <Image projection device>

[0077] Next, regarding the above-mentioned Figure 4 A more detailed example of the structure of the image projection device 500, including the projector 100, projection signal output unit 110, and control unit 120, is shown below. Figure 5 Please provide a detailed explanation.

[0078] The projection optical system 501 is an optical system that projects images onto a road surface, etc., and includes lenses and / or mirrors. The display element 502 is an element that modulates transmitted or reflected light to generate an image, such as using a transmissive liquid crystal panel, a reflective liquid crystal panel, or a DMD (Digital Micromirror Device) panel. The display element driving unit 503 sends a driving signal to the display element 502, causing the display element 502 to generate an image. The light source 505 generates light for image projection, using a high-pressure mercury lamp, xenon lamp, LED light source, laser light source, etc. The power supply 506 supplies power to the light source 505. Furthermore, the power supply 506 also supplies necessary power to other components. The illumination optical system 504 converges and further homogenizes the light generated by the light source 505 before illuminating the display element 502. The cooling unit 515 cools the light source 505, power supply 506, or display element 502, etc., which may become hot, using either air cooling or liquid cooling as needed. The operation input unit 507 is a receiver for operation buttons or remote control signals, and it receives operation signals from the user.

[0079] The image signal input unit 531 connects to an external image output device to input image data. The audio signal input unit 533 connects to an external audio output device to input audio data. The audio output unit 540 can output audio based on the audio data input to the audio signal input unit 533. Additionally, the audio output unit 540 can also output built-in operation tones or error alarm tones. The communication unit 532 connects to, for example, an external information processing device to input and output various control signals.

[0080] Non-volatile memory 508 stores various data used by the projector's functions. The data stored in non-volatile memory 508 also includes pre-prepared image data and video data for projection onto the road. Memory 509 stores the image data to be projected and control parameters for each part of the device. Control unit 510 controls the operation of each connected component.

[0081] The image adjustment unit 560 performs image processing on the image data input through the image signal input unit 531 and the image data or image data stored in the non-volatile memory 508. Examples of this image processing include scaling processing (enlarging, reducing, or distorting the image), brightness adjustment processing (changing the brightness), contrast adjustment processing (changing the contrast curve of the image), and Retinex processing (decomposing the image into light components and changing the weight of each component).

[0082] The storage unit 570 records images, pictures, sounds, and various data. For example, images, pictures, sounds, and various data can be pre-recorded at the time of product shipment, or images, pictures, sounds, and various data obtained from external devices or external servers via the communication unit 532 can be recorded. The images, pictures, and various data recorded in the storage unit 570 can be output as projected images via the display element 502 and the projection optical system 501. The sounds recorded in the storage unit 570 can be output as sounds via the sound output unit 540.

[0083] As explained above, the image projection device 500 can perform various functions. However, the image projection device 500 does not necessarily require all of the above structures. As long as it has the function of projecting images, it can be of any structure.

[0084] Figure 6 This is a light diagram of the projector, including the image plane. In the diagram, the image light emitted from a light source (not shown) such as an LED passes through the image display element, is refracted by filters and various lens systems, and then reflected according to the structure before being projected onto the image plane 8 (road surface, etc.).

[0085] In this way, in the image projection device 500 described above, relative to the projection distance of 700mm, the length of the long side of the projected image range is 10061-542=9519≈9520mm, so the projection ratio is 700 / 9520=0.07, achieving an unprecedentedly large wide-angle projection.

[0086] The foregoing description describes one image projection device 500 and its projection optical system. However, as mentioned above, the present invention can also mount one or more (e.g., a pair) projectors on a vehicle (or integrate them with headlights and taillights) to project desired images onto the road surface, etc. In this case, especially as described above... Figure 1 (A) and Figure 2 As shown in (A), when using multiple (e.g., a pair) image projection devices 500, the same image can be projected from each image projection device 500 onto the road surface, etc. (in this case, in Figure 5 The same image can be displayed on the display element 502, or different images can be projected from the left and right image projection devices 500 and combined on the road surface, etc. (in this case, in Figure 5 The display element 502 displays an image obtained by splitting the desired image horizontally.

[0087] Furthermore, while the image projection device 500 for projecting images onto a road surface or similar surface has been described above using a transmissive liquid crystal image display element, the present invention is not limited to this. Various other image projection devices 500 can also be used, such as a reflective image projection device 500 composed of micromirrors (e.g., a DLP (Digital Light Processing) device), or an image projection device 500 capable of projecting image light from a light-modulated planar light-emitting diode via a projection optical system. In short, the present invention only requires that the image projection device 500 can project a desired image onto a road surface or similar surface.

[0088] <Projected images displaying various information on the road surface, etc.>

[0089] Next, refer to the following Figures 7-26 As will be explained in detail, a specific example is provided where the image projection device 500, as described above, is mounted at the front and / or rear of the vehicle body, and thereby projects various images onto the road surface, etc., according to their relationship with vehicle information.

[0090] By utilizing the image projection devices 500 installed in various parts of the vehicle 10 as described above, it is possible to display not only the state of the vehicle 10, but also the thoughts of the driver of the vehicle 10.

[0091] Figure 7 This refers to an example where, for instance, when the vehicle 10 is stopped at an intersection, a message is displayed to other nearby vehicles. Here, for other oncoming vehicles 10' that have indicated a right turn by illuminating their turn signals, a projection image 203 such as "Please turn right first" is displayed in front of the vehicle 10.

[0092] The display is performed by the image projection device 500 in such a way that the image to be displayed is pre-stored in the storage unit, namely the memory 509, included in the aforementioned light distribution control ECU (see reference). Figure 5 Within the dashboard, for example, the image can be displayed using a switch or similar device located on the dashboard. Additionally, such as... Figure 10 As shown, in order to make it easier for the drivers of other oncoming vehicles 10' to understand the displayed content, it is preferable to display in the opposite direction from the usual situation.

[0093] Additionally, when displaying the above message, to make it easy for people to understand which vehicle is displaying the message, such as... Figure 8 As shown, the display area for the message can be trapezoidal or triangular, or a portion of the projected image 203 can include an arrow 204 indicating the direction of the vehicle displaying the message, or the vehicle's license plate number 205, etc. Alternatively, it can be displayed using animation, although this is not illustrated here.

[0094] Or, such as Figure 9 As shown, in addition to displaying the projected image 203, its content can also be used as sound 250 for composite display.

[0095] Furthermore, such as Figure 10 As shown, the projected image 203 can also be displayed in front of another vehicle 10'.

[0096] In addition, such as Figure 11 As shown, for pedestrians or others intending to cross the road in front of this vehicle 10, the same message can be displayed as described above. Furthermore, in this case, the display of message 203, etc., can be achieved more effectively by using not only image display but also sound prompts via a loudspeaker installed on this vehicle 10, thus delivering the message to the other party more efficiently. Additionally, in this case, information pre-stored in the aforementioned memory 509 (see reference 509) can be utilized. Figure 5 The sound signal inside the vehicle can be transmitted, or the driver's voice 250 can be transmitted through a microphone set on the dashboard, etc.

[0097] In addition, regarding the display of the above message, such as Figure 12 As shown, especially when the vehicle 10 is a taxi, it is also possible to display the advertising content as message 206 on the road surface adjacent to the rear door. Alternatively, for public service vehicles such as buses and trains, it is possible to display the advertising content message 206 at their entrances and exits, although no illustration is provided here.

[0098] Furthermore, regarding the display of message 206 concerning the aforementioned advertising content, for example... Figure 13 As shown in (A), when from Figure 4 When the vehicle speed sensor 54 receives a stop signal, the ECU 40 selects multiple advertisements stored in the RAM 42 and displays them via the image projection device 500. At this time, a different advertisement or a predetermined number of advertisements can be displayed each time the vehicle stops, or multiple advertisements can be displayed sequentially for a predetermined period of time.

[0099] Or, it can be like Figure 13 As shown in (B), by further configuring the router 1000, the ECU 40 obtains advertising information from outside the vehicle 10 via WiFi and displays the obtained advertising content.

[0100] Additionally, especially when displaying ads as message 206, it can also be like... Figure 14 As shown, for example, using Figure 13The structure shown in (B) receives advertisements from advertisers such as shopping malls near the vehicle 10 via WiFi and displays their content as messages 206 on the road surface, etc.

[0101] In addition, such as Figure 15 As shown, it can also replace the aforementioned advertisements, etc., and utilize information from... Figure 3 The navigation information from the communication department displays information that the driver of vehicle 10 wants to know (so-called navigation information), such as "15km from the destination," as message 206 on the sidewalk, roadside strip, road surface, etc. By displaying it on the sidewalk, roadside strip, and road surface, it is possible to prevent drivers of vehicles other than vehicle 10 from being misled.

[0102] In addition, regarding the information that the driver wants to know, such as Figure 16 As shown, the message 206 to be displayed can also simultaneously display so-called navigation information (the direction of travel of the vehicle 10, the distance to the destination), vehicle information or alarms such as the driving speed and remaining fuel of the vehicle 10, as well as information about the portable terminal such as the smartphone held by the driver, such as the receipt of emails.

[0103] In addition, such as Figure 17 As shown, for example, a warning message such as "Attention! This vehicle is malfunctioning" can also be displayed as message 206. Furthermore, at this time, as... Figure 23 As shown, since this information is a reminder to the driver of another vehicle 10' traveling in the opposite direction, the message 206 is preferably displayed in front of the other vehicle 10' in the opposite lane. For this purpose, a wide-angle display of the image projection device 500 or changing the direction of the image projection device 500 can be considered.

[0104] In addition, the following content can also be considered as the content projected and displayed using the aforementioned image projection device 500.

[0105] Drivers make various measurements visually while driving; as one example, a display is used to assist in these measurements. Figure 18 This example illustrates a ruler displayed as a projected image 207 in front of the vehicle 10. In this example, based on the ruler 207 displayed in front of the vehicle 10, the driver of the vehicle 10 can easily measure the distance (inter-vehicle distance) between the vehicle 10 and another vehicle 10' traveling in front of it, thus contributing to safe driving.

[0106] in addition, Figure 19 This refers to a display image 207' that allows for easy measurement of the height of structures (bridge-like objects S) with height restrictions, such as bridges or tunnels. Figure 19It shows the state of the host vehicle 10 traveling toward the object S as observed from the rear.

[0107] In this height measurement display, from the image projection devices 500 provided on the headlights on both sides (left and right) in the front of the host vehicle 10 (refer to (A) of Figure 1 ), bar-shaped images 207' in a roughly "卜" shape formed by a combination of vertical bars and horizontal bars are respectively projected upward onto the road surface in the traveling direction. And this pair of bar-shaped images 207' are pre-set such that at a distance farther than the set specified distance (distance > d), the backs of the vertical bars are separated from each other, and its horizontal bar is set to be at a specified height (for example, the height at which the host vehicle 10 can safely pass) at this specified distance (d).

[0108] As a result, when the host vehicle 10 is at a distance farther than the set specified distance (distance > d), as shown in (A) of Figure 19 , the above pair of bar-shaped images 207' are displayed separately from each other. After that, when the host vehicle 10 coincides with the set specified distance (distance = d), as shown in (B) of Figure 19 , the pair of "卜" shaped bar-shaped images 207' are closely together, forming a cross shape. And at this time, the horizontal bar of the "卜" shaped bar-shaped image 207' represents the height at which the host vehicle 10 can safely pass. By confirming the position of the horizontal bar of the bar-shaped image 207' that has become a cross shape, the driver can know whether the host vehicle can pass safely. In addition, after that, as shown in (C) of Figure 19 , the pair of "卜" shaped bar-shaped images 207' are displayed overlapping each other.

[0109] In addition, it is also possible to consider such a situation. For example, the road surface on which the host vehicle 10 displays various information as images is an Figure 20 unpaved road surface with unevenness as shown. In this case, as shown in Figure 20 , a road surface sensor 15 such as a camera (for example, an infrared stereo camera, etc.) is installed in front of the host vehicle 10 (in the traveling direction). Based on the image plane captured by this camera, the state (shape, reflectivity, etc.) of the road surface, etc. is obtained, and based on the result, the image to be projected onto the road surface, etc. is corrected. Thus, an image that is easy to observe and has excellent recognition performance, which has been corrected based on the shape and reflectivity of the road surface, etc., can be displayed.

[0110] In addition, by using the above-mentioned camera and other road surface sensors 15, the above ECU 40 can also judge whether to display the image according to the process shown in Figure 21 . Among them, in Figure 21In the example, the image projection device 500 is activated (step 210), the left and right driving lines of the vehicle 10 are read from the image from the camera and the width of the driving lines is measured, the road width is detected (step 211), and it is determined whether there is enough road width for displaying the image (step 212). If it is determined in step 212 that the road width is sufficient to display the image, the image is displayed (step 213). If it is determined in step 212 that the road width is insufficient to display the image, the image is not displayed (step 214).

[0111] Alternatively, by utilizing the aforementioned road surface sensors 15, such as cameras, etc. Figure 22 As shown, in narrow alleys, the distance between the vehicle and the projected image 206 is set to be relatively small (reference). Figure 22 (A)), and on wide roads, the distance between the vehicle and the projected image 206 is set relatively large (refer to...). Figure 22 (B)). This allows for the display of images with excellent recognizability. Additionally, the halftone dots in the figure represent the projection area of ​​the image projection device 500.

[0112] In addition, such as Figure 23 As shown, the aforementioned camera can also be installed at the rear of the vehicle 10, projecting images of other vehicles 10' obtained by the camera onto the front of the vehicle 10 for display. Thus, when the vehicle 10 is stationary, the driver can easily check the situation behind without turning around, which is very convenient.

[0113] In addition, such as Figure 24 As shown, based on images of other vehicles 10' obtained from a camera installed behind the vehicle 10, the ECU 40 can also display warnings to the following vehicle based on the distance between the two vehicles, their speed, and a threshold. That is, if the distance between the two vehicles is determined to be too close based on their speed, a red arrow (see reference) may be displayed behind the vehicle 10. Figure 24 (A) indicates a situation where the distance is not excessively close, but should be kept at a distance that warrants attention, for example, by displaying a yellow arrow (see reference). Figure 24 (B)). If the workshop distance is deemed sufficient, no display is made (see reference). Figure 24 (C)).

[0114] The examples described above illustrate situations where image light from the image projection device 500 is projected onto the road surface or other surfaces surrounding the vehicle 10. However, the present invention is not limited to this; for example, within the projection area of ​​the image projection device 500, a portion of the objects may also be highlighted.

[0115] As an example, such as Figure 25As shown, based on image signals from road surface sensors such as a camera mounted in front of the vehicle 10, the ECU 40 detects obstacles (trees in this example) in the direction of travel (reference). Figure 25 (A) and (B)). Specifically, when projecting image light using the image projection device 500, a portion of the obstacle (in this example, the trunk of a tree) is highlighted, for example by flashing, to selectively display the obstacle and alert the driver (see reference). Figure 25 (C)). Among them, in Figure 25 In (B), the longitudinal display range of the image light 206 projected from the image projection device 500 near the trees is represented by lighter dots, while... Figure 25 In (C), the area where the flashing is ON is represented by darker dots. Furthermore, if the ECU40 does not determine that it is an obstacle, the flashing is turned OFF (see reference). Figure 25 (D)).

[0116] In addition, such as Figure 26 As shown, for pedestrians and oncoming vehicles 10' detected by infrared illumination, the vehicle 10 can precisely position and emphasize the corresponding portion of the image light 206 by changing its displayed color (e.g., red). Furthermore, as a method of emphasis, the brightness of the image light projected onto the obstacle and / or its surroundings can be modulated or made to flash. Animation can also be used. Moreover, the object for emphasizing obstacles (e.g., trees) does not change its display position even when the vehicle 10 moves. In addition, it is not limited to obstacles; similar displays can also be made for hazardous objects such as manhole covers or wheel chocks.

[0117] Here, in the above description, the image projection device 500 (reference) Figure 5 The display of the various information described above is performed as needed. In particular, information displayed in front of and behind this vehicle 10 cannot be effectively displayed if the vehicle is not sufficiently far from other vehicles in front or behind. Therefore, although not illustrated here, the aforementioned camera or sensor can be used to detect the vehicle's distance, and the projected image will only be displayed when a sufficient distance is ensured. If the distance is closer than the specified distance, the display will stop.

[0118] In addition, with the above Figure 20 Relatedly, the following describes the details of the techniques used to correct the shape and reflectivity of road surfaces, etc., in order to display easily observable and highly recognizable images.

[0119] First, regarding the deviation (undulation) in the road surface shape, for example... Figure 27As shown in (A) and (B), an image 201 with a grid pattern inserted into the projected image 200 is projected onto the road surface by an image projection device installed in front of the vehicle 10. On the other hand, an image in front of the vehicle is acquired by a camera 61 installed on the vehicle 10, and the aforementioned ECU 40 performs prescribed image processing on the image to detect road surface deviation. The projected image is then corrected according to the detected road surface deviation, so that regardless of the road surface deviation, an easily observable and highly recognizable image without deviation can be obtained. However, this processing requires a predetermined amount of time and is difficult to perform in real time.

[0120] Therefore, such as Figure 28 As shown in the flowchart, the skew correction process described above is switched ON and OFF appropriately according to the vehicle's speed. Furthermore, the type of projected image is also considered as a switching condition. This is because, for example, if the displayed information is text, the driver's attention might be drawn to understanding the text, which is not ideal for safe driving.

[0121] Specifically, as shown in the figure, when a road projection ON signal is received (S2801), it is determined whether the vehicle is currently stopped (S2802). If the result is "yes" (the vehicle is stopped), the aforementioned skew correction process is performed (details described later). On the other hand, if the vehicle is not stopped ("no"), it is further determined whether the vehicle's speed is less than a set speed (S2803). If the result is "yes" (the vehicle is less than a set speed), the aforementioned skew correction process is performed. If the speed is greater than a set speed ("no"), it is determined whether the projected image is text (or whether it contains text) (S2804). If the result is "yes" (the projected image is text), the aforementioned road projection ON signal is switched to OFF (S2805). If the projected image is not text ("no"), the aforementioned road projection ON signal is not switched (S2806).

[0122] Furthermore, if the result of the above judgment (S2802) is that the vehicle is parked (“Yes”) or if the result of the above judgment (S2802) is that the driving speed is less than the set speed (“Yes”), in the skew correction process, firstly, a skew detection image is projected, namely, the image 201 with a grid pattern inserted into the projected image 200 (S2807). Then, an image is captured using the camera, and the grid pattern inserted into the projected image 200 is compared with the grid pattern in the image captured by the camera (S2808). Then, by judgment (S2809), if it is determined that the skew of the grid pattern in the image captured by the camera is greater than a predetermined value (threshold) (“Yes”) (i.e., the skew is too large to be corrected), the road projection ON signal is switched to OFF (S2810), that is, the road projection is stopped. If the deviation is determined to be less than the specified value (threshold) ("No"), the road projection image is corrected (S2811), the switching of the road projection ON signal is not performed (S2812), and road projection is performed. Furthermore, the above-described processing is, for example, by the aforementioned... Figure 4 The CPU (central processing unit) 41 of the light distribution control ECU40 shown can be used for implementation.

[0123] As can be clearly seen from the above description, in the above embodiments, image projection is basically only performed at speeds that ensure safe driving, including when the vehicle is parked, and especially when the projected image contains text, image display is suppressed. Furthermore, if the deviation on the road surface to which the image is to be projected is too large (deviation amount > threshold), image projection onto the road surface is stopped. This is because if the deviation is large, the image deviation of the corrected image will also be large for observers at different viewpoints, therefore, image display is intentionally stopped.

[0124] Furthermore, due to the influence of road surface color or pedestrian crossing patterns, the brightness or color of the projected image may deviate from the intended effect. In such cases, the driver's intention in projecting the image onto the road may not be accurately conveyed to the surroundings. Therefore, in the embodiments detailed later, by detecting the uneven distribution of color and illuminance (so-called non-uniformity) of the projected image on the road surface, brightness correction and color balance correction are performed at various locations on the road surface to obtain an easily observable and highly recognizable image, thereby enabling the image intended (desired) by the driver to be projected onto the road surface.

[0125] Regarding the aforementioned deviation (unevenness) in road surface shape, specifically, in addition to the above... Figure 27 The image shown for skew detection is an image 201 (reference) projected onto the road surface from an image projection device mounted in front of the vehicle 10, with a grid pattern inserted. Figure 29In addition to (A), a completely white image (an image containing light of R, G, and B colors) can also be projected onto the road surface, although no illustration is given here. This completely white image can also be intermittently projected onto the road surface together with the aforementioned image 201 with inserted grid patterns, for brightness correction as described later.

[0126] Therefore, it is possible to obtain the above-mentioned camera 61 (refer to the above). Figure 27 In the captured image, the distribution of brightness is detected based on the uneven illumination on the road surface, and the illuminance balance of each color is detected based on the uneven color. Based on these detection results, brightness correction and color balance correction are performed at various locations on the road surface to project the image, thereby enabling the display of the image intended by the driver on the road surface. Furthermore, the above description describes the case of intermittently displaying a completely white image along with the image 201 with inserted grid patterns. However, the present invention is not limited to this. For example, even if R, G, and B color light are inserted sequentially or intermittently, the same effect can be obtained, which goes without saying for those skilled in the art.

[0127] Furthermore, when the aforementioned image projection device displays an image by tilting the road surface, which serves as the projection surface, i.e., by oblique projection, the size of the projected image will change significantly due to the relationship between the image projection device and the road surface, i.e., the relative angle (tilt angle) between them. Therefore, the image projection device and the road surface are preferably parallel to each other.

[0128] For example, when vehicle 10 is parallel to the road surface, such as Figure 29 As shown in (A), the grid pattern inserted into the projected image is displayed without skew (its original shape). And as... Figure 29 As shown in (B), when the vehicle 10 is tilted relative to the road surface, especially to the left in relation to the direction of travel, the image projected from the image projection device onto the road surface is distorted and skewed, deviating from its original shape. When tilted to the right, as... Figure 29 As shown in (C), the image also becomes skewed. Furthermore, while the image inserted into the projected image is described here as a grid pattern, it goes without saying that road surface skew can be detected equally using rectangular images or simply rectangular frames.

[0129] In addition, such as Figure 30 As mentioned above, the vehicle 10 is typically required to be set parallel to the road surface in the direction of travel (see reference). Figure 30 (A)). However, it is also possible to take into account, for example, tilting forward (see reference). Figure 30 (B) or tilted backward (see reference) Figure 30In the case of (C), when the vehicle body is tilted forward or backward, the image projected from the image projection device onto the road surface will shrink at the rear or expand at the front relative to its original shape (rectangle), that is, it will also be skewed due to deformation.

[0130] Therefore, for example, during the period before the image is displayed when the vehicle starts, the aforementioned rectangular or grid-shaped image pattern is inserted, and the aforementioned camera 61 (refer to the above) is used. Figure 27 The system captures images projected onto the road surface and performs prescribed image processing to detect the tilt (both in the direction of travel and lateral) of the image projection device relative to the road surface. Based on this detected tilt (both in the direction of travel and lateral), the tilt of the image projection device relative to the road surface is corrected, resulting in a skew-free, easily observable, and highly recognizable image. This detected tilt (both in the direction of travel and lateral) can also be used, similar to the automatic leveling function of the headlights, in vehicle attitude control performed by actuators installed within the vehicle.

[0131] In addition, the above Figure 21 This describes a process that uses road surface sensors such as cameras to determine whether an image executed by the ECU 40 should be displayed or not. An example described is determining whether the road width is sufficient for image display; if so, the image is displayed; otherwise, it is not displayed. However, the invention is not limited to this, and the display described below can also be performed.

[0132] More specifically, before projecting the desired image onto the road, for example... Figure 31 As shown in (A), when the road width is sufficiently wide, an image 201 with an inserted grid pattern is projected, and a camera compares the projected image with the real image to detect the presence of walls or obstacles on the left, right, or front of the road. However, in reality, for the size of the image to be projected, in cases such as... Figure 31 As shown in (B), when the displayed image overlaps with detected obstacles such as walls, it may be considered to disable the image display, or as... Figure 31 (C) shows that the projected image is reduced in size.

[0133] also, Figure 32 This illustrates a situation where an oncoming vehicle 10' (obstacle) is encountered in a narrow alley or similar location. Here, as indicated by the arrows in the diagram, the area of ​​the image projected from the image projection device (the thick line in the reference diagram) is limited to the area that can be displayed on the road (the dashed line in the reference diagram), or the display is reduced in size.

[0134] Figure 33 Here is one example of the processing flow under the above circumstances. First, when the road projection ON signal is received (S3301), the so-called road width / obstacle detection image, which is a grid pattern, is inserted into the projection image and projected onto the road surface from the image projection device (S3302). Then, the image projected onto the road surface is captured by the camera, and it is determined whether the width of the projected image is greater than the width of the road (S3303). If the result is that the width of the projected image is greater than the width of the road ("yes"), the road projection of the image is stopped (OFF) (S3304).

[0135] On the other hand, if it is determined that the width of the projected image is less than the width of the road ("No"), the image captured by the aforementioned camera is used to determine whether there is an obstacle on the road surface (S3305). If the result is that there is no obstacle on the road surface ("No"), road surface projection of the image is performed (ON) (S3306). If there is an obstacle ("Yes"), it is further determined whether the image can be displayed without avoiding the obstacle (S3307). If the image can be displayed without avoiding the obstacle ("Yes"), the projection position on the road surface is corrected (S3308), and then road surface projection is performed (ON) (S3309). In addition, the above-described process is performed by the aforementioned... Figure 4 The CPU (central processing unit) 41 of the light distribution control ECU40 shown can be used for implementation.

[0136] In addition, the above Figure 24 The text describes a technology that displays warnings to following vehicles based on the inter-vehicle distance, speed, and threshold values. The details are further described below.

[0137] Generally, a safe following distance, to allow for stopping after detecting a hazard, is considered to be the value obtained by subtracting 15 meters from the vehicle's speed at speeds below 60 km / h. Therefore, the vehicle's speed is calculated based on a speed pulse, and the distance to the vehicle behind is calculated using a camera mounted at the rear of the vehicle. If the following distance is insufficient, a red arrow is displayed as a warning to the vehicle behind. Furthermore, if the following distance is only about 10% more than the necessary distance, a yellow arrow is used to alert the driver. Alternatively, LiDAR can be used to detect the following distance instead of the aforementioned camera.

[0138] Furthermore, the stopping distance of a vehicle varies depending on the road surface condition. Generally, a stopping distance of 1.5 times the normal distance is required when it is raining, while a stopping distance of 3 times the normal distance is required when the road surface is icy. Therefore, the setting of the necessary stopping distance calculated based on the driving speed is preferably adjusted according to the surrounding environment. For example, rain detection can usually be performed using an infrared sensor, specifically by detecting changes in reflection caused by raindrops adhering to the window glass. Icing can be detected based on the specular reflection intensity of the road surface. That is, on a normal road surface, diffuse reflection is strong due to surface unevenness, but when icy, specular reflection is enhanced due to the formation of an ice film. As a result, for example, the specular reflection of headlights illuminating oncoming vehicles is enhanced, so the icing condition can be detected by detecting the amount of reflected light from the road surface. Additionally, this safety / caution stopping distance data is pre-stored as a table in memory.

[0139] The above explanation describes how effective display is impossible, especially when the vehicle is not sufficiently far from other vehicles behind it. Therefore, the vehicle distance is checked, and the projected image is only displayed when a sufficient distance is ensured. If the distance is closer than the specified distance, the display stops. However, this is not the only possibility. Figure 34 As shown, effective display is impossible when there is insufficient vehicle-to-vehicle distance between the vehicle 10 and the vehicle 10' in front. Additionally, Figure 34 (A) indicates that the workshop distance is sufficient. Figure 34 (B) indicates a situation where the workshop distance is insufficient. Figure 34 (C) indicates a situation where the workshop distance is almost negligible.

[0140] Here, in Figure 35 The diagram illustrates one example of a procedure for issuing a warning to the vehicle behind, as described above. In the diagram, the following steps are taken: First, the distance between the vehicle and the vehicle behind is detected (S3501). Next, the vehicle's speed is detected (S3502). Then, the presence or absence of rain is detected using the aforementioned rain sensor (S3503). Furthermore, icing on the road surface is detected using a road icing sensor based on the aforementioned principle (S3504). Afterward, based on the detection results, the necessary safe / cautionary distance is searched from the aforementioned table and set accordingly (S3505).

[0141] Then, it is determined whether the detected vehicle distance is less than the safe vehicle distance set above (S3506). If the result is determined to be greater than the safe vehicle distance ("No"), it is further determined whether it is less than the caution vehicle distance (S3507). On the other hand, if the determination (S3506) is that it is less than the safe vehicle distance ("Yes"), the aforementioned warning image for following vehicles is projected onto the road surface (S3510).

[0142] If, in the aforementioned judgment (S3506), it is determined that the following distance is greater than the safe vehicle distance ("No"), but in the judgment (S3507), it is determined that the following distance is less than the caution vehicle distance ("Yes"), then instead of the aforementioned warning image, a caution image for the following vehicle is projected onto the road surface (S3508). Furthermore, if, in the aforementioned judgment (S3506), it is determined that the following distance is greater than the safe vehicle distance ("No"), and in the judgment (S3507), it is also determined that the following distance is greater than the caution vehicle distance ("No"), then the display of the aforementioned safety / reminder information for the following vehicle is stopped (OFF) (S3509). Additionally, the above-described processing is performed by the aforementioned... Figure 4 The CPU (central processing unit) 41 of the light distribution control ECU40 shown can be used for implementation.

[0143] In order to project images in addition to the aforementioned warnings to vehicles behind, sufficient space of at least one vehicle length is required for adequate display, depending on the image to be displayed. Therefore, it is preferable not to display images when the vehicle's clearance from the vehicles in front and behind is narrow for the required image size. For example, if a 4-meter-wide image is displayed on the road 10 meters ahead, from the perspective of a person 170cm tall, the image appears as a 600mm square image 10 meters ahead. In this case, if the naked eye's visual acuity is 0.1 or higher, a size of 30mm or more can be discerned at 10 meters ahead. Therefore, it is possible to achieve a display resolution of 16×16 or higher required for text display.

[0144] Figure 36 This illustrates one example of a processing flow for projecting images onto a road surface based on the aforementioned viewpoint. In the figure, firstly, when a road surface projection ON signal is received (S3601), it is determined whether the image to be projected is to be displayed in front of the vehicle (S3602).

[0145] If the above determination indicates that the image to be displayed is an image to be displayed in front of the vehicle ("Yes"), then the vehicle-to-vehicle distance between the vehicle in front and the vehicle is detected (S3603). Next, it is determined whether the size of the image to be projected in front of the vehicle is greater than the vehicle-to-vehicle distance detected above (S3604). If the result is that the image size is greater than the vehicle-to-vehicle distance ("Yes"), road surface projection of the image is stopped (OFF) (S3605). If it is less than the vehicle-to-vehicle distance ("No"), road surface projection of the image is executed (ON) (S3606).

[0146] On the other hand, if the result of the above determination (S3602) is that the image to be displayed is an image displayed behind the vehicle ("No"), the vehicle-to-vehicle distance between the following vehicle and the vehicle is detected (S3607). Then, it is determined whether the size of the image to be projected behind the vehicle is greater than the vehicle-to-vehicle distance detected above (S3608). If the result is that the size of the image is greater than the vehicle-to-vehicle distance ("Yes"), the road projection of the image is stopped (OFF) (S3609), and if it is less than the vehicle-to-vehicle distance ("No"), the road projection of the image is executed (ON) (S3510).

[0147] Furthermore, in the above embodiments, images inserted into the projected image, such as those for detecting road surface deviation or for detecting obstacles, were described as grid patterns, rectangular images, or simple rectangular frames. In this case, it is preferable to use light in the spectral intensity band centered at a wavelength of 1.4 μm from the light spectral intensity referred to as "AM1.5". This is because some wavelength components of sunlight outside the atmosphere are absorbed by atmospheric components and cannot reach the ground. In the spectral intensity referred to as "AM1.5", some spectral components are reduced or removed, especially the intensity of light in the near-infrared region centered at a wavelength of 1.4 μm, which is approximately zero (0). That is, on the ground where the vehicle is traveling, sunlight does not contain the aforementioned AM1.5 light. In other words, by using this light, road surface condition information can be obtained stably and unaffected by sunlight.

[0148] In addition, regarding the brightness correction of the projected image described above, please refer to the following: Figure 37 A detailed explanation will follow. Furthermore, similarly to the above, the processing of the flowchart in this diagram is as described above. Figure 4 The CPU (central processing unit) 41 of the light distribution control ECU40 shown can be used for implementation.

[0149] First, upon receiving the road surface projection ON signal (S3701), a road surface illuminance detection image is projected onto the road surface (S3702). This road surface illuminance detection image is the aforementioned all-white display image (an image containing light of R, G, and B colors). Then, during this all-white display, the unevenness (so-called deviation) of the road surface illuminance is detected based on the image captured by the camera (S3703). Next, the detected illuminance deviation (or its respective value) is compared with a predetermined threshold (S3704).

[0150] If the result of the above comparison is that the illuminance deviation is greater than the threshold ("Yes"), then it is further determined whether the illuminance deviation is greater than the limit value (S3705). The limit value is the maximum value of the range that can be corrected using the light source of the image projection device. If the result is determined to be greater than the limit value ("Yes"), then the road surface projection of the image is stopped (OFF) (S3706).

[0151] If the value is determined to be less than the limit ("No"), the illuminance correction of the image to be projected onto the road surface is performed (S3707). Then, similar to the case where the illuminance deviation is less than the threshold in the comparison (S3704) above, the road surface projection of the image is performed (ON) (S3708).

[0152] According to the above embodiments, an image that is easy to observe and has excellent recognizability can be obtained, thereby reliably and clearly illuminating the image intended by the driver on the road surface. In addition, as the image for detecting road surface illumination, instead of the above-mentioned all-white displayed image, the brightness of the above-mentioned projected image is corrected using a pure color pattern of red (R), green (G), and blue (B) (for example, performed sequentially), thereby enabling the detection of deviations in each color and thus enabling color difference correction.

[0153] Furthermore, the present invention is not limited to the embodiments described above, but also includes various modifications. For example, the embodiments described above have been detailed to illustrate the overall system for ease of understanding, but are not limited to all the structures described. Additionally, a portion of the structure of one embodiment can be replaced with the structure of another embodiment, and structures of other embodiments can be added to the structure of one embodiment. Furthermore, it is possible to add, delete, or replace other structures with portions of the structures of each embodiment.

[0154] Explanation of reference numerals in the attached figures

[0155] 10…This vehicle (passenger car), 10'…Other vehicles, 11…Headlights, 12…Window, 13, 13'…Taillights, 14…Side mirrors, 40…Light distribution control ECU, 51…Directional indicator sensor, 52…Steering wheel angle sensor, 53…Shift position sensor, 54…Vehicle speed sensor, 55…Accelerator operation sensor, 56…Brake operation sensor, 57…Illuminance sensor, 58…Color sensor, 59…Engine start sensor, 60…Hazard warning light sensor, 61…Camera, 62…Image processing unit, 63…GPS signal Receiver, 64…Map information output unit, 66…Headlight sensor, 67…High / low sensor, 68…Door handle sensor, 69…Door lock sensor, 70…Human body sensor, 71…Transmission sensor, 100…Projector, 110…Projection signal output unit, 120…Control unit, 500…Image projection device, 501…Projection optical system, 502…Display element, 503…Display element driver, 504…Illumination optical system, 505…Light source, 531…Image signal input unit, 533…Audio signal input unit, 532…Communication unit.

Claims

1. A vehicle characterized by comprising: include: A storage device for storing images; and The image stored in the memory is projected onto a projection unit on the road outside the vehicle. The projection unit projects an arrow identifying the vehicle and a vehicle identification number, along with the image, to be displayed according to an operational input. The display direction of the image and the vehicle identification number is for use by drivers of oncoming vehicles. Furthermore, the projected image projected by the projection unit is detected using a camera mounted on the vehicle. Based on the width of the road and obstacles on the road, the projection of the image is controlled using the projected image detected by the camera. If the width of the projected image is greater than the width of the road, the image is not projected. If it is determined that the width of the projected image is smaller than the width of the road, the projected image detected by the camera is used to determine whether there is an obstacle on the road. If there is no obstacle on the road, the image is projected. If there is an obstacle on the road, it is determined whether the image can be projected without avoiding the obstacle. If the image can be projected without avoiding the obstacle, the projection position on the road is corrected and the image is projected.

2. The vehicle as described in claim 1, characterized in that: The image projected by the projection unit is an image representing a message sent from the driver of the vehicle equipped with the projection display device to the driver of the oncoming vehicle.

3. The vehicle as described in claim 1, characterized in that: The image projected by the projection unit is an image that alerts the driver of the oncoming vehicle.

4. The vehicle as described in claim 1, characterized in that: The projection unit projects the image onto the front of the vehicle equipped with the projection display device.

5. The vehicle as described in claim 1, characterized in that: The projection unit projects the image onto the side of the oncoming lane diagonally in front of the vehicle, where the projection display device is mounted.

6. The vehicle as described in claim 1, characterized in that: The number used to identify the vehicle is the vehicle's license plate number.

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