Image Display System

Abstract

To provide an image display system for a road surface, which when another vehicle traveling behind an object vehicle overtakes the object vehicle, enables improvement of the safety of the other vehicle.SOLUTION: An image display system 10 comprises: a projector 12 which is mounted on an object vehicle 30 and projects an image onto a road surface in the periphery of the object vehicle 30; and an image controller 20 which when another vehicle 40 traveling behind the object vehicle 30 starts the operation of overtaking the object vehicle 30, causes the projector 12 to project a support image 62 including at least one of an image showing an entrance impossible range in which entrance of the other vehicle 40 is inhibited and an image showing a passage range through which the other vehicle 40 should pass upon the overtaking operation, onto the road surface in the periphery of the object vehicle 30.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] This specification discloses an image display system that projects and displays an image on a road surface around a vehicle. [Background technology]

[0002] In recent years, a technology has been known that uses a projector mounted on a vehicle to project an image onto the road surface around the vehicle. For example, Patent Document 1 discloses a vehicle drawing device that draws a marker on the road surface in the traveling direction of the vehicle when the turn signal lamp is on. According to this technology, the traveling direction of the vehicle can be clearly communicated to drivers of other vehicles and pedestrians when changing lanes or turning right or left, thereby improving safety. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-193689 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the technology of Patent Document 1, an image is projected onto the road only when the vehicle (hereinafter referred to as the "target vehicle") on which the projector is mounted itself performs a specific action (in this case, turning on the turn signal lamp). Therefore, with the technology of Patent Document 1, when another vehicle traveling behind the target vehicle overtakes the target vehicle, road projection is not performed. In other words, with the conventional technology, the road projection technology could not be used to improve safety when another vehicle overtakes the target vehicle.

[0005] Therefore, this specification discloses an image display system that can further improve safety when another vehicle traveling behind a target vehicle overtakes the target vehicle. [Means for solving the problem]

[0006] The image display system disclosed in this specification is characterized by comprising: a projector mounted on a target vehicle for projecting an image onto the road surface around the target vehicle; and an image controller for causing the projector to project, when another vehicle traveling behind the target vehicle begins to overtake the target vehicle, a support image onto the road surface around the target vehicle, the support image including at least one of an image indicating a no-entry area where the other vehicle is prohibited from entering and an image indicating a passage area through which the other vehicle must pass when making the overtaking operation.

[0007] With this configuration, when performing an overtaking maneuver, the driver of the other vehicle can easily recognize the areas where the other vehicle cannot enter or the areas where the other vehicle must pass, thereby improving the safety of the overtaking maneuver.

[0008] In this case, the vehicle may further include a rear sensor that detects the condition behind the target vehicle, and the image controller may calculate the relative speed between the target vehicle and another vehicle traveling behind the target vehicle based on the detection result by the rear sensor, and may determine the start of the overtaking operation based at least on the relative speed.

[0009] With this configuration, the start of an overtaking maneuver can be accurately determined. Also, many vehicles are usually equipped with a sensor that detects the state behind the vehicle. By using such a sensor as the rear sensor, the start of an overtaking maneuver can be determined without adding a new sensor.

[0010] In this case, the image controller may identify at least one of the steering condition and the turn signal lighting condition of the other vehicle traveling behind based on the detection result of the rear sensor, and determine the start of the overtaking operation based on at least one of the steering condition and the lighting condition and the relative speed.

[0011] With this configuration, the start of an overtaking maneuver can be determined more accurately.

[0012] The image controller may terminate the projection of the support image based on at least a detection result of the rear sensor.

[0013] This configuration can prevent the support image from being projected for an unnecessarily long period of time, thereby reducing power consumption. Also, by ending the projection of the support image at an appropriate time, it is possible to prevent other vehicles and pedestrians who are not involved in the overtaking operation from being confused by the support image.

[0014] The image controller may also terminate projection of the supporting image based on at least an elapsed time from the start of the overtaking operation.

[0015] With this configuration, the timing to end the projection of the support image can be determined with a simple configuration. Also, with this configuration, the support image can be prevented from being projected for an unnecessarily long period of time, thereby reducing power consumption. Furthermore, by ending the projection of the support image at an appropriate timing, it is possible to prevent other vehicles and pedestrians unrelated to the overtaking operation from becoming confused by seeing the support image.

[0016] The vehicle may further include a forward sensor that detects a state in front of the target vehicle, and the image controller may terminate the projection of the support image based on at least a detection result of the forward sensor.

[0017] With this configuration, the projection of the support image can be terminated when the other vehicle reaches in front of the target vehicle, in other words, when the overtaking operation is reliably completed. Also, with this configuration, it is possible to prevent the support image from being unnecessarily projected for a long period of time, thereby reducing power consumption. Furthermore, by terminating the projection of the support image at an appropriate timing, it is possible to prevent other vehicles and pedestrians unrelated to the overtaking operation from becoming confused by seeing the support image.

[0018] The image controller may change at least one of a size and a projection position of the support image in response to steering of the target vehicle.

[0019] With this configuration, the movement of the target vehicle can be communicated to the driver of the other vehicle, allowing the other vehicle to perform an overtaking operation more safely.

[0020] The vehicle may further include an acceleration sensor that detects acceleration in a vehicle width direction of the target vehicle, and the image controller may change at least one of the size and the projection position of the support image according to a detection result of the acceleration sensor.

[0021] With this configuration, the movements of the target vehicle, especially movements unintended by the driver of the target vehicle (such as movements of the target vehicle caused by strong winds or uneven road surfaces, etc.), can be communicated to the driver of the other vehicle, allowing the other vehicle to perform overtaking operations more safely. Effect of the Invention

[0022] According to the image display system disclosed in this specification, the safety of another vehicle traveling behind a target vehicle when overtaking the target vehicle can be further improved. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a block diagram showing a configuration of an image display system. [Diagram 2] FIG. 2 is an image diagram showing a target vehicle in motion. [Diagram 3] FIG. 13 is an image diagram showing a state in which a supporting image is drawn. [Figure 4] FIG. 13 is an image diagram showing another example of a supporting image. [Diagram 5] FIG. 13 is an image diagram showing another example of a supporting image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, the configuration of the image display system 10 will be described with reference to the drawings. Fig. 1 is a block diagram showing the configuration of the image display system 10. This image display system 10 is mounted on a target vehicle and projects an image onto the road surface around the target vehicle.

[0025] As shown in FIG. 1, the image display system 10 includes a projector 12, a rear sensor 14, a front sensor 16, a steering angle sensor 17, an acceleration sensor 18, and an image controller 20. The projector 12 projects an image on the road surface around the target vehicle. The configuration of the projector 12 is not limited as long as it has one or more light sources and can irradiate the road surface with light that constitutes an image. Therefore, the projector 12 may be a liquid crystal projector of the LCD type, DLP type, or LCOS type that projects an image using light from an LED or the like. The projector 12 may also be a projector that projects light from a light source such as a normal headlamp using a lens. In this example, the projector 12 has a function of changing the content, position, and size of the image drawn on the road surface.

[0026] The rear sensor 14 is a sensor that detects the state behind the target vehicle. More specifically, the rear sensor 14 detects the state of a predetermined rear detection area set behind the target vehicle. The rear sensor 14 can detect the presence or absence of another vehicle in this rear detection area and the distance to the other vehicle in the rear detection area. The rear sensor 14 may further detect at least one of the position of the other vehicle and the lighting status of the turn signal lamp of the other vehicle. For example, the rear sensor 14 may have a plurality of sensors installed at separate locations on the target vehicle. For example, the rear sensor 14 may have at least one of a camera, a millimeter wave radar, a quasi-millimeter wave radar, an ultrasonic sensor, and a LiDAR.

[0027] The forward sensor 16 detects the state of a predetermined forward detection area set in front of the target vehicle. The forward sensor 16 detects the presence or absence of other vehicles in the forward detection area, the distance to the other vehicles, the positions of the other vehicles, the illumination status of the turn signal lamps of the other vehicles, etc. Such a forward sensor 16 may have, for example, a plurality of sensors installed at separate locations on the target vehicle. For example, the forward sensor 16 may have at least one of a camera, a millimeter wave radar, a quasi-millimeter wave radar, an ultrasonic sensor, and a LiDAR.

[0028] The steering angle sensor 17 detects the steering of the target vehicle. For example, the steering angle sensor 17 is attached to a steering shaft of the target vehicle and detects the rotation direction and rotation angle of the steering shaft. For example, the steering angle sensor 17 is an optical or magnetic rotary encoder.

[0029] The acceleration sensor 18 detects the acceleration of the target vehicle in three orthogonal axial directions, i.e., the vehicle longitudinal axis, the vehicle vertical axis, and the vehicle width axis. The detection result is transmitted to the image controller 20. The image controller 20 calculates the speed of the target vehicle by integrating the detected acceleration, and calculates the displacement of the target vehicle by integrating the acceleration twice. Note that a vehicle is usually equipped with sensors such as a camera and a millimeter wave radar for driving assistance (e.g., an automatic braking function, a lane keeping assist function, etc.) and driving control. Such existing sensors may be used as the above-mentioned sensors 14, 16, 17, and 18. In addition to the existing sensors, a dedicated sensor may be additionally installed in the vehicle for the image display system 10.

[0030] The image controller 20 controls the operation of the projector 12 to project an image onto the road surface. More specifically, the image controller 20 determines whether or not another vehicle traveling behind the target vehicle has started an overtaking operation based on the detection result of the rear sensor 14. When it is determined that the other vehicle has started an overtaking operation, the image controller 20 instructs the projector 12 to project a supporting image 62 (described later) onto the road surface, which will be described later.

[0031] The image controller 20 is physically a computer having a processor 22 and a memory 24. This "computer" also includes a microcontroller in which a computer system is incorporated into a single integrated circuit. The processor 22 refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0032] The memory 24 means a device that holds digital data to be processed by a computer. The memory 24 includes at least one of a main memory connected to the processor 22 via a memory bus and a secondary storage device accessed by the processor 22 via an input / output channel. The memory 24 may include at least one of a semiconductor memory (e.g., RAM, ROM, solid state drive, etc.) and a magnetic disk (e.g., hard disk drive, etc.). The memory 24 in this example is pre-installed with a program that detects whether or not another vehicle is attempting to overtake based on the detection result of the rear sensor 14, and causes the projector 12 to project a predetermined image onto the road surface based on the detection result.

[0033] Such an image controller 20 may be a single computer, or may be composed of multiple computers that are mechanically separated from one another. The image controller 20 may be provided exclusively for the image display system 10. An existing computer that is pre-installed in the target vehicle for driving control of the target vehicle or the like may be used as the image controller 20. A part of the processing of the image controller 20 may be executed by another computer provided outside the target vehicle.

[0034] Next, a description will be given of the image display process performed by the image display system 10. Fig. 2 is a conceptual diagram showing a target vehicle 30 in motion. Fig. 3 is a conceptual diagram showing a state in which a supporting image 62 is rendered.

[0035] 2 and 3, the target vehicle 30 is traveling on a one-lane road in accordance with the traffic rule of keeping to the left. Therefore, a center line 58 exists at the right end of the travel lane 50 of the target vehicle 30, and an outer lane 60 exists at the left end. In addition, an oncoming lane 56 exists to the right of the center line 58, and a shoulder 52 exists between the outer lane 60 and the sidewalk 54.

[0036] As described above, the target vehicle 30 is provided with the rear sensor 14 and the front sensor 16. In the illustrated example, the rear sensor 14 has three sensors provided near the rear end of the target vehicle 30, and the detection ranges of these three sensors form a rear detection area 32. Similarly, the front sensor 16 has three sensors provided near the front end of the target vehicle 30, and the detection ranges of these three sensors form a front detection area 34.

[0037] The image controller 20 monitors whether or not another vehicle 40 traveling behind the target vehicle 30 has started to overtake the target vehicle 30. Here, "overtaking" refers to the act of changing lanes to get in front of the vehicle traveling ahead. This "overtaking" also includes "slip-through" where a two-wheeled vehicle passes beside a four-wheeled vehicle to get in front of the four-wheeled vehicle without changing lanes. On the other hand, "overtaking" does not include "overtaking" where a vehicle traveling in one lane on a road with multiple lanes in each direction passes another vehicle traveling in an adjacent lane (e.g., an overtaking lane) without changing lanes.

[0038] The image controller 20 may determine the start of an overtaking operation based on, for example, the relative speed of the other vehicle 40 with respect to the target vehicle 30. For example, the image controller 20 may determine that an overtaking operation has started when the relative speed is greater than a specified reference speed. In this case, the reference speed may always be a constant fixed value. Also, the reference speed may be a variable value that varies depending on the distance between the target vehicle 30 and the other vehicle 40, the vehicle speed of the target vehicle 30, the type of the other vehicle 40 (i.e., whether it is a four-wheeled vehicle or a two-wheeled vehicle), the traffic congestion situation, the speed limit of the travel lane 50, the behavior of the other vehicle 40 described later, and the like. For example, when the other vehicle 40 approaches the target vehicle 30 sufficiently and the distance between the vehicles is small, but the relative speed is high, the other vehicle 40 is highly likely to perform overtaking. Therefore, the reference speed may be made smaller as the distance between the vehicles is smaller. Also, when it is desired to complete overtaking in N seconds, the relative speed Vr required for overtaking is theoretically Vr = √(Vt x A / N) where Vt is the speed of the target vehicle 30 and A is the coefficient. In other words, the higher the speed Vt of the target vehicle 30, the higher the relative speed Vr required for overtaking in N seconds. Therefore, the higher the speed Vt of the target vehicle 30, the higher the reference speed for determining that overtaking has started. Also, when the overtaking vehicle (the other vehicle 40 in FIG. 4) is a four-wheeled vehicle, it is more likely to run into the adjacent lane than when the overtaking vehicle is a two-wheeled vehicle. Therefore, it can be said that, in general, a four-wheeled vehicle needs to complete the overtaking operation more quickly than a two-wheeled vehicle, and the relative speed required for overtaking is higher. Therefore, when the other vehicle 40 is a four-wheeled vehicle, the reference speed may be higher than when it is a two-wheeled vehicle.

[0039] The relative speed may be determined from the detection result of the rear sensor 14. For example, if the rear sensor 14 has a millimeter wave radar or a quasi-millimeter wave radar that detects the distance between vehicles, the image controller 20 may determine the relative speed from a change in the distance between vehicles detected by the millimeter wave radar or the like. Also, if the rear sensor 14 has a camera that captures an image behind the target vehicle 30, the image controller 20 may determine the distance between vehicles and, therefore, the relative speed by analyzing the obtained image.

[0040] The image controller 20 may determine the start of an overtaking operation based on the behavior of the other vehicle 40 in addition to the relative speed. For example, the image controller 20 may determine that an overtaking operation has started when the relative speed is a speed at which overtaking is possible and the other vehicle 40 moves to the side. Such a lateral movement of the other vehicle 40 may be detected, for example, by analyzing a change in the position of the other vehicle 40 detected by a millimeter wave radar or an image captured by a camera. The image controller 20 may determine that an overtaking operation has started when the relative speed is a speed at which overtaking is possible and the other vehicle 40 turns on a turn signal lamp. Such lighting of the turn signal lamp may be detected by analyzing an image captured by a camera. In this way, the start of an overtaking operation can be more accurately determined by taking into account the behavior of the other vehicle 40 in addition to the relative speed.

[0041] In FIG. 3, when the image controller 20 determines that the other vehicle 40 has started an overtaking operation, it instructs the projector 12 to project a support image 62 onto the road surface. The support image 62 is an image that supports the overtaking operation of the target vehicle 30 by the other vehicle 40. In this example, the support image 62 is an image that indicates a no-entry area that prohibits the other vehicle 40 from entering during the overtaking operation. That is, in order to safely overtake, the other vehicle 40 needs to run with a certain distance from the target vehicle 30 so as not to interfere with the target vehicle 30. In other words, for safe overtaking, a certain area around the target vehicle 30 should be a no-entry area where the other vehicle 40 is prohibited from entering. The support image 62 indicates such a no-entry area.

[0042] In the example of FIG. 3, the support image 62 is a combination of a line indicating the boundary of the no-entry area and a cross mark indicating that entry is not permitted. In the example of FIG. 3, the support image 62 is displayed only on the side of the target vehicle 30. The support image 62 may be projected only on one side of the target vehicle 30, or on both sides. For example, when it is expected that the other vehicle 40 will pass on the right side of the target vehicle 30 to overtake, the support image 62 may be projected only on the road surface on the right side of the target vehicle 30. In any case, the other vehicle 40 can safely perform an overtaking operation without interfering with the target vehicle 30 by driving the other vehicle 40 while avoiding the no-entry area indicated by the support image 62.

[0043] The image controller 20 may end the projection of the support image 62 at a timing when the other vehicle 40 cannot be detected by the rear sensor 14 after the projection of the support image 62 has started, that is, at a timing when the other vehicle 40 moves outside the rear detection area 32. As another embodiment, the image controller 20 may end the projection of the support image 62 at a timing when the other vehicle 40 can be detected by the front sensor 16 after the projection of the support image 62 has started, that is, at a timing when the other vehicle 40 moves into the front detection area 34. As another embodiment, the image controller 20 may end the projection of the support image 62 at a timing when a specified overtaking time has elapsed after the projection of the support image 62 has started. In this case, the overtaking time is a time when it can be considered that the other vehicle 40 has finished overtaking the target vehicle 30. The overtaking time may be a fixed value or a variable value that changes depending on the relative speed, etc. Furthermore, the image controller 20 may combine the above-mentioned techniques, and may end the projection of the supporting image 62 at the earlier of the timing when the overtaking time has elapsed and the timing when the forward sensor 16 detects another vehicle 40. Of course, the timing to end the projection of the supporting image 62 may also be determined according to conditions other than those described above.

[0044] Next, the support image 62 will be described in detail. As described above, the support image 62 in this example is an image showing a no-entry area into which the other vehicle 40 performing an overtaking operation is prohibited from entering. The form of the support image 62 (i.e., size, projection position, shape, brightness, color, etc.) may be always constant or may be changed according to the behavior of the target vehicle 30.

[0045] For example, the target vehicle 30 may move in the vehicle width direction regardless of the steering operation due to the unevenness of the road surface or the influence of the wind. Also, the driver of the target vehicle 30 may perform a steering operation for some reason, causing the target vehicle 30 to move in the vehicle width direction. If such a movement of the target vehicle 30 in the vehicle width direction can be notified to the other vehicle 40, the other vehicle 40 can perform an overtaking operation more safely.

[0046] Therefore, the image controller 20 may change at least one of the size and the projection position of the supporting image 62 in response to the movement of the target vehicle 30. Specifically, the image controller 20 may change the width W of the supporting image 62 based on the detection results of the steering angle sensor 17 and the acceleration sensor 18.

[0047] For example, when the driver of the target vehicle 30 operates the steering wheel to the left or right, the target vehicle 30 moves in the steering direction. In this case, in order to safely perform an overtaking operation, it is necessary to secure a wide no-entry range in the steering direction. Therefore, when the steering angle sensor 17 detects steering to the left or right, the image controller 20 may increase the width W of the support image 62 in the steering direction according to the steering angle amount, or may shift the projection position of the support image 62 in the steering direction. Therefore, when the steering wheel is operated, for example, to the right, the width W of the support image 62 on the right side of the target vehicle 30 may be increased compared to the width of the support image 62 on the left side.

[0048] Even if the driver is not operating the steering wheel, the target vehicle 30 may move in the vehicle width direction due to unevenness of the road surface, wind, etc. Such a movement may be detected by the acceleration sensor 18 and reflected in the support image 62. Therefore, for example, when the acceleration sensor 18 detects acceleration in the vehicle width direction, the image controller 20 may change at least one of the width W and the projection position of the support image 62 according to the direction and magnitude of the acceleration. For example, when it is determined that the target vehicle 30 is swaying in the vehicle width direction based on the acceleration detected by the acceleration sensor 18, the image controller 20 may increase the width W of the support image 62 or shift the projection position of the support image 62 in a direction away from the target vehicle 30 according to the amplitude of the sway. Also, when it is determined that the target vehicle 30 is moving to the left or right based on the acceleration, the image controller 20 may increase the width W of the support image 62 in the moving direction according to the detected acceleration, or shift the projection position of the support image 62 in the moving direction according to the detected acceleration.

[0049] The image controller 20 may further change at least one of the size and the projection position of the support image 62 according to another condition. For example, the distance to be maintained between the target vehicle 30 and the other vehicle 40 when overtaking varies depending on the weather, the vehicle speed, the road width, and the like. Therefore, the width W and the projection position of the support image 62 may be changed in consideration of the weather, the vehicle speed, and the road width. For example, in the case of rainfall, snowfall, strong wind, or frozen road, the width W of the support image 62 may be increased. Rainfall and snowfall may be detected by a raindrop sensor mounted on the vehicle for the auto wiper function. Also, frozen road may be estimated from the detection result of a temperature sensor. In addition to or instead of the detection result of such a sensor, the image controller 20 may estimate the condition of rainfall, snowfall, strong wind, frozen road, and the like based on meteorological information acquired by Internet communication or the like.

[0050] In addition, at least one of the width W and the projection position of the support image 62 may be changed according to the vehicle speed of the target vehicle 30 or the relative speed of the other vehicle 40 with respect to the target vehicle 30. For example, the width W of the support image 62 may be increased as the relative speed increases. Furthermore, at least one of the width W and the projection position of the support image 62 may be changed according to the road width. For example, when the width of the travel lane 50 itself is large, or when an overtaking lane exists adjacent to the travel lane 50, the width W of the support image 62 may be increased. The road width may be identified, for example, from map information recorded in a navigation device, or may be identified by analyzing an image captured by a camera.

[0051] The size and projection position of the support image 62 may be set so as not to extend beyond the oncoming lane 56 and the sidewalk 54 (including the "side strip"). To achieve this configuration, the image controller 20 may analyze an image captured by a camera mounted on the target vehicle 30 to identify the relative positions of the oncoming lane 56 and the sidewalk 54 with respect to the target vehicle 30.

[0052] The configuration of the support image 62 itself may also be changed as appropriate. For example, when overtaking another vehicle 40, the other vehicle 40 often interferes with the rear and front corners of the target vehicle 30. In order to prevent such interference, the support image 62 may be made longer than the overall length of the target vehicle 30, and the front-rear end of the support image 62 may be positioned outward in the front-rear direction from the front-rear end of the target vehicle 30. In other words, the support image 62 may have a shape indicated by reference symbol 62a in FIG. 4.

[0053] 5, the supporting image 62 may be projected not only on the side of the target vehicle 30 but also in front and behind the target vehicle 30. When the supporting image 62 is projected also in front of the target vehicle 30, the driver of the target vehicle 30 can easily view the supporting image 62. By viewing the supporting image 62, the driver of the target vehicle 30 can easily notice the presence of another vehicle 40 that is about to overtake the target vehicle 30, thereby improving the safety of the overtaking operation.

[0054] 3, the supporting image 62 has a shape that combines a rectangle and a cross mark, but the supporting image 62 may be changed to another shape as long as the driver of the other vehicle 40 can understand the meaning of the supporting image 62. Therefore, the supporting image 62 may have a shape that combines a line indicating the boundary of a no-entry area and a road sign indicating no entry, as shown by reference symbol 62a in FIG.

[0055] In the above description, the support image 62 is an image showing the no-entry range of the other vehicle 40, but the support image 62 may be an image showing the passage range where the other vehicle 40 should pass when overtaking. Reference numeral 62b in FIG. 4 is an example of a support image showing the passage range. As is clear from FIG. 4, the support image 62b showing the passage range is projected onto the road surface outside the no-entry range. In this case, the support image 62b may be a shape that encourages the other vehicle 40 to pass, for example, a shape including an arrow showing the direction of travel. The support image 62b may be a shape including stripes or a grid. In this case, the driver of the other vehicle 40 can easily grasp the unevenness of the road surface from the distortion of the lines that make up the stripes or grid. As a result, the driver of the other vehicle 40 can perform a driving operation that takes the unevenness into consideration, and therefore can perform an overtaking operation more safely. Furthermore, the image controller 20 may project onto the road surface only one of the supporting image 62a indicating the no-entry area and the supporting image 62b indicating the passable area, or may project both of them simultaneously.

[0056] The image controller 20 may also change the luminance of the support image 62 according to the brightness of the surroundings of the target vehicle 30. For example, in a bright environment such as outdoors during the day, the luminance of the support image 62 may be higher than in a dark environment such as at night or in a tunnel. The brightness may be determined from the detection result of a luminance sensor provided for the auto light function, or may be determined from the lighting status of lights such as headlights that are required to be turned on at night. The color of the support image 62 may also be changed according to the color of the road surface. For example, some roads are painted red to serve as an anti-slip material. In the case of such roads, the color of the support image 62 may be changed to a color with less red components compared to a normal asphalt-paved road that is not painted red. The color of the road surface may be determined by analyzing an image captured by a camera. The support image 62 may also be a video that changes over time. For example, the support image 62b in FIG. 4 may be a video in which at least one of the position, color, and size of the arrow included in the support image 62b changes over time.

[0057] As is clear from the above description, the image display system 10 disclosed in this specification projects a support image 62 indicating a no-entry range and / or a passage range onto the road surface when the other vehicle 40 starts an overtaking operation. As a result, interference between the target vehicle 30 and the other vehicle 40 can be effectively prevented, and the safety of the overtaking operation of the other vehicle 40 can be further improved. Note that the above-mentioned configurations are all examples, and other configurations may be changed as appropriate as long as the support image 62 is projected onto the road surface when the other vehicle 40 starts an overtaking operation. For example, the vehicle types of the target vehicle 30 and the other vehicle 40 are not specified. Therefore, the target vehicle 30 and the other vehicle 40 may be two-wheeled vehicles, four-wheeled vehicles, or vehicles of other forms. Furthermore, the image display system 10 may project other types of images onto the road surface in addition to the above-mentioned support image 62. For example, the image display system 10 may project an image indicating the traveling direction of the target vehicle 30 onto the road surface when the target vehicle 30 turns right or left. [Explanation of symbols]

[0058] 10 image display system, 12 projector, 14 rear sensor, 16 front sensor, 17 steering angle sensor, 18 acceleration sensor, 20 image controller, 22 processor, 24 memory, 30 target vehicle, 32 rear detection area, 34 front detection area, 40 other vehicles, 50 driving lane, 52 road shoulder, 54 sidewalk, 56 oncoming lane, 58 center line, 60 outer side line of roadway, 62 supporting image.

Claims

1. A projector mounted on a target vehicle and configured to project an image onto a road surface around the target vehicle; an image controller that, when another vehicle traveling behind the target vehicle starts to overtake the target vehicle, causes the projector to project a support image including at least one of an image showing a no-entry area where the other vehicle is prohibited from entering and an image showing a passage area through which the other vehicle should pass when overtaking the target vehicle, onto a road surface around the target vehicle; Equipped with the image controller determines an end of the projection of the support image based on at least an elapsed time from the start of the overtaking operation; 1. An image display system comprising:

2. 2. The image display system according to claim 1, further comprising: A rear sensor is provided to detect a rear state of the target vehicle, the image controller determines a relative speed between the other vehicle traveling behind the target vehicle and the target vehicle based on a detection result by the rear sensor, and determines a start of the overtaking operation based on at least the relative speed.

1. An image display system comprising:

3. 3. The image display system according to claim 2, The image controller identifies at least one of the steering condition and turn signal lighting condition of the other vehicle traveling behind based on the detection result of the rear sensor, and determines the start of the overtaking operation based on at least one of the steering condition and the lighting condition and the relative speed.

4. 4. The image display system according to claim 2, The image display system according to claim 1, wherein the image controller further determines an end of projection of the support image based on a detection result of the rear sensor.

5. 5. The image display system according to claim 1, A forward sensor is provided to detect a forward state of the target vehicle, The image display system according to claim 1, wherein the image controller further determines an end of projection of the support image based on a detection result of the front sensor.

6. 6. An image display system according to claim 1, The image display system according to claim 1, wherein the image controller changes at least one of a size and a projection position of the support image in response to steering of the target vehicle.

7. 7. The image display system according to claim 1, further comprising: An acceleration sensor that detects acceleration in a vehicle width direction of the target vehicle, the image controller changes at least one of a size and a projection position of the support image in response to a detection result of the acceleration sensor; 1. An image display system comprising:

Images