Projection device for vehicle

Abstract

To provide a projection device for a vehicle capable of improving visibility.SOLUTION: A projection device 1 for a vehicle according to the present embodiment includes a projector 10 that projects projection light within a projectable area 42 to display an image 41, and a control unit 20 that acquires information related to brightness within the projectable area 42 and determines a region in which the brightness is equal to or lower than a predetermined value as an actual projection area 43 in which the projection light is to be projected. The control unit 20 determines a size of the image 41 to be projected by the projector 10 on the basis of a dimension of the actual projection area 43.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a projection device for a vehicle. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a technology has been known in which a vehicle is equipped with a projector and an image showing necessary information or the like is projected onto the road surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-089544 Summary of the Invention [Problem to be solved by the invention]

[0004] By projecting images onto the road surface, information is provided to passengers of other vehicles and pedestrians for the purpose of alerting them to hazards. However, there is a risk that the visibility of the images may decrease depending on the surrounding brightness and road surface conditions. For this reason, there is a demand for improving the visibility of the images to ensure that information is transmitted reliably.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a projection device for a vehicle that can improve visibility. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the vehicle projection device disclosed herein comprises a projector that projects projection light into a projectable area to display an image, and a control unit that acquires information regarding the brightness of the projectable area and determines an area where the brightness is below a predetermined value as the actual projection area into which the projection light will be projected. [Effects of the Invention]

[0007] The projection device for a vehicle according to the present disclosure can improve visibility. [Brief explanation of the drawings]

[0008] [Figure 1] 3A and 3B are explanatory diagrams showing examples of projection by the vehicle projection device according to the embodiment; [Figure 2] FIG. 2 is a schematic functional block diagram showing the functional configuration of the vehicle projection device. [Figure 3] An xy chromaticity diagram of the CIE1931 color space, an example of a color system. [Figure 4] 5 is a flowchart illustrating an image projection process executed by the vehicle projection device. [Figure 5] 10A and 10B are explanatory diagrams showing a vehicle and an image display during image projection processing; [Figure 6] 10A and 10B are explanatory diagrams showing a vehicle and an image display during image projection processing; [Figure 7] 10A and 10B are explanatory diagrams showing a vehicle and an image display during image projection processing; [Figure 8] 10A and 10B are explanatory diagrams showing a vehicle and an image display during image projection processing; [Figure 9] 10 is another explanatory diagram showing the vehicle and the image display during image projection processing; FIG. [Figure 10] FIG. 10 is yet another explanatory diagram showing the vehicle and the image display during image projection processing. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a vehicle projection device according to the present disclosure will be described with reference to the accompanying drawings. The vehicle projection device according to the present disclosure can be applied to any vehicle, such as an automobile, a motorcycle, agricultural machinery, or construction machinery. In this embodiment, an example in which the vehicle projection device is mounted on an automobile will be described.

[0010] FIG. 1 is an explanatory diagram conceptually showing an example of projection by a vehicle projection device 1 according to this embodiment.

[0011] FIG. 2 is a schematic functional block diagram showing the functional configuration of the vehicle projection device 1. As shown in FIG.

[0012] In the following description, "front," "rear," "right," and "left" follow the definitions of "Fr.", "Re.", "R," and "L" in Figures 1, 5 to 10. "Front" refers to the direction in which the vehicle 2 is traveling, and "rear" refers to the opposite direction to the traveling direction.

[0013] The vehicle projection device 1 (hereinafter referred to as the “projection device 1”) includes a projector 10 and a control unit 20.

[0014] The projector 10 is mounted in a position where it can project projection light onto the outside of the vehicle 2, such as on the left and right door mirrors 5, the front bumper 6, or the rear bumper 7 of the vehicle 2. The projector 10 projects the projection light into a projectable area 42 that is provided on a projection surface, such as a road surface 4, to display an image 41. The projectable area 42 is an area that is determined in advance for each projector 10 disposed in each section, and is an area where the projector 10 can project the image 41. The projector 10 has a projection optical unit 11 and a drive unit 12.

[0015] The projection optical unit 11 has three light sources, for example, red, green, and blue, and generates and projects projection light for an image 41 in a required color. For example, as shown in Fig. 1, the projection optical unit 11 can display an image 41 of a yellow or white arrow between white lines on the road surface in an actual projection area 43 set within a projectable area 42, which is an image 41 for informing other vehicles that the driver is changing lanes to the left lane on a two-lane road.

[0016] The drive unit 12 changes the projection angle of the projection optical unit 11. In this way, the projection optical unit 11 can change the projection destination of the projection light within the projectable area .

[0017] The control unit 20 controls the projector 10 to project projection light. The control unit 20 may be configured integrally with the projector 10, or may be placed in a location different from where the projector 10 is placed and connected to the projector 10 via a cable. The control unit 20 has an image analysis unit 21, an actual projection area determination unit 22, an image determination unit 23, a projection angle control unit 24, and an image database 25 (image DB25).

[0018] The video analysis unit 21 acquires and analyzes video captured by the camera 8 mounted on the vehicle 2. The camera 8 is a camera that can capture video from which information regarding the brightness and color of the projectable area 42 and the presence or absence of obstacles 46 can be obtained, and may be disposed on the vehicle 2 independently of the projection device 1, or may be included in the projection device 1. Specifically, the video analysis unit 21 acquires information regarding the brightness of the projectable area 42 from the acquired video. The video analysis unit 21 acquires, for example, the brightness of the road surface 4 from the video.

[0019] Furthermore, the image analysis unit 21 acquires the image captured by the camera 8 and acquires the color of the projectable area 42. The color of the projectable area 42 changes depending on, for example, the headlights of other vehicles and the road surface conditions. For example, if the headlights are LED (Light Emitting Diode) light sources, the road surface 4 will be white, and if the headlights are halogen light sources, the road surface 4 will be yellow. Furthermore, if there is snow on the road surface 4, the road surface 4 will be white.

[0020] Furthermore, the image analysis unit 21 acquires the image captured by the camera 8 and acquires information about obstacles 46 located within the projectable area 42. The obstacles 46 are objects that obstruct the projection of the projection light, such as other vehicles, pedestrians, and structures placed on the road surface.

[0021] The actual projection area determination unit 22 determines an actual projection area 43 from within the projectable area 42 based on information acquired from the image analysis unit 21. Specifically, the actual projection area determination unit 22 determines an area within the projectable area 42 where the brightness is equal to or less than a predetermined value as the actual projection area 43 based on information related to brightness. The actual projection area 43 is an area onto which the projector 10 actually projects the projection light. The actual projection area determination unit 22 determines a road surface brightness of, for example, 10 cd / m as the brightness at which sufficient visibility is obtained when the image 41 is projected. 2 The actual projection area determination unit 22 may determine an area having brightness equal to or less than a predetermined value and having a predetermined size or larger onto which the image 41 can be projected as the actual projection area 43.

[0022] Furthermore, based on information relating to an obstacle 46 located within the projectable area 42 acquired from the image analysis unit 21, the actual projection area determination unit 22 determines, as the actual projection area 43, an area other than the area where the obstacle 46 is located among the area 45 where the brightness is equal to or less than a predetermined value. This is because even if projection light is projected onto the obstacle 46, visibility cannot be obtained.

[0023] The actual projection area determination unit 22 supplies information about the determined actual projection area 43 to the image determination unit 23 and the projection angle control unit 24. The actual projection area determination unit 22 also supplies information about the color of the actual projection area 43 to the image determination unit 23. Furthermore, the actual projection area determination unit 22 acquires information necessary for the image projection process, which will be described later, from a vehicle ECU (Electronic Control Unit) 9 that controls the vehicle 2 in an integrated manner.

[0024] The image determination unit 23 determines the image 41 to be projected by the projector 10 based on the obtained dimensions of the actual projection area 43. Specifically, the image determination unit 23 extracts an image according to the dimensions of the actual projection area 43 from the images stored in the image DB 25. Note that instead of extracting an image from the image DB 25, the image determination unit 23 may generate an image each time based on the dimensions of the actual projection area 43 or adjust the size of the image.

[0025] Furthermore, image determination unit 23 determines the color of image 41 to be projected by projector 10 based on the obtained color of actual projection area 43. Here, Fig. 3 is an xy chromaticity diagram of the CIE1931 color space, which is an example of a color system, and is an explanatory diagram showing an example of color determination.

[0026] The image determination unit 23 calculates the chromaticity range to which the color belongs from the acquired color information. Then, it determines the color of the chromaticity range corresponding to the calculated chromaticity range from a database prepared in advance. For example, if the chromaticity of the actual projection area 43 is within a range R1 of x = 0.35 to 0.6 and y = 0.4 to 0.6, and the color of the road surface 4 can be considered yellow due to the lights of other companies, the image determination unit 23 determines the color of the image 41 to be white, which is a color that is highly visible compared to yellow. Alternatively, if the chromaticity of the actual projection area 43 is within a range R2 of x = 0.2 to 0.35 and y = 0.2 to 0.4, and the color of the road surface 4 can be considered white due to the lights of other companies, the image determination unit 23 determines the color of the image 41 to be yellow, which is a color that is highly visible compared to white. The image determination unit 23 supplies the determined image 41 and color information to the projection optical unit 11.

[0027] The projection angle control unit 24 controls the drive unit 12 to change the projection angle of the projection optical unit 11 so that the projection light is projected onto the obtained actual projection area 43 .

[0028] Next, the image projection process executed by the projection device 1 in this embodiment will be described. Fig. 4 is a flowchart illustrating the image projection process executed by the projection device 1. Figs. 5 to 8 are explanatory diagrams showing the vehicle 2 and the image 41 displayed during the image projection process. This image projection process is repeatedly executed, for example, while the ignition switch of the vehicle 2 is on.

[0029] In step S1, the image analysis unit 21 analyzes the image acquired from the camera 8. As the analysis result, the image analysis unit 21 supplies information regarding the brightness, color, and presence or absence of obstacles 46 of the projectable area 42 to the actual projection area determination unit 22. In step S2, the actual projection area determination unit 22 determines and stores the actual projection area 43. If the actual projection area determination unit 22 has already stored the actual projection area 43, it updates it to the newly determined actual projection area 43. If the actual projection area determination unit 22 cannot determine an area that will become the actual projection area 43 because, for example, the brightness is greater than a predetermined value across the entire projectable area 42, the actual projection area determination unit 22 determines that there is no actual projection area 43.

[0030] For example, as shown in FIG. 5, the actual projection area determination unit 22 determines the area of ​​the projectable area 42 other than the area where the brightness is greater than a predetermined value due to illumination by the headlights of the vehicle 2, other vehicles 3a and 3b, and street lamps 3c (areas where the brightness is equal to or less than a predetermined value) as the actual projection area 43 (colored (hatched) area in the figure).

[0031] In step S3, the actual projection area determination unit 22 determines whether or not the turn signal has been turned on by the driver of the vehicle 2, based on information acquired from the vehicle ECU 9. If the actual projection area determination unit 22 determines that the turn signal has not been turned on (NO in step S3), it returns to step S1 and repeats the analysis step S1 to the lighting determination step S3 until the turn signal is turned on.

[0032] 6, when it is determined that the turn signal is turned on, for example, by turning on the left turn signal 47 arranged on the front, side, or rear of the vehicle 2 to make a left turn (YES in step S3), the actual projection area determination unit 22 determines in step S4 whether or not there is a determined actual projection area 43. When it is determined that there is no actual projection area 43 (NO in step S4), the actual projection area determination unit 22 returns to step S1 and repeats the analysis step S1 to the area existence determination step S4 until it is determined that there is an actual projection area 43.

[0033] On the other hand, if the actual projection area determination unit 22 determines that there is an actual projection area 43 (YES in step S4), then in step S5 the image determination unit 23 determines the image 41 and color to be projected by the projector 10 based on information relating to the actual projection area 43 and the like acquired from the actual projection area determination unit 22. For example, to indicate to other vehicles 3b and the like that a left turn is to be made, the image 41 relating to the arrow indicating a left turn shown in FIG. 7 is extracted from the image DB 25, and is dimensionally displayable in the actual projection area 43. Furthermore, if the road surface 4 can be considered white, the image determination unit 23 determines the color of the image 41 to be yellow.

[0034] In step S6, the projection angle control unit 24 determines the projection angle of the projection optical unit 11 based on information about the actual projection area 43, etc., acquired from the actual projection area determination unit 22. The projection angle control unit 24 also controls the drive unit 12 based on the determined projection angle. In step S7, the drive unit 12 controls the angle of the projection optical unit 11. In step S8, the projection optical unit 11 generates and projects projection light related to the image 41 based on the image 41 and the color related to the image 41 acquired from the image determination unit 23.

[0035] While the vehicle 2 is traveling, the brightness or color of the actual projection area 43 may change after projection, or obstacles 46 may appear, but once projection is performed, projection continues under the same conditions. This allows the projection device 1 to reduce the processing load and the discomfort felt by viewers of the image 41 due to sudden changes in the image 41.

[0036] In step S9, the projection optical unit 11 determines whether or not the turn signal has been turned off based on information acquired from the vehicle ECU 9. If the projection optical unit 11 determines that the turn signal has not been turned off (NO in step S9), the process returns to step S8, and the projection step S8 to the turn-off determination step S9 are repeated until the turn signal is turned off. On the other hand, if the projection optical unit 11 determines that the turn signal has been turned off, for example, because a left turn is completed and the left turn signal 47 is turned off as shown in FIG. 8 (YES in step S9), the process ends.

[0037] The display of the image 41 when the blinker is turned on, as explained with reference to FIGS. 5 to 8, is just an example, and the image 41 may be projected as shown below.

[0038] FIG. 9 is another explanatory diagram showing the vehicle 2 and the display of the image 41 during the image projection process.

[0039] When the projection device 1 detects that the brakes have been applied due to the presence of a pedestrian 3d ahead, the projection device 1 may display an image 41 consisting of "STOP" and a pictogram showing a pedestrian in the actual projection area 43 to alert other vehicles 3b behind that there is a pedestrian 3d and that they should stop. In this case, the projection device 1 uses the projector 10 mounted on the rear bumper 7 to display the image 41 in the actual projection area 43 behind the vehicle 2.

[0040] FIG. 10 is yet another explanatory diagram showing the vehicle 2 and the display of the image 41 during the image projection process.

[0041] When the projection device 1 detects that the vehicle has been shifted into reverse gear, it may display an image 41 consisting of "BACK" in the actual projection area 43 to alert pedestrians 3d behind or other vehicles to move backward.

[0042] The projection device 1 may keep these images 41 lit, or may blink them to draw attention.

[0043] The projection device 1 in this embodiment can improve visibility by determining the image 41 displayed by the projector 10 according to the condition of the road surface 4 on which the image is to be projected. Furthermore, the projection device 1 does not project the image 41 under conditions where visibility is poor, thereby suppressing unnecessary projection.

[0044] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0045] For example, although the projection target on which the projectable area 42 is set is the road surface 4 in the example described above, a surface other than the road surface 4 may be used as the projection target. [Explanation of symbols]

[0046] 1 Vehicle projection device (projection device) 2 vehicles 3a, 3b Other vehicles 3c street light 3d pedestrian 4 Road surface 5 Door mirrors 6. Front bumper 7 Rear bumper 8. Camera 9. Vehicle ECU (Electronic Control Unit) 10 Projectors 11 Projection optical section 12 Drive unit 20 Control Unit 21 Video Analysis Department 22 Actual projection area determination unit 23 Video Decision Department 24 Projection angle control section 25 Video Database (DB) 41 Video 42 Projection area 43 Actual projection area 46 Obstacles 47 Left turn signal R1, R2 range

Claims

1. a projector that projects projection light into a projection area to display an image; a control unit that acquires information about the brightness of the projectable area and determines an area where the brightness is equal to or less than a predetermined value as an actual projection area onto which the projection light is projected.

2. The vehicle projection device according to claim 1 , wherein the control unit determines the dimensions of the image to be projected by the projector based on the dimensions of the actual projection area.

3. The vehicle projection device according to claim 1 , wherein the control unit further acquires information about a color of the projectable area, and determines a color of the image to be projected by the projector based on the color.

4. 2. The vehicle projection device according to claim 1, wherein the control unit acquires information about an obstacle located within the projectable area that obstructs the projection of the projection light, and determines an area other than the area where the obstacle is located as the actual projection area.

5. 2. The vehicle projection device according to claim 1, wherein the projectable area is an area on a road surface.

Images