Vehicular projection device

Abstract

To provide a projection device for a vehicle capable of displaying an image easily visible for a viewer on a road surface by using darkness of a shadow even under a bright environment in the daytime.SOLUTION: The device includes a projection part 2 for irradiating a road surface R with first irradiation light L1 for displaying a first image M1, a detection part 2 for detecting brightness of a surrounding environment of a vehicle C, and a control part 4 for controlling the projection part 2. The control unit 4 performs a brightness determination process of determining whether or not the brightness detected by the detection unit 2 is equal to or higher than a predetermined brightness, and an image position determination process of determining whether or not at least a part of the first image M1 displayed on the road surface R by the projection unit 2 is located outside the shadow region RF. And image adjustment processing for adjusting the first emission light M1 so that the whole of the first image L1 is positioned inside the shadow area RF when it is determined by the image position determination processing that the first emission light LA is positioned outside the shadow area RF.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle projection device that projects a desired image to a viewer outside the vehicle. [Background technology]

[0002] Conventionally, an image projection device is known, for example, as described in Patent Document 1. This image projection device projects and displays information relating to a vehicle, such as the running state of a moving object represented by an automobile, onto a road surface, a wall, or the vehicle itself. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7437449 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional image projection device described above has a problem in that the display brightness of the projector is insufficient during the day when sunlight is bright, making it difficult for the viewer to see the displayed content.

[0005] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a projection device for a vehicle that can display an image on the road surface that is easy for the viewer to see by taking advantage of the darkness of shadows, even in a bright daytime environment. [Means for solving the problem]

[0006] The present invention is a vehicle projection device 1 provided on a vehicle C traveling on a road surface R, comprising at least one projection unit 2 that irradiates a first irradiation light L1 to display a first predetermined image M1 on the road surface R, a detection unit 3 that detects the brightness of the environment surrounding the vehicle C, and a control unit 4 that controls the at least one projection unit 2, wherein the control unit 4 executes a brightness determination process that determines whether the brightness detected by the detection unit 3 is equal to or greater than a predetermined brightness, an image position determination process that determines whether at least a portion of the first predetermined image M1 displayed on the road surface R by the projection unit 2 is located outside a shadow RF of the vehicle C that appears on the road surface R, and an image adjustment process that adjusts the first irradiation light L1 from the projection unit 2 so that the entire first predetermined image M1 is located within the shadow RF, triggered by the brightness determination process that the brightness is equal to or greater than the predetermined brightness and the image position determination process that the first predetermined image M1 is located outside the shadow RF. [Effects of the Invention]

[0007] According to the present invention, even during the day when the sunlight is bright, the entire first predetermined image can be clearly viewed against a shadow in the background. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a vehicle projection device according to a first embodiment of the present invention. [Figure 2] 1 is a functional block diagram showing the configuration of a vehicle projection device according to a first embodiment of the present invention. [Figure 3] 1 is a functional block diagram showing the configuration of a control unit in a vehicle projection device according to a first embodiment of the present invention. [Figure 4] 1A and 1B are diagrams showing how the shadow identification unit in the vehicle projection device according to the first embodiment of the present invention identifies shadow areas when the sun is directly above the vehicle, as viewed from the front of the vehicle, and as viewed from the side of the vehicle. [Figure 5]1A and 1B are diagrams showing how the shadow identification unit in the vehicle projection device according to the first embodiment of the present invention identifies shadow areas when the sun is diagonally directed from the vehicle, as viewed from the front of the vehicle and as viewed from the side of the vehicle. [Figure 6] 3A and 3B are diagrams showing a state before and after an image adjustment unit adjusts the position of a first image in the vehicle projection device according to the first embodiment of the present invention. [Figure 7] 3A and 3B are diagrams showing a state before and after an image adjustment unit adjusts the position and size of a first image in the vehicle projection device according to the first embodiment of the present invention. [Figure 8] 5A and 5B are diagrams illustrating a process in which the image adjustment unit in the vehicle projection device according to the first embodiment of the present invention rotates and adjusts the first image when the shadow area is large and when the shadow area is small, respectively. [Figure 9] 4 is a flowchart showing the operation of the vehicle projection device according to the first embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing a state in which a second projection unit projects and displays a second image in a vehicle projection device according to a second embodiment of the present invention. [Figure 11] FIG. 10 is a view of a state in which a second projection unit projects and displays a second image in a vehicle projection device according to a second embodiment of the present invention, as viewed from the front side of the vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment of the present invention) The vehicular projection device 1 according to this embodiment will be described with reference to Figures 1 to 9. When projecting and displaying a predetermined image M onto a road surface R around a vehicle C, the vehicular projection device 1 controls the illumination of the projected and displayed image M so that a shadow area (hereinafter referred to as a shadow area RF) becomes the background.

[0010] Fig. 1 is a schematic diagram of a vehicle C equipped with a vehicular projection device 1 according to this embodiment, and Fig. 2 is a functional block diagram showing the configuration of the vehicular projection device 1 according to this embodiment. In Figs. 1 and 2, the vehicular projection device 1 includes at least one projection unit 2 that emits first irradiation light L1 to display a predetermined first image M1 (first predetermined image), a detection unit 3 that detects the brightness of the surroundings of the vehicle C, and a control unit 4 that controls the projection unit 2 in accordance with the detection result of the detection unit 3. Although not shown in Fig. 1, the control unit 4 may be configured to acquire position information (latitude and longitude) of the vehicle C from a GPS 6 installed in the vehicle C, or to acquire image information from a camera 5 that can capture images of the road surface R around the vehicle C, as necessary.

[0011] The projection unit 2 is, for example, a projector, and is attached to each of the left side mirror (inside or below the side mirror) and the right side mirror (inside or below the side mirror) of the vehicle C. Under the control of the control unit 4, the projection unit 2 irradiates a first irradiation light L1 representing a first image M1 onto a road surface R around the vehicle C.

[0012] The projection unit 2 may be attached only to either the left or right side mirror, for example, the driver's seat side mirror. In this case, the first illumination light L1 is projected and displayed only on either the left or right side of the vehicle C, and the first illumination light L1 is not irradiated onto the road surface R on the side where the projection unit 2 is not attached.

[0013] Furthermore, the projector of the projection unit 2 may, for example, house the light source unit inside the dashboard of the vehicle C, place the emission unit below the side mirror, connect the light source unit and the emission unit with an optical fiber, send the RGB light generated by the light source unit to the emission unit, and emit the first irradiation light L1 as a display image from the emission unit.

[0014] Furthermore, the projector of the projection unit 2 may be installed anywhere other than the side mirrors, such as on the front and rear bumpers, as long as it can project and display the first image M1 onto the road surface around the vehicle C. Furthermore, the first image M1 shown in Fig. 1 is an image that is projected and displayed when notifying a person outside the vehicle C that the doors of the vehicle C have been unlocked, but is not limited to this.

[0015] The detection unit 3 is a sensor that detects light, such as a photosensor or illuminance sensor, and is arranged in the side mirror near the projection unit 2. The detection unit 3 detects the brightness of the environment around the vehicle C, in particular the brightness of the illumination area of ​​the road surface R that is illuminated with the first illumination light L1 representing the first image M1. The brightness detected here is, for example, illuminance or luminance.

[0016] The detection unit 3 may be installed not only near the projection unit 2 on the side mirror, but also by using various sensors that are previously installed in various parts of the vehicle C for other purposes.

[0017] The control unit 4 has a computer connected to at least the projection unit 2 and the detection unit 3 in a state where it can send and receive any information, including control signals, to and from them, and is housed in, for example, an instrument panel. The control unit 4 receives the detection result from the detection unit 3 and executes a brightness determination process to determine whether the detected brightness is equal to or greater than a predetermined brightness. The control unit 4 also executes an image position determination process to determine whether at least a portion of the first image M1 projected and displayed on the road surface R by the projection unit 2 is located outside the shadow region RF of the vehicle C that appears on the road surface R. When the brightness determination process determines that the detected brightness is equal to or greater than the predetermined brightness and the image position determination process determines that at least a portion of the first image M1 is located outside the shadow region RF of the vehicle C, the control unit 4 executes an image adjustment process to adjust the first irradiation light L1 from the projection unit 2 so that the entire first image M1 is located within the shadow region RF of the vehicle C.

[0018] 3 is a functional block diagram showing the configuration of the control unit 4 in the vehicle projection device 1 according to this embodiment. The control unit 4 includes a brightness determination unit 31 that determines whether the brightness is equal to or greater than a predetermined value based on the brightness detection result of the detection unit 3, a shadow identification unit 32 that identifies the position of a shadow region RF of the vehicle C cast on the road surface R by sunlight based on image information captured by the camera 5 or using information such as the position (GPS 6), shape (vehicle body information storage unit 35 (storage unit)), and sun position (sun position acquisition unit 36) of the vehicle C, an image position determination unit 33 that determines whether at least a portion of a first image M1 displayed on the road surface R by the projection unit 2 is located outside the shadow region RF of the vehicle C based on the result of identification by the shadow identification unit 32, and an image adjustment unit 34 that adjusts the first irradiation light L1 irradiated by the projection unit 2 based on the processing results of the brightness determination unit 31 and the image position determination unit 33 so that the entire first image M1 is located within the shadow region RF of the vehicle C.

[0019] The brightness determination unit 31 executes a brightness determination process to determine whether the brightness (e.g., illuminance or brightness) value detected by the detection unit 3 is equal to or greater than a predetermined value. The predetermined value is set, for example, to a value (at least higher than the brightness of the first image M1) such that if the brightness becomes higher than this value, the first image M1 represented by the first irradiation light L1 emitted by the projection unit 2 becomes difficult for the viewer to recognize. In addition to this, it is also possible to perform brightness determination that takes into account not only the detection result of the detection unit 3 but also the illuminance of the first irradiation light L1 emitted by the projection unit 2. Specifically, the display illuminance (lx) of the first irradiation light L1 relative to the background road surface illuminance (lx) may be calculated as a contrast, and whether this contrast is equal to or greater than a predetermined value may be determined. In this case, the predetermined value may be adjusted to an appropriate value depending on the brightness according to the time of day and weather (e.g., bright in the morning or afternoon and dark at night, bright on sunny days and dark on cloudy or rainy days) and the wavelength of the first irradiation light L1 (e.g., differences in the color of the emitted light).

[0020] The shadow identification unit 32 executes a shadow identification process to identify the position of the shadow region RF of the vehicle C cast on the road surface R by sunlight. This can be done by executing either of the following two processes. The first process acquires an image from the camera 5 capable of capturing images of the area around the vehicle C, and performs image analysis on the acquired image to identify the shadow region RF. That is, the image analysis detects the edge between the shadow region RF and a non-shadow area to identify the shadow region RF. The second process identifies the shadow region RF cast by the vehicle C based on information indicating the position of the sun acquired by the sun position acquisition unit 36 ​​based on the position information of the vehicle C acquired from the GPS 6, etc., and shape information related to the body shape (including size) of the vehicle C registered in advance in the vehicle body information storage unit 35.

[0021] Here, a detailed description of the first process will be omitted since a known image analysis technique can be used for the first process. The second process will be specifically described below.

[0022] The solar position acquisition unit 36 ​​utilizes the GPS 6 of the car navigation system installed in the vehicle C to acquire vehicle C's position information (latitude, longitude) and other available calendar and time information, and executes a position information acquisition process to calculate the position of the sun based on this information. Methods for calculating the solar position are widely known, and here we will briefly explain an example using a solar position database. The solar position database records, for example, the solar declination, geocentric solar distance, and equation of time for each calendar day. These may be publicly available data, or may be calculated by calculation to create a database. The solar position acquisition unit 36 ​​calculates the position of the sun (the azimuth and altitude (elevation angle) of the sun as seen from the Earth's surface) at the position of the vehicle C at that time on the acquired calendar day.

[0023] The position of the sun may be obtained by calculation as described above, or it may be obtained by using, for example, commonly available software or applications (including those available online), inputting the necessary parameters, and obtaining only the results.

[0024] The vehicle body information storage unit 35 stores in advance information about the shape of the vehicle body, such as the overall width, overall length, overall height, and body type of the vehicle C.

[0025] The shadow identification unit 32 identifies a shadow region RF occurring around the vehicle C by using the relative position of the sun as seen from the vehicle C at the current time acquired by the sun position acquisition unit 36 ​​and shape information registered in the vehicle body information storage unit 35. Fig. 4 is a diagram showing how the shadow identification unit 32 in the vehicular projection device 1 according to this embodiment identifies the shadow region RF when the sun is directly above the vehicle C, and Fig. 5 is a diagram showing how the shadow identification unit 32 in the vehicular projection device 1 according to this embodiment identifies the shadow region RF when the sun is obliquely directed from the vehicle C. Figs. 4(A) and 5(A) are front views of the vehicle C, and Figs. 4(B) and 5(B) are side views of the vehicle C.

[0026] As shown in Figures 4 and 5, in the second process, the relative positional relationship between the sun and vehicle C and vehicle body information are identified, and the shadow area RF of vehicle C caused by the sun can be calculated and identified.

[0027] The vehicle body shape registered in the vehicle body information storage unit 35 may be registered in a state that approximates a simplified rectangular shape, for example, as shown by the dotted lines in Figures 4 and 5. Furthermore, a conversion that approximates the simplified shape as shown by the dotted lines may be performed during the calculation process of the shadow identification unit 32. This simplifies the calculation for identifying the shadow region RF.

[0028] 3, the control unit 4 is configured to be able to execute both the first process and the second process, but it may be configured to be able to execute only one of the processes. In other words, if only the first process is executable, input from the GPS 6, the vehicle body information storage unit 35, and the sun position acquisition unit 36 ​​are not required to execute the shadow identification process. On the other hand, if only the second process is executable, input from the camera 5 is not required to execute the shadow identification process.

[0029] The image position determination unit 33 executes an image position determination process to determine whether at least a part of the first image M1 projected and displayed by the projection unit 2 onto the road surface R is located outside the shadow region RF. That is, the image position determination unit 33 compares the display area of ​​the first image M1 projected and displayed by the projection unit 2 under the control of the control unit 4 with the shadow region RF identified by the shadow identification unit 32, and determines whether the entire display area is included in the shadow region RF.

[0030] When the brightness determination unit 31 determines that the brightness is above a predetermined level and the image position determination unit 33 determines that at least a portion of the first image M1 is located outside the shadow area RF of the vehicle C, the image adjustment unit 34 executes an image adjustment process to adjust the first irradiation light L1 from the projection unit 2 so that the entire first image M1 is located within the shadow area RF of the vehicle C.

[0031] 6A and 6B are diagrams showing a process in which the image adjustment unit 34 adjusts the position of the first image M1 in the vehicle projection device 1 according to this embodiment. Fig. 6A shows the state before adjustment by the image adjustment unit 34, and Fig. 6B shows the state after adjustment by the image adjustment unit 34. In Fig. 6, the image adjustment unit 34 moves the first image M1 toward the vehicle C and adjusts the first irradiation light L1 from the projection unit 2 so that the entire first image M1 is located within the shadow region RF.

[0032] That is, as shown in Fig. 6(A), before the adjustment, the first image M1 is projected and displayed in a sunny area where sunlight directly hits (hereinafter referred to as the non-shadow area RZ), so the background road surface R is bright and the contrast with the first irradiated light L1 representing the first image M1 is small, making it difficult for the viewer to view the first image M1. On the other hand, as shown in Fig. 6(B), after the adjustment, the entire first image M1 is projected and displayed in the shadow area RF, so the contrast between the brightness of the background road surface R and the first irradiated light L1 is large, making it easier for the viewer to view the first image M1.

[0033] Note that Figure 6(A) shows a state in which the entire first image M1 is projected and displayed in the non-shadow region RZ, but as described above, the image adjustment process may be performed if even a portion of the first image M1 is projected and displayed in the non-shadow region RZ.

[0034] Furthermore, each processing unit of the brightness determination unit 31, the shadow identification unit 32, the image position determination unit 33 and the image adjustment unit 34 may be constantly executed to maintain a state in which the entire first image M1 is always within the shadow region RF, or may be executed periodically (for example, every few seconds to a few minutes) in accordance with the movement of the sun to minimize the state in which the first image M1 becomes difficult to see, or may be executed in response to a detected change in the direction of the vehicle C or the weather, etc.

[0035] Although Fig. 6 describes the process of moving the projection display position of the first image M1 into the shadow region RF, other image adjustment processes are also possible. Fig. 7 is a diagram showing the process of adjusting the position and size of the first image M1 by the image adjustment unit 34 in the vehicular projection device 1 according to this embodiment. Fig. 7(A) shows the state before adjustment by the image adjustment unit 34 when the vehicle C is viewed from above, and Fig. 7(B) shows the state after adjustment by the image adjustment unit 34 when the vehicle C is viewed from above. In Fig. 7, the image adjustment unit 34 adjusts the first irradiation light L1 from the projection unit 2 so as to reduce the size of the first image M1 and position the entire first image M1 within the shadow region RF.

[0036] That is, as shown in Figure 7, when the size of the shadow region RF is small compared to the display area of ​​the first image M1 in the state of Figure 7(A), and the entire first image M1 does not fit within the shadow region RF simply by moving the display position of the first image M1, as shown in Figure 7(B), by adjusting the first irradiation light L1 to reduce the size of the first image M1, the entire first image M1 is made to fit within the shadow region RF.

[0037] In addition, the image adjustment unit 34 can adjust the first irradiation light L1 from the projection unit 2 so as to variably rotate the first image M1. Fig. 8 is a diagram showing the process in which the image adjustment unit 34 rotates and adjusts the first image M1 in the vehicle projection device 1 according to this embodiment. Fig. 8(A) shows the display state when the shadow region RF is large, and Fig. 8(B) shows the display state when the shadow region RF is small (both when the vehicle C is viewed from above).

[0038] As shown in FIG. 8, when the sun gradually rises in the morning, the shadow region RF gradually transitions from the state of the shadow region RF in FIG. 8(A) to the state of the shadow region RF in FIG. 8(B). That is, the shadow region RF gradually becomes smaller. Accordingly, the first image M1 gradually moves toward the vehicle C through the processing performed by each processing unit of the control unit 4. At this time, the image adjustment unit 34 rotates the first image M1. That is, as shown as an example in FIG. 8, when a viewer opens a side door of the vehicle C, the first irradiation light L1 from the projection unit 2 is adjusted to rotate in an arc around a position where the viewer is estimated to stop when opening the door, depending on the size of the shadow region RF. This improves the viewer's visibility. In particular, when the first image M1 is a character, visibility is significantly improved.

[0039] In Figure 8, the first image M1 is rotated in accordance with changes in the shadow region RF, but regardless of changes in the shadow region RF, i.e., even if the entire first image M1 is contained within the shadow region RF, when the presence of a viewer is detected, the first irradiation light L1 from the projection unit 2 may be adjusted so that the first image M1 is variably rotated to improve visibility for the viewer.

[0040] Next, the operation of the vehicle projection device 1 will be described. FIG. 9 is a flowchart showing the operation of the vehicle projection device 1 according to this embodiment. First, the detection unit 3 detects the brightness of the environment surrounding the vehicle C (S1). The brightness determination unit 31 of the control unit 4 determines whether the detected brightness is equal to or greater than a predetermined brightness (S2). If the brightness is not equal to or greater than the predetermined brightness, it can be determined that the brightness does not pose a problem in the visibility of the first image M1, and the process ends without doing anything. If the brightness is equal to or greater than the predetermined brightness, it can be determined that there may be a problem in the visibility of the first image M1, and the process proceeds to the subsequent steps.

[0041] If the brightness of the environment surrounding the vehicle C is equal to or greater than a predetermined level, the shadow identification unit 32 identifies a shadow region RF caused by the vehicle C (S3). In this process at S3, the shadow region RF is identified using either the first process or the second process, as described above. The image position determination unit 33 determines whether at least a portion of the first image M1 is located outside the shadow region RF based on the irradiation range of the first irradiation light L1 emitted by the projection unit 2 and the shadow region RF identified in S3 (S4). If the first image M1 is not located outside the shadow region RF, it is determined that there is no problem with visibility, and the process ends. If the first image M1 is located outside the shadow region RF, the image adjustment unit 34 adjusts the first irradiation light L1 so that the entire first image M1 is located within the shadow region RF (S5). The projection unit 2 irradiates the road surface R with the first irradiation light L1 adjusted by the control unit 4 (S6), and the process ends.

[0042] As described above, the vehicle projection device 1 of this embodiment includes at least one projection unit 2 that emits first illumination light L1 to display a first image M1 on the road surface R, a detection unit 3 that detects the brightness of the environment surrounding the vehicle C, and a control unit 4 that controls the at least one projection unit 2. The control unit 4 performs a brightness determination process to determine whether the brightness detected by the detection unit 3 is equal to or greater than a predetermined brightness, an image position determination process to determine whether at least a portion of the first image M1 displayed on the road surface R by the projection unit 2 is located outside the shadow of the vehicle C that appears on the road surface R, and an image adjustment process to adjust the first illumination light L1 from the projection unit 2 so that the entire first image M1 is located inside the shadow of the vehicle C, when the brightness determination process determines that the brightness is equal to or greater than the predetermined brightness and the image position determination process determines that the first image M1 is located outside the shadow of the vehicle C. Therefore, even during the day when the sunlight is bright, the contrast of the first image M1 is increased by using the shadow as a background, and the viewer can clearly see the first image M1.

[0043] Furthermore, if necessary, the vehicle projection device 1 of this embodiment includes at least one projection unit 2 that irradiates first irradiation light L1 to display a first image M1 on the road surface R, and a control unit 4 that controls the at least one projection unit 2. The control unit 4 performs a shadow identification process to identify the position of the shadow of the vehicle C cast on the road surface R by sunlight, an image position determination process to determine whether or not at least a portion of the first image M1 displayed on the road surface R by the projection unit 2 is located outside the shadow of the vehicle C based on the identification result of the shadow identification process, and an image adjustment process to adjust the first irradiation light L1 from the projection unit 2 so that the entire first image M1 is located inside the shadow of the vehicle C when it is determined by the image position determination process that the first image M1 is located outside the shadow of the vehicle C. Therefore, even during the day when the sunlight is bright, the contrast of the first image M1 is increased by using the shadow as a background, and the viewer can clearly see the first image M1.

[0044] Furthermore, if necessary, the device is further provided with a detection unit 3 that detects the brightness of the environment surrounding the vehicle C, and the control unit 4 executes a brightness determination process that determines whether the brightness detected by the detection unit 3 is equal to or greater than a predetermined brightness. If the image position determination process determines that the vehicle is located outside the shadow of the vehicle C and the brightness determination process determines that the brightness is equal to or greater than the predetermined brightness, the image adjustment process adjusts the first irradiation light L1 from the projection unit 2 so that the entire first image M1 is located within the shadow of the vehicle C. Therefore, even if the brightness detected by the detection unit 3 is such that the road surface R is bright to a certain extent and the first image M1 is difficult to see as it is, the first irradiation light L1 can be adjusted to make the first image M1 clearly visible.

[0045] Furthermore, if necessary, the control unit 4 further has a vehicle body information storage unit 35 that stores shape information of the vehicle C, and the control unit 4 executes a position information acquisition process to acquire position information of the sun, and in the shadow identification process, the position of the shadow of the vehicle C is identified based on the shape information of the vehicle C stored in the vehicle body information storage unit 35 and the position information of the sun acquired in the position information acquisition process.In order to do this, for example, by utilizing the results of a publicly known sun position database, an application or software that calculates the sun position, etc., the sun's position information can be acquired easily and inexpensively, and the shadow area RF can be accurately identified based on the acquired information and the shape information of the vehicle C.

[0046] Furthermore, if necessary, in the image adjustment process, the control unit 4 adjusts the first irradiation light L1 from the projection unit 2 so as to move the first image M1 toward the vehicle C and position the entire first image M1 within the shadow region RF.Therefore, the first image M1, which would otherwise extend outside the shadow region RF formed around the vehicle C, can be moved inside the shadow region RF so as to move it closer to the vehicle C, thereby making it easier to see.

[0047] Furthermore, if necessary, in the image adjustment process, the control unit 4 adjusts the first irradiation light L1 from the projection unit 2 to reduce the size of the first image M1 and position the entire first image M1 within the shadow area RF.Therefore, by reducing the first image M1, which would otherwise extend beyond the shadow by a size larger than the shadow area RF formed around the vehicle C, and fitting it within the shadow area RF, it is possible to clarify visibility.

[0048] Furthermore, if necessary, the control unit 4 adjusts the first irradiation light L1 from the projection unit 2 in the image adjustment process so as to variably rotate the first image M1, thereby rotating the first image at an appropriate angle depending on the size of the shadow area RF formed around the vehicle C, for example, so that the first image can be displayed in an orientation that is easier for the viewer to understand.

[0049] (Second embodiment of the present invention) The vehicular projection device 1 according to this embodiment will be described with reference to Figures 10 and 11. The vehicular projection device 1 according to this embodiment projects and displays an image M when the sun is directly above the vehicle C and a shadow region RF is only present under the vehicle body. Note that descriptions of this embodiment that overlap with those of the first embodiment will be omitted.

[0050] In the vehicle projection device 1 according to this embodiment, the projection unit 2 is made up of a first projection unit 2a that emits first illumination light L1 representing a first image M1, and a second projection unit 2b that is separate from the first projection unit 2a. The first projection unit 2a is installed so as to emit illumination light onto the road surface R from the side mirror, as in the first embodiment, and the second projection unit 2b is installed so as to emit illumination light onto the road surface R directly below from, for example, the back side of the side sill of the vehicle C (the side edge of the bottom of the vehicle body).

[0051] The control unit 4 of the vehicular projection device 1 according to this embodiment executes a shadow determination process to determine whether or not a shadow region RF of the vehicle C exists within the illumination range (first projection range) of the first illumination light L1 by the first projection unit 2a on the road surface R. This shadow determination process is executed by a shadow determination unit (not shown), and may determine whether or not the illumination range of the first illumination light L1 can be secured based on the area of ​​the shadow region RF identified by the shadow identification unit 32, or may determine whether or not the entire first image M1 represented by the first illumination light L1 can be projected and displayed within the shadow region RF based on the position of the shadow region RF.

[0052] Alternatively, whether or not a shadow region RF exists in the irradiation range of the first irradiation light L1 may be determined based on whether or not the position of the sun calculated by the sun position acquisition unit 36 ​​is within a preset range of azimuth and altitude (elevation angle). Furthermore, whether or not a shadow region RF exists in the irradiation range of the first irradiation light L1 may be determined based on whether or not the brightness detected by the detection unit 3 is equal to or greater than a predetermined brightness (brightness at which it can be determined that the shadow region RF is almost absent and that sunlight is directly irradiating the area). Furthermore, whether or not a shadow region RF exists in the irradiation range of the first irradiation light L1 may be determined by analyzing the image captured by the camera 5.

[0053] When it is determined in the shadow determination process by the shadow determination unit that no shadow region RF exists, the control unit 4 further executes a projection control process to control the second projection unit 2b to irradiate a second irradiation light L2 for displaying a second image M2 (second predetermined image) corresponding to the first image M1 into an irradiation range (second projection range) that is located directly below the vehicle C with respect to the irradiation range of the first irradiation light L1 on the road surface R and that is included in a direct shadow region RG generated by the vehicle C directly below the vehicle C.

[0054] This projection control process is executed by a projection control unit (not shown), and as described above, when the first projection unit 2a is unable to irradiate the first irradiation light L1 into the shadow region RF, the second projection unit 2b irradiates the second irradiation light L2 representing the second image M2 into the direct shadow region RG that always appears directly below the vehicle C regardless of the position of the sun. This second image M2 has the same content as the first image M1 but is different in size, orientation, etc.

[0055] 10A and 10B are diagrams illustrating a state in which the second projection unit 2b projects and displays the second image M2 in the vehicle projection device 1 according to this embodiment. Fig. 10A illustrates a state in which the first projection unit 2a projects and displays the second image M2, and Fig. 10B illustrates a state in which the second projection unit 2b projects and displays the second image M2. As shown in Fig. 10A, there is no shadow region RF that encompasses the entire illumination range of the first illumination light L1 emitted by the first projection unit 2a. Therefore, as shown in Fig. 10B, the second projection unit 2b irradiates the second illumination light L2 representing the second image M2 onto the necessarily present direct shadow region RG.

[0056] As described above, the second image M2 is projected and displayed at a different size from the first image M1, and it is desirable that the size of this second image M2 be approximately the width of the tires of the vehicle C. Fig. 11 is a view from the front of the vehicle C showing a state in which the second projection unit 2b projects and displays the second image M2 in the vehicular projection device 1 according to this embodiment. As shown in Fig. 11, the second image M2 is projected and displayed within the range of the tire width, so that the viewer can reliably view the second image M2 without missing it.

[0057] As described above, in the vehicle projection device 1 according to this embodiment, at least one projection unit 2 is a plurality of projection units 2 including a first projection unit 2a that irradiates the first irradiation light L1 and a second projection unit 2b that is different from the first projection unit 2a, and the control unit 4 performs a shadow determination process to determine whether or not a shadow region RF of the vehicle C exists in the irradiation range of the first irradiation light L1 by the first projection unit 2a on the road surface R, and, when it is determined that no shadow region RF exists in the shadow determination process, performs a shadow determination process to determine whether or not a shadow region RF of the vehicle C exists in the irradiation range of the road surface R that is located directly below the vehicle C with respect to the irradiation range of the first irradiation light L1 and that is included in the shadow region RG directly below the vehicle C. A projection control process is executed to control the second projection unit 2b to emit the second irradiation light L2 for displaying the image M2. In this case, for example, if the sun is positioned almost directly above the vehicle C, the shadow area RF caused by sunlight may hardly be formed outside the vehicle C, and may deviate from the predetermined irradiation range for irradiating the first irradiation light L1. In order to deal with such cases, a second projection unit 2b separate from the first projection unit 2a is prepared in advance, and by irradiating the second irradiation light L2 onto the direct shadow area RG generated directly below the vehicle C, a second image M2 corresponding to the above-mentioned first image M1 can be projected and displayed. [Explanation of symbols]

[0058] C vehicle L1 1st irradiation light L2 2nd irradiation light M1 1st image M2 2nd image R Road surface RF shadow area RG Direct shadow area RZ non-shadow area 1. Vehicle projection device 2 Projection section 2a 1st projection section 2b 2nd projection section 3. Detection unit 4. Control section 5. Camera 6. GPS 31 Brightness determination unit 32 Shadow identification part 33 Image position determination section 34 Image adjustment section 35 Vehicle information storage unit 36 Sun position acquisition part

Claims

1. A vehicle projection device provided on a vehicle traveling on a road, at least one projection unit that projects a first projection light for displaying a first predetermined image on the road surface; a detection unit that detects the brightness of the surrounding environment of the vehicle; a control unit that controls the at least one projection unit; Equipped with The control unit a brightness determination process for determining whether the brightness detected by the detection unit is equal to or greater than a predetermined brightness; an image position determination process for determining whether or not at least a part of the first predetermined image displayed on the road surface by the projection unit is located outside a shadow of the vehicle that appears on the road surface; When the brightness determination process determines that the brightness is equal to or greater than the predetermined brightness and the image position determination process determines that the image is located outside the shadow, an image adjustment process is executed to adjust the first irradiation light from the projection unit so that the entire first predetermined image is located inside the shadow. A vehicle projection device.

2. A vehicle projection device provided on a vehicle traveling on a road, at least one projection unit that projects a first projection light for displaying a first predetermined image on the road surface; a control unit that controls the at least one projection unit; Equipped with The control unit a shadow identification process for identifying a position of a shadow of the vehicle cast on the road surface by sunlight; an image position determination process that determines whether or not at least a part of the first predetermined image displayed on the road surface by the projection unit is located outside the shadow, based on an identification result of the shadow identification process; When it is determined that the first predetermined image is located outside the shadow by the image position determination process, an image adjustment process is executed to adjust the first irradiation light from the projection unit so that the entire first predetermined image is located inside the shadow. A vehicle projection device.

3. A detection unit that detects the brightness of the surrounding environment of the vehicle is further provided, The control unit further executes a brightness determination process to determine whether the brightness detected by the detection unit is equal to or greater than a predetermined brightness; When the image position determination process determines that the image is located outside the shadow and the brightness determination process determines that the brightness is equal to or greater than the predetermined brightness, the image adjustment process adjusts the first irradiation light from the projection unit so that the entire first predetermined image is located inside the shadow.

3. The vehicle projection device according to claim 2.

4. Further, a storage unit that stores the shape information of the vehicle is provided. The control unit further Execute a position information acquisition process to acquire the position information of the sun, In the shadow identification process, the position of the shadow is identified according to the shape information of the vehicle stored in the storage unit and the position information of the sun acquired in the position information acquisition process.

4. The vehicle projection device according to claim 3.

5. The control unit In the image adjustment process, the first predetermined image is moved toward the vehicle, and the first irradiation light from the projection unit is adjusted so that the entire first predetermined image is positioned inside the shadow.

3. The vehicle projection device according to claim 1 or 2.

6. The control unit In the image adjustment process, the size of the first predetermined image is reduced and the first irradiation light from the projection unit is adjusted so that the entire first predetermined image is positioned inside the shadow.

3. The vehicle projection device according to claim 1 or 2.

7. The control unit In the image adjustment process, the first irradiation light from the projection unit is adjusted so as to variably rotate the first predetermined image.

3. The vehicle projection device according to claim 1 or 2.

8. The at least one projection unit a plurality of projection units including a first projection unit that irradiates the first irradiation light and a second projection unit that is different from the first projection unit, The control unit further a shadow determination process for determining whether or not the shadow of the vehicle exists within a first projection range on the road surface by the first projection unit; and executing a projection control process for controlling the second projection unit to irradiate a second projection range, which is located directly below the vehicle with respect to the first projection range on the road surface and is included in the shadow of the vehicle, with second irradiation light for displaying a second predetermined image corresponding to the first predetermined image, when it is determined in the shadow determination process that the shadow does not exist.

3. The vehicle projection device according to claim 1 or 2.

Images