Road surface drawing device

Abstract

According to the present invention, a light pattern is divided into a plurality of first regions in the traveling direction of a vehicle. The first regions are further divided into a plurality of second regions in the traveling direction of the vehicle. After the second regions located closest to the vehicle in the plurality of first regions are drawn, the remaining second regions not drawn in the plurality of first regions are drawn.

Description

road surface drawing device

[0001] The present disclosure relates to a road surface drawing device.

[0002] Patent Document 1 discloses a road surface drawing device that is mounted on a vehicle and illuminates the road surface to draw a light pattern on the road surface, thereby indicating intentions to other traffic participants (pedestrians, occupants of other vehicles, etc.).

[0003] International Publication No. 2020 / 067113

[0004] However, the inventor noticed that, for example, when a light pattern is drawn in which the illuminated area changes gradually from the area closest to the vehicle to the area farthest from the vehicle, there is a risk that traffic participants such as pedestrians around the vehicle may be delayed in recognizing the light pattern.

[0005] One of the objects of the present disclosure is to provide a road surface drawing device that can quickly communicate the vehicle's traveling direction to traffic participants located far from the vehicle.

[0006] Furthermore, for example, when a light pattern is drawn so as to flash, it may be difficult for traffic participants such as pedestrians around the vehicle to grasp the traveling direction of the vehicle represented by the flashing light pattern. Also, for example, there is a method of representing the traveling direction of the vehicle by drawing a light pattern in which the illuminated area changes stepwise from the area closest to the vehicle to the area farthest from the vehicle, but there is a risk that the timing at which traffic participants such as pedestrians who are far from the vehicle recognize the light pattern may be delayed.

[0007] One of the objects of the present disclosure is to provide a road surface drawing device that can quickly communicate the vehicle's traveling direction to traffic participants around the vehicle.

[0008] A road surface drawing device according to one aspect of the present invention is a road surface drawing device that is mounted on a vehicle and draws a light pattern on a road surface, wherein the light pattern is divided into a plurality of first areas in the direction of travel of the vehicle, and the first areas are further divided into a plurality of second areas in the direction of travel of the vehicle, and after each of the second areas that are located closest to the vehicle among the plurality of first areas is drawn, the remaining second areas that have not been drawn among the plurality of first areas are drawn.

[0009] According to the above configuration, at least a portion of each of the multiple first regions is drawn first, so that at least a portion of the first regions located farthest from the vehicle are also drawn. Furthermore, since the multiple second regions are drawn in stages in order of proximity to the vehicle, the movement of light corresponding to the vehicle's movement can be expressed in each first region. This allows the vehicle's traveling direction to be quickly communicated to traffic participants located farther from the vehicle.

[0010] A road surface drawing device according to one aspect of the present disclosure is a road surface drawing device that is mounted on a vehicle and draws a light pattern on a road surface, wherein the light pattern is divided into a plurality of regions in the direction of travel of the vehicle, and light is irradiated onto all of the regions as soon as drawing of the light pattern begins, and the illuminance of the farthest region located farthest from the vehicle is lower than the illuminance of the nearest region located nearest to the vehicle at the start of drawing, and increases as the drawing time of the light pattern passes.

[0011] According to the above configuration, all areas constituting the light pattern are drawn simultaneously, allowing traffic participants located far from the vehicle to quickly recognize the light pattern. Furthermore, since the illuminance of the farthest area increases over the drawing time, the light pattern changes so that the illuminance increases from the area closest to the vehicle over the drawing time. This allows traffic participants around the vehicle to recognize that the illuminated area of ​​the light pattern is drawn gradually increasing from the nearest area to the farthest area. Therefore, the vehicle's traveling direction can be quickly communicated to traffic participants around the vehicle.

[0012] According to the present disclosure, it is possible to provide a road surface drawing device that can quickly communicate the vehicle's traveling direction to traffic participants located far from the vehicle.

[0013] According to the present disclosure, it is possible to provide a road surface drawing device that can quickly communicate the vehicle's traveling direction to traffic participants around the vehicle.

[0014] FIG. 1 illustrates a light pattern drawn on a road surface by a road drawing device mounted on a vehicle. FIG. 2 illustrates the configuration of the road drawing device. FIG. 3 illustrates the timing of turning on and off light sources forming a first region located closest to the vehicle that constitutes the light pattern shown in FIG. 1. FIG. 4 illustrates the timing of turning on and off light sources forming a first region located in the center that constitutes the light pattern shown in FIG. 1. FIG. 5 illustrates the timing of turning on and off light sources forming a first region located farthest from the vehicle that constitutes the light pattern shown in FIG. 1. FIG. 6 illustrates the manner in which a light pattern is drawn based on the timing of turning on and off light sources shown in FIGS. 3 to 5. FIG. 7 illustrates a road situation in which a wall exists between a pedestrian and the light pattern. FIG. 8 illustrates another example of the timing of turning on and off light sources forming a first region located closest to the vehicle that constitutes the light pattern shown in FIG. 1. FIG. 9 illustrates another example of the timing of turning on and off light sources forming a first region located in the center that constitutes the light pattern shown in FIG. 1. FIG. 10 shows another example of the timing of turning on and off light sources that form the first region located farthest from the vehicle, which constitutes the light pattern shown in FIG. 1 . FIG. 11 illustrates an example of drawing a light pattern formed based on the timing of turning on and off shown in FIGS. 8 to 10 . FIG. 12 shows another example of a light pattern drawn on a road surface by a road surface drawing device mounted on a vehicle. FIG. 13 illustrates an example of a light pattern drawn on a road surface by a road surface drawing device mounted on a vehicle. FIG. 14 illustrates an example of the configuration of a road surface drawing device. FIG. 15 illustrates an example of a time chart showing the turning on and off of semiconductor light-emitting elements of the light source unit. FIG. 16 illustrates an example of drawing a light pattern formed based on the time chart showing the turning on and off of the light source unit shown in FIG. 15 . FIG. 17 illustrates an example of a time chart showing the turning on and off of semiconductor light-emitting elements of the light source unit according to Modification 1. FIG. 18 illustrates an example of drawing a light pattern formed based on the turning on and off of the light source unit shown in FIG. 17 . FIG. 19 illustrates an example of a time chart showing the turning on and off of semiconductor light-emitting elements of the light source unit according to Modification 2. FIG. 20 illustrates a time chart showing the turning on and off of the semiconductor light emitting elements of the light source unit according to the third modification.Fig. 21 illustrates a time chart showing the turning on and off of semiconductor light-emitting elements of a light source unit according to Modification 4. Fig. 22 illustrates a time chart showing the turning on and off of semiconductor light-emitting elements of a light source unit according to Modification 5. Fig. 23 illustrates a light pattern in which a drawing is erased based on the turning on and off of the light source unit shown in Fig. 22. Fig. 24 illustrates a time chart showing the turning on and off of semiconductor light-emitting elements of a light source unit according to Modification 6.

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component. Furthermore, in the drawings described below, the symbol U indicates the upward direction. The symbol D indicates the downward direction. The symbol F indicates the forward direction. The symbol B indicates the rearward direction. The symbol L indicates the leftward direction. The symbol R indicates the rightward direction. These directions correspond to the directions as seen by a passenger aboard the vehicle 100.

[0016] 1 illustrates a light pattern P1 drawn by a road surface drawing device 1 according to this embodiment. The road surface drawing device 1 is mounted on a vehicle 100. In this example, the road surface drawing device 1 is disposed in a lamp chamber of a headlight of the vehicle 100.

[0017] The road surface drawing device 1 is configured to irradiate the road surface with light and draw a light pattern P1 on the road surface. In this example, the light pattern P1 is a pattern for notifying those around the vehicle 100 that the vehicle 100 will change course to the left. The light pattern P1 is drawn on the road surface, for example, while a lamp (not shown) for notifying those around the vehicle 100 that the vehicle 100 will change course to the left is on.

[0018] The light pattern P1 is divided into a plurality of first regions in the traveling direction of the vehicle 100. In this example, the light pattern P1 includes three first regions P11, P12, and P13. The first regions P11, P12, and P13 are divided in the left front direction of the vehicle 100. The first region P11 is located closest to the vehicle 100. The first region P13 is located farthest from the vehicle 100. The first region P12 is located between the first region P11 and the first region P13. The first regions P11, P12, and P13 are lined up with gaps between them along the left front direction of the vehicle 100. The "left front direction" is a direction extending "to the left" and "forward."

[0019] In this example, the first regions P11, P12, and P13 are each formed in a chevron shape. The farther the first regions P11, P12, and P13 are from the vehicle 100, the larger their areas become.

[0020] Fig. 2 illustrates an example of the configuration of the road surface drawing device 1. As illustrated in Fig. 2, the road surface drawing device 1 includes a lamp body 2 and an outer cover 3. The lamp body 2 is configured to have an opening in front of the lamp fixture. The outer cover 3 is translucent and is configured to cover the opening of the lamp body 2. The lamp body 2 and the outer cover 3 form a lamp chamber 4.

[0021] The road surface drawing device 1 includes a light source unit 5, an optical member 6, and a control unit 7. The light source unit 5, the optical member 6, and the control unit 7 are housed in a lamp chamber 4.

[0022] The light source unit 5 includes, for example, a plurality of semiconductor light-emitting elements (not shown). Examples of the semiconductor light-emitting elements include light-emitting diodes (LEDs), laser diodes (LDs), and EL elements. The plurality of semiconductor light-emitting elements are arranged in an array on the substrate 50, for example, vertically and horizontally.

[0023] The optical member 6 is configured to refract the light emitted from the light source unit 5 and emit it in the direction of the road surface. The optical member 6 is, for example, a plano-convex lens whose front surface is a convex surface and whose rear surface is a flat surface. The optical member 6 is formed of a light-transmitting material, for example, a transparent resin such as acrylic.

[0024] The control unit 7 is configured to control the turning on and off of the light source unit 5. Specifically, the control unit 7 individually controls the turning on and off of the multiple semiconductor light-emitting elements that make up the light source unit 5 so that at least a portion of the light pattern P1 is drawn on the road surface. The control unit 7 includes, for example, a microcontroller and an analog drive control circuit. The microcontroller has a general-purpose microprocessor such as a CPU, MPU, or GPU, and general-purpose memory such as a ROM or RAM. The analog drive control circuit has a current control circuit configured to control the current supplied to each of the multiple semiconductor light-emitting elements of the light source unit 5.

[0025] The on / off control of the light source unit 5 by the control unit 7 will be described in detail below.

[0026] First, the on / off control of the light source unit 5 for drawing the first region P11 of the light pattern P1 will be described with reference to Fig. 3. Fig. 3 illustrates the on / off timing of the semiconductor light-emitting element of the light source unit 5 that emits light that forms the first region P11 of the light pattern P1.

[0027] As illustrated in the upper part of Figure 3, the first region P11 of the light pattern P1 is divided into a plurality of second regions in the traveling direction of the vehicle 100. In this example, the first region P11 includes three second regions A1, A2, and A3. The second regions A1, A2, and A3 are divided in the left front direction of the vehicle 100. The second region A1 is located closest to the vehicle 100. The second region A3 is located farthest from the vehicle 100. The second region A2 is located between the second region A1 and the second region A2. The second regions A1, A2, and A3 are lined up without any gaps along the left front direction.

[0028] The control unit 7 controls the lighting of the light source unit 5 so that after the second area A1 located closest to the vehicle 100 is drawn on the road surface, the remaining multiple second areas A2, A3 are drawn on the road surface in stages in order of their proximity to the vehicle 100.

[0029] 3, the control unit 7 controls the light source unit 5 so that, at the start of drawing the light pattern P1, the semiconductor light-emitting elements that emit light to form the second region A1 among the plurality of semiconductor light-emitting elements of the light source unit 5 are turned on. When drawing of the light pattern P1 starts at time t1, the control unit 7 turns on the semiconductor light-emitting elements that emit light to form the second region A1 at time t1.

[0030] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light-emitting elements that emit light to form the second region A2, among the plurality of semiconductor light-emitting elements of the light source unit 5, are turned on. Specifically, the control unit 7 turns on the semiconductor light-emitting elements that emit light to form the second region A2 at time t2. For example, time t2 can be set to approximately 0.1 to 0.4 seconds after time t1. As a result, the second region A2 is drawn on the road surface approximately 0.1 to 0.4 seconds after the second region A1 is drawn.

[0031] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light-emitting elements that emit light to form the second region A3, among the plurality of semiconductor light-emitting elements of the light source unit 5, are turned on. Specifically, the control unit 7 turns on the semiconductor light-emitting elements that emit light to form the second region A3 at time t3. For example, time t3 can be set to approximately 0.1 to 0.4 seconds after time t2. As a result, the second region A3 is drawn on the road surface approximately 0.1 to 0.4 seconds after the second region A2 is drawn.

[0032] The control unit 7 then controls the light source unit 5 so that the images in the second regions A1, A2, and A3 are simultaneously erased when the drawing of the light pattern P1 is completed. Specifically, after all of the second regions A1, A2, and A3 have been drawn, the control unit 7 simultaneously turns off the semiconductor light-emitting elements that emit light to form the second regions A1, A2, and A3 at time t4. For example, time t4 can be set to approximately 0.3 to 1.2 seconds after time t3. As a result, the images in the second regions A1, A2, and A3 are erased approximately 0.3 to 1.2 seconds after the drawing of the second region A3.

[0033] The light pattern P1 is repeatedly drawn in synchronization with the blinking of a lamp (not shown) that notifies those around the vehicle 100 that the vehicle 100 is changing course to the left, for example.

[0034] When the drawing of the light pattern P1 is repeated at a predetermined cycle T1, the drawing of the first region P11 is also repeated at a predetermined cycle T1. The cycle T1 is appropriately set to match the blinking cycle of a lamp (not shown) that notifies those around the vehicle 100 that the vehicle 100 is changing course to the left. The cycle T1 is, for example, approximately 0.5 to 1.0 seconds.

[0035] Specifically, as illustrated in the lower part of Figure 3, at time t5, which is a period T1 after time t1, the control unit 7 turns on the semiconductor light-emitting element that emits light that forms the second region A1 among the multiple semiconductor light-emitting elements of the light source unit 5.

[0036] Next, at time t6, the control unit 7 turns on the semiconductor light emitting elements that emit light to form the second region A2 among the plurality of semiconductor light emitting elements of the light source unit 5. Next, at time t7, the control unit 7 turns on the semiconductor light emitting elements that emit light to form the second region A3 among the plurality of semiconductor light emitting elements of the light source unit 5. Then, after all of the second regions A1, A2, and A3 have been drawn, the control unit 7 simultaneously turns off the plurality of semiconductor light emitting elements that emit light to form the second regions A1, A2, and A3 at time t8.

[0037] Next, the on / off control of the light source unit 5 for drawing the first region P12 of the light pattern P1 will be described with reference to Fig. 4. Fig. 4 illustrates the on / off timing of the semiconductor light-emitting element of the light source unit 5 that emits light that forms the first region P12 of the light pattern P1. The first region P12 is drawn in the same manner as the first region P11.

[0038] Specifically, as illustrated in the upper part of Figure 4, the first region P12 of the light pattern P1 is divided into a plurality of second regions in the traveling direction of the vehicle 100. In this example, the first region P12 includes three second regions B1, B2, and B3. The second regions B1, B2, and B3 are divided in the left front direction of the vehicle 100. The second region B1 is located closest to the vehicle 100. The second region B3 is located farthest from the vehicle 100. The second region B2 is located between the second region B1 and the second region B2. The second regions B1, B2, and B3 are lined up without any gaps along the left front direction.

[0039] The control unit 7 controls the light source unit 5 to turn on and off so that after the second area B1 located closest to the vehicle 100 is drawn on the road surface, the remaining multiple second areas B2, B3 are drawn on the road surface in stages in order of their proximity to the vehicle 100.

[0040] 4, the control unit 7 controls the light source unit 5 so that, at the start of drawing the light pattern P1, the semiconductor light-emitting elements of the light source unit 5 that emit light to form the second region B1 are turned on. That is, the control unit 7 turns on the semiconductor light-emitting elements that emit light to form the second region B1 at time t1. As a result, the second region B1 of the first region P12 is drawn simultaneously with the second region A1 of the first region P11.

[0041] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light to form the second region B2 among the plurality of semiconductor light emitting elements of the light source unit 5 are turned on. Specifically, the control unit 7 turns on the semiconductor light emitting elements that emit light to form the second region B2 at time t2. As a result, the second region B2 of the first region P12 is drawn simultaneously with the second region A2 of the first region P11.

[0042] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light to form the second region B3 among the plurality of semiconductor light emitting elements of the light source unit 5 are turned on. Specifically, the control unit 7 turns on the semiconductor light emitting elements that emit light to form the second region B3 at time t3. As a result, the second region B3 of the first region P12 is drawn simultaneously with the second region A3 of the first region P11.

[0043] The control unit 7 then controls the light source unit 5 so that the images in the second regions B1, B2, and B3 are simultaneously erased when the drawing of the light pattern P1 is completed. Specifically, after the drawing of all of the second regions B1, B2, and B3 has been completed, the control unit 7 simultaneously turns off the semiconductor light-emitting elements that emit light to form the second regions B1, B2, and B3 at time t4. As a result, the images in the second regions B1, B2, and B3 in the first region P12 are erased simultaneously with the drawing of the second regions A1, A2, and A3 in the first region P11.

[0044] When the drawing of the light pattern P1 is repeated at a predetermined cycle T1, the drawing of the first region P12 is also repeated at the predetermined cycle T1, similar to the drawing of the first region P11.

[0045] Next, the on / off control of the light source unit 5 for drawing the first region P13 of the light pattern P1 will be described with reference to Fig. 5. Fig. 5 illustrates the on / off timing of the semiconductor light-emitting element of the light source unit 5 that emits light that forms the first region P13 of the light pattern P1. The first region P13 is drawn in the same manner as the first regions P11 and P12.

[0046] Specifically, as illustrated in the upper part of Figure 5, the first region P13 of the light pattern P1 is divided into a plurality of second regions in the traveling direction of the vehicle 100. In this example, the first region P13 includes three second regions C1, C2, and C3. The second regions C1, C2, and C3 are divided in the left front direction of the vehicle 100. The second region C1 is located closest to the vehicle 100. The second region C3 is located farthest from the vehicle 100. The second region C2 is located between the second region C1 and the second region C2. The second regions C1, C2, and C3 are lined up without any gaps along the left front direction.

[0047] The control unit 7 controls the light source unit 5 to turn on and off so that after the second area C1 located closest to the vehicle 100 is drawn on the road surface, the remaining multiple second areas C2, C3 are drawn on the road surface in stages in order of their proximity to the vehicle 100.

[0048] 5 , the control unit 7 controls the light source unit 5 so that, at the start of drawing the light pattern P1, the semiconductor light-emitting elements of the light source unit 5 that emit light to form the second region C1 are turned on. Specifically, the control unit 7 turns on the semiconductor light-emitting elements that emit light to form the second region C1 at time t1. As a result, the second region C1 of the first region P13 is drawn simultaneously with the second region A1 of the first region P11 and the second region B1 of the first region P12.

[0049] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light that forms the second region C2 among the plurality of semiconductor light emitting elements of the light source unit 5 are turned on. Specifically, the control unit 7 turns on the semiconductor light emitting elements that emit light that forms the second region C2 at time t2. As a result, the second region C2 of the first region P13 is drawn simultaneously with the second region A2 of the first region P11 and the second region B2 of the first region P12.

[0050] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light to form the second region C3 among the plurality of semiconductor light emitting elements of the light source unit 5 are turned on. Specifically, the control unit 7 turns on the semiconductor light emitting elements that emit light to form the second region C3 at time t3. As a result, the second region C3 of the first region P13 is drawn simultaneously with the second region A3 of the first region P11 and the second region B3 of the first region P12.

[0051] The control unit 7 then controls the light source unit 5 so that the images in the second regions C1, C2, and C3 are simultaneously erased when the drawing of the light pattern P1 is completed. Specifically, after all of the second regions C1, C2, and C3 have been drawn, the control unit 7 simultaneously turns off the semiconductor light-emitting elements that emit light to form the second regions C1, C2, and C3 at time t4. As a result, the second regions C1, C2, and C3 in the first region P13 are drawn simultaneously with the second regions A1, A2, and A3 in the first region P11.

[0052] When the drawing of the light pattern P1 is repeated at a predetermined cycle T1, the drawing of the first region P13 is also repeated at the predetermined cycle T1, similar to the drawing of the first regions P11 and P12.

[0053] Fig. 6 illustrates an example of how the light pattern P1 is drawn based on the timing of turning on and off the light source unit 5 shown in Fig. 3 to Fig. 5. In Fig. 6, the area surrounded by the dashed line is an area where light is not irradiated from the road surface drawing device 1 and no drawing is made on the road surface, and the area surrounded by the solid line is an area where light is irradiated from the road surface drawing device 1 and a drawing is made on the road surface.

[0054] 3 to 5, drawing of the light pattern P1 has not started yet, and the areas on the road surface where the first areas P11, P12, and P13 are drawn are not irradiated with light from the road surface drawing device 1. Subsequently, at time t1, when drawing of the light pattern P1 starts, second areas A1, B1, and C1 that are located closest to the vehicle 100 within the first areas P11, P12, and P13 are drawn, respectively.

[0055] Subsequently, at time t2, the second regions A2, B2, and C2 adjacent to the second regions A1, B1, and C1 in the first regions P11, P12, and P13 are respectively drawn. That is, in the light pattern P1, both the second regions A1, B1, and C1 in the first regions P11, P12, and P13 and the second regions A2, B2, and C2 are drawn.

[0056] Subsequently, at time t3, the second regions A3, B3, and C3 that are located farthest from the vehicle 100 within the first regions P11, P12, and P13 are respectively drawn. That is, in the light pattern P1, all of the second regions within the first regions P11, P12, and P13 are drawn.

[0057] Then, at time t4, the drawing of all second areas in the first areas P11, P12, and P13 is erased. When the drawing of the light pattern P1 is repeated at a predetermined cycle T1, the drawing of the first areas P11, P12, and P13 is repeated at the predetermined cycle T1.

[0058] However, for example, if a light pattern is drawn in which the illuminated area changes gradually from the area closest to vehicle 100 to the area farthest from vehicle 100, there is a risk that traffic participants such as pedestrians around vehicle 100 will be delayed in recognizing the light pattern.

[0059] 7 illustrates a situation in which a wall 300 is present between a pedestrian 200 and the first region P11 of the light pattern P1, preventing the pedestrian 200 from seeing the first region P11. The pedestrian 200 is an example of a traffic participant. The wall 300 is an example of an obstacle.

[0060] For example, when the light pattern P1 drawn on the road surface is drawn in stages from a first region P11 closest to the vehicle 100 to a first region P13 farthest from the vehicle 100, the pedestrian 200 cannot see the first region P11 because a wall 300 exists between the pedestrian 200 and the first region P11 closest to the vehicle 100. As a result, in a situation where only the first region P11 is drawn when the drawing of the light pattern P1 begins, the pedestrian 200 cannot recognize the light pattern P1.

[0061] In contrast, with the road surface rendering device 1 according to this embodiment, as illustrated in FIG. 7 , at least a portion of each of the multiple first regions P11, P12, and P13 (second regions A1, B1, and C1) is first rendered when rendering of the light pattern P1 begins. That is, at least a portion of the first region P13, which is located far from the vehicle 100, is also rendered when rendering of the light pattern P1 begins. This allows a pedestrian 200 located far from the vehicle 100 to recognize the light pattern P1 from the moment rendering of the light pattern P1 begins. Furthermore, since the multiple second regions in the first regions P11, P12, and P13 are rendered in stages in order of proximity to the vehicle 100, it is possible to express the movement of light corresponding to the motion of the vehicle 100 (in this example, motion moving forward and to the left) in each of the first regions P11, P12, and P13. This allows the traveling direction of the vehicle 100 to be quickly communicated to a pedestrian 200 located far from the vehicle 100.

[0062] In this embodiment, the light pattern P1 is divided into three first regions P11, P12, and P13. However, the light pattern P1 may be divided into two first regions or four or more first regions.

[0063] In this embodiment, each of the first regions P11, P12, and P13 is divided into three second regions. However, each of the first regions P11, P12, and P13 may be divided into two second regions or four or more second regions.

[0064] In this embodiment, the rendering of all second regions in the first regions P11, P12, and P13 of the light pattern P1 is simultaneously erased. However, the road surface rendering device 1 may be configured so that after the rendering of the second regions A1, B1, and C1 that are located closest to the vehicle 100 in the first regions P11, P12, and P13 of the light pattern P1 are erased, the rendering of the remaining second regions A2, A3, B2, B3, C2, and C3 is erased.

[0065] 8 to 11 , another example of the on / off control of the light source unit 5 by the control unit 7 will be described. Fig. 8 illustrates the timing of turning on and off the semiconductor light-emitting element of the light source unit 5 that emits light that forms the first region P11 of the light pattern P1.

[0066] The control unit 7 controls the lighting of the light source unit 5 so that after the second area A1 located closest to the vehicle 100 is drawn on the road surface, the remaining second areas A2 and A3 are drawn on the road surface in stages in order of proximity to the vehicle 100. Note that the lighting control of the light source unit 5 is the same as the lighting control of the light source unit 5 illustrated in Fig. 3, and therefore a detailed description thereof will be omitted.

[0067] The control unit 7 controls the light source unit 5 to be turned off so that after all of the second areas A1, A2, and A3 have been drawn, the drawing of the second area A1 located closest to the vehicle 100 is erased, and then the drawings of the remaining second areas A2 and A3 are erased.

[0068] 8, the control unit 7 controls the light source unit 5 so that the semiconductor light-emitting elements that emit light that forms the second region A1 among the plurality of semiconductor light-emitting elements of the light source unit 5 are turned off. Specifically, the control unit 7 turns off the semiconductor light-emitting elements that emit light that forms the second region A1 at time t11. For example, time t11 can be set to approximately 0.3 to 1.2 seconds after time t1.

[0069] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light-emitting elements that emit light to form the second region A2 among the plurality of semiconductor light-emitting elements of the light source unit 5 are turned off. Specifically, the control unit 7 turns off the semiconductor light-emitting elements that emit light to form the second region A2 at time t12. For example, time t12 can be set to approximately 0.1 to 0.4 seconds after time t11. As a result, the drawing in the second region A2 is erased approximately 0.1 to 0.4 seconds after the drawing in the second region A1 is erased.

[0070] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light-emitting elements that emit light to form the second region A3 among the plurality of semiconductor light-emitting elements of the light source unit 5 are turned off. Specifically, the control unit 7 turns off the semiconductor light-emitting elements that emit light to form the second region A3 at time t13. For example, time t13 can be set to approximately 0.1 to 0.4 seconds after time t12. As a result, the drawing in the second region A3 is erased approximately 0.1 to 0.4 seconds after the drawing in the second region A2 is erased.

[0071] When the drawing of the light pattern P1 is repeated at a predetermined cycle T1, the erasure of the drawing of the first region P11 is also repeated. Specifically, after all of the second regions A1, A2, and A3 have been drawn, the control unit 7 turns off, at time t14, the semiconductor light-emitting elements of the light source unit 5 that emit light to form the second region A1. Subsequently, at time t15, the control unit 7 turns off the semiconductor light-emitting elements of the light source unit 5 that emit light to form the second region A2. Subsequently, at time t16, the control unit 7 turns off the semiconductor light-emitting elements of the light source unit 5 that emit light to form the second region A3.

[0072] FIG. 9 illustrates the timing of turning on and off the semiconductor light emitting elements of the light source unit 5 that emit light that forms the first region P12 of the light pattern P1.

[0073] The control unit 7 controls the lighting of the light source unit 5 so that after the second area B1 located closest to the vehicle 100 is drawn on the road surface, the remaining second areas B2 and B3 are drawn on the road surface in stages in order of their proximity to the vehicle 100. Note that the lighting control of the light source unit 5 is the same as the lighting control of the light source unit 5 illustrated in Fig. 4, and therefore a detailed description thereof will be omitted.

[0074] The control unit 7 controls the light source unit 5 to be turned off so that after all of the second areas B1, B2, and B3 have been drawn, the drawing of the second area B1 located closest to the vehicle 100 is erased, and then the drawings of the remaining second areas B2 and B3 are erased.

[0075] 9 , the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light to form the second region B1 among the plurality of semiconductor light emitting elements of the light source unit 5 are turned off. Specifically, the control unit 7 turns off the semiconductor light emitting elements that emit light to form the second region B1 at time t11. As a result, the drawing of the second region B1 in the first region P12 is erased simultaneously with the drawing of the second region A1 in the first region P11.

[0076] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light to form the second region B2 are turned off among the plurality of semiconductor light emitting elements of the light source unit 5. Specifically, the control unit 7 turns off the semiconductor light emitting elements that emit light to form the second region B2 at time t12. As a result, the drawing of the second region B2 in the first region P12 is erased simultaneously with the drawing of the second region A2 in the first region P11.

[0077] Next, the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light to form the second region B3 are turned off among the plurality of semiconductor light emitting elements of the light source unit 5. Specifically, the control unit 7 turns off the semiconductor light emitting elements that emit light to form the second region B3 at time t13. As a result, the drawing of the second region B3 in the first region P12 is erased simultaneously with the drawing of the second region A3 in the first region P11.

[0078] When the drawing of the light pattern P1 is repeated at a predetermined cycle T1, the erasure of the drawing in the first region P12 is also repeated in the same manner as the first region P11.

[0079] FIG. 10 illustrates the timing of turning on and off the semiconductor light emitting elements of the light source unit 5 that emit light that forms the first region P13 of the light pattern P1.

[0080] The control unit 7 controls the lighting of the light source unit 5 so that after the second area C1 located closest to the vehicle 100 is drawn on the road surface, the remaining second areas C2 and C3 are drawn on the road surface in stages in order of their proximity to the vehicle 100. Note that the lighting control of the light source unit 5 is the same as the lighting control of the light source unit 5 illustrated in Fig. 5 , and therefore a detailed description thereof will be omitted.

[0081] The control unit 7 controls the light source unit 5 to be turned off so that after all of the second areas C1, C2, and C3 have been drawn, the drawing of the second area C1 located closest to the vehicle 100 is erased, and then the drawings of the remaining second areas C2 and C3 are erased.

[0082] 10 , the control unit 7 controls the light source unit 5 so that the semiconductor light emitting elements that emit light to form the second region C1 among the plurality of semiconductor light emitting elements of the light source unit 5 are turned off. Specifically, the control unit 7 turns off the semiconductor light emitting elements that form the second region C1 at time t11. As a result, the drawing of the second region C1 in the first region P13 is erased simultaneously with the drawing of the second region A1 in the first region P11 and the second region B1 in the first region P12.

[0083] Next, the control unit 7 controls the light source unit 5 to turn off the semiconductor light emitting elements that emit light that forms the second region C2 among the multiple semiconductor light emitting elements of the light source unit 5. Specifically, the control unit 7 turns off the semiconductor light emitting elements that emit light that forms the second region C2 at time t12. As a result, the drawing of the second region C2 in the first region P13 is erased simultaneously with the drawing of the second region A2 in the first region P11 and the second region B2 in the first region P12.

[0084] Next, the control unit 7 controls the light source unit 5 to turn off the semiconductor light emitting elements that emit light that forms the second region C3 among the multiple semiconductor light emitting elements of the light source unit 5. Specifically, the control unit 7 turns off the semiconductor light emitting elements that form the second region C3 at time t13. As a result, the drawing of the second region C3 in the first region P13 is erased simultaneously with the drawing of the second region A3 in the first region P11 and the second region B3 in the first region P12.

[0085] When the drawing of the light pattern P1 is repeated at a predetermined cycle T1, the erasure of the drawing in the first region P13 is also repeated in the same manner as the first regions P11 and P12.

[0086] Fig. 11 illustrates an example of how the light pattern P1 is drawn based on the timing of turning on and off the light source unit 5 shown in Fig. 8 to Fig. 10. In Fig. 11, the area surrounded by the dashed line is an area where light is not irradiated from the road surface drawing device 1 and no drawing is made on the road surface, and the area surrounded by the solid line is an area where light is irradiated from the road surface drawing device 1 and a drawing is made on the road surface.

[0087] 11, at time t3, all of the first areas P11, P12, and P13 are rendered. Then, at time t11, the rendering of the second areas A1, B1, and C1 that are located closest to the vehicle 100 among the first areas P11, P12, and P13 is erased.

[0088] Subsequently, at time t12, the images in the second regions A2, B2, and C2 adjacent to the second regions A1, B1, and C1 in the first regions P11, P12, and P13 are erased. That is, in the light pattern P1, the images in both the second regions A1, B1, and C1 and the second regions A2, B2, and C2 in the first regions P11, P12, and P13 are erased.

[0089] Subsequently, at time t13, the images of the second areas A3, B3, and C3 that are located farthest from the vehicle 100 within the first areas P11, P12, and P13 are erased. That is, in the light pattern P1, the images of all areas within the first areas P11, P12, and P13 are erased.

[0090] In this way, the drawings of multiple second areas within the first areas P11, P12, and P13 are gradually erased starting from the area closest to the vehicle 100, so that the movement of light corresponding to the operation of the vehicle 100 can be expressed within each of the first areas P11, P12, and P13.

[0091] In the above embodiment, the first regions P11, P12, and P13 of the light pattern P1 are formed in a chevron shape. However, the first regions P11, P12, and P13 of the light pattern P1 may be formed in a shape other than a chevron shape. For example, the first regions P11, P12, and P13 of the light pattern P1 may be formed in a polygonal shape such as a triangle or trapezoid that is convex in the desired pointing direction, an elliptical shape that extends in the desired pointing direction, or an arrow shape that extends in the desired pointing direction.

[0092] In the above embodiment, the light pattern P1 may be drawn so that it appears as a three-dimensional obstacle when viewed from the pedestrian 200.

[0093] FIG. 12 illustrates an example of a light pattern P2 that is drawn three-dimensionally on the road surface by the road surface drawing device 1 mounted on the vehicle 100.

[0094] 12 , the light pattern P2 is divided into a plurality of first regions in the traveling direction of the vehicle 100. In this example, the light pattern P2 includes three first regions P21, P22, and P23. The first regions P21, P22, and P23 are divided in the left front direction of the vehicle 100. The first region P21 is located closest to the vehicle 100. The first region P23 is located farthest from the vehicle 100. The first region P22 is located between the first region P21 and the first region P23. The first regions P21, P22, and P23 are lined up along the left front direction with gaps between them.

[0095] Each of the first regions P21, P22, and P23 includes a bright portion 10 and a dark portion 20. The dark portion 20 has a lower luminance than the bright portion 10. For example, the luminance of the dark portion 20 is approximately 50% of the luminance of the bright portion 10. The control unit 7, for example, lights up the semiconductor light-emitting element that emits light that forms the dark portion 20, among the multiple semiconductor light-emitting elements of the light source unit 5, at an illuminance lower than that of the semiconductor light-emitting element that emits light that forms the bright portion 10.

[0096] The dark portions 20 are formed so as to follow at least a portion of the bright portions 10. For example, the dark portions 20 are formed so that the outer edge of the bright portions 10 close to the pedestrian 200 appears to rise from the road surface. Specifically, the control unit 7 determines the positions of the dark portions in the first regions P21, P22, and P23 based on pedestrian information including the position of the pedestrian 200. Note that the pedestrian information can be acquired, for example, from a camera (not shown) mounted on the vehicle 100.

[0097] Although detailed explanation and illustrations are omitted, in this example too, the control unit 7 controls the light source unit 5 so that after the second areas A1, B1, and C1 located closest to the vehicle 100 among the multiple first areas P21, P22, and P23 are each drawn, the remaining second areas A2, A3, B2, B3, C2, and C3 among the multiple first areas P21, P22, and P23 that have not been drawn are drawn.

[0098] In this way, each of the first regions P21, P22, and P23 is formed so that the dark portion 20 is aligned with at least a portion of the light portion 10, and therefore the light pattern P2 appears as a three-dimensional obstacle when viewed from the pedestrian 200. This makes it easier for the pedestrian 200 to recognize the light pattern P2 compared to the light pattern P1, which is rendered with a uniform brightness. Furthermore, the sense of intimidation that the light pattern P2 gives to the pedestrian 200 is reduced.

[0099] 13 illustrates a light pattern P3 drawn by a road surface drawing device 1 according to this embodiment. The road surface drawing device 1 is mounted on a vehicle 100. In this example, the road surface drawing device 1 is disposed in a lamp chamber of a headlight of the vehicle 100.

[0100] The road surface drawing device 1 is configured to irradiate the road surface with light and draw a light pattern P3 on the road surface. In this example, the light pattern P3 is a pattern for notifying those around the vehicle 100 that the vehicle 100 will change course to the left. The light pattern P3 is drawn on the road surface, for example, while a lamp (not shown) for notifying those around the vehicle 100 that the vehicle 100 will change course to the left is on.

[0101] The light pattern P3 is divided into multiple regions in the traveling direction of the vehicle 100. In this example, the light pattern P3 includes a first region P31, a second region P32, and a third region P33. The first region P31, the second region P32, and the third region P33 are divided in the left front direction of the vehicle 100. The first region P31 is located closest to the vehicle 100. The third region P33 is located farthest from the vehicle 100. The second region P32 is located between the first region P31 and the third region P33. The first region P31, the second region P32, and the third region P33 are aligned with gaps along the left front direction of the vehicle 100. The "left front direction" is a direction extending "to the left" and "forward." The first region P31 is an example of a nearest region. The second region P32 is an example of an intermediate region. The third region P33 is an example of a farthest region.

[0102] In this example, the first region P31, the second region P32, and the third region P33 are each formed in a chevron shape. The first region P31, the second region P32, and the third region P33 have a larger area as they are further away from the vehicle 100.

[0103] Fig. 14 illustrates the configuration of the road surface drawing device 1. As illustrated in Fig. 14, the road surface drawing device 1 includes a lamp body 2 and an outer cover 3. The lamp body 2 is configured to have an opening in front of the lamp fixture. The outer cover 3 is translucent and is configured to cover the opening of the lamp body 2. The lamp body 2 and the outer cover 3 form a lamp chamber 4.

[0104] The road surface drawing device 1 includes a light source unit 5, an optical member 6, and a control unit 7. The light source unit 5, the optical member 6, and the control unit 7 are housed in a lamp chamber 4.

[0105] The light source unit 5 includes, for example, a plurality of semiconductor light-emitting elements (not shown). Examples of the semiconductor light-emitting elements include light-emitting diodes (LEDs), laser diodes (LDs), and EL elements. The plurality of semiconductor light-emitting elements are arranged in an array on the substrate 50, for example, vertically and horizontally.

[0106] The optical member 6 is configured to refract the light emitted from the light source unit 5 and emit it in the direction of the road surface. The optical member 6 is, for example, a plano-convex lens whose front surface is a convex surface and whose rear surface is a flat surface. The optical member 6 is formed of a light-transmitting material, for example, a transparent resin such as acrylic.

[0107] The control unit 7 is configured to individually control the turning on and off of the multiple semiconductor light-emitting elements that make up the light source unit 5. The control unit 7 includes, for example, a microcontroller and an analog drive control circuit. The microcontroller has a general-purpose microprocessor such as a CPU, MPU, or GPU, and general-purpose memory such as a ROM or RAM. The analog drive control circuit has a current control circuit configured to control the current supplied to each of the multiple semiconductor light-emitting elements of the light source unit 5. The first region P31, second region P32, and third region P33 of the light pattern P3 are each formed by light emitted by one or more semiconductor light-emitting elements of the light source unit 5.

[0108] The control unit 7 controls the turning on and off of each semiconductor light-emitting element of the light source unit 5 so that light is irradiated onto all of the first region P31, the second region P32, and the third region P33 when the drawing of the light pattern P3 starts, and so that irradiation of light onto all of the first region P31, the second region P32, and the third region P33 stops when the drawing of the light pattern P3 ends. In addition, the control unit 7 adjusts the luminance of each semiconductor light-emitting element of the light source unit 5 so that the illuminance of at least the third region P33 of the light pattern P3 is lower than the illuminance of the first region P31 when the drawing of the light pattern P3 starts, and increases as the drawing time passes.

[0109] For example, when the dimming method of the semiconductor light emitting element is analog dimming, the control unit 7 adjusts the DC level of the drive current flowing through the semiconductor light emitting element.For example, when the dimming method of the semiconductor light emitting element is PWM (Phase Width Modulation) dimming, the control unit 7 switches the drive current flowing through the semiconductor light emitting element and adjusts the ratio of the ON period to adjust the average level of the drive current.

[0110] 15 and 16 , the on / off control of the light source unit 5 by the control unit 7 according to this embodiment will be described in detail below. Fig. 15 illustrates a time chart showing the on / off of the semiconductor light-emitting elements of the light source unit 5. In Fig. 15 , the horizontal axis represents time, and the vertical axis represents the luminance value of the semiconductor light-emitting elements of the light source unit 5.

[0111] For example, when the control unit 7 receives a signal S1 that determines whether the vehicle 100 will change course to the left from a vehicle control unit 11 that controls the traveling of the vehicle 100 shown in Fig. 14, the control unit 7 controls the light source unit 5 to turn on and off so that the light pattern P3 is repeatedly drawn at a predetermined cycle T11 based on the signal S1, as illustrated in Fig. 15. For example, the cycle T11 is set to be the same as the blinking cycle of a lamp that notifies those around the vehicle 100 that the vehicle 100 will change course to the left. Specifically, the cycle T11 is set to, for example, about 0.5 to 1.0 seconds.

[0112] In addition, the control unit 7 controls the turning on and off of the semiconductor light-emitting elements of the light source unit 5 so that the illuminance of the second region P32 and the illuminance of the third region P33 are lower than the illuminance of the first region P31 when the drawing of the light pattern P3 begins, and become higher as the drawing time passes.

[0113] Specifically, as illustrated in Figure 15, when drawing of light pattern P3 begins at time t1, the control unit 7 turns on the semiconductor light-emitting element that emits light to form the first region P31, the second region P32, and the third region P33 at time t1.

[0114] In addition, the control unit 7 sets the brightness of the semiconductor light-emitting element of the light source unit 5 so that the illuminance of the second region P32 and the illuminance of the third region P33 at the start of drawing are each lower than the illuminance of the first region P31.

[0115] For example, the luminance a1 of the semiconductor light-emitting element that emits light to form the first region P31, the luminance b1 of the semiconductor light-emitting element that emits light to form the second region P32, and the luminance c1 of the semiconductor light-emitting element that emits light to form the third region P33 are each set so that the illuminance of the second region P32 and the illuminance of the third region P33 are approximately 10% of the illuminance of the first region P31.

[0116] Next, the control unit 7 changes the brightness of the semiconductor light-emitting element that emits light to form the second region P32 and the brightness of the semiconductor light-emitting element that emits light to form the third region P33 so that the illuminance of the second region P32 and the illuminance of the third region P33 increase as the drawing time of the light pattern P3 passes.

[0117] 15 , the control unit 7 first changes the luminance of the semiconductor light-emitting element that emits light that forms the second region P32 so that the illuminance of the second region P32 becomes higher. Specifically, at time t2, the control unit 7 changes the luminance of the semiconductor light-emitting element that emits light that forms the second region P32 of the light source unit 5 from b1 to b2 so that the illuminance of the second region P32 becomes the same as the illuminance of the first region P31. Time t2 can be set, for example, approximately 0.05 to 0.1 seconds after time t1.

[0118] Subsequently, at time t3, the control unit 7 changes the luminance of the semiconductor light-emitting element that emits light that forms the third region P33 of the light source unit 5 from c1 to c2 so that the illuminance of the third region P33 becomes the same as the illuminance of the first region P31. Time t3 can be set, for example, approximately 0.05 to 0.1 seconds after time t2.

[0119] Then, at time t4 when drawing of the light pattern P3 is completed, the control unit 7 simultaneously turns off the semiconductor light-emitting elements that emit light to form the first region P1, the second region P32, and the third region P33. For example, time t4 can be set to approximately 0.05 to 0.8 seconds after time t3.

[0120] The light pattern P3 is repeatedly drawn in a predetermined cycle T11. That is, as illustrated in Fig. 15 , at time t5, which is the time period T11 after time t1, the control unit 7 turns on the semiconductor light-emitting elements that emit light to form the first region P31, the second region P32, and the third region P33, to start drawing the light pattern P3. The control unit 7 repeats drawing the light pattern P3, for example, until it receives a signal from the vehicle control unit 11 to stop drawing the light pattern P3.

[0121] Fig. 16 illustrates an example of how the light pattern P3 formed based on the on / off state of the light source unit 5 shown in Fig. 15 is drawn. In Fig. 16, the area surrounded by the dashed line is an area not irradiated with light from the road surface drawing device 1 and therefore not drawn on the road surface, while the area surrounded by the solid line is an area irradiated with light from the road surface drawing device 1 and therefore drawn on the road surface. In Fig. 16, the illuminance of each area is represented by different hatching within the area surrounded by the solid line. Specifically, areas with high illuminance are represented by light hatching, and areas with low illuminance are represented by dark hatching.

[0122] 16, at time t0 (see FIG. 15) when drawing of the light pattern P3 has not yet started, no light is emitted from the road surface drawing device 1, and the light pattern P3 is not drawn. Then, at time t1 when drawing of the light pattern P3 starts, light emitted from the light source unit 5 is irradiated onto the first region P31, second region P32, and third region P33 of the light pattern P3, and the light pattern P3 is drawn on the road surface, with the illuminance of the second region P32 and the illuminance of the third region P33 being lower than the illuminance of the first region P31.

[0123] Subsequently, at time t2, the light pattern P3 drawn on the road surface changes to a light pattern in which the illuminance of the second region P32 is the same as the illuminance of the first region P31.

[0124] Subsequently, at time t3, the light pattern P3 drawn on the road surface changes to a light pattern in which the illuminance in the third region P33 is the same as the illuminance in the first region P31 and the illuminance in the second region P32.

[0125] Then, at time t4 when the drawing of the light pattern P3 is completed, the irradiation of light onto the first area P31, the second area P32, and the third area P33 is stopped, and the drawing in the first area P31, the second area P32, and the third area P33 is erased.

[0126] However, when the light pattern P3 is flashed with a uniform illuminance, it may be difficult for traffic participants such as pedestrians around the vehicle 100 to grasp the traveling direction of the vehicle 100 represented by the light pattern P3 (e.g., the direction in which the vehicle 100 will change course). As a method for representing the traveling direction of the vehicle 100, it is also possible to draw a light pattern P3 in which light is sequentially emitted from the first region P31 to the third region P33, thereby gradually changing the irradiation region of the light pattern P3. However, with such a light pattern drawing method, for example, if there is an obstacle such as a wall between the first region P31 and a pedestrian located far from the vehicle 100, the pedestrian may not be able to see the first region P31, which may delay the timing at which the pedestrian recognizes the light pattern P3.

[0127] In contrast, with the road surface drawing device 1 according to this embodiment, the first region P31, the second region P32, and the third region P33 that constitute the light pattern P3 are all drawn simultaneously, so that even traffic participants located far from the vehicle 100 can quickly recognize the light pattern P3. Furthermore, because the illuminance of the second region P32 and the illuminance of the third region P33 increase over the lapse of drawing time, the illuminance of the light pattern P3 changes over the lapse of drawing time, increasing from the region closer to the vehicle 100. This allows traffic participants around the vehicle 100 to recognize that the light pattern P3 is drawn so that the illuminated region gradually increases from the first region P31 to the third region P33. Therefore, the vehicle's traveling direction can be quickly communicated to traffic participants around the vehicle 100.

[0128] (Modification 1) Next, the on / off control of the light source unit 5 by the control unit 7 according to Modification 1 will be described with reference to Fig. 17 and Fig. 18. Fig. 17 illustrates a time chart showing the on / off of the semiconductor light-emitting elements of the light source unit 5 according to Modification 1. In Fig. 17, the horizontal axis represents time, and the vertical axis represents the luminance value of the semiconductor light-emitting elements of the light source unit 5. Note that in this modification, detailed description of the same control as the on / off control of the light source unit 5 illustrated in Fig. 15 will be omitted.

[0129] As illustrated in Figure 17, the control unit 7 in variant example 1 sets the brightness of each semiconductor light-emitting element of the light source unit 5 so that the illuminance of the third region P33 at time t1 when drawing of the light pattern P3 begins is higher than the illuminance of the second region P32.

[0130] For example, the luminance a1 of the semiconductor light-emitting element that emits light to form the first region P31, the luminance b1 of the semiconductor light-emitting element that emits light to form the second region P32, and the luminance c11 of the semiconductor light-emitting element that emits light to form the third region P33 are each set so that the illuminance of the second region P32 is approximately 10% of the illuminance of the first region P31 and the illuminance of the third region P33 is approximately 40% of the illuminance of the first region P31.

[0131] Fig. 18 illustrates an example of the drawing of the light pattern P3 formed based on the turning on and off of the light source unit 5 shown in Fig. 17. Similar to Fig. 16, Fig. 18 uses dashed lines, solid lines, and hatching to represent the drawing and illuminance of each of the first region P31, second region P32, and third region P33 of the light pattern P3.

[0132] 18, at time t0 (see FIG. 17) when drawing of the light pattern P3 has not yet started, no light is emitted from the road surface drawing device 1, and the light pattern P3 is not drawn. Then, at time t1 when drawing of the light pattern P3 starts, light emitted from the light source unit 5 is irradiated onto the first region P31, second region P32, and third region P33 of the light pattern P3, and the light pattern P3 is drawn on the road surface such that the illuminance of the third region P33 is lower than the illuminance of the first region P31 and higher than the illuminance of the second region P32.

[0133] Next, at time t2, the light pattern P3 drawn on the road surface changes to a light pattern in which the illuminance of the second region P32 is the same as the illuminance of the first region P31. Next, at time t3, the light pattern P3 drawn on the road surface changes to a light pattern in which the illuminance of the third region P33 is the same as the illuminance of the first region P31 and the illuminance of the second region P32. Then, at time t4 when the drawing of the light pattern P3 is completed, the irradiation of the first region P31, the second region P32, and the third region P33 with light is stopped, and the drawings in the first region P31, the second region P32, and the third region P33 are erased.

[0134] With this configuration, the illuminance of the third region P33, which is the farthest from the vehicle 100, is relatively high, so that traffic participants located far from the vehicle 100 can more easily recognize the light pattern P3.

[0135] (Modification 2) Next, the on / off control of the light source unit 5 by the control unit 7 according to Modification 2 will be described with reference to Fig. 19. Fig. 19 illustrates a time chart showing the on / off of the semiconductor light-emitting elements of the light source unit 5 according to Modification 2. In Fig. 19, the horizontal axis represents time, and the vertical axis represents the luminance value of the semiconductor light-emitting elements of the light source unit 5. Note that in this modification, detailed description of the same control as the on / off control of the light source unit 5 illustrated in Fig. 15 will be omitted.

[0136] As illustrated in Figure 19, the control unit 7 in variant example 2 adjusts the brightness of each semiconductor light-emitting element of the light source unit 5 so that the illuminance of the second region P32 and the illuminance of the third region P33 each increase in a stepwise manner as the drawing time passes.

[0137] Specifically, the control unit 7 adjusts the luminance of the semiconductor light-emitting element that irradiates the light that forms the second region P32 of the light source unit 5 so that the illuminance of the second region P32 of the light pattern P3 increases stepwise as the drawing time elapses between time t1 and time t2. The timing and amount of increase in the illuminance of the second region P32 can be set as appropriate.

[0138] Next, the control unit 7 adjusts the brightness of the semiconductor light-emitting element of the light source unit 5 that emits light to form the third region P33 so that the illuminance of the third region P33 of the light pattern P3 increases stepwise as the drawing time elapses between time t6 (after time t2) and time t3. For example, time t6 can be set to approximately 0.05 to 0.1 seconds after time t2. The timing and amount of increase in the illuminance of the third region P33 can be set as appropriate.

[0139] This configuration makes it possible to form a light pattern P3 whose illuminance changes differently from the illuminance change of the light pattern P3 shown in Fig. 16. Furthermore, changing the illuminance of the second region P32 and the illuminance of the third region P33 stepwise rather than gradually changing each of them makes the difference in illuminance before and after the change greater, making it easier for traffic participants to recognize that the illuminance of the light pattern P3 has changed.

[0140] (Modification 3) Next, the on / off control of the light source unit 5 by the control unit 7 according to Modification 3 will be described with reference to Fig. 20. Fig. 20 illustrates a time chart showing the on / off of the semiconductor light-emitting elements of the light source unit 5 according to Modification 3. In Fig. 20, the horizontal axis represents time, and the vertical axis represents the luminance value of the semiconductor light-emitting elements of the light source unit 5. Note that in this modification, detailed description of the same control as the on / off control of the light source unit 5 illustrated in Figs. 15 and 19 will be omitted.

[0141] As illustrated in Figure 20, the control unit 7 of variant example 3 adjusts the brightness of each semiconductor light-emitting element of the light source unit 5 so that the illuminance of the second region P32 and the illuminance of the third region P33 increase in a stepwise manner at the same timing as the drawing time passes.

[0142] Specifically, the control unit 7 adjusts the luminance of the semiconductor light-emitting element that irradiates the light that forms the second region P32 of the light source unit 5 so that the illuminance of the second region P32 of the light pattern P3 increases stepwise as the drawing time elapses from time t1 to time t2. The timing and amount of increase in the illuminance of the second region P32 can be set as appropriate.

[0143] Furthermore, the control unit 7 adjusts the brightness of the semiconductor light-emitting element of the light source unit 5 that emits light to form the third region P33 so that the illuminance of the third region P33 of the light pattern P3 increases stepwise as the drawing time elapses between time t1 and time t2. The timing at which the illuminance of the third region P33 increases is set to be the same as the timing at which the illuminance of the second region P32 increases. The amount of increase in the illuminance of the third region P33 may be set to be the same as the amount of increase in the illuminance of the second region P32, or may be set to be smaller than the amount of increase in the illuminance of the second region P32.

[0144] With this configuration, the illuminance of the third area P33, which is farthest from the vehicle 100, changes immediately after drawing begins, so that pedestrians located far from the vehicle 100 can also recognize the change in the light pattern P3 at an early stage.

[0145] (Modification 4) Next, the on / off control of the light source unit 5 by the control unit 7 according to Modification 4 will be described with reference to Fig. 21. Fig. 21 illustrates a time chart showing the on / off of the semiconductor light-emitting elements of the light source unit 5 according to Modification 4. In Fig. 21, the horizontal axis represents time, and the vertical axis represents the luminance value of the semiconductor light-emitting elements of the light source unit 5. Note that in this modification, detailed description of the same control as the on / off control of the light source unit 5 illustrated in Fig. 20 will be omitted.

[0146] As illustrated in FIG. 21 , the control unit 7 according to the fourth modification adjusts the brightness of each semiconductor light-emitting element of the light source unit 5 so that the illuminance of the second region P32 and the illuminance of the third region P33 increase stepwise at the same timing as the drawing time elapses, and so that the illuminance of the third region P33 becomes the same as the illuminance of the first region P31 after the illuminance of the second region P32 becomes the same as the illuminance of the first region P31.

[0147] Specifically, the control unit 7 adjusts the luminance of the semiconductor light-emitting element that irradiates the light that forms the second region P32 of the light source unit 5 so that the illuminance of the second region P32 of the light pattern P3 increases stepwise as the drawing time elapses between time t1 and time t2. The timing and amount of increase in the illuminance of the second region P32 can be set as appropriate.

[0148] Furthermore, the control unit 7 adjusts the brightness of the semiconductor light-emitting element of the light source unit 5 that emits light to form the third region P33 so that the illuminance of the third region P33 of the light pattern P3 increases stepwise as the drawing time elapses from time t1 to time t7 after time t2, until it becomes the same as the illuminance of the first region P31 at time t7. For example, time t7 can be set approximately 0.05 to 0.1 seconds after time t2. The timing at which the illuminance of the third region P33 increases is set to the same as the timing at which the illuminance of the second region P32 increases from time t1 to time t2. The timing at which the illuminance of the third region P33 increases and the amount of increase in the illuminance of the third region P33 from time t2 to time t7 can be set as appropriate.

[0149] With this configuration, the light pattern P3 changes so that the illuminance increases from the area closest to the vehicle 100 as the drawing time passes, so that traffic participants around the vehicle 100 can recognize that the light pattern P3 is drawn so that the illuminated area gradually increases from the first area P31 to the third area P33.

[0150] (Modification 5) Next, the on / off control of the light source unit 5 by the control unit 7 according to Modification 5 will be described with reference to Fig. 22 and Fig. 23. Fig. 22 illustrates a time chart showing the on / off of the semiconductor light-emitting elements of the light source unit 5 according to Modification 5. In Fig. 22, the horizontal axis represents time, and the vertical axis represents the luminance value of the semiconductor light-emitting elements of the light source unit 5. Note that in this modification, detailed description of the same control as the on / off control of the light source unit 5 illustrated in Fig. 15 will be omitted.

[0151] In the control unit 7 of variant example 5, the illuminance of at least the first region P31 of the light pattern P3 decreases as the drawing time passes, and when the drawing of the light pattern P3 is completed, the irradiation of light toward all of the first region P31, the second region P32, and the third region P33 stops.

[0152] 22 , the control unit 7 adjusts the brightness of the semiconductor light-emitting element of the light source unit 5 that emits light to form the first region P31 so that the illuminance of the first region P31 of the light pattern P3 decreases stepwise as the drawing time elapses from time t8 to time t4, when drawing of the light pattern P3 is completed. For example, time t8 can be set to approximately 0.1 to 0.5 seconds before time t4. The timing and amount of decrease in the illuminance of the first region P31 can be set as appropriate.

[0153] Furthermore, the control unit 7 adjusts the brightness of the semiconductor light-emitting element of the light source unit 5 that emits light to form the second region P32 so that the illuminance of the second region P32 of the light pattern P3 decreases stepwise as the drawing time passes from time t9 after time t8 to time t4 when drawing of the light pattern P3 is completed. For example, time t9 can be set to about 0.4 to 0.05 seconds before time t4.

[0154] The timing at which the illuminance of the second region P32 decreases is set to be the same as the timing at which the illuminance of the first region P31 decreases. That is, at time t9, the illuminance of the second region P32 decreases together with the illuminance of the first region P31. The amount by which the illuminance of the second region P32 decreases can be set as appropriate. For example, the amount by which the illuminance of the second region P32 decreases may be set so that the illuminance of the second region P32 at time t9 is higher than the illuminance of the first region P31, or the amount by which the illuminance of the second region P32 decreases may be set so that the illuminance of the second region P32 at time t9 is the same as the illuminance of the first region P31.

[0155] Fig. 23 illustrates the state of the light pattern P3 in which the drawing is erased based on the turning on and off of the light source unit 5 shown in Fig. 22. Similar to Fig. 16, Fig. 22 uses dashed lines, solid lines, and hatching to represent the drawing and illuminance of each of the first region P31, second region P32, and third region P33 of the light pattern P3.

[0156] 23 , at time t3, the illuminance of the first region P31, the second region P32, and the third region P33 in the light pattern P3 is the same. Then, at time t8, the light pattern P3 drawn on the road surface changes to a light pattern in which the illuminance of the first region P31 is lower than the illuminance of the second region P32 and the third region P33.

[0157] Subsequently, at time t9, the light pattern P3 drawn on the road surface changes to a light pattern in which the illuminance of the second region P32 is lower than the illuminance of the third region P33, and the illuminance of the first region P31 is lower than the illuminance of the second region P32. Then, at time t4 when the drawing of the light pattern P3 ends, the irradiation of the first region P31, the second region P32, and the third region P33 with light is stopped, and the drawings in the first region P31, the second region P32, and the third region P33 are erased.

[0158] With this configuration, the illuminance of the first region P31 and the second region P32 decreases over the lapse of drawing time, and so the illuminance of the light pattern P3 changes over the lapse of drawing time, decreasing from the region closest to the vehicle 100. This allows traffic participants around the vehicle 100 to perceive as if the light pattern P3 is drawn so that the irradiation region gradually decreases from the first region P31 to the third region P33.

[0159] In addition, the illuminance of the first area P31 and the illuminance of the second area P32 decrease in a stepwise manner as the drawing time passes, so the difference in illuminance before and after the change is greater than if the illuminance of the first area P31 and the illuminance of the second area P32 were changed gradually, making it easier for traffic participants to recognize that the illuminance of the light pattern P3 has changed.

[0160] 14 and 24 , a description will be given of the on / off control of the light source unit 5 by the control unit 7 according to Modification 6. Note that in this modification, detailed description of the same control as the on / off control of the light source unit 5 illustrated in FIG.

[0161] The control unit 7 in variant example 6 sets the brightness of each semiconductor light-emitting element of the light source unit 5 so that the illuminance of the second area P32 and the illuminance of the third area P33 at the start of drawing change in accordance with the ambient illuminance around the vehicle 100.

[0162] 14 , an illuminance sensor 12 is connected to the vehicle control unit 11. The illuminance sensor 12 is mounted on the vehicle 100 and configured to detect the environmental illuminance around the vehicle 100. Note that the illuminance sensor 12 may be directly connected to the control unit 7.

[0163] The control unit 7 receives a signal S2 from the vehicle control unit 11 regarding the ambient illuminance around the vehicle 100 detected by the illuminance sensor 12, and based on the signal S2, sets the brightness of the semiconductor light-emitting element that emits light to form the second area P32 and the third area P33 at the start of drawing.

[0164] For example, the control unit 7 sets the luminance of the semiconductor light-emitting elements that form the second region P32 and the third region P33 so that the illuminance of the second region P32 and the illuminance of the third region P33 at the start of drawing when the environmental illuminance around the vehicle 100 is high are higher than the illuminance of the second region P32 and the third region P33 at the start of drawing when the environmental illuminance around the vehicle 100 is low. For example, an example of a case when the environmental illuminance around the vehicle 100 is high is sunset, and an example of a case when the environmental illuminance around the vehicle 100 is low is nighttime.

[0165] 24 illustrates a time chart showing the turning on and off of the semiconductor light-emitting elements of the light source unit 5 when the environmental illuminance around the vehicle 100 is high. In FIG. 24 , the horizontal axis represents time, and the vertical axis represents the luminance value of the semiconductor light-emitting elements of the light source unit 5.

[0166] The illuminance of the second region P32 and the illuminance of the third region P33 at the start of drawing in FIG. 24 are set higher than the illuminance of the second region P32 and the illuminance of the third region P33 at the start of drawing in FIG.

[0167] For example, the luminance a1 of the semiconductor light-emitting element that emits light to form the first region P31, the luminance b11 of the semiconductor light-emitting element that emits light to form the second region P32, and the luminance c12 of the semiconductor light-emitting element that emits light to form the third region P33 are set so that the illuminance of the second region P32 and the illuminance of the third region P33 at the start of drawing are approximately 40% to approximately 50% of the illuminance of the first region P31.

[0168] When the environmental illuminance around the vehicle 100 is high, the control unit 7 controls the light source unit 5 based on the on / off control shown in Fig. 24. When the environmental illuminance around the vehicle 100 is low, the control unit 7 controls the light source unit 5 based on the on / off control shown in Fig. 15.

[0169] However, when the illuminance of the second region P32 and the illuminance of the third region P33 are fixed at the start of drawing, the illuminance of the second region P32 and the third region P33 is low, and therefore the second region P32 and the third region P33 of the light pattern P3 become difficult to see at sunset when the environmental illuminance around the vehicle 100 is high compared to at night when the environmental illuminance around the vehicle 100 is low.

[0170] In contrast, according to the road surface drawing device 1 of the sixth modification, the illuminance of the second region P32 and the illuminance of the third region P33 at the start of drawing are changed in accordance with the environmental illuminance around the vehicle 100. For example, the illuminance of the second region P32 and the illuminance of the third region P33 at the start of drawing of the light pattern P3 drawn at sunset when the environmental illuminance is high are set higher than the illuminance of the second region P32 and the third region P33 at the start of drawing of the light pattern P3 drawn at night when the environmental illuminance is low. This improves the visibility of the light pattern P3 due to the environmental illuminance around the vehicle 100.

[0171] In this example, the control unit 7 determines the environmental illuminance around the vehicle 100 based on the detection value of the illuminance sensor. However, the control unit 7 may be configured to estimate the environmental illuminance around the vehicle 100 from, for example, sunset time information, weather information, current time information, current location information, etc., acquired by a wireless communication unit (not shown) mounted on the vehicle 100. Alternatively, the control unit 7 may acquire operation information of headlights that are controlled in accordance with the environmental illuminance around the vehicle 100, and determine the environmental illuminance around the vehicle 100 from the information.

[0172] In the second embodiment and the modified example described above, the first region P31, the second region P32, and the third region P33 of the light pattern P3 are formed in an arrow feather (chevron) shape. However, the first region P31, the second region P32, and the third region P33 of the light pattern P3 may be formed in a shape other than an arrow feather shape. For example, the first region P31, the second region P32, and the third region P33 of the light pattern P3 may be formed in a polygonal shape such as a triangle or a trapezoid that is convex in the desired pointing direction, an oval shape that extends in the desired pointing direction, an arrow shape that extends in the desired pointing direction, or the like.

[0173] In the second embodiment and the modified example described above, the light source unit 5 is controlled to turn on and off so that the illuminance of the second region P32 as well as the illuminance of the third region P33 is lower than the illuminance of the first region P31 at the start of drawing the light pattern P3 and increases as the drawing time elapses. However, the light source unit 5 may be controlled to turn on and off so that the illuminance of the second region P32 is constant while the light pattern P3 is being drawn, similar to the illuminance of the first region P31.

[0174] In the second embodiment and the modified example described above, the light pattern P3 is divided into three regions: a first region P31, a second region P32, and a third region P33. However, the light pattern P3 may be divided into two regions or four or more regions.

[0175] The present disclosure has been described above based on the embodiments. The present embodiment is an example of the present disclosure, and is not limited to the above-described embodiment, and can be freely modified, improved, etc. as appropriate. In addition, the material, shape, dimensions, numerical values, form, number, placement location, etc. of each component in the above-described embodiment are arbitrary and not limited as long as the present disclosure can be achieved.

[0176] In the above-described first embodiment, second embodiment, and modified example, the road surface drawing device 1 is disposed in a headlight lamp chamber of the vehicle 100. However, the road surface drawing device 1 may be disposed in a location other than the headlight lamp chamber in the front part of the vehicle 100. The road surface drawing device 1 may also be disposed in the rear part of the vehicle 100. For example, the road surface drawing device 1 may be disposed in a lamp chamber of a rear combination lamp of the vehicle 100. When the road surface drawing device 1 is disposed in the rear part of the vehicle 100, the road surface drawing device 1 may be configured to draw a light pattern on the road surface to notify those around the vehicle 100 that the vehicle 100 is reversing. The light pattern to notify those around the vehicle 100 that the vehicle 100 is reversing may be formed to have, for example, a plurality of rectangular areas.

[0177] The following configurations also constitute part of the present disclosure. (1) A road surface drawing device mounted on a vehicle and drawing a light pattern on a road surface, wherein the light pattern is divided into a plurality of first regions in a traveling direction of the vehicle, and each of the first regions is further divided into a plurality of second regions in the traveling direction of the vehicle, and after each of the second regions closest to the vehicle among the plurality of first regions is drawn, the remaining second regions among the plurality of first regions that have not been drawn are drawn. (2) The road surface drawing device described in (1), wherein the first region is divided into three or more second regions, and after each of the second regions closest to the vehicle among the plurality of first regions is drawn, the remaining second regions among the plurality of first regions that have not been drawn are drawn in stages in order of proximity to the vehicle. (3) The road surface drawing device described in (1) or (2), wherein the first region includes a bright region and a dark region that is formed along at least a portion of the bright region and has a lower brightness than the bright region. (4) The road surface drawing device according to any one of (1) to (3), wherein, after the drawing of the second area closest to the vehicle among the plurality of first areas is erased, the drawing of the remaining second areas among the plurality of first areas that have been drawn is erased. (5) A road surface drawing device mounted on a vehicle and drawing a light pattern on a road surface, wherein the light pattern is divided into a plurality of areas in the traveling direction of the vehicle, and light is irradiated onto all of the areas when drawing of the light pattern starts, and at the start of drawing, the illuminance of the farthest area that is farthest from the vehicle is lower than the illuminance of the nearest area that is nearest to the vehicle, and the illuminance of the farthest area increases as the drawing time of the light pattern passes. (6) The road surface drawing device according to (5), wherein the light pattern is divided into the nearest area, the farthest area, and an intermediate area that is located between the nearest area and the farthest area, and at the start of drawing, the illuminance of the farthest area is lower than the illuminance of the nearest area and higher than the illuminance of the intermediate area. (7) The road surface drawing device according to (5) or (6), wherein the illuminance of the farthest area at the start of drawing changes in accordance with the environmental illuminance around the vehicle.(8) A road surface drawing device according to any one of (5) to (7), wherein the illuminance of the nearest region decreases as the drawing time elapses, and when drawing is completed, irradiation of light to all of the regions stops. (9) A road surface drawing device according to any one of (5) to (8), wherein the illuminance of the farthest region increases in a stepped manner as the drawing time elapses. (10) A road surface drawing device according to (8), wherein the illuminance of the nearest region decreases in a stepped manner as the drawing time elapses.

[0178] This application is based on Japanese Patent Application No. 2023-199093 filed on November 24, 2023, and Japanese Patent Application No. 2023-199094 filed on November 24, 2023, the contents of which are incorporated herein by reference.

Claims

1. A road surface drawing device mounted on a vehicle for drawing a light pattern on a road surface, wherein the light pattern is divided into a plurality of first regions in the traveling direction of the vehicle, each of the first regions is further divided into a plurality of second regions in the traveling direction of the vehicle, and after each of the second regions located closest to the vehicle among the plurality of first regions is drawn, the remaining second regions among the plurality of first regions that have not been drawn are drawn.

2. The road surface drawing device according to claim 1, wherein the first area is divided into three or more second areas, and after each of the second areas located closest to the vehicle among the plurality of first areas is drawn, the remaining plurality of second areas not yet drawn among the plurality of first areas are drawn in stages in order of their proximity to the vehicle.

3. A road surface drawing device as described in claim 1 or claim 2, wherein the first area includes a bright area and a dark area that is formed along at least a part of the bright area and has a lower brightness than the bright area.

4. A road surface drawing device as described in claim 1 or claim 2, wherein after the drawing of the second area that is located closest to the vehicle among the plurality of first areas is erased, the drawing of the remaining drawn second areas among the plurality of first areas is erased.

5. A road surface drawing device mounted on a vehicle for drawing a light pattern on a road surface, wherein the light pattern is divided into a plurality of regions in the direction of travel of the vehicle, and light is irradiated onto all of the regions when drawing of the light pattern begins, and the illuminance of the farthest region located farthest from the vehicle is lower than the illuminance of the nearest region located closest to the vehicle at the start of drawing, and the illuminance of the farthest region increases as the drawing time of the light pattern elapses.

6. A road surface drawing device as described in claim 5, wherein the light pattern is divided into the nearest region, the farthest region, and an intermediate region located between the nearest region and the farthest region, and when drawing starts, the illuminance of the farthest region is lower than the illuminance of the nearest region and higher than the illuminance of the intermediate region.

7. A road surface drawing device according to claim 5 or 6, wherein the illuminance of the farthest area at the start of drawing is changed in accordance with the environmental illuminance around the vehicle.

8. A road surface drawing device according to claim 5 or 6, wherein the illuminance of the nearest region decreases as the drawing time elapses, and when drawing is completed, irradiation of light to all of the nearest region is stopped.

9. A road surface drawing device according to claim 5 or 6, wherein the illuminance of the farthest area increases in a stepped manner as the drawing time elapses.

10. A road surface drawing device according to claim 8, wherein the illuminance of the nearest region decreases in a stepped manner as the drawing time elapses.