Vehicular road surface marking device and vehicular road surface marking method

Abstract

A vehicular road surface marking device (20) comprises: a road surface marking unit (21) that projects a marking pattern by emitting light onto a road surface; and a control unit (25) that controls the projection state of the marking pattern. The marking pattern includes a first marking pattern (PB) that is projected onto the road surface behind the vehicle when a shift lever (17) is set to the reverse position, and a second marking pattern (PH) that is projected onto at least one of the road surface in front of, behind, and to the side of the vehicle in synchronization with the lighting of hazard lamps (14). If the projection time of the first marking pattern (PB) and the projection time of the second marking pattern (PH) overlap, the control unit (25) causes the road surface marking unit (21) to execute one of: (a) turning off at least a portion of the second marking pattern (PH); (b) at least temporarily reducing the brightness of at least a portion of the second marking pattern (PH); and (c) adjusting the brightness of at least a portion of the second marking pattern (PH).

Description

Vehicle road surface drawing apparatus and vehicle road surface drawing method

[0001] The present disclosure relates to a vehicle road surface drawing apparatus and a vehicle road surface drawing method.

[0002] Patent Document 1 discloses a vehicle road surface drawing apparatus that projects unit drawn images representing a predetermined character onto a road surface by emitting light. In the road surface drawing apparatus of Patent Document 1, when a hazard switch is turned on, both a right turn signal and a left turn signal mounted on the vehicle are caused to blink, and light is emitted from the road surface drawing apparatus to project drawn images onto the road surfaces on the right side and the left side of the vehicle. It is also described that when the depression amount of a brake is equal to or greater than a threshold value, light is emitted from the road surface drawing apparatus to project a drawn image onto the road surface behind the vehicle.

[0003] International Publication No. 2021 / 100712

[0004] Incidentally, when a plurality of images for notifying traffic participants around a vehicle of different situations are projected from the vehicle onto the road surface, one image is less noticeable than the other image, which may possibly hinder information transmission to the traffic participants.

[0005] Accordingly, one object of the present disclosure is to provide a vehicle road surface drawing apparatus and a vehicle road surface drawing method that allow traffic participants to easily recognize a road surface drawing pattern for transmitting information related to reversing of a vehicle.

[0006] Furthermore, when the timing of turning on and off a lamp mounted on a vehicle is different from the timing of turning on and off a drawn image projected onto a road surface around the vehicle, traffic participants such as pedestrians around the vehicle who visually recognize both the lamp and the drawn image may possibly feel annoyed.

[0007] Accordingly, one object of the present disclosure is to provide a vehicle road surface drawing apparatus and a vehicle road surface drawing method that are capable of projecting a drawing pattern, which is less likely to annoy traffic participants around a vehicle, onto a road surface.

[0008] A vehicle road surface drawing device according to one aspect of the present disclosure is a vehicle road surface drawing device mounted on a vehicle that projects a drawing pattern onto a road surface, comprising: a road surface drawing unit that emits light onto the road surface to project the drawing pattern; and a control unit that controls the projection state of the drawing pattern, wherein the drawing pattern includes: a first drawing pattern projected onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range; and a second drawing pattern projected onto at least one road surface in front of, behind, and to the side of the vehicle in synchronization with the illumination of the vehicle's hazard lamps, wherein if the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap, the control unit causes the road surface drawing unit to perform one of the following: (a) turn off at least a portion of the second drawing pattern; (b) at least temporarily dim at least a portion of the second drawing pattern; or (c) adjust the brightness of at least a portion of the second drawing pattern.

[0009] A vehicle road surface drawing method according to another aspect of the present disclosure is a vehicle road surface drawing method for projecting a drawing pattern onto a road surface, comprising: a first road surface drawing step of projecting a first drawing pattern onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range; a second road surface drawing step of projecting a second drawing pattern onto at least one road surface in front of, behind, and to the side of the vehicle in synchronization with the illumination of the vehicle's hazard lights; and a lighting control step of controlling the projection state of the second drawing pattern to perform one of the following when the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap: (a) turning off at least a portion of the second drawing pattern; (b) at least temporarily dimming at least a portion of the second drawing pattern; or (c) adjusting the brightness of at least a portion of the second drawing pattern.

[0010] According to the vehicle road surface drawing device and vehicle road surface drawing method described herein, the first drawing pattern, which indicates information regarding the vehicle reversing, and the second drawing pattern, which is linked to the hazard lights, can be made more prominent at the time when both are projected onto the road surface. This makes it easier for traffic participants to recognize the first drawing pattern related to the vehicle reversing.

[0011] Furthermore, a vehicle road surface drawing device according to one aspect of the present disclosure is a vehicle road surface drawing device mounted on a vehicle that projects a drawing pattern onto a road surface, comprising: a road surface drawing unit that emits light onto the road surface to project the drawing pattern; and a control unit that controls the projection state of the drawing pattern, wherein the drawing pattern includes a first drawing pattern that is projected onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range, and the control unit controls the road surface drawing unit to project the first drawing pattern in synchronization with the illumination of the vehicle's hazard lamps.

[0012] A road surface drawing method for a vehicle according to another aspect of the present disclosure is a road surface drawing method for a vehicle that projects a drawing pattern onto a road surface, comprising: a road surface drawing step of projecting the drawing pattern onto the road surface behind the vehicle by emitting light; and a projection control step of projecting the drawing pattern in synchronization with the illumination of hazard lights mounted on the vehicle.

[0013] According to the vehicle road surface drawing device and vehicle road surface drawing method described herein, by projecting a drawing pattern onto the road surface behind the vehicle in synchronization with the illumination of the hazard lights, it is less likely to cause inconvenience to traffic participants who are viewing both the hazard lights and the drawing pattern.

[0014] This disclosure provides a vehicle road surface drawing device and a vehicle road surface drawing method that make it easy for traffic participants to understand road surface drawing patterns that convey information about the vehicle reversing.

[0015] Furthermore, this disclosure provides a vehicle road surface drawing device and a vehicle road surface drawing method that can project images onto the road surface that are less likely to cause inconvenience to traffic participants around the vehicle.

[0016] Figure 1 is a block diagram of the system configuration of a vehicle, including a vehicle road surface drawing device. Figure 2 is a diagram illustrating a drawing pattern projected around a vehicle by the vehicle road surface drawing device. Figure 3 is a flowchart illustrating an example of the operation of a vehicle including the vehicle road surface drawing device according to the first embodiment. Figure 4 is a timing chart of electrical signals input to each lamp in the first embodiment. Figure 5 is a diagram illustrating a drawing pattern projected onto the road surface by the vehicle road surface drawing device according to the first and third embodiments. Figure 6 is a diagram illustrating a drawing pattern projected onto the road surface by the vehicle road surface drawing device according to the first embodiment. Figure 7 is a diagram illustrating a drawing pattern projected onto the road surface by the vehicle road surface drawing device according to the first and fourth embodiments. Figure 8 is a flowchart illustrating an example of the operation of a vehicle including the vehicle road surface drawing device according to the second embodiment. Figure 9 is a diagram showing the change in light intensity of the backup drawing lamp and hazard drawing lamp provided in the vehicle road surface drawing device according to the second embodiment. Figure 10 is a diagram showing the change in light intensity of the backup drawing lamp and hazard drawing lamp provided in the vehicle road surface drawing device according to Modification 1. Figure 11 is a flowchart showing an example of the operation of a vehicle including a road surface drawing device for vehicles according to the third embodiment. Figure 12 is a timing chart of the electrical signals input to each lamp in the third embodiment. Figure 13 is a flowchart showing an example of the operation of a vehicle including a road surface drawing device for vehicles according to the fourth embodiment. Figure 14 is a diagram illustrating a drawing pattern projected onto the road surface by the road surface drawing device for vehicles according to the fourth embodiment. Figure 15 is a flowchart showing an example of the operation of a vehicle including a road surface drawing device for vehicles according to modified example 3.

[0017] The embodiments of this disclosure will be described below with reference to the drawings. For the sake of clarity, the description of components having the same reference numeral as those already described in the description of the embodiments will be omitted. Furthermore, the dimensions of the components shown in these drawings may differ from the actual dimensions of the components for the sake of clarity.

[0018] Furthermore, in the description of this embodiment, for the sake of explanation, the terms "left-right direction," "up-down direction," and "front-back direction" may be referred to as appropriate. These directions are relative directions set for the vehicle 100 illustrated in Figure 2. Here, the "left-right direction" includes the "left direction" and the "right direction," as well as the vehicle width direction of the vehicle 100 on which the road surface drawing device 20 (an example of a road surface drawing device for vehicles) is mounted. The "up-down direction" includes the "up direction" and the "down direction." The "front-back direction" is the front-back direction of the vehicle 100, and includes the "forward direction" and the "rear direction." The front-back direction is perpendicular to the left-right direction and the up-down direction. In each figure, the symbol F indicates the forward direction. The symbol B indicates the rear direction. The symbol L indicates the left direction. The symbol R indicates the right direction. The left-right direction is an example of the horizontal direction.

[0019] This disclosure illustrates the operation of the road surface drawing device 20 when, for example, a vehicle 100 is parked in reverse within a parking lot. However, this disclosure may be applied to operations such as when the vehicle 100 is driven forward, and is not limited to this example.

[0020] (First Embodiment) The road surface drawing device 20 according to the first embodiment will be described with reference to Figures 1 to 7. Figure 1 is a block diagram of the system configuration of the vehicle 100, including the road surface drawing device 20. Figure 2 is a plan view conceptually showing the drawing pattern projected onto the road surface from the road surface drawing device 20 mounted on the vehicle 100. The road surface drawing device 20 is a device that draws a pattern of a predetermined shape on the road surface around the vehicle 100 using light.

[0021] As shown in Figure 1, the vehicle 100 is equipped with headlights 11, taillights 12, reverse lights 13, hazard lights 14, brakes 16, a shift lever 17, a hazard switch 18, and a road marking device 20.

[0022] The headlight 11 has a left headlight 11L and a right headlight 11R. The left headlight 11L and the right headlight 11R illuminate simultaneously, for example, when a light switch (not shown) is operated. The headlight 11 is configured to be switchable between low beam, high beam, or daytime running lights, for example, by the driver of the vehicle 100 or by automatic control.

[0023] The taillight 12 has a left taillight 12L and a right taillight 12R. The left taillight 12L and the right taillight 12R illuminate simultaneously, for example, when the brake 16, which will be described later, is pressed.

[0024] The reverse lamp 13 has a left reverse lamp 13L and a right reverse lamp 13R. The left reverse lamp 13L and the right reverse lamp 13R illuminate simultaneously, for example, when the shift lever 17, described later, is set to the reverse range.

[0025] In this disclosure, the turn signal lamps located on the front left and right and rear left and right of the vehicle 100 are configured to flash simultaneously to function as hazard lamps 14. That is, as shown in Figure 2, each of the turn signal lamps 14FL, 14FR, 14BL, and 14BR functions as a hazard lamp 14. The turn signal lamp 14FL is located close to the left headlight 11L. The turn signal lamp 14FR is located close to the right headlight 11R. The turn signal lamp 14BL is located close to the left taillight 12L. The turn signal lamp 14BR is located close to the right taillight 12R. Each of the turn signal lamps 14FL, 14FR, 14BL, and 14BR, which function as hazard lamps 14, lights up and flashes simultaneously when the hazard switch 18 (described later) is operated and the state in which each of the turn signal lamps 14FL, 14FR, 14BL, and 14BR flashes is selected. Although not shown in the figures, the hazard lamps 14 may also include turn signal lamps provided on the left and right side mirrors.

[0026] The brake 16 includes a pedal depression sensor (not shown). The pedal depression sensor is connected to the control unit 25, which will be described later, and outputs a signal to the control unit 25 corresponding to the amount the brake 16 is depressed.

[0027] The shift lever 17 is an operating lever that switches the gear shift state of the transmission of the vehicle 100, and includes a shift position sensor (not shown). The shift position sensor outputs a signal to the control unit 25 according to the set position of the shift lever 17. For example, the shift position sensor outputs a signal indicating that the shift lever 17 is set to the drive range when it is set to the drive range, a signal indicating that the shift lever 17 is set to the reverse range when it is set to the reverse range, and a signal indicating that the shift lever 17 is set to the parking range when it is set to the parking range.

[0028] The hazard switch 18 is a switch that instructs the driver whether or not to flash the hazard lights 14, and is connected to the control unit 25. For example, when the hazard switch 18 is turned on, the hazard switch 18 outputs a signal to the control unit 25 instructing the hazard lights 14 to flash.

[0029] The road surface drawing device 20 comprises a road surface drawing unit 21 and a control unit 25. The road surface drawing unit 21 includes a backlight drawing lamp 22 and a hazard drawing lamp 24. Each of the drawing lamps 22 and 24 of the road surface drawing unit 21 is connected to the control unit 25.

[0030] The backlighting lamp 22 comprises a first backlighting lamp 22L and a second backlighting lamp 22R. The first backlighting lamp 22L is installed, for example, close to the left taillight 12L. The second backlighting lamp 22R is installed close to the right taillight 12R. Each backlighting lamp 22 includes, for example, a semiconductor light-emitting element such as an LED, a first lens for projecting light emitted from the semiconductor light-emitting element onto a projection screen, and a second lens for drawing an image of a predetermined shape on the projection screen toward the road surface. The projection screen may have a transparent area formed from the beginning corresponding to the predetermined shape to be drawn on the road surface. Alternatively, various patterns of light may be transmitted by selectively driving a plurality of elements arranged in a matrix, such as a transmissive liquid crystal.

[0031] As shown in Figure 2, each backup lamp 22 emits light onto the road surface at a predetermined distance behind the vehicle 100 to draw a backup pattern PB. The backup pattern PB is a road surface image that, along with the illumination of the backup lamps 13, promptly informs traffic participants that the vehicle 100 is moving backward. The first backup lamp 22L projects the first backup pattern PB1, which consists of three roughly rectangular marks arranged in parallel at a fixed interval, onto the rear left side of the vehicle 100. The second backup lamp 22R projects the second backup pattern PB2, which consists of three roughly rectangular marks arranged in parallel at a fixed interval, onto the rear right side of the vehicle 100. When the first pattern PB1 and the second pattern PB2 are not distinguished, they are referred to as the backup pattern PB. The predetermined shape of the back drawing pattern PB formed by the back drawing lamps 22L and 22R is not limited to this; any shape that indicates the direction of travel of the vehicle 100 (the reverse direction of the vehicle 100 in the example of Figure 2) should be displayed on the road surface.

[0032] The hazard indicator lamps 24 include a first hazard indicator lamp 24FL, a second hazard indicator lamp 24FR, a third hazard indicator lamp 24BL, and a fourth hazard indicator lamp 24BR. Each hazard indicator lamp 24, like the backup indicator lamps 22, has, for example, a semiconductor light-emitting element such as an LED, a first lens for projecting light emitted from the semiconductor light-emitting element onto a projection screen, and a second lens for drawing an image of a predetermined shape on the projection screen toward the road surface.

[0033] As shown in Figure 2, the first hazard indicator lamp 24FL is installed, for example, close to the left headlight 11L. The first hazard indicator lamp 24FL emits light onto the road surface at a predetermined distance to the left and in front of the vehicle 100 to draw a hazard indicator pattern (forward indicator pattern) PH1. The second hazard indicator lamp 24FR is installed, for example, close to the right headlight 11R. The second hazard indicator lamp 24FR emits light onto the road surface at a predetermined distance to the right and in front of the vehicle 100 to draw a hazard indicator pattern (forward indicator pattern) PH2. The third hazard indicator lamp 24BL is installed, for example, close to the left taillight 12L. The third hazard indicator lamp 24BL emits light onto the road surface at a predetermined distance to the left and in rear of the vehicle 100 to draw a hazard indicator pattern (rear indicator pattern) PH3. The fourth hazard lamp 24BR is installed, for example, in close proximity to the right taillight 12R. The fourth hazard lamp 24BR emits light onto the road surface at a predetermined distance to the right rear of the vehicle 100 to draw a hazard pattern (rearward drawing pattern) PH4. The hazard patterns PH (PH1 to PH4) are road surface images that, along with the illumination of the hazard lamp 14, promptly inform traffic participants that the vehicle 100 is parked, stopped, or in an emergency situation. Each hazard pattern PH (PH1 to PH4) consists of three roughly inverted V-shaped marks arranged in parallel at a certain interval from each other. Although the diagram shows three inverted V-shaped marks with their acute angles pointing away from the vicinity of the vehicle 100 as the hazard pattern PH, the shape of the hazard pattern is not limited to this.

[0034] The control unit 25 may, for example, be part of the electronic control unit (ECU) of the vehicle 100, or it may be provided separately from the ECU. Examples of such a control unit 25 include integrated circuits such as a microcontroller, IC (Integrated Circuit), LSI (Large-scale Integrated Circuit), ASIC (Application Specific Integrated Circuit), or NC (Numerical Control) device.

[0035] The control unit 25 controls the illumination or flashing of the taillights 12 based on the amount the brake 16 is pressed. The control unit 25 also controls the flashing or illumination of the reverse lights 13 and the drawing of the reverse indicator lights 22 based on the operation of the shift lever 17. Furthermore, the control unit 25 controls the flashing or illumination of the hazard lights 14 and the drawing of the hazard indicator lights 24 based on the operation of the hazard switch 18. The control unit 25 controls the illumination of each of the above lights 12, 13, 14, 22, and 24 at predetermined timings.

[0036] Next, the operation of the vehicle 100 including the road surface drawing device 20 in the first embodiment will be described with reference to Figures 3 to 7. Figure 3 is a flowchart showing an example of the operation of the vehicle 100 including the road surface drawing device 20 according to the first embodiment. Figure 4 is a timing chart of the electrical signals input to the hazard lamp 14, hazard drawing lamp 24, reverse lamp 13, and reverse drawing lamp 22 according to the first embodiment. Figures 5 to 7 show an example of a drawing pattern projected onto the road surface by the road surface drawing device 20.

[0037] In this embodiment, for example, when the ignition power of the vehicle 100 is turned on, the control unit 25 starts controlling the road surface drawing process. In this embodiment, at the start of the process, the reverse drawing lamp 22 and hazard drawing lamp 24 provided by the road surface drawing unit 21 are not lit and are in the off state.

[0038] First, the control unit 25 determines whether a predetermined signal has been input from the hazard switch 18 (step S11). As described above, when the hazard switch 18 is turned on, the control unit 25 receives a signal instructing the hazard lamps (each turn signal lamp) 14 to flash. If no predetermined signal has been input from the hazard switch 18 in step S11 (No. in step S11), the control unit 25 repeats this step. In this case, the back drawing lamp 22 and hazard drawing lamp 24 of the road surface drawing unit 21 remain off.

[0039] On the other hand, if a predetermined signal is input from the hazard switch 18 (Yes in step S11), the control unit 25 outputs a predetermined control signal to the hazard lamp 14. In this disclosure, when the hazard switch 18 is turned on, the hazard lamp 14 flashes. Specifically, as shown in Figure 4, the control unit 25 alternately inputs an ON signal and an OFF signal to the hazard lamp 14. As a result, the hazard lamp 14 flashes at a predetermined cycle (step S12).

[0040] Next, the control unit 25 outputs a predetermined control signal to each of the first hazard lamp 24FL, the second hazard lamp 24FR, the third hazard lamp 24BL, and the fourth hazard lamp 24BR. The predetermined control signal includes timing signals related to the ON and OFF signals that are alternately input to the hazard lamps 14 in step S12. As a result, each hazard lamp 24 turns on, and light is emitted from each hazard lamp 24 at a predetermined period based on the timing signal (step S13). Specifically, as shown in Figure 5, the first hazard lamp 24FL emits light onto the road surface to the left front of the vehicle 100, projecting the hazard pattern PH1, and the second hazard lamp 24FR emits light onto the road surface to the right front of the vehicle 100, projecting the hazard pattern PH2. Furthermore, the third hazard lamp 24BL emits light onto the road surface to the left rear of the vehicle 100, projecting the hazard pattern PH3, and the fourth hazard lamp 24BR emits light onto the road surface to the right rear of the vehicle 100, projecting the hazard pattern PH4. As shown in Figure 4, the control unit 25 alternately inputs ON and OFF signals to each hazard lamp 24 in synchronization with the timing of the alternating input of ON and OFF signals to the hazard lamps 14. As a result, the four hazard patterns PH projected onto the road surface to the left front, right front, left rear, and right rear of the vehicle 100 flash at a frequency synchronized with the flashing period of the hazard lamps 14. Here, synchronization of the flashing period of the hazard lamps 14 and the flashing period of the hazard patterns PH means that their respective flashing periods are approximately the same, and their rising or falling timings are equal.

[0041] Next, the control unit 25 determines whether or not a signal indicating that the shift lever 17 is set to the reverse range is input from the shift position sensor of the shift lever 17 (step S14). As described above, the control unit 25 receives a signal from the shift position sensor corresponding to the set position of the shift lever 17. In step S14, if the signal input to the control unit 25 from the shift position sensor is not a signal indicating that the shift lever 17 is set to the reverse range (No. in step S14), the control unit 25 repeats this step.

[0042] On the other hand, if a signal indicating that the shift lever 17 is set to the reverse range is input from the shift position sensor to the control unit 25 (Yes in step S14), the control unit 25 interrupts outputting control signals to the third hazard lamp 24BL and the fourth hazard lamp 24BR (rear hazard lamps), which are mounted at the rear of the vehicle 100, out of the first hazard lamp 24FL, second hazard lamp 24FR, third hazard lamp 24BL, and fourth hazard lamp 24BR. As a result, as shown in Figures 4 and 6, the flashing projection of the forward hazard patterns PH1 and PH2 is maintained, while the flashing projection of the rear hazard patterns PH3 and PH4 is interrupted (step S15).

[0043] Next, the control unit 25 outputs control signals to the left and right reverse lamps 13L and 13R to illuminate them. As a result, the left and right reverse lamps 13L and 13R illuminate continuously, as shown in Figure 4 (step S16).

[0044] Next, the control unit 25 outputs a predetermined control signal to the back drawing lamp 22. Similar to step S13, the predetermined control signal includes a timing signal related to the ON signal and OFF signal alternately input to the hazard lamp 14 in step S12. As a result, the back drawing lamp 22 is turned on, and light is emitted from the back drawing lamp 22 at a predetermined cycle based on the timing signal (step S17). Specifically, as shown in FIG. 7, light is emitted from the back drawing lamps 22 (22L, 22R), and a back drawing pattern PB (PB1, PB2) is projected onto the road surface behind the vehicle 100. As shown in FIG. 4, the control unit 25 alternately inputs the ON signal and the OFF signal to the back drawing lamp 22 in synchronization with the timing of inputting the ON signal and the OFF signal to the hazard lamp 14. Accordingly, the back drawing lamp 22 blinks at a cycle synchronized with the blinking cycle of the hazard lamp 14. As a result, the back drawing pattern PB is projected in a blinking manner by the light emitted from the back drawing lamp 22. In this way, when the hazard lamp 14 blinks, the back drawing pattern PB projected onto the road surface behind the vehicle 100 also blinks in synchronization with the hazard lamp 14.

[0045] Next, the control unit 25 again determines whether or not a signal indicating that the shift lever 17 is set to the reverse range is input from the shift position sensor of the shift lever 17 (step S18). In step S18, when the signal input from the shift position sensor to the control unit 25 is not a signal indicating that the shift lever 17 is set to the reverse range (No in step S18), the control unit 25 repeats this step.

[0046] On the other hand, if in step S18 the signal input from the shift position sensor to the control unit 25 is not a signal indicating that the shift position is set to the reverse range (Yes in step S18), the control unit 25 interrupts the output of a control signal for turning on the back lamp 13 (13L, 13R) to the back lamp 13. Further, the control unit 25 interrupts the output of a control signal for blinking the reverse drawing lamp 22 to the reverse drawing lamp 22. Accordingly, the back lamp 13 is turned off, and the reverse drawing lamp 22 is also turned off (step S19). As a result, the blinking projection of the reverse drawing pattern PB (PB1, PB2) is interrupted, and the drawing pattern projected onto the road surface returns to the state shown in FIG. 6.

[0047] After the back lamp 13 and the reverse drawing lamp 22 are turned off in step S19, the control unit 25 outputs a control signal including a timing signal again to the third hazard drawing lamp 24BL and the fourth hazard drawing lamp 24BR. Accordingly, in addition to the front hazard drawing patterns PH1 and PH2 that are blinking projected on the road surface in front of the vehicle 100, the rear hazard drawing patterns PH3 and PH4 are projected again on the road surface behind the vehicle 100, and blink in synchronization with the blinking of the hazard lamp 14 (step S20). That is, the drawing pattern projected onto the road surface returns to the state shown in FIG. 5.

[0048] Next, the control unit 25 determines again whether a predetermined signal is input from the hazard switch 18 (step S21). In this step, when a signal instructing turning on the hazard lamp 14 is input from the hazard switch 18 to the control unit 25 (No in step S21), the control unit 25 repeats this step. In this case, the blinking of the hazard drawing patterns PH (PH1 to PH4) on the road surfaces at the left front, right front, left rear and right rear of the vehicle 100 is maintained.

[0049] On the other hand, if no signal instructing the hazard lamp 14 to turn on is input from the hazard switch 18 to the control unit 25 (Yes in step S21), the control unit 25 interrupts outputting a control signal to the hazard lamp 14 to make it blink. The control unit 25 also interrupts outputting control signals to each of the hazard lamps 24 to make the first hazard lamp 24FL, second hazard lamp 24FR, third hazard lamp 24BL, and fourth hazard lamp 24BR blink. As a result, the hazard lamp 14 turns off, and the first hazard lamp 24FL, second hazard lamp 24FR, third hazard lamp 24BL, and fourth hazard lamp 24BR also turn off (step S22). Consequently, the drawing of the hazard pattern PH (PH1 to PH4) on the road surface around the vehicle 100 is interrupted.

[0050] As described above, the road surface drawing device 20 of this disclosure includes a road surface drawing unit 21 that emits light onto the road surface to project a drawing pattern, and a control unit 25 that controls the projection state of the drawing pattern. The drawing pattern includes a reverse drawing pattern PB (PB1, PB2) that is projected onto the road surface behind the vehicle 100 when the shift lever 17 is set to the reverse range, and hazard drawing patterns PH (PH1 to PH4) that are projected onto the road surface to the left front, right front, left rear, and right rear of the vehicle 100 in synchronization with the illumination of the hazard lamps 14. If the projection time of the reverse drawing pattern PB and the projection time of the hazard drawing pattern PH overlap, the control unit 25 instructs the road surface drawing unit 21 to turn off the rear hazard drawing patterns PH3 and PH4 of the hazard drawing pattern PH that are projected onto the road surface behind the vehicle 100. With this configuration, when the vehicle 100 is parking, etc., at the timing when both the reverse drawing pattern PB, which indicates information about the vehicle 100 reversing, and the hazard drawing pattern PH, which is linked to the hazard lamp 14, are projected onto the road surface, the hazard drawing patterns PH3 and PH4 on the rear side of the vehicle, which tend to get mixed up with the reverse drawing pattern PB, are made less noticeable, thereby making the reverse drawing pattern PB more prominent. This prevents the drawing patterns from getting mixed up behind the vehicle 100, making it easier for traffic participants to understand the reverse drawing pattern PB related to the vehicle 100 reversing.

[0051] In the first embodiment described above, at the timing when the backlight pattern PB and the hazard pattern PH are projected simultaneously, only the rear hazard patterns PH3 and PH4 are turned off among the hazard patterns PH (PH1 to PH4) projected onto the road surface in front of and behind the vehicle 100. However, at the timing when the backlight pattern PB and the hazard pattern PH are projected simultaneously, all hazard patterns PH1 to PH4 projected onto the road surface in front of and behind the vehicle 100 may be turned off. With this configuration, not only the rear hazard patterns PH3 and PH4 projected onto the road surface behind the vehicle 100, but also the hazard patterns PH1 and PH2 projected onto the road surface in front of the vehicle 100 are turned off, thereby reducing the inconvenience caused to road users. Furthermore, in this disclosure, the hazard patterns PH are projected onto the left front, right front, left rear, and right rear of the vehicle. However, the hazard pattern PH may be projected onto at least one of the road surfaces in front of, behind, and to the side of the vehicle 100. In this case as well, at the time when the backlight pattern PB and the hazard pattern PH are projected together, the inconvenience to road users can be reduced by turning off at least a portion of the hazard pattern PH projected around the vehicle 100.

[0052] Furthermore, in the first embodiment described above, at the timing when the background drawing pattern PB and the hazard drawing pattern PH overlap and are projected, at least a portion of the hazard drawing patterns PH1 to PH4 are turned off. However, instead of turning off at least a portion of the hazard drawing patterns PH1 to PH4, the configuration may be such that at least a portion of the hazard drawing patterns PH1 to PH4 are dimmed before projection. Even when at least a portion of the hazard drawing patterns PH1 to PH4 are dimmed before projection, the hazard drawing pattern PH can be made less conspicuous, thereby making the background drawing pattern PB more conspicuous and preventing the mixing of drawing patterns, especially behind the vehicle 100.

[0053] (Second Embodiment) Next, the operation of a vehicle 100 including the road surface drawing device 20 according to the second embodiment will be described with reference to Figures 8 and 9. Figure 8 is a flowchart showing an example of the operation of a vehicle 100 including the road surface drawing device 20 according to the second embodiment. Figure 9 is a diagram showing the change in light intensity of the back drawing pattern PB and the hazard drawing pattern PH irradiated onto the road surface by the road surface drawing device 20 according to the second embodiment. Steps S11 to S14, S21 and S22 in Figure 8 are the same as steps S11 to S14, S21 and S22 in Figure 3, so a detailed explanation will be omitted.

[0054] In the second embodiment, when the hazard lamp 14 is illuminated and the shift lever 17 is set to the reverse range, instead of turning off at least a portion of the hazard indicator lamp 24, at least a portion of the hazard indicator lamp 24 is dimmed. In this disclosure, "dimming" means, for example, changing the rate at which the light intensity of the light emitted from the hazard indicator lamp 24 changes.

[0055] As shown in Figure 8, when a signal indicating that the shift lever 17 is set to the reverse range is input to the control unit 25 from the shift position sensor (Yes in step S14), the control unit 25 changes the rate of change in the light intensity emitted from each hazard indicator lamp 24 (24FL, 24FR, 24BL, 24BR) (step S31). As shown in Figure 9, the control unit 25 adjusts the brightness of the hazard indicator lamps 24 so that the time t3 from when the hazard indicator lamp 24 starts lighting up to reach the reference light intensity TH is longer than the time t1 from when the backup indicator lamp 22 starts lighting up to reach the reference light intensity TH. In other words, the rate of increase in the light intensity of the light emitted from the hazard indicator lamps 24 is made slower than the rate of increase in the light intensity of the light emitted from the backup indicator lamps 22. For example, the rate of increase in the light intensity of the light emitted from the hazard indicator lamps 24 can be changed by changing the rate of increase of the drive current supplied to the hazard indicator lamps 24. Furthermore, as shown in Figure 9, when the backdrop lamp 22 and the hazard lamp are turned off, the control unit 25 adjusts the brightness of the hazard lamp 24 such that the time t4 from the start of dimming from the reference light intensity TH to the complete extinguishing of the hazard lamp 24 is longer than the time t2 from the start of dimming from the reference light intensity TH to the complete extinguishing of the backdrop lamp 22. In other words, the rate of decrease in the light intensity of the light emitted from the hazard lamp 24 is made slower than the rate of decrease in the light intensity of the light emitted from the backdrop lamp 22. For example, the rate of decrease in the light intensity of the light emitted from the hazard lamp 24 can be changed by changing the rate of decrease in the amount of drive current supplied to the hazard lamp 24. Thus, in step S31, the hazard pattern PH irradiated from the hazard lamp 24 is switched on and off with a more gradual change than the backdrop pattern PB irradiated from the backdrop lamp 22.

[0056] Next, the control unit 25 proceeds to step S16. Steps S16 to S19 in Figure 6 are the same as steps S16 to S19 in Figure 3, so a detailed explanation is omitted. In the second embodiment, after the backup lamp 13 and backup indicator lamp 22 are turned off in step S19, the control unit 25 interrupts the dimming of the hazard indicator lamp 24 and returns the rate of change of light intensity emitted from the hazard indicator lamp 24 to the normal rate (step S32). That is, the control unit 25 changes the rate of increase of light intensity of the hazard indicator lamp 24 so that the time from when the backup indicator lamp 22 is turned on until it reaches the reference light intensity TH is approximately the same as the time from when the hazard indicator lamp 24 is turned on until it reaches the reference light intensity TH. Furthermore, the control unit 25 changes the light intensity reduction rate of the hazard indicator lamp 24 so that the time from when the dimming of the backlight indicator lamp 22 starts from the reference light intensity TH until it is completely turned off is approximately the same as the time from when the dimming of the hazard indicator lamp 24 starts from the reference light intensity TH until it is completely turned off. Finally, the control unit 25 proceeds to steps S21 and S22.

[0057] As described above, in the road surface drawing device 20 according to the second embodiment, the control unit 25 controls the road surface drawing unit 21 to dim at least a portion of the hazard drawing pattern PH when the projection time of the background drawing pattern PB overlaps with the projection time of the hazard drawing pattern PH. Here, dimming at least a portion of the hazard drawing pattern PH includes, for example, making the time t3 from when the hazard drawing lamp 24 starts lighting up to reach the reference light level TH longer than the time t1 from when the background drawing lamp 22 starts lighting up the background drawing pattern PB to reach the reference light level TH. With this configuration, at the timing when the background drawing pattern PB and the hazard drawing pattern PH are projected at the same time, the background drawing pattern PB reaches the reference light level TH earlier than the hazard drawing pattern PH. In other words, the rising and falling edges of the flashing background pattern PB are steeper than those of the flashing background pattern PH, making the background pattern PB more conspicuous than the hazard pattern PH. This ensures reliable information transmission to traffic participants based on the background pattern PB.

[0058] In the second embodiment, the dimming of the hazard pattern PH may be performed on all hazard patterns PH1 to PH4 projected onto the road surface around the vehicle 100, or it may be performed on only some of the hazard patterns PH. For example, the dimming of the front hazard patterns PH1 and PH2 may not be performed, while the dimming of only the rear hazard patterns PH3 and PH4 may be performed.

[0059] (Modification 1) Next, with reference to Figure 10, the operation of a vehicle 100 including the road surface drawing device 20 according to Modification 1 will be described. Figure 10 is a diagram showing the change in light intensity of the back drawing pattern PB and the hazard drawing pattern PH projected onto the road surface by the road surface drawing device 20 according to Modification 1. In the second embodiment described above, at the timing when the back drawing pattern PB and the hazard drawing pattern PH are projected simultaneously, the control unit 25 flashes the hazard lamp 14 and the hazard drawing pattern PH and the back drawing pattern PB in synchronous motion, as shown in Figure 9. However, the back drawing pattern PB and the hazard drawing pattern PH may be flashed alternately so that the hazard drawing pattern PH is not projected when the back drawing pattern PB is projected. Specifically, as shown in Figure 10, the control unit 25 may control the road surface drawing unit 21 so that the hazard drawing lamp 24 is turned off while the back drawing lamp 22 is lit, and the back drawing lamp 22 is turned off while the hazard drawing lamp 24 is lit. In this case as well, it is preferable to make the time t3 from when the hazard indicator lamp 24 starts lighting up to reach the reference light level TH longer than the time t1 from when the back indicator lamp 22 starts lighting up to reach the reference light level TH. Also, it is preferable to make the time t4 from when the hazard indicator lamp 24 starts dimming up to reach the reference light level TH longer than the time t2 from when the back indicator lamp 22 starts dimming up to reach the reference light level TH.

[0060] Thus, in the road surface drawing device 20 according to Modification 1, at the timing when the background drawing pattern PB and the hazard drawing pattern PH are projected simultaneously, the control unit 25 alternately flashes the background drawing pattern PB and the hazard drawing pattern PH. With this configuration, it is possible to more reliably prevent the background drawing pattern PB and the hazard drawing pattern PH from being mixed together.

[0061] (Modification 2) In the first and second embodiments described above, when the hazard switch 18 is ON, i.e., when the hazard lamp 14 is lit, the backup drawing lamp 22 is lit and the backup drawing pattern PB is projected onto the road surface behind the vehicle 100 when the shift lever 17 is set to the reverse range. However, when the hazard lamp 14 is lit, the backup drawing lamp 22 may be lit and the backup drawing pattern PB may be projected when the shift lever 17 is set to the reverse range and the brake 16 is released. Specifically, after the shift lever 17 is set to the reverse range, the control unit 25 may determine whether a predetermined signal is input from the brake 16 depression amount sensor, and when the signal indicates that the brake 16 depression amount is not above a threshold, it may determine that the brake 16 has been released and light up the backup drawing lamp 22. With this configuration, the projection of the reverse drawing pattern PB is started when the shift lever 17 is set to the reverse range and the brake 16 is released, that is, when the vehicle 100 starts moving backward. This allows traffic participants to be notified in a timely manner that the vehicle 100 is moving backward.

[0062] (Third Embodiment) Next, the operation of the vehicle 100 including the road surface drawing device 20 in the third embodiment will be described with reference to Figures 1, 5, 11, and 12. Figure 11 is a flowchart showing an example of the operation of the vehicle 100 including the road surface drawing device 20 according to the third embodiment. Figure 12 is a timing chart of the electrical signals input to the hazard lamp 14, hazard drawing lamp 24, reverse lamp 13, and reverse drawing lamp 22 according to the third embodiment.

[0063] In this embodiment, for example, when the ignition power of the vehicle 100 is turned on, the control unit 25 starts controlling the road surface drawing process. In this embodiment, at the start of the process, the reverse drawing lamp 22 and hazard drawing lamp 24 provided by the road surface drawing unit 21 are not lit and are in the off state.

[0064] First, the control unit 25 determines whether a predetermined signal has been input from the hazard switch 18 (step S111). As described above, when the hazard switch 18 is turned on, the control unit 25 receives a signal instructing the hazard lamps (each turn signal lamp) 14 to flash. If no predetermined signal has been input from the hazard switch 18 in step S111 (No. in step S111), the control unit 25 repeats this step. In this case, the back display lamp 22 and hazard display lamp 24 of the road surface display unit 21 remain off.

[0065] On the other hand, if a predetermined signal is input from the hazard switch 18 (Yes in step S111), the control unit 25 outputs a predetermined control signal to the hazard lamp 14. In this disclosure, when the hazard switch 18 is turned on, the hazard lamp 14 flashes. Specifically, as shown in Figure 12, the control unit 25 alternately inputs an ON signal and an OFF signal to the hazard lamp 14. As a result, the hazard lamp 14 flashes at a predetermined cycle (step S112).

[0066] Next, the control unit 25 outputs a predetermined control signal to each of the first hazard lamp 24FL, the second hazard lamp 24FR, the third hazard lamp 24BL, and the fourth hazard lamp 24BR. The predetermined control signal includes timing signals related to the ON and OFF signals that are alternately input to the hazard lamps 14 in step S112. As a result, each hazard lamp 24 turns on, and light is emitted from each hazard lamp 24 at a predetermined period based on the timing signal (step S113). Specifically, as shown in Figure 5 (common to the first embodiment), the first hazard lamp 24FL emits light onto the road surface to the left front of the vehicle 100, projecting the hazard pattern PH1, and the second hazard lamp 24FR emits light onto the road surface to the right front of the vehicle 100, projecting the hazard pattern PH2. Furthermore, the third hazard lamp 24BL emits light onto the road surface to the left rear of the vehicle 100, projecting the hazard pattern PH3, and the fourth hazard lamp 24BR emits light onto the road surface to the right rear of the vehicle 100, projecting the hazard pattern PH4. As shown in Figure 12, the control unit 25 alternately inputs ON and OFF signals to each hazard lamp 24 in synchronization with the timing of the alternating input of ON and OFF signals to the hazard lamps 14. As a result, the four hazard patterns PH projected onto the road surface to the left front, right front, left rear, and right rear of the vehicle 100 flash at a frequency synchronized with the flashing period of the hazard lamps 14. Here, synchronization of the flashing period of the hazard lamps 14 and the flashing period of the hazard patterns PH means that their respective flashing periods are approximately the same, and their rising or falling timings are equal.

[0067] Next, the control unit 25 determines whether or not a signal indicating that the shift lever 17 is set to the reverse range is input from the shift position sensor of the shift lever 17 (step S114). As described above, the control unit 25 receives a signal from the shift position sensor corresponding to the set position of the shift lever 17. In step S114, if the signal input to the control unit 25 from the shift position sensor is not a signal indicating that the shift lever 17 is set to the reverse range (No. in step S114), the control unit 25 repeats this step.

[0068] On the other hand, if a signal indicating that the shift lever 17 is set to the reverse range is input to the control unit 25 from the shift position sensor (Yes in step S114), the control unit 25 outputs control signals to the left and right reverse lamps 13L and 13R to illuminate them. As a result, the left and right reverse lamps 13L and 13R illuminate continuously, as shown in Figure 12 (step S115).

[0069] Next, the control unit 25 outputs a predetermined control signal to the backup lamp 22. Similar to step S113, the predetermined control signal includes timing signals related to the ON and OFF signals that are alternately input to the hazard lamp 14 in step S112. As a result, the backup lamp 22 turns on, and light is emitted from the backup lamp 22 at a predetermined period based on the timing signal (step S116). Specifically, as shown in Figure 1, light is emitted from the backup lamp 22 (22L, 22R), and the backup pattern PB (PB1, PB2) is projected onto the road surface behind the vehicle 100. As shown in Figure 12, the control unit 25 alternately inputs ON and OFF signals to the backup lamp 22 in synchronization with the timing of inputting ON and OFF signals to the hazard lamp 14. As a result, the backup lamp 22 blinks at a period synchronized with the blinking period of the hazard lamp 14. As a result, the light emitted from the backup projection lamp 22 causes the backup projection pattern PB to flash and be projected. In this way, when the hazard lamp 14 flashes, the backup projection pattern PB projected onto the road surface behind the vehicle 100 also flashes in sync with the hazard lamp 14.

[0070] Next, the control unit 25 determines again whether or not a signal indicating that the shift lever 17 is set to the reverse range is input from the shift position sensor of the shift lever 17 (step S117). In step S117, if the signal input to the control unit 25 from the shift position sensor is a signal indicating that the shift lever 17 is set to the reverse range (No. in step S117), the control unit 25 repeats this step.

[0071] On the other hand, in step S117, if the signal input from the shift position sensor to the control unit 25 is not a signal indicating that the reverse range has been set (Yes in step S117), the control unit 25 interrupts outputting a control signal to the backup lamps 13 (13L, 13R) to turn them on. The control unit 25 also interrupts outputting a control signal to the backup indicator lamps 22 to make them blink. As a result, the backup lamps 13 and the backup indicator lamps 22 turn off (step S118). Consequently, as shown in Figure 5, the blinking projection of the hazard pattern PH (PH1 to PH4) is maintained, while the blinking projection of the backup pattern PB (PB1, PB2) is interrupted.

[0072] Next, the control unit 25 determines again whether a predetermined signal is input from the hazard switch 18 (step S119). If a signal instructing the hazard lamp 14 to light up is input from the hazard switch 18 to the control unit 25 (No. in step S119), the control unit 25 repeats this step. In this case, the flashing of hazard drawing patterns PH (PH1 to PH4) is maintained on the road surface to the left front, right front, left rear, and right rear of the vehicle 100.

[0073] On the other hand, if no signal to instruct the hazard lamp 14 to turn on is input from the hazard switch 18 to the control unit 25 (Yes in step S119), the control unit 25 interrupts outputting a control signal to the hazard lamp 14 to make it blink. The control unit 25 also interrupts outputting control signals to each of the hazard lamps 24 to make the first hazard lamp 24FL, second hazard lamp 24FR, third hazard lamp 24BL, and fourth hazard lamp 24BR blink. As a result, the hazard lamp 14 turns off, and the first hazard lamp 24FL, second hazard lamp 24FR, third hazard lamp 24BL, and fourth hazard lamp 24BR also turn off (step S120). Consequently, the drawing of the hazard pattern PH (PH1 to PH4) on the road surface around the vehicle 100 is interrupted.

[0074] As described above, the road surface drawing device 20 of the third embodiment includes a road surface drawing unit 21 that emits light onto the road surface behind the vehicle 100 when the shift lever 17 of the vehicle 100 is set to the reverse range, projecting a back drawing pattern PB (an example of a first drawing pattern), and a control unit 25 that controls the projection state of the back drawing pattern PB. The control unit 25 controls the road surface drawing unit 21 to project the back drawing pattern PB in synchronization with the illumination of the vehicle 100's hazard lamp 14. Specifically, the control unit 25 controls the back drawing lamp 22 of the road surface drawing unit 21 to flash the back drawing pattern PB in synchronization with the flashing of the hazard lamp 14. With this configuration, the flashing of the hazard lamp 14 and the flashing of the back drawing pattern PB are synchronized, making it less likely to cause inconvenience to traffic participants who are looking at both the hazard lamp 14 and the back drawing pattern PB.

[0075] Furthermore, the road surface drawing unit 21 can project a hazard drawing pattern PH (an example of a second drawing pattern) onto the road surface around the vehicle 100 based on the illumination of the hazard lamps 14, and the control unit 25 controls the road surface drawing unit 21 to illuminate the hazard drawing pattern PH in synchronization with the illumination of the hazard lamps 14. With this configuration, not only the back drawing pattern PB projected onto the road surface behind the vehicle 100, but also the hazard drawing pattern PH projected around the vehicle is projected in synchronization with the illumination of the hazard lamps 14, further reducing the inconvenience caused to road users. In this disclosure, the hazard drawing pattern PH is projected onto the left front, right front, left rear, and right rear of the vehicle. However, the hazard drawing pattern PH only needs to be projected onto at least one road surface in front of, behind, and to the side of the vehicle 100.

[0076] (Fourth Embodiment) Next, the operation of the vehicle 100 including the road surface drawing device 20 according to the fourth embodiment will be described with reference to Figures 8, 13, and 14. Figure 13 is a flowchart showing an example of the operation of the vehicle 100 including the road surface drawing device 20 according to the fourth embodiment. Figure 14 is a diagram showing an example of a drawing pattern projected onto the road surface by the road surface drawing device 20 according to the fourth embodiment. Steps S111 to S114, S119, and S120 in Figure 13 are the same as steps S111 to S114, S119, and S120 in Figure 11, so a detailed explanation will be omitted.

[0077] In the fourth embodiment, when the hazard lamp 14 is illuminated and the shift lever 17 is set to the reverse range, some of the multiple hazard indicator lamps 24 are turned off. That is, when a signal indicating that the shift lever 17 is set to the reverse range is input from the shift position sensor to the control unit 25 (Yes in step S114), the control unit 25 interrupts outputting control signals to the third hazard indicator lamp 24BL and the fourth hazard indicator lamp 24BR, which are mounted at the rear of the vehicle 100, out of the first hazard indicator lamp 24FL, the second hazard indicator lamp 24FR, the third hazard indicator lamp 24BL, and the fourth hazard indicator lamp 24BR (step S131). As a result, as shown in Figure 14, the flashing projection of the forward hazard indicator patterns PH1 and PH2 is maintained, while the flashing projection of the rear hazard indicator patterns PH3 and PH4 is interrupted.

[0078] Next, the control unit 25 proceeds to step S115. Specifically, the control unit 25 outputs control signals to each of the left and right reverse lamps 13L and 13R to light them up, causing each of the reverse lamps 13L and 13R to light up continuously (step S115). Next, the control unit 25 turns on the reverse drawing lamp 22 and causes the reverse drawing lamp 22 to emit light at a predetermined period based on the timing signal (step S116). As a result, the reverse drawing lamp 22 flashes at a period synchronized with the flashing period of the hazard lamp 14, and as shown in Figure 7, the light emitted from the reverse drawing lamp 22 projects the reverse drawing pattern PB onto the road surface behind the vehicle 100 in a flashing manner. At this time, the flashing projection of the rear hazard drawing patterns PH3 and PH4 is interrupted.

[0079] In the fourth embodiment, in step S117 the shift lever 17 is set to the reverse range, and in step S118 the backup lamps 13L, 13R and backup indicator lamps 22L, 22R are turned off. Then the control unit 25 outputs control signals, including timing signals, again to the third hazard indicator lamp 24BL and the fourth hazard indicator lamp 24BR. As a result, in addition to the forward hazard indicator patterns PH1, PH2 that are flashing and projected onto the road surface in front of the vehicle 100, the rear hazard indicator patterns PH3, PH4 are projected again onto the road surface behind the vehicle 100 and flash in sync with the flashing of the hazard lamps 14 (step S132). In step S132 the indicator patterns projected onto the road surface are the same as those shown in Figure 5. Finally, the control unit 25 proceeds to steps S119 and S120.

[0080] As described above, in the vehicle road surface drawing device 20 according to the fourth embodiment, the control unit 25 controls the road surface drawing unit 21 so that while the back drawing pattern PB is being projected, it projects the forward hazard drawing patterns PH1 and PH2 (an example of a forward drawing pattern) from the hazard drawing patterns PH, while turning off the rear hazard drawing patterns PH3 and PH4 (an example of a rear drawing pattern). With this configuration, at the timing when both the back drawing pattern PB projected onto the road surface behind the vehicle 100 and the hazard drawing patterns PH projected onto the road surface around the vehicle 100 are being projected, the rear hazard drawing patterns PH3 and PH4, which tend to mix with the back drawing pattern PB, are not projected, thereby preventing the mixing of drawing patterns projected onto the road surface.

[0081] (Modification 3) In the third embodiment described above, when the hazard switch 18 is ON, i.e., when the hazard lamp 14 is lit, the backup drawing lamps 22L and 22R are lit when the shift lever 17 is set to the reverse range. However, when the hazard lamp 14 is lit, the backup drawing lamp 22 may be lit when the shift lever 17 is set to the reverse range and the brake 16 is released. Figure 15 is a flowchart showing an example of the operation of a vehicle 100 including the road surface drawing device 20 according to Modification 3. Steps S111 to S115, S119 and S120 in Figure 15 are the same as steps S111 to S115, S119 and S120 in Figure 11, so a detailed explanation is omitted.

[0082] In the modified example 3 shown in Figure 15, after the backup lamps 13L and 13R are illuminated in step S115, the control unit 25 determines whether or not a predetermined signal is input from the brake 16 depression amount sensor (step S141). As described above, the control unit 25 receives a signal from the depression amount sensor corresponding to the amount the brake 16 is depressed. When a signal indicating that the brake 16 depression amount is greater than or equal to a threshold is input to the control unit 25 from the depression amount sensor, the control unit 25 determines that the brake 16 is not released (No in step S141) and repeats this step. On the other hand, when the signal input from the depression amount sensor to the control unit 25 indicates that the brake 16 depression amount is not greater than or equal to a threshold, the control unit 25 determines that the brake 16 is released (Yes in step S141) and outputs a predetermined control signal to the backup indicator lamp 22. The predetermined control signal includes timing signals related to the ON signal and OFF signal that are alternately input to the hazard lamp 14 in step S112. As a result, the backup drawing lamp 22 is turned on, and light is emitted from the backup drawing lamp 22 at a predetermined period based on the timing signal (step S116). Consequently, as shown in Figure 12, the backup drawing pattern PB is flashed and projected onto the rear of the vehicle 100 by the backup drawing lamp 22.

[0083] Next, the control unit 25 determines again whether a predetermined signal is input from the brake 16 depression amount sensor (step S142). If the signal input from the depression amount sensor to the control unit 25 is a signal indicating that the depression amount of the brake 16 is not above a threshold, the control unit 25 determines that the brake 16 remains in a released state (No in step S142) and repeats this step. On the other hand, if the signal input from the depression amount sensor to the control unit 25 is a signal indicating that the depression amount of the brake 16 is above a threshold, the control unit 25 determines that the brake 16 has turned ON (Yes in step S142) and interrupts outputting a predetermined control signal to the backup drawing lamp 22 (step S143). As a result, the emission of light from the backup drawing lamp 22 is interrupted, and the drawing pattern projected onto the road surface becomes as shown in Figure 5. That is, the backup drawing pattern PB becomes non-projected.

[0084] Next, the control unit 25 determines again whether a signal indicating that the shift lever 17 is set to the reverse range is input from the shift position sensor of the shift lever 17 (step S117). If the signal input from the shift position sensor to the control unit 25 is a signal indicating that the reverse range has been set (No in step S117), the control unit 25 repeats this step. On the other hand, if the signal input from the shift position sensor to the control unit 25 is not a signal indicating that the reverse range has been set (Yes in step S117), the control unit 25 stops outputting a control signal to the reverse lamps 13 (13L, 13R) to turn them on. As a result, the reverse lamps 13 turn off (step S144). Finally, the control unit 25 proceeds to steps S119 and S120.

[0085] Thus, in the road surface drawing device 20 according to Modification 3, the control unit 25 starts projecting the reverse drawing pattern PB when the shift lever 17 is set to the reverse range and the brake 16 is released. With this configuration, by starting the projection of the reverse drawing pattern PB when the shift lever 17 is set to the reverse range and the brake 16 is released, that is, at the timing when the vehicle 100 starts moving backward, it is possible to promptly inform traffic participants that the vehicle 100 is moving backward.

[0086] While embodiments of this disclosure have been described above, it goes without saying that the technical scope of this disclosure should not be interpreted restrictively by the description of these embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the disclosure described in the claims. The technical scope of this disclosure should be determined based on the scope of the disclosure described in the claims and its equivalents.

[0087] This disclosure includes the following embodiments: (1) A vehicle road surface drawing device mounted on a vehicle that projects a drawing pattern onto a road surface, comprising: a road surface drawing unit that emits light onto the road surface to project the drawing pattern; and a control unit that controls the projection state of the drawing pattern, wherein the drawing pattern includes: a first drawing pattern projected onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range; and a second drawing pattern projected onto at least one road surface in front of, behind, and to the side of the vehicle in synchronization with the illumination of the vehicle's hazard lamps, wherein the control unit causes the road surface drawing unit to perform any of the following actions when the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap: (a) turning off at least a portion of the second drawing pattern; (b) at least temporarily dimming at least a portion of the second drawing pattern; or (c) adjusting the brightness of at least a portion of the second drawing pattern. (2) (c) The vehicle road surface drawing device according to (1), wherein dimming at least a portion of the second drawing pattern is made longer than the time from the start of illumination of the first drawing pattern until it reaches a standard light level. (3) The vehicle road surface drawing device according to (1) or (2), wherein the control unit flashes the first drawing pattern in synchronization with the flashing of the hazard lamps. (4) The vehicle road surface drawing device according to any one of (1) to (3), wherein the control unit flashes the second drawing pattern in synchronization with the flashing of the hazard lamps. (5) The vehicle road surface drawing device according to (1) or (2), wherein the control unit flashes the first drawing pattern and the second drawing pattern alternately so that the second drawing pattern is not projected when the first drawing pattern is projected.(6) The vehicle road surface drawing device according to any one of (1) to (5), wherein the second drawing pattern includes at least a forward drawing pattern projected in front of the vehicle and a rear drawing pattern projected behind the vehicle, and the control unit causes the road surface drawing unit to perform any of the following when the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap: (d) turn off at least a part of the rear drawing pattern, (e) at least temporarily dim at least a part of the rear drawing pattern, or (f) adjust the brightness of at least a part of the rear drawing pattern. (7) The vehicle road surface drawing device according to any one of (1) to (6), wherein the control unit causes the first drawing pattern to light up when the shift lever is set to the reverse range and the brake of the vehicle is released. (8) A road surface drawing method for a vehicle that projects a drawing pattern onto a road surface, comprising: a first road surface drawing step of projecting a first drawing pattern onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range; a second road surface drawing step of projecting a second drawing pattern onto at least one road surface in front of, behind, and to the side of the vehicle in synchronization with the illumination of the vehicle's hazard lamps; and a lighting control step of controlling the projection state of the second drawing pattern to perform one of the following when the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap: (a) turning off at least a portion of the second drawing pattern; (b) at least temporarily dimming at least a portion of the second drawing pattern; or (c) adjusting the brightness of at least a portion of the second drawing pattern.

[0088] The present disclosure also includes the following embodiments: (9) A vehicle road surface drawing device mounted on a vehicle and projecting a drawing pattern onto a road surface, comprising: a road surface drawing unit that emits light onto the road surface to project the drawing pattern; and a control unit that controls the projection state of the drawing pattern, wherein the drawing pattern includes a first drawing pattern that is projected onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range, and the control unit controls the road surface drawing unit to project the first drawing pattern in synchronization with the illumination of the vehicle's hazard lamps. (10) The vehicle road surface drawing device according to (9), wherein the control unit controls the road surface drawing unit to flash the first drawing pattern in synchronization with the flashing of the hazard lamps. (11) The vehicle road surface drawing device according to (9) or (10), wherein the drawing pattern further includes a second drawing pattern projected onto at least one road surface in front of, behind, and to the side of the vehicle based on the illumination of the hazard lamps, and the control unit controls the road surface drawing unit to project the second drawing pattern in synchronization with the illumination of the hazard lamps. (12) The vehicle road surface drawing device according to (11), wherein the second drawing pattern includes at least a front drawing pattern projected in front of the vehicle and a rear drawing pattern projected behind the vehicle, and the control unit controls the road surface drawing unit to project the front drawing pattern while at least temporarily turning off or dimming the rear drawing pattern while the first drawing pattern is being projected. (13) The vehicle road surface drawing device according to any one of (9) to (12), wherein the control unit starts projecting the first drawing pattern when the shift lever is set to the reverse range and the brakes of the vehicle are released. (14) A road surface drawing method for a vehicle that projects a drawing pattern onto a road surface, comprising: a road surface drawing step of emitting light onto the road surface behind the vehicle to project the drawing pattern; and a projection control step of projecting the drawing pattern in synchronization with the illumination of hazard lights mounted on the vehicle.

[0089] This application is based on Japanese Patent Application No. 2025-039094 and Japanese Patent Application No. 2025-039095, both filed on March 12, 2025, the contents of which are incorporated herein by reference.

Claims

1. A vehicle road surface drawing device mounted on a vehicle that projects a drawing pattern onto a road surface, comprising: a road surface drawing unit that emits light onto the road surface to project the drawing pattern; and a control unit that controls the projection state of the drawing pattern, wherein the drawing pattern includes: a first drawing pattern projected onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range; and a second drawing pattern projected onto at least one road surface in front of, behind, and to the side of the vehicle in synchronization with the illumination of the vehicle's hazard lamps, wherein the control unit causes the road surface drawing unit to perform one of the following actions when the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap: (a) turning off at least a portion of the second drawing pattern; (b) at least temporarily dimming at least a portion of the second drawing pattern; or (c) adjusting the brightness of at least a portion of the second drawing pattern.

2. (c) The vehicle road surface drawing device according to claim 1, wherein dimming at least a portion of the second drawing pattern includes making the time from the start of illumination of the second drawing pattern to reaching a standard light level longer than the time from the start of illumination of the first drawing pattern to reaching a standard light level.

3. The vehicle road surface drawing device according to claim 1 or 2, wherein the control unit flashes the first drawing pattern in synchronization with the flashing of the hazard lamps.

4. The vehicle road surface drawing device according to claim 1 or 2, wherein the control unit flashes the second drawing pattern in synchronization with the flashing of the hazard lamp.

5. The vehicle road surface drawing device according to claim 1 or 2, wherein the control unit alternately flashes the first drawing pattern and the second drawing pattern so that the second drawing pattern is not projected when the first drawing pattern is being projected.

6. The vehicle road surface drawing device according to claim 1 or 2, wherein the second drawing pattern includes at least a forward drawing pattern projected in front of the vehicle and a rear drawing pattern projected behind the vehicle, and the control unit causes the road surface drawing unit to perform any of the following when the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap: (d) turn off at least a portion of the rear drawing pattern; (e) at least temporarily dim at least a portion of the rear drawing pattern; or (f) adjust the brightness of at least a portion of the rear drawing pattern.

7. The vehicle road surface drawing device according to claim 1 or 2, wherein the control unit starts lighting the first drawing pattern when the shift lever is set to the reverse range and the brakes of the vehicle are released.

8. A road surface drawing method for a vehicle that projects a drawing pattern onto a road surface, comprising: a first road surface drawing step of projecting a first drawing pattern onto the road surface behind the vehicle when the vehicle's shift lever is set to the reverse range; a second road surface drawing step of projecting a second drawing pattern onto at least one road surface in front of, behind, and to the side of the vehicle in synchronization with the illumination of the vehicle's hazard lights; and a lighting control step of controlling the projection state of the second drawing pattern to perform one of the following when the projection time of the first drawing pattern and the projection time of the second drawing pattern overlap: (a) turning off at least a portion of the second drawing pattern; (b) at least temporarily dimming at least a portion of the second drawing pattern; or (c) adjusting the brightness of at least a portion of the second drawing pattern.

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