Vehicle projection device, control method thereof, and vehicle lamp

Abstract

To improve the lighting timing or lighting mode of a projection unit in relation to lighting of a turn lamp.SOLUTION: A piece of vehicular lighting apparatus includes: a projection unit 4d that has a light source 21 and projects predetermined images 5a-5c onto a road surface, based on lighting of the light source; and a lighting control unit 31 that controls the light source 21. The lighting control unit 31 controls the light source 21 so that a required time from a first point of time at which the light source 21 starts lighting in response to input of a turn signal or a hazard signal to a second point of time at which the light source 21 reaches a target light intensity ends later than a third point of time at which the turn lamp or the hazard lamp starts lighting at the target light intensity in response to input of the turn signal or the hazard signal.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a vehicle projection device, a control method thereof, and a vehicle lamp. [Background technology]

[0002] A technology has been developed that enhances safety by projecting a pattern (e.g., an arrow) that indicates the vehicle's traveling direction onto the road surface. For example, when a vehicle turns left or changes lanes to the left, an arrow pointing diagonally forward and left is projected onto the road surface on the left side in front of the vehicle. This promotes attention to pedestrians and drivers around the vehicle. It can also reduce the risk that the blinking of the vehicle's left headlamp in response to a turn signal will not be immediately visible to pedestrians and drivers around the vehicle due to the traffic conditions around the vehicle (degree of vehicle congestion) and buildings (walls along the road, etc.).

[0003] Patent Document 1 discloses a technique in which, when a turn signal lamp is on, drawing of a marker on the road surface in the traveling direction of the vehicle starts, and when the turn signal lamp is off, drawing of the marker ends. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-193689 A Summary of the Invention [Problem to be solved by the invention]

[0005] There is room for improvement with respect to the timing or manner in which the projection unit is turned on in relation to the lighting of the turn signal lamps. [Means for solving the problem]

[0006] A vehicle projection device according to one aspect of the present disclosure includes a projection unit that has a light source and projects a predetermined image onto a road surface based on the lighting of the light source, and a lighting control unit that controls lighting of at least the light source of the projection unit, The lighting control unit is configured to control the lighting of the light source of the projection unit so that the period required from a first point in time when the light source of the projection unit starts to light in response to input of a turn signal or a hazard signal to a second point in time when the light source of the projection unit reaches a target luminous intensity ends later than a third point in time when the turn lamp or hazard lamp lights up at its target luminous intensity in response to input of the turn signal or hazard signal.

[0007] In some embodiments, the required period is 200 ms or less.

[0008] In some embodiments, the specified image includes a plurality of sub-regions, the projection unit includes a plurality of light sources arranged for individual projection onto the plurality of sub-regions, and the lighting control unit is configured (i) to start lighting the plurality of light sources in a specified sequence in response to input of the turn signal or hazard signal, and (ii) to control the lighting of the plurality of light sources so that the required period of each of the plurality of light sources ends later than the third point in time.

[0009] In some embodiments, the lighting control unit is configured to control lighting of the plurality of light sources such that the required periods of each of the plurality of light sources have the same length of time.

[0010] In some embodiments, the lighting control unit is configured to control lighting of the plurality of light sources such that the required periods of each of the plurality of light sources are different lengths of time.

[0011] In some embodiments, the lighting control unit is configured to control the lighting of the multiple light sources so that the multiple light sources simultaneously reach a target luminous intensity and / or the multiple light sources simultaneously turn off.

[0012] In some embodiments, the lighting control unit is configured to generate a plurality of PWM (Pulse Width Modulation) signals for individual lighting control of the plurality of light sources.

[0013] In some embodiments, the lighting control unit is configured to control lighting of the light source such that the light source has a luminous intensity that changes continuously during the required period.

[0014] A vehicle projection device according to one aspect of the present disclosure includes a projection unit having a light source and projecting a predetermined image onto a road surface based on the lighting of the light source, and a lighting control unit that controls the lighting of the light source. The lighting control unit is configured to control the lighting of the light source so that the required period from a first time point at which the light source starts to light in response to input of a turn signal or a hazard signal to a second time point at which the light source reaches a target luminous intensity is shortened according to an increase in the speed of the vehicle. According to this device, it is possible to realize projection that is optimized for both low-speed driving and high-speed driving. That is, during low-speed driving, it is possible to gently alert surrounding pedestrians and drivers. During high-speed driving, it is possible to immediately alert surrounding pedestrians and drivers. The luminous intensity of the light source is controlled to increase stepwise or continuously over the required period.

[0015] In some embodiments, the lighting control unit is configured to control lighting of the light source so that the required period becomes longer in response to a speed reduction of the host vehicle.

[0016] In some embodiments, the lighting control unit is configured to adjust the duty ratio of a PWM (Pulse Width Modulation) signal stepwise or continuously with a required period inversely proportional to the speed of the vehicle. The lighting control unit may include a PWM signal generating unit and an adjustment signal generating unit that generates an adjustment signal for adjusting the duty ratio of the PWM signal generated by the PWM signal generating unit. The adjustment signal may be a lamp signal that specifies the duty ratio. The increase rate of the lamp signal may be adjusted to be proportional to the speed of the vehicle.

[0017] In some embodiments, the speed of the vehicle referred to for adjusting the required period is the speed acquired in synchronization with the rising edge of a turn signal or a hazard signal. The speed of the vehicle is acquired multiple times, and the rate of change of the duty ratio of the PWM signal can be changed.

[0018] In some embodiments, the predetermined image has a plurality of sub-areas that are distinguishable from one another, and the projection unit is controlled to project the plurality of sub-areas onto the road surface in sequence in synchronization with a turn signal or a hazard signal.

[0019] In some embodiments, the projection unit further includes a shading member having a plurality of transparent portions that selectively transmit light emitted from the light source, and a focusing lens disposed between the light source and the shading member and configured to focus the light emitted from the light source onto the plurality of transparent portions.

[0020] In some embodiments, the projection unit is controlled to simultaneously project multiple images corresponding to multiple transparent portions onto the road surface in synchronization with a turn signal or a hazard signal, or to sequentially project individual images included in the multiple images corresponding to the multiple transparent portions onto the road surface in synchronization with a turn signal or a hazard signal.

[0021] A vehicle lamp according to another aspect of the present disclosure includes any one of the vehicle projection devices described above and a turn signal lamp that flashes in synchronization with a turn signal. The turn signal lamp can be controlled to start lighting at a time later than the time when the light source of the projection unit starts lighting.

[0022] A method for controlling a projection device for a vehicle according to another aspect of the present disclosure is a method for controlling the projection device for a vehicle, comprising: A lighting control unit receives a turn signal or a hazard signal; The method includes a step in which the lighting control unit controls the lighting of the light source so that the period required from a first point in time when the light source begins to turn on in response to a turn signal or a hazard signal to a second point in time when the light source reaches a target luminous intensity is shortened in response to an increase in the speed of the vehicle.

[0023] A method according to yet another aspect of the present disclosure includes a projection unit having a light source and projecting a predetermined image onto a road surface based on lighting of the light source; A method for controlling a vehicle projection device including a lighting control unit that controls lighting of the light source of the projection unit, The lighting control unit receives a turn signal or a hazard signal; The lighting control unit includes a step of controlling the lighting of the light source of the projection unit so that the period required from a first point in time when the light source of the projection unit starts to light in response to the turn signal or hazard signal to a second point in time when the light source of the projection unit reaches a target luminous intensity ends later than a third point in time when the turn lamp or hazard lamp lights up at its target luminous intensity in response to input of the turn signal or hazard signal. Effect of the Invention

[0024] According to one aspect of the present disclosure, it is possible to improve the lighting timing or lighting manner of the projection unit in relation to the lighting of the turn signal lamp. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic diagram of a system configuration of a vehicle according to one embodiment of the present disclosure. [Diagram 2] 1 is a diagram showing a schematic configuration of a headlamp according to an embodiment of the present disclosure; [Diagram 3] 1 is a schematic perspective view of a projection unit of a projection device according to an embodiment of the present disclosure. [Figure 4] 1 is a diagram showing a schematic configuration of a lighting control unit that controls lighting of a turn signal lamp and a projection unit. [Diagram 5] 5 is a schematic time chart relating to lighting control of a turn lamp and a projection unit. [Figure 6] FIG. 2 is a diagram showing a non-limiting example of the configuration of a lighting control unit of a projection device. [Figure 7] FIG. 2 is a diagram showing a configuration of a non-limiting example of a lamp ECU. [Figure 8] 1 is a time chart showing how the time required from when the light-emitting part of the projection unit starts to turn on until the target luminance level is reached changes depending on the vehicle speed, where (a) shows control during high-speed driving, (b) shows control during medium-speed driving, and (c) shows control during low-speed driving. [Figure 9] FIG. 13 is a diagram showing a schematic configuration of a lamp ECU according to another embodiment of the present disclosure. [Figure 10] FIG. 10 is a time chart showing how the period required from when the light-emitting part of the projection unit starts to turn on until when the target luminance level is reached changes depending on the vehicle speed, in which (a) shows control when driving at high speeds, (b) shows control when driving at medium speeds, and (c) shows control when driving at low speeds. [Figure 11] FIG. 13 is a diagram showing a schematic system configuration of a turn signal and a projection unit according to another embodiment of the present disclosure, in which three projection units are provided. [Figure 12] FIG. 2 is a schematic diagram showing multiple mutually distinguishable sub-regions of a given image being illuminated sequentially; [Figure 13] 4 is a time chart showing sequential control of a projection unit. [Figure 14] 13 is a diagram showing a schematic configuration of a lighting control unit that controls the lighting of a turn signal lamp and a projection unit according to another embodiment. FIG. [Figure 15] 13 is a schematic time chart relating to lighting control of a turn signal lamp and a projection unit according to another embodiment. [Figure 16] FIG. 13 is a diagram showing a schematic system configuration of a turn signal and a projection unit according to yet another embodiment, in which three projection units are provided. [Figure 17] 1 is a schematic diagram of a projection unit of a projection device according to an embodiment of the present disclosure. [Figure 18] 5 is a time chart relating to lighting control of a turn signal lamp and a projection unit. [Figure 19] 5 is a time chart relating to lighting control of a turn signal lamp and a projection unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, non-limiting embodiments and features of the present invention will be described with reference to the drawings. Those skilled in the art can combine the embodiments and / or features without excessive explanation, and can understand the synergistic effect of this combination. In principle, overlapping explanations between embodiments will be omitted. The reference drawings are primarily intended to describe the invention, and are simplified for the convenience of drawing. Each feature is not only effective for the vehicle lamp disclosed in this specification, but is understood as a universal feature that is also applicable to various other vehicle lamps not disclosed in this specification.

[0027] In this specification, the front-rear direction, left-right direction, and up-down direction are understood based on the vehicle 1. The inside of the vehicle is any direction from the outside of the vehicle toward the inside of the vehicle. The outside of the vehicle is any direction from the inside of the vehicle toward the outside of the vehicle. The up-down direction coincides with or extends along the vertical direction.

[0028] Vehicle 1 is a two-, three-, or four-wheeled, self-propelled mobile body that runs on power generated by an internal combustion engine or an electric motor. Vehicle 1 is configured with vehicle lighting devices attached to the vehicle body, and each vehicle includes individual vehicle and lighting systems 2, 3. Vehicle system 2 is configured with individual elements connected via an in-vehicle network. For ease of explanation, FIG. 1 shows only some of the elements included in vehicle system 2 (vehicle ECU (Electronic Control Unit) 71, direction indicator 72, speed sensor 73, hazard switch 74, brake sensor 75, accelerator opening sensor 76, and steering sensor 77).

[0029] The vehicle ECU 71 may be composed of one or more sub-ECUs. The direction indicator 72 is operated by the driver's voice, hand, foot, etc. to generate a turn signal. The hazard switch 74 is operated by the driver's voice, hand, foot, etc. to generate a hazard signal. These turn signals and hazard signals are transmitted to the lighting system 3 via or without the vehicle ECU 71.

[0030] The lighting system 3 includes left and right front lamps (vehicle lamps) 4 for illuminating the area ahead in the traveling direction of the vehicle. Each front lamp 4 has a low beam lamp 4a, a high beam lamp 4b, a turn signal lamp 4c, a projection unit 4d, and a constant light lamp 4e, for example, as shown in Fig. 2, and these are provided in a common lamp chamber. The lamp chamber is defined by mounting an outer lens in a concave housing.

[0031] The turn lamp 4c flashes in synchronization with the turn signal and the hazard signal, i.e., it starts to light up when the signal rises and goes out when the signal falls. The turn lamp 4c may include one or more semiconductor light emitting elements such as LEDs (Light Emitting Diodes) and LDs (Laser Diodes) as a light source, but is not limited to these, and halogen bulbs, incandescent bulbs, etc. may also be used. The turn lamp 4c may be of a sequential type, but is not limited to this.

[0032] The projection unit 4d projects a predetermined image onto the road surface in synchronization with the turn signal and the hazard signal, that is, it starts projecting the predetermined image onto the road surface in response to the rising edge of the signal and stops projecting the predetermined image onto the road surface in response to the falling edge of the signal. The projection unit 4d operates so that the luminous intensity of its light source increases stepwise or continuously, and as a result, the illuminance of the predetermined image projected onto the road surface increases stepwise or continuously. When the vehicle speed is low, it is possible to gently call the attention of surrounding pedestrians and drivers. The projection unit 4d will be described further below with reference to Figs. 3 to 8. It is not necessary to arrange the projection unit 4d adjacent to the turn lamp 4c, and it is also possible to provide it outside the front lamp (for example, on a side mirror). The low beam lamp 4a, the high beam lamp 4b, and the constant lighting lamp 4e can be those well known in the art, and detailed explanations will be omitted.

[0033] As shown in FIG. 1, three arrows 5a to 5c are projected onto the road surface from the projection unit 4d of the left front lamp. Each of the arrows 5a to 5c is for informing the surroundings of the movement of the vehicle 1 to the left, and here, as an example, is shaped like a flat inverted V. The arrows 5a to 5c are projected onto the road surface along a direction away from the vehicle 1. As will be understood from the description below, when the vehicle 1 travels at a low speed, the arrows 5a to 5c brighten stepwise or continuously to the target illuminance in a longer time, and can gently call the attention of surrounding pedestrians and drivers. When the vehicle 1 travels at a high speed, the arrows 5a to 5c brighten stepwise or continuously to the target illuminance in a shorter time, and can quickly call the attention of surrounding pedestrians and drivers. That is, the projection of the arrows 5a to 5c is optimized for the current traveling speed of the vehicle 1. The same description is also applicable to the projection unit of the right front lamp. Moreover, the same type of projection unit can also be used for the rear lamp of the vehicle 1.

[0034] As shown in Fig. 3, the projection unit 4d of the projection device includes a light source 21, a mounting board 22, a heat sink 23, a condenser lens 24, a light blocking member 25 having transmission parts 26a, 26b, and 26c, a projection lens 27, and a housing 28. The light source 21 includes one or more semiconductor light emitting elements such as, but not limited to, an LED (Light Emitting Diode) and an LD (Laser Diode). The light source 21 may be configured as a module in which the semiconductor light emitting elements are arranged in a matrix. Heat generated when the semiconductor light emitting elements are energized is transferred to the heat sink 23 via or without the mounting board 22 and dissipated.

[0035] The condenser lens 24 condenses the light beam emitted from the light source 21 onto the transmitting portions 26a, 26b, and 26c of the light blocking member 25, thereby improving the light utilization efficiency. The projection lens 27 projects the light transmitted through the transmitting portions 26a, 26b, and 26c of the light blocking member 25 onto the road surface in front of the vehicle 1. The light source 21, the condenser lens 24, the light blocking member 25, and the projection lens 27 are accommodated in the housing 28, thereby preventing stray light from being generated within the lamp chamber. The housing 28 is configured by combining an upper housing with a lower housing (shown in FIG. 3). The optical axis AX of the projection portion 4d extends diagonally downward and forward, and diagonally intersects with the horizontal direction perpendicular to the vertical direction, but this is not necessarily the case.

[0036] The light blocking member 25 is provided with a plurality of transmission parts 26a, 26b, and 26c that selectively transmit the light emitted from the light source 21. The light blocking member 25 is formed by mounting a filter 25b on a frame body 25a. The filter 25b is provided with one or more (three in this case) transmission parts 26a, 26b, and 26c that correspond to a predetermined image to be projected on the road surface, and transmits or blocks the light emitted from the light source 21 depending on the incident position. The transmission parts 26a, 26b, and 26c are arranged in this order from the top in the vertical direction. The filter 25b can be formed, for example, by forming a light absorbing layer or a light reflecting layer on one surface of a transparent substrate and removing the light absorbing layer or the light reflecting layer corresponding to the predetermined image.

[0037] The light emitted from the light source 21 propagates along the optical axis AX of the projection unit 4d (the condenser lens 24 or the projection lens 27) through the condenser lens 24, the transmission parts 26a, 26b, and 26c, and the projection lens 27. The condenser lens 24 condenses the light beam onto the transmission parts 26a, 26b, and 26c of the light blocking member 25. An image formed of the light beam transmitted through the transmission parts 26a, 26b, and 26c is inverted via the projection lens 27 and projected onto the road surface in front of the vehicle 1.

[0038] Specifically, the light beam transmitted through transmitting portion 26c is refracted by the front and rear lens surfaces of projection lens 27 and projected onto the road surface at a position a first distance away from vehicle 1. The light beam transmitted through transmitting portion 26b is refracted by the front and rear lens surfaces of projection lens 27 and projected onto the road surface at a position a second distance away from vehicle 1. The light beam transmitted through transmitting portion 26a is refracted by the front and rear lens surfaces of projection lens 27 and projected onto the road surface at a position a third distance away from vehicle 1. The first distance > second distance > third distance is satisfied.

[0039] The operation of the turn lamp 4c and the projection unit 4d will be described below with reference to FIG. 4 and FIG. 5. When the driver operates the direction indicator 72, a turn signal is input from the direction indicator 72 to the lighting control unit 31 directly or via the vehicle ECU 71. As shown in FIG. 5, the lighting control unit 31 turns on the light source 41 of the turn lamp 4c in synchronization with the input of the turn signal (the rising edge of the turn signal or the turn signal at H level), and similarly turns on the light source 21 of the projection unit 4d in synchronization with the input of the turn signal. As shown in FIG. 5, the light source 21 of the projection unit 4d is controlled to turn on earlier than the light source 41 of the turn lamp 4c. This makes it possible to call the attention of pedestrians and drivers who are in a position where the turn lamp 4c is not in their field of vision. Of course, the lighting start timing of the turn lamp 4c and the lighting start timing of the projection unit 4d may be substantially the same, or the former may be turned on earlier than the latter. A delay circuit may be used to adjust the lighting start timing of the turn lamp and the projection device.

[0040] In this embodiment, the lighting control unit 31 is configured to control the lighting of the light source 21 of the projection unit 4d so that the required period from the first time (time t1 in FIG. 5) when the light source 21 of the projection unit 4d starts to light in response to the input of a turn signal or a hazard signal to the second time (time t3 in FIG. 5) when the light source 21 of the projection unit 4d reaches the target luminous intensity (i.e., the "luminous intensity increase period" between time t1 and time t3 in FIG. 5) ends later than the third time (time t2 in FIG. 5) when the turn lamp 4c (or the hazard lamp) lights up at its target luminous intensity in response to the input of a turn signal or a hazard signal. This increases the possibility that the lighting of the turn lamp 4c is perceived by surrounding drivers and pedestrians before the projection of the image on the road surface by the projection unit 4d. The role of the turn lamp 4c is more well known than the role of the projection unit 4d, and therefore the driver's intention can be communicated to surrounding drivers (or pedestrians) smoothly. Moreover, the projection unit 4d does not instantaneously transition from an off state to a lighting state at the target luminance, but has a luminance increasing period as described above, that is, the luminance increases intermittently or continuously to reach the target luminance. This can mitigate the impression given to drivers and pedestrians around the vehicle that an image (for example, arrows 5a to 5c) suddenly appears on the road surface. In FIG. 5, the turn lamp 4c is turned on at time t2, but it may start to be turned on at time t1 or immediately after time t1. Typically, the turn lamp 4c instantaneously transitions from an off state to lighting at the target luminance as shown in FIG. 5, but this is not necessarily the case. The light source 21 of the projection unit 4d has a period during which it continues to be turned on at the target luminance after the luminance increasing period. The target luminance can be expressed as maximum luminance.

[0041] The luminosity of the light source is correlated with the current flowing through the light source, and is typically proportional. Therefore, the above-mentioned characteristics regarding the luminosity can also be described with respect to the energization of the light source as follows. The lighting control unit 31 is configured to drive the light source 21 of the projection unit 4d so that the required period from the first time point (time point t1 in FIG. 5 or a time point very slightly delayed from time point t1) at which the supply of current to the light source 21 of the projection unit 4d starts in response to the input of a turn signal or a hazard signal to the second time point (time point t3 in FIG. 5) at which the current flowing through the light source 21 of the projection unit 4d reaches the target value (i.e., the "current increase period" between time points t1 and t3 in FIG. 5) ends later than the third time point (time point t2 in FIG. 5) at which the turn lamp 4c (or the hazard lamp) is turned on at its target luminosity in response to the input of a turn signal or a hazard signal. The target value of the current can be expressed in other words as the maximum value of the current.

[0042] If the luminance increase period and the current increase period are too long, there is a risk that the period during which the light source 21 of the projection unit 4d is turned on at the target luminance may not be sufficiently long due to regulatory constraints. From this perspective, it is advantageous that the period required from the time t1 when the turn signal (or hazard signal) is input to the time t3 when the luminance of the light source 21 of the projection unit 4d reaches the target luminance is 200 ms or less. That is, the luminance increase period and the current increase period are 200 ms or less. Also, if the luminance increase period and the current increase period are too short, there is a risk that the above-mentioned effects may be difficult to obtain. Therefore, it is advantageous that the luminance increase period and the current increase period are 100 ms or more or 150 ms or more.

[0043] The lighting control unit 31 has a driving unit 32 for driving the light source 21 of the projection unit 4d, a driving unit 33 for driving the light source 41 of the turn lamp 4c, and a lamp ECU 34. The driving units 32 and 33 drive the light sources 21 and 41 by supplying a PWM (Pulse Width Modulation) signal to the light sources 21 and 41, although this is not necessarily limited thereto. The lamp ECU 34 controls the driving state of the driving unit 32 and / or the driving unit 33. The lamp ECU 34 may be composed of one or more elements or a combination of two or more elements such as a digital circuit, an ASIC (Application Specific Integrated Circuit), a CPU (Central Processing Unit), a memory, a bus, and an I / O. A program stored in the memory can be executed by the CPU (Central Processing Unit) to perform desired control.

[0044] When a turn signal is input to the lighting control unit 31, the lighting control unit 31 drives the light source 41 of the turn lamp 4c to light it. When a turn signal is input to the lighting control unit 31, the lighting control unit 31 drives the light source 21 of the projection unit 4d to light it. When the turn lamp 4c has a plurality of light sources, the lighting control unit 31 can control the turn lamp 4c to light sequentially (for example, in the vehicle width direction). The lighting control unit 31 controls the lighting of the light source 21 so that the luminance of the light source 21 increases stepwise or continuously. As a result, the illuminance of the image projected onto the road surface from the projection unit 4d increases stepwise or continuously. By performing an effect in which an image gradually appears on the road surface in front of the vehicle 1, it is possible to gently call the attention of surrounding pedestrians and drivers. The turn signal can be input only to the lamp ECU 34, or only to the drive unit 32, or both to the lamp ECU 34 and the drive unit 32.

[0045] In FIG. 5, for ease of understanding, the luminous intensity of the light source 21 of the projection unit 4d is adjusted in three stages. At time t1, the turn signal rises to H level, and after a slight delay, the light source 21 emits light of a first luminous intensity. At time t2, the light source 21 emits light of a second luminous intensity. After the light source 21 starts to turn on (not necessarily at time t2), the light source 41 of the turn lamp 4c turns on. At time t3, the light source 21 emits light of a third luminous intensity. The relationship of first luminous intensity<second luminous intensity<third luminous intensity is satisfied.

[0046] In this embodiment, the time required from time t1 when the light source 21 starts to turn on to time t3 when the light source 21 reaches the target luminance is shortened according to an increase in the speed of the vehicle 1. Similarly, the time required is lengthened according to a decrease in the speed of the vehicle 1. As a result, when the vehicle 1 travels at a low speed, the arrows 5a to 5c can be gradually brightened until they reach the target luminance in a longer time, and the surrounding pedestrians and the driver can be gently alerted. When the vehicle 1 travels at a high speed, the arrows 5a to 5c can be rapidly brightened until they reach the target luminance in a shorter time, and the surrounding pedestrians and the driver can be immediately alerted. In this way, the projection operation of the projection unit 4d can be optimized according to the travel speed of the vehicle 1.

[0047] In order to realize the above-mentioned control, various system configurations (software control, digital circuit, logic circuit, analog circuit, etc.) can be adopted. In some cases, as shown in Fig. 6 and Fig. 7, the lighting control unit 31 changes the duty ratio of the PWM signal at a timing that is changed according to the speed of the vehicle 1.

[0048] 6, the driving unit 32 has a PWM signal generating unit 36 ​​that generates a PWM signal with a predetermined duty ratio. In response to an input of an H-level turn signal, the PWM signal generating unit 36 ​​generates a PWM signal with a first duty ratio and supplies it to a switching element 38. In response to an input of an adjustment signal from the lamp ECU 34, the PWM signal generating unit 36 ​​generates a PWM signal with a duty ratio different from (typically larger than) the first duty ratio and supplies it to the switching element 38. The switching element 38 is, for example, a field effect transistor, and the PWM signal is supplied to its gate terminal.

[0049] As shown in FIG. 7, the lamp ECU 34 has a speed determination unit 35 that determines the current speed of the vehicle 1 acquired by the speed sensor 73 of the vehicle 1, and an adjustment signal generation unit 37 that detects a timing that can be changed according to the determination result by the speed determination unit 35 and generates an adjustment signal. In a form in which a plurality of (for example, two) thresholds T1, T2 are used for speed determination, when the current speed is equal to or less than the threshold T1, it is determined to be a low speed (for example, a speed less than 10 km / hour), when the current speed is between the threshold T1 and the threshold T2, it is determined to be a medium speed (for example, a speed within a range of 10 to 20 km / hour), and when the current speed exceeds the threshold T2, it is determined to be a high speed (for example, a speed exceeding 20 km / hour). A determination signal indicating such a determination result is transmitted from the speed determination unit 35 to the adjustment signal generation unit 37.

[0050] The speed determination unit 35 can be realized by executing a program in the lamp ECU 34 that compares the speed value with a threshold value. The use of an analog circuit such as an amplifier is not essential. The current speed of the vehicle 1 can be input to the lighting control unit 31 (for example, the lamp ECU 34) in synchronization with the turn signal becoming H level. The lamp ECU 34 can constantly monitor the current speed of the vehicle 1 and use the speed value acquired when the turn signal of H level is input for the determination.

[0051] The adjustment signal generating unit 37 has first and second timing detecting units 37a and 37b corresponding to two adjustment timings of the luminous intensity of the light source 21 (see FIG. 5). The first and second timing detecting units 37a and 37b detect adjustable timings according to the determination signal. For example, when the determination signal indicates that the vehicle speed is high, the first timing detecting unit 37a obtains the rising edge of the fifth clock counted from the time when the turn signal is input as the first timing. The second timing detecting unit 37b obtains the rising edge of the tenth clock counted from the time when the turn signal is input as the second timing. When the determination signal indicates that the vehicle speed is low, the first timing detecting unit 37a obtains the rising edge of the 50th clock counted from the time when the turn signal is input as the first timing. The second timing detecting unit 37b obtains the rising edge of the 150th clock counted from the time when the turn signal is input as the second timing. Similarly, when the determination signal indicates that the vehicle speed is medium, the timing can be adjusted by changing the final count clock number. Various other timing circuits can be used without relying on clock counts.

[0052] The number of timing detection units can be increased to increase the number of adjustment timings. The clock may be any clock with a predetermined frequency, and may be a clock used in the lamp ECU 34 or a clock provided by the vehicle 1. A dedicated or dual-purpose clock signal generator may be provided for timing detection.

[0053] When the first timing detection unit 37a acquires the first timing, the adjustment signal generation unit 37 outputs a first adjustment signal to the PWM signal generation unit 36 ​​to instruct the PWM signal generation unit 36 ​​to increase the duty ratio. Similarly, when the second timing detection unit 37b acquires the second timing, the adjustment signal generation unit 37 outputs a second adjustment signal to the PWM signal generation unit 36 ​​to instruct the PWM signal generation unit 36 ​​to further increase the duty ratio. In response to the first adjustment signal, the PWM signal generation unit 36 ​​outputs a PWM signal of the second duty ratio to the switching element 38. In response to the second adjustment signal, the PWM signal generation unit 36 ​​outputs a PWM signal of a third duty ratio to the switching element 38. The relationship of first duty ratio<second duty ratio<third duty ratio is satisfied.

[0054] With reference to FIG. 8, the lighting control of the light source 21 of the vehicle 1 when the vehicle 1 travels on the first road, then enters the intersection of the first road and the second road, then passes through the opposite lane of the first road and enters the second road will be described. In the case shown in FIG. 8(a), when the turn signal becomes H level, the traveling speed of the vehicle 1 exceeds the threshold value T1. In the case shown in FIG. 8(b), when the turn signal becomes H level, the traveling speed of the vehicle 1 is between the threshold value T1 and the threshold value T2. In the case shown in FIG. 8(c), when the turn signal becomes H level, the traveling speed of the vehicle 1 is less than the threshold value T2. Therefore, the required period between the time when the light source 21 of the projection unit 4d starts to light up and the time when the light source 21 reaches the target luminous intensity becomes longer in the order of FIG. 8(a), FIG. 8(b), and FIG. 8(c).

[0055] In FIG. 8(a)-(c), the turn signal becomes H level at time t1. In response to the input of the H level turn signal, the lighting control unit 31 instructs the light source 41 of the turn lamp 4c to turn on, and similarly instructs the light source 21 of the projection unit 4d to turn on. In order to turn on the light source 21 of the projection unit 4d, the PWM signal generation unit 36 ​​generates a PWM signal with a first duty ratio and supplies it to the switching element 38. The switching element 38 periodically repeats on and off in response to the PWM signal, and as a result, the light source 21 turns on at the first luminous intensity. Since the switching cycle is fast, a time-averaged luminous intensity is observed. The luminous intensity is observed on the optical axis AX of the projection unit 4d. In this specification, luminous intensity can be read as luminance.

[0056] After the turn signal of H level is input, the speed of the vehicle 1 is determined by the speed determination unit 35 of the lamp ECU 34. A determination signal indicating this determination result is transmitted from the speed determination unit 35 to the adjustment signal generation unit 37. The adjustment signal generation unit 37 sets the detection timing of the first and second timing detection units 37a, 37b according to the determination signal. In the case of FIG. 8(a), the first and second timing detection units 37a, 37b are set to detect the timing at the first and second count numbers. In the case of FIG. 8(b), the first and second timing detection units 37a, 37b are set to detect the timing at the third and fourth count numbers. In the case of FIG. 8(c), the first and second timing detection units 37a, 37b are set to detect the timing at the fifth and sixth count numbers. The relationship of first count number<second count number<third count number<fourth count number<fifth count number<sixth count number is satisfied. As a result, the required period of FIG. 8(a) is minimized as described above. The required period in Fig. 8(c) is the longest, and the required period in Fig. 8(b) is intermediate between the required periods in Fig. 8(a) and Fig. 8(c).

[0057] In Fig. 8(a) to (c), after time t1, the adjustment signal generating unit 37 generates a first adjustment signal, and the PWM signal generating unit 36 ​​generates a PWM signal with a second duty ratio. In this way, at time t2, the light source 21 starts to be turned on at the second luminous intensity. After time t2, the adjustment signal generating unit 37 generates a second adjustment signal, and the PWM signal generating unit 36 ​​generates a PWM signal with a third duty ratio. In this way, at time t3, the light source 21 starts to be turned on at the third luminous intensity. The projection of the image onto the road surface by the projection unit 4d ends when the turn signal changes from H level to L level (i.e., in synchronization with the falling edge of the turn signal).

[0058] As can be seen from the above description, in this embodiment, the required period is adjusted inversely proportional to the speed of the vehicle 1. This allows a slow road surface projection effect when the vehicle speed is low, and such effect can be (substantially) omitted when the vehicle speed is high. The effect at low speeds can gently alert surrounding pedestrians and drivers. The (substantial) omission of the effect at high speeds can prompt a more immediate alert to surrounding pedestrians and drivers, improving safety.

[0059] In order to achieve the above-mentioned object, the lighting control unit 31 can be configured differently. As shown in FIG. 9, the lamp ECU 34 has a lamp signal generating unit 39. The lamp signal generating unit 39 generates a lamp signal in response to the input of a turn signal. The lamp signal means a signal (for example, a voltage signal, a current signal, or a digital signal) that increases over time. When no lamp signal is input (lamp signal=L level), the PWM signal generating unit 36 ​​does not generate a PWM signal. The lamp signal generating unit 39 functions as an adjustment signal generating unit, and the lamp signal functions as an adjustment signal.

[0060] The ramp signal generating unit 39 generates a ramp signal such that the slope (rate of increase) of the ramp signal is proportional to the velocity value. That is, the larger the velocity value, the larger the slope of the ramp signal. The smaller the velocity value, the smaller the slope of the ramp signal. The slope of the ramp signal corresponds to the rate of change (rate of increase or decrease) of the duty ratio, and also corresponds to the rate of change (rate of increase or decrease) of the luminous intensity of the light source 21.

[0061] As shown in Figs. 10(a) to (c), when the vehicle speed is high (Fig. 10(a)), the slope θ of the lamp signal becomes large, and the time required from the start of illumination of the light source 21 until the target luminance is reached becomes short, and when the vehicle speed is low (Fig. 10(c)), the slope θ of the lamp signal becomes small, and the time required from the start of illumination of the light source 21 until the target luminance is reached becomes long. When the vehicle speed is medium (Fig. 10(b)), the required time is intermediate between the required time in Fig. 10(a) and the required time in Fig. 10(c). As described above, the required time is adjusted in inverse proportion to the speed of the vehicle 1. This allows a gentle road surface projection effect when the vehicle speed is low, and such an effect can be (substantially) omitted when the vehicle speed is high. The effect at low speeds can gently alert surrounding pedestrians and drivers. The (substantially) omission of the effect at high speeds encourages surrounding pedestrians and drivers to be more quickly alerted, improving safety. It should be noted that other values ​​or signals transmitted from the vehicle 1 may be used to adjust the slope of the ramp signal.

[0062] By acquiring the speed of the vehicle 1 not only when the turn signal of H level is input, it is possible to realize an adjustment with improved time resolution. For example, after generating a lamp signal with a certain slope according to the speed of the vehicle 1 acquired when the turn signal becomes H level, the speed of the vehicle 1 is acquired at any timing before the luminous intensity of the light source 21 reaches the target luminous intensity, and the slope of the lamp signal is updated. In this way, the lamp signal and the luminous intensity of the light source 21 are adjusted to have two or more slopes. The same can be done when judging the speed using a threshold value. For example, when speed evaluation is performed again at time t2 in FIG. 8(b), the timing of time t3 can be delayed as shown in FIG. 8(c) because the speed is less than the threshold value T2.

[0063] An application example of the above-mentioned embodiment will be described with reference to Figs. 11 to 13. As shown in Fig. 11, first to third projection units 4d1 to 4d3 are provided as the projection unit 4d. The first to third projection units 4d1 to 4d3 are each an individual module as shown in Fig. 3. The first projection unit 4d1 is controlled to project an arrow 5a shown in Fig. 12 onto the road surface. The second projection unit 4d2 is controlled to project an arrow 5b shown in Fig. 12 onto the road surface. The third projection unit 4d3 is controlled to project an arrow 5c shown in Fig. 12 onto the road surface. The arrows 5a to 5c are sub-areas of a predetermined image (see Fig. 12(c)) consisting of a combination of these.

[0064] As shown in FIG. 13, in response to the input of the H-level turn signal at time t1, the lighting control unit 31 supplies a PWM signal to the first light source of the first projection unit 4d1 to start lighting. At time t2 when a first time has elapsed since the input time t1 of the H-level turn signal, the lighting control unit 31 supplies a PWM signal to the second light source of the second projection unit 4d2 to start lighting. In addition, the lighting control unit 31 supplies a PWM signal to the light source 41 of the turn lamp 4c to start lighting. At time t3 when a second time has elapsed since the input time t1 of the H-level turn signal, the lighting control unit 31 supplies a PWM signal to the third light source of the third projection unit 4d3 to start lighting. The lighting control unit 31 can sequentially light the first projection units 4d1 to 4d3 by referring to a timer, but sequential lighting can also be achieved by inserting a delay circuit.

[0065] As described above, the required period is adjusted inversely proportional to the speed of the vehicle 1, and similar control is performed for the light sources of the first to third projection units 4d1 to 4d3.

[0066] As shown in FIG. 14, a configuration is also assumed in which the lighting control unit 31 of the lighting system receives a turn signal (or a hazard signal) from the vehicle side (for example, the vehicle ECU 71) but does not receive a speed signal. In such a case, the features described with reference to FIG. 5 are effective. That is, with reference to FIG. 15 corresponding to FIG. 5, the following description can be given in the same manner as described above. The lighting control unit 31 is configured to control the lighting of the light source 21 of the projection unit 4d so that the required period (the period between time t1 and time t3 in FIG. 15) from the first time point (time t1 in FIG. 15 or a time very slightly delayed from time t1) at which the light source 21 of the projection unit 4d starts to light in response to the input of the turn signal to the second time point (time t3 in FIG. 15) at which the light source 21 of the projection unit 4d reaches the target luminous intensity ends later than the third time point (time t1 in FIG. 15 or a time very slightly delayed from time t1) at which the turn lamp 4c lights up at its target luminous intensity in response to the input of the turn signal. Similarly, the lighting control unit 31 is configured to drive the light source 21 of the projection unit 4d so that the required period from the first time point (time point t1 in FIG. 15 or a time point very slightly delayed from time point t1) at which the supply of current to the light source 21 of the projection unit 4d starts in response to the input of the turn signal to the second time point (time point t3 in FIG. 15) at which the current flowing through the light source 21 of the projection unit 4d reaches the target value (i.e., the "current increase period" between time points t1 and t3 in FIG. 15) ends later than the third time point (time point t2 in FIG. 15) at which the turn lamp 4c is turned on at its target luminance in response to the input of the turn signal. Note that the turn signal can be read as a hazard signal, and the turn lamp can be read as a hazard lamp. Advantageously, the luminance increase period and the current increase period are 200 ms or less. More preferably, the luminance increase period and the current increase period are 100 ms or more or 150 ms or more, and 200 ms or less.

[0067] As shown in Fig. 16 and Fig. 17, a configuration in which the projection unit 4d is adapted for sequential lighting is also assumed. The predetermined image projected onto the road surface by the projection unit 4d includes a plurality of sub-regions (e.g., arrows 5a to 5c). The projection unit 4d includes a plurality of light sources (e.g., one or more semiconductor light-emitting elements such as LEDs (Light Emitting Diodes) and LDs (Laser Diodes)) 21a to 21c provided for individual projection of the plurality of sub-regions. Note that the number of sub-regions and the number of light sources in the predetermined image are not limited to three, and may be four, five, six or more.

[0068] As can be seen from FIG. 17, a common optical system and housing can be adopted for a plurality of light sources in order to miniaturize the projection unit 4d. As an alternative to the light source 21 in FIG. 3, three light sources 21a to 21c are provided. As an alternative to the condenser lens 24 in FIG. 3, a lens 24' including lens portions 24a to 24bc adapted for individual control of the light emitted from the three light sources 21a to 21c is provided. In addition, a light shielding plate 29 for suppressing crosstalk between channels is provided between the lens 24' and the light shielding member 25. The light shielding plate 29m optically separates the channel CH1 for the light emitted from the light source 21a and the channel CH2 for the light emitted from the light source 21b, and the light shielding plate 29n optically separates the channel CH2 for the light emitted from the light source 21b and the channel CH3 for the light emitted from the light source 21c.

[0069] The operation of the lighting control unit 31 shown in FIG. 16 will be described with reference to FIG. 18. The lighting control unit 31 receives a turn signal at time t1 and immediately instructs the light source 41 of the turn lamp 4c to be turned on. For example, the lighting control unit 31 supplies a lighting signal (e.g., a high-level pulse signal) to a switch (e.g., connected in series) that determines the power supply state of the light source 41 of the turn lamp 4c. In response to this, the switch is turned on and the light source 41 is turned on. In response to the switch being turned on, a direct or alternating current flows through the light source 41, or a direct or alternating voltage is applied to the light source 41, and the light source 41 is turned on. The light source 41 reaches the target luminous intensity immediately (almost simultaneously) after the switch is turned on, and therefore, in FIG. 18, the light source 41 is illustrated as reaching the target luminous intensity at time t1. The light source 41 continues to be turned on at the target luminous intensity until time t5 when the turn signal changes to the L level.

[0070] In parallel with the lighting control of the light source 41 of the turn lamp 4c in response to the above-mentioned turn signal, the lighting control unit 31 also starts lighting control of the first light source 21a of the projection unit 4d (for example, the light source 21a shown in FIG. 17) in response to the turn signal. Specifically, the lighting control unit 31 supplies a PWM signal to a switch (for example, connected in series) that determines the energization state of the first light source 21a of the projection unit 4d. The luminous intensity of the first light source 21a can be increased stepwise or linearly by increasing the duty ratio of the PWM signal stepwise or continuously. In FIG. 18, the luminous intensity of the first light source 21a increases linearly until time t2, and reaches the target luminous intensity at time t2. The lighting of the first light source 21a at the target luminous intensity continues until time t5 when the turn signal changes to the L level.

[0071] The lighting control unit 31 starts lighting control of the second light source 21b (for example, the light source 21b shown in FIG. 17) of the projection unit 4d at time t2 when a predetermined time has elapsed from time t1. For example, the lighting control unit 31 supplies a PWM signal to a switch (for example, connected in series) that determines the energized state of the second light source 21b of the projection unit 4d. The luminous intensity of the second light source 21b can be increased stepwise or linearly by increasing the duty ratio of the PWM signal stepwise or continuously. In FIG. 18, the luminous intensity of the second light source 21b increases linearly until time t3, and reaches the target luminous intensity at time t3. The lighting of the second light source at the target luminous intensity continues until time t5 when the turn signal changes to the L level.

[0072] The lighting control unit 31 starts lighting control of the third light source 21c (for example, the light source 21c shown in FIG. 17) of the projection unit 4d at time t3 when a predetermined time has elapsed from time t1. For example, the lighting control unit 31 supplies a PWM signal to a switch (for example, connected in series) that determines the energized state of the third light source 21c of the projection unit 4d. The luminous intensity of the third light source can be increased linearly by increasing the duty ratio of the PWM signal stepwise or continuously. In FIG. 18, the luminous intensity of the third light source 21c increases linearly until time t4, and reaches the target luminous intensity at time t4. The lighting of the third light source 21c at the target luminous intensity continues until time t5 when the turn signal changes to the L level.

[0073] The period required for each of the first to third light sources of the projection unit 4d from the start of lighting to the time when the target luminous intensity is reached ends later than the time when the turn lamp 4c lights up at the target luminous intensity in response to the input of a turn signal or a hazard signal (time t1 in FIG. 18 or a time very slightly delayed from time t1). This provides the same effects as those described with reference to FIG. 5 and FIG. 15.

[0074] The time interval between the time t1 when the turn signal is input and the time t4 when the luminance of the light source 21c that lastly starts to turn on in the projection unit 4d reaches its target luminance may be 200 ms or less. This allows the state in which all of the light sources 21a to 21c of the projection unit 4d are fully turned on to be maintained for a desired period of time, and drivers and pedestrians around the vehicle can be more fully alerted. Advantageously, the time interval between the time t1 when the turn signal is input and the time t4 when the luminance of the light source 21c that lastly starts to turn on in the projection unit 4d reaches its target luminance is 100 ms or more or 150 ms or more.

[0075] Although not necessarily so, the time interval between time t1 and time t2, the time interval between time t2 and time t3, the time interval between time t3 and time t4, and the time interval between time t4 and time t5 are equal. In this case, the first to third light sources have equal lengths of luminous intensity increase periods (similarly, current increase periods). This can provide a visual effect in which the individual images (e.g., arrows 5a to 5c) gradually appear on the road surface in the same manner.

[0076] Although not necessarily limited to this, the rate of change in the luminance of the first light source 21a (in other words, the rate of change in the current flowing through the first light source) during the required period for the first light source 21a (the period between time t1 and time t2), the rate of change in the luminance of the second light source 21b (in other words, the rate of change in the current flowing through the second light source) during the required period for the second light source 21b (the period between time t2 and time t3), and the rate of change in the luminance of the third light source 21c (in other words, the rate of change in the current flowing through the third light source) during the required period for the third light source 21c (the period between time t3 and time t4) are equal. This makes it possible to obtain a visual effect in which the individual images (for example, arrows 5a to 5c) gradually appear on the road surface in the same manner.

[0077] In the case shown in FIG. 19, the lighting control unit 31 controls the lighting of the light sources 21a to 21c so that the light sources 21a to 21c reach the target luminous intensity simultaneously. Since the light sources 21a to 21c start lighting at different times, the light sources 21a to 21c have different required periods and different rates of increase in luminous intensity (along the time axis). In FIG. 19, the rate of increase in luminous intensity of the first light source 21a that starts lighting at time t1 is the minimum value (i.e., the luminous intensity changes most slowly along the time axis), the rate of increase in luminous intensity of the second light source 21b that starts lighting at time t2 is the intermediate value (i.e., the luminous intensity changes at an intermediate degree along the time axis), and the rate of increase in luminous intensity of the third light source 21c that starts lighting at time t3 is the maximum value (i.e., the luminous intensity changes most rapidly along the time axis). In this way, the first to third light sources 21a to 21c reach the target luminous intensity simultaneously at time t4. Although the period during which all of the light sources 21a to 21c of the projection unit 4d are fully lit (the period between time t4 and time t5) becomes shorter, the lighting of the turn lamp 4c can be made more noticeable compared to the lighting of the projection unit 4d. Note that, as described above, the first to third light sources 21a to 21c are simultaneously turned off in response to the transition of the turn signal to the L level.

[0078] In light of the above description, those skilled in the art can make various modifications to each embodiment. A hazard signal can be used in addition to or instead of a turn signal. The projection unit can be provided in a location or lamp chamber different from the low beam lamp and the high beam lamp. The lighting fixture ECU can be understood as an adjustment unit that adjusts the luminous intensity or duty ratio. [Explanation of symbols]

[0079] 4d projection part 21 Light source 31 Lighting control unit

Claims

1. a projection unit having a light source and projecting a predetermined image onto a road surface based on the lighting of the light source; A vehicle projection device including a lighting control unit that controls lighting of the light source of the projection unit, the lighting control unit is configured to control lighting of the light source of the projection unit such that a required period from a first time point at which the light source of the projection unit starts to light in response to input of a turn signal or a hazard signal to a second time point at which the light source of the projection unit reaches a target luminous intensity ends later than a third time point at which the turn lamp or the hazard lamp lights up at its target luminous intensity in response to input of the turn signal or the hazard signal, The turn signal or the hazard signal is turned on at a time point later than the first time point.

2. The vehicle projection device according to claim 1 , wherein the required period is 200 ms or less.

3. The predetermined image includes a plurality of sub-areas, and the projection unit includes a plurality of light sources provided for individual projection of the plurality of sub-areas, 3. The vehicle projection device according to claim 1, wherein the lighting control unit is configured to (i) start lighting the plurality of light sources in a predetermined order in response to input of the turn signal or the hazard signal, and (ii) control the lighting of the plurality of light sources so that the required period of each of the plurality of light sources ends later than the third point in time.

4. The vehicle projection device according to claim 3 , wherein the lighting control unit is configured to control lighting of the plurality of light sources so that the required periods of each of the plurality of light sources are the same length of time.

5. The vehicle projection device according to claim 3 , wherein the lighting control unit is configured to control lighting of the plurality of light sources such that the required periods of the respective light sources have different lengths of time.

6. 6. The vehicle projection device according to claim 3, wherein the lighting control unit is configured to control lighting of the plurality of light sources so that the plurality of light sources simultaneously reach a target luminous intensity and / or are simultaneously turned off.

7. The vehicle projection device according to claim 3 , wherein the lighting control unit is configured to generate a plurality of PWM (Pulse Width Modulation) signals for individual lighting control of the plurality of light sources.

8. The vehicle projection device according to claim 1 , wherein the lighting control unit is configured to control lighting of the light source so that the light source has a luminous intensity that changes continuously during the required period.

9. The vehicle projection device according to claim 1 , wherein the lighting control unit is configured to control lighting of the light source such that the required period is shortened in response to an increase in speed of the host vehicle.

10. The vehicle projection device according to claim 9, wherein the lighting control unit is configured to control lighting of the light source such that the required period becomes longer in accordance with a speed reduction of the host vehicle.

11. 11. The vehicle projection device according to claim 9, wherein the lighting control unit is configured to adjust a duty ratio of a PWM (Pulse Width Modulation) signal stepwise or continuously in the required period inversely proportional to the speed of the vehicle.

12. 12. The projection device for a vehicle according to claim 9, wherein the speed of the vehicle referenced for adjusting the required period is a speed obtained in synchronization with a rising edge of the turn signal or the hazard signal.

13. the predetermined image has a plurality of sub-regions that are distinguishable from one another; 13. The projection device for a vehicle according to claim 9, wherein the projection unit is controlled to sequentially project the plurality of sub-areas onto a road surface in synchronization with the turn signal or the hazard signal.

14. The projection unit is a light-shielding member provided with a plurality of transmission portions that selectively transmit the radiation light from the light source; 14. The vehicle projection device according to claim 9, further comprising a condenser lens disposed between the light source and the light blocking member, the condenser lens condensing the light emitted from the light source onto the plurality of transmission portions.

15. 15. The vehicle projection device according to claim 14, characterized in that the projection unit is controlled to simultaneously project a plurality of images corresponding to the plurality of transparent portions onto the road surface in synchronization with the turn signal or hazard signal, or to sequentially project each image included in the plurality of images corresponding to the plurality of transparent portions onto the road surface in synchronization with the turn signal or hazard signal.

16. A vehicle projection device according to any one of claims 1 to 15, A vehicle lamp including a turn lamp that flashes in synchronization with the turn signal, The lighting control unit is configured to also control the lighting of the turn lamp.

17. a projection unit having a light source and projecting a predetermined image onto a road surface based on the lighting of the light source; A method for controlling a vehicle projection device including a lighting control unit that controls lighting of the light source of the projection unit, The lighting control unit receives a turn signal or a hazard signal; The lighting control unit controls lighting of the light source of the projection unit so that a required period from a first time point at which the light source of the projection unit starts to light in response to the turn signal or hazard signal to a second time point at which the light source of the projection unit reaches a target luminous intensity ends later than a third time point at which the turn lamp or hazard lamp lights up at its target luminous intensity in response to the input of the turn signal or hazard signal, The control method for a projection device for a vehicle, wherein the turn signal or the hazard signal starts to be turned on at a time point later than the first time point.

Images