JP2009101926A - Vehicular lighting system, and lighting control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular lighting system for preventing a driver in an opposite vehicle from being dazzled while securing a sufficient quantity of light when a road surface is in a wet condition, and to provide a lighting control method. <P>SOLUTION: The vehicle lighting system 100 is provided for controlling the mode of light to be emitted from a head lamp 14. It comprises a rainfall detecting means 12 for detecting rainfall, and a light emitting intensity control means 21 for making the light emitting intensity of the head lamp 14 with its wavelength shorter than a predetermined wavelength A, lower when the rainfall detecting mean 12 detects rainfall than when it does not detect rainfall. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicular illumination device and the like, and more particularly, to a vehicular illumination device and a lighting control method having a headlamp in which the aspect of light to be irradiated is variable.

  When driving at night or when fog is generated, the headlamps are turned on, but the reflection characteristics of the headlamps on the road surface change greatly depending on the degree of wetness of the road surface. It is known that the driver may be dazzled. Therefore, a vehicle lamp device has been proposed that detects weather conditions and road surface conditions and changes the light distribution, light quantity, or light color of the headlamps based on the detected information (see, for example, Patent Document 1). . The vehicular lamp device described in Patent Document 1 improves the lighting effect by distributing light so that light is incident on the front side of the host vehicle in consideration of a decrease in road surface reflection when the road surface is wet. In addition, there is described light distribution control for preventing dazzling of an oncoming vehicle driver by distributing light in the direction of the road shoulder when the road surface is wet.

In addition, in order to improve the visibility of road signs and road markings during rainy weather, an illuminating device that illuminates by arranging ultraviolet rays in the near ultraviolet region has been proposed (for example, see Patent Document 2). The illumination device described in Patent Document 2 improves the visibility of the illuminated part and is less perceived by the driver of the oncoming vehicle, so there is less risk of dazzling.
Japanese Patent Laid-Open No. 11-32440 JP 2000-16163 A

  However, when the road surface is wet, paying attention to the road surface reflection reflected toward the oncoming vehicle, the road surface reflection does not necessarily decrease, but in the wet state, more road surface reflection occurs and the driver of the oncoming vehicle is dazzled. It has become experimentally clear that it may be a cause.

Fig.1 (a) shows the figure which showed the relationship between the wavelength range of light, and a road surface reflectance for every rainfall. This wavelength range is mainly visible light, the short wavelength range corresponds to blue, the middle wavelength range corresponds to green, and the long wavelength range corresponds to red. Further, in FIG. 1A, the road surface reflectance is displayed by dividing the rainfall into three levels of large, small and zero. From FIG.
・ If there is a lot of rainfall, the road surface reflectance will increase over the entire wavelength range.
・ The higher the rainfall, the higher the road surface reflectance in the short wavelength region.
I understand that.

FIG. 1B is a diagram showing the relationship between the wavelength range of light and the tendency of glare. Note that the glare is the degree to which the driver of the oncoming vehicle feels dazzling. From FIG.
-The shorter the wavelength, the stronger the glare.
I understand that.

  Therefore, from the above knowledge, there exists a problem that the oncoming vehicle may be further dazzled in the vehicle lamp device described in Patent Document 1. In other words, if the amount of light is increased to ensure the visibility of the host vehicle, the glare light on the oncoming vehicle will become stronger. There is a possibility of falling into a situation where good visibility cannot be secured.

  Moreover, if near-ultraviolet light is colored and illuminated as in the illumination device described in Patent Document 2, there is a risk of placing a burden on the vision of the driver of the host vehicle and other vehicles.

  In view of the above problems, an object of the present invention is to provide a vehicular lighting device and a lighting control method that prevent a driver of an oncoming vehicle from being dazzled while securing a sufficient amount of light when the road surface is wet. .

  In view of the above problems, the present invention provides a vehicle lighting device that controls the mode of light emitted from a headlamp, and a rain detection unit that detects rain, and when the rain detection unit detects rain, Emission intensity control means for reducing the emission intensity on the shorter wavelength side than the predetermined wavelength A than when no rain is detected is provided.

  According to the present invention, since the light emission intensity on the short wavelength side where glare is easily felt is lowered as compared with the case where no rain is detected, it is possible to reduce the feeling of glare to the driver of the oncoming vehicle during rain.

  In one embodiment of the present invention, the light emission intensity control means may detect the light emission intensity of the headlamp on the longer wavelength side than the wavelength B of the wavelength A or more when the rain detection means detects rain, when the rain is not detected. It is characterized by increasing.

  According to the present invention, since the emission intensity on the long wavelength side is increased, it is possible to prevent the light quantity of the headlamp from decreasing even if the short wavelength side is decreased.

  Further, in one aspect of the present invention, there is an oncoming vehicle detection unit that detects an oncoming vehicle, and the light emission intensity control unit is more than the wavelength A of the headlamp only when the oncoming vehicle detection unit detects the oncoming vehicle. The light emission intensity on the short wavelength side is lowered as compared with the case where no rain is detected.

  According to the present invention, when the oncoming vehicle is detected, the light emission intensity on the short wavelength side is reduced. Therefore, in a driving environment that rarely passes the corresponding vehicle, it is as natural as it is in the case of rain (zero) even in rainy weather. Illumination as a field of view becomes possible.

  In one embodiment of the present invention, the light emission intensity control means controls the light emission intensity of the headlamp according to the relative distance from the oncoming vehicle measured by the oncoming vehicle detection means.

  According to the present invention, since the light emission intensity gradually changes according to the distance from the oncoming vehicle, it is possible to prevent the driver of the own vehicle or the oncoming vehicle from feeling uncomfortable.

  In one embodiment of the present invention, the light emission intensity control means is configured such that when the rain detection means detects rain, the light emission intensity of the headlamp on the shorter wavelength side than the predetermined wavelength A is greater than when no rain is detected. And lowering the emission intensity on the longer wavelength side than the wavelength B equal to or greater than the wavelength A by an amount corresponding to the reduced emission intensity on the shorter wavelength side than when no rain is detected. .

  According to the present invention, the total light quantity of the headlamp can be kept constant even when the emission intensity on the short wavelength side is lowered.

  In one embodiment of the present invention, the light emission intensity control means controls the light emission intensity of the headlamp according to the amount of rainfall measured by the rain detection means.

  According to the present invention, the light emission intensity can be adjusted according to the rainfall.

  In one embodiment of the present invention, the emission intensity control means reduces the emission intensity of the headlamp on the shorter wavelength side than the wavelength A as the amount of rainfall increases.

  According to the present invention, since the light emission intensity is reduced according to the rainfall, it is possible to prevent the driver from feeling uncomfortable when the rainfall is low.

  It is possible to provide a vehicular lighting device and a lighting control method that prevent a driver of an oncoming vehicle from being dazzled while securing a sufficient amount of light when the road surface is wet.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. The vehicle lighting device 100 according to the present embodiment reduces the light emission intensity in a short wavelength region (for example, luminous intensity represented by lumens or candela) according to the amount of rain, so that the driver of the oncoming vehicle can feel a glare when it rains. Prevent feeling. The light emission intensity is the brightness of the light source, but in the present embodiment, visible light (about 380 nm to 780 nm) is controlled, and may be psychological brightness detected by humans based on vision ( For example, the brightness of the illuminated road surface expressed in lumens). Hereinafter, the overall brightness of the vehicular lighting device 100 may be referred to as a light amount.

  Further, in the present embodiment, the aspect of light (hereinafter referred to as irradiation characteristics) irradiated by the vehicular lighting device 100 is controlled. The irradiation characteristics refer to the emission intensity for each wavelength region, and the light color (spectral distribution) and Both the amount of light (brightness) can be controlled independently.

  In addition, as described in FIG. 1, the road surface reflectance increases when the road surface is wet, and glare to the driver of the oncoming vehicle increases. However, even if the road surface is not wet, light in the short wavelength region is Reflected on the road surface, the driver of the oncoming vehicle perceives it visually. Experiments have also shown that oncoming drivers can feel glare even when the road surface is not wet. Therefore, although the case where the road surface is wet will be described below as an example, the vehicular illumination device 100 of the present embodiment can be suitably applied even when the road surface is not wet.

  FIG. 2 shows an example of a block diagram of the vehicular lighting device 100 of the present embodiment. The vehicular lighting device 100 is configured by connecting a head lamp switch 11, a raindrop sensor 12, and a variable color headlamp 14 to a control ECU (Electronic Control Unit) 13. The control ECU 13 that controls the vehicle lighting device 100 includes a CPU that executes a program, a RAM that serves as a program execution work area and that temporarily stores data, a flash memory that retains data even when the ignition is turned off, and a data interface An input / output interface, a communication controller that communicates with other ECUs, and a ROM that stores a program. When the CPU executes the program, the light emission intensity control means 21 for controlling the irradiation characteristics of the variable color headlamp 14 is realized. Further, the control ECU 13 stores a light emission intensity map 22 in a nonvolatile memory such as a flash memory or a ROM.

  The headlamp switch 11 is a switch for the driver to input on / off of the headlamp and switching of the high beam or the low beam. When the headlamp switch 11 is turned on, the control ECU 13 controls the variable color headlamp 14. Lights up. The raindrop sensor 12 includes, for example, an emitting portion that emits infrared rays toward the windshield and a light receiving portion that receives infrared rays reflected by the windshield, and the infrared rays received by the light receiving portion when raindrops adhere to the detection region. The amount of raindrops is detected when the amount of received light changes (decreases). Therefore, it is detected that the amount of rain increases as the amount of decrease in the amount of received light increases. The raindrop sensor 12 may be configured by a sensor that detects a change in capacitance or a temperature drop due to the attachment of waterdrops and outputs a voltage corresponding to the amount of raindrops. Further, instead of directly detecting the rain amount by the sensor, it may be detected indirectly from the operation speed of the wiper device (setting of Hi, Low or INT, or actual operation speed at the time of setting Auto). Alternatively, a road marking such as a white line may be photographed with a camera, the contrast of the white line portion may be obtained from the photographed image, and the rain amount may be detected indirectly (the contrast decreases as the rain amount increases).

  The variable color headlamp 14 will be described. The variable color headlamp 14 is a headlamp capable of controlling the emission intensity for each wavelength region. FIG. 3A shows an example of a schematic sectional view of the variable color headlamp 14. The variable color headlamp 14 includes a lamp body 33 having openings on the light projecting surface and the back surface, a translucent cover 36 covering the light projecting surface, a lens 32 and an LED light source 31 provided in the lamp body 33, And a controller 37 of the LED light source 31.

  The lamp body 33 is formed of, for example, resin, and the lens 32 is provided by a bracket 34 connected to the inner periphery of the light projecting surface of the lamp body 33 so that the lens 32 is disposed at the approximate center of the LED light source 31 when viewed from the front of the vehicle. To fix. In the LED light source 31, light emitting elements having emission intensity peaks at wavelengths such as blue, red, yellow, and white are arranged in a front view, a lattice shape, or a concentric shape.

  The lens 32 collects the light from the LED light source 31 and further distributes the light. The light from the LED light source 31 guided to the lens 32 is reflected from a mortar-shaped extension reflector 35 that extends from the inside of the light projecting surface of the lamp body 33 and bends obliquely, and is guided in the irradiation direction in front of the vehicle. The extension reflector 35 has a mirror surface on the outer surface, and reflects the light emitted from the lens 32 to guide it in the irradiation direction.

  Based on the signal from the control ECU 13, the controller 37 controls the luminance of the light emitting elements of the LED light source 31 individually or for each light emitting element having a peak at the same wavelength, thereby controlling the light emission intensity in each wavelength region and irradiating light. It is possible to do. Thereby, the light quantity and light color of the variable color headlamp 14 are individually controlled. The variable color headlamp 14 of this embodiment is configured to use the LED light source 31 of FIG.

  FIG. 3B shows another example of a schematic sectional view of the variable color headlamp 14. The variable color headlamp 14 in FIG. 3B has a halogen lamp 39 as a light source and emits light in a fixed wavelength range. The light irradiated by the halogen lamp 39 is reflected by the reflector 40 and irradiates light traveling straight in the road surface direction slightly from the optical axis of the halogen lamp 39. A disc-shaped short wavelength cut filter 38 is pin-supported in the vehicle width direction on the lamp body 33, and the halogen lamp 39 is rotated by rotating the short wavelength cut filter 38 within a range of 0 to 90 degrees about the pin axis. The shielding area of the light irradiated by can be made variable.

  The short wavelength cut filter 38 is an optical filter that cuts or reduces the transmission of light in the short wavelength region, and reduces the light in the short wavelength region that reaches the road surface as the rotation angle of the short wavelength cut filter 38 approaches 90 degrees. Can do. The control ECU 13 controls a predetermined actuator to control the angle of the short wavelength cut filter 38 and adjust the wavelength distribution. In the case where the variable color headlamp 14 is in the form shown in FIG. 3B, it is preferable that a separate light source that mainly emits long wavelength light is provided in order to prevent a decrease in the amount of light of the entire variable color headlamp 14.

  The control of irradiation characteristics will be described. As described with reference to FIG. 1 (a), the greater the amount of rain, the wetter the road surface, so that the glare feeling felt by the driver of the oncoming vehicle increases. For this reason, it is preferable that the light emission intensity control means 21 irradiates light having a reduced light emission intensity in the short wavelength region as the amount of rain detected by the raindrop sensor 12 increases. The relationship between the wavelength range corresponding to the rainfall and the emission intensity is registered in the emission intensity map 22.

  FIG. 4 shows an example of the emission intensity map 22. The emission intensity map 22 associates the wavelength range with the emission intensity of the variable color headlamp 14 for each rainfall. In the case of rainfall (zero), the emission intensity is almost constant regardless of the wavelength, but in the case of rain (low), the emission intensity in the short wavelength region is lower than the rainfall (zero), and the ), The emission intensity in the short wavelength region is lower than the rainfall (low). The light emission intensity control means 21 extracts the light emission intensity for each wavelength region from the light emission intensity map 22 according to the rainfall, and controls the LED light source 31.

  In the emission intensity map 22 of FIG. 4, for example, the emission intensity in a short wavelength region suddenly decreases from 500 nm as a boundary, but this 500 nm is a short wavelength at which the driver of the oncoming vehicle feels a glare. It can be experimentally obtained as the wavelength range of. Therefore, for example, the emission intensity in the short wavelength region may be drastically decreased at the boundary of 600 nm, for example, the emission intensity in the short wavelength region may be rapidly decreased at the boundary of 450 nm, or the amount of rain may be reduced. It may be variable accordingly. In FIG. 4, the emission intensity in the short wavelength region is suddenly reduced with 500 nm as a boundary. However, the emission intensity may be gradually decreased from the long wavelength region to the short wavelength region.

  By the way, if the emission intensity in the short wavelength region is lowered during rainy weather as shown in FIG. 4, the amount of light emitted from the variable color headlamp 14 is reduced. In consideration of a decrease in contrast such as road markings when it rains, it is preferable that the amount of light does not decrease. Therefore, it is conceivable to reduce the emission intensity in the short wavelength region and increase the emission intensity in the long wavelength region.

  FIG. 5A shows an example of a light emission intensity map 22 for reducing the light emission intensity in the short wavelength region and increasing the light emission intensity in the long wavelength region. In FIG. 5A, the emission intensity in the wavelength region longer than 500 nm is larger than the rainfall (zero) and substantially constant. Then, in order to compensate for the reduced light intensity in order to reduce the light emission intensity in the short wavelength region, the area A surrounded by the light emission intensity in the case of rain (zero) and the light intensity of rain of 500 nm or less (many) and the rain (zero) ) And the area B surrounded by the light emission intensity of rain (many) greater than 500 nm are approximately the same.

  By adopting the light emission intensity map 22 as shown in FIG. 5A, the glare feeling felt by the driver of the oncoming vehicle in the rainy weather is reduced and the driver of the own vehicle is prevented from feeling a decrease in the light amount. it can.

  In addition, when increasing the light emission intensity in the long wavelength region to compensate for the decrease in the amount of light, it is preferable to determine the light emission intensity increased in the long wavelength region so that the driver feels uncomfortable. FIG. 5B shows another example of a light emission intensity map 22 that decreases the light emission intensity in the short wavelength region and increases the light emission intensity in the long wavelength region.

  The light emission intensity map 22 in FIG. 5B increases the light emission intensity on the short wavelength side even in the long wavelength range, and gradually decreases the light emission intensity on the long wavelength side in order to supplement the light emission intensity in the short wavelength range. Therefore, it is possible to reduce unevenness of the irradiation light in red and to minimize the uncomfortable feeling felt by the driver.

  In other words, the emission intensity in the long wavelength region when the emission intensity in the short wavelength region is reduced is determined so that the driver feels that the driver of the own vehicle or the oncoming vehicle can reduce the discomfort as much as possible even if the emission intensity in the short wavelength region is reduced. do it. Moreover, since the sensitivity of the human eye with respect to light varies depending on the wavelength, the areas A and C and the areas A and B do not necessarily match.

Instead of extracting the emission intensity for each wavelength region from the emission intensity map 22, the emission intensity for each wavelength region may be calculated. For example, the light emission intensity control means 21 calculates the light emission intensity for each wavelength region as follows, for example.
For a wavelength range larger than 500 nm,
Light emission intensity = Light emission intensity of rain (zero) + α
For a wavelength range of 500 nm or less,
Emission intensity = Emission intensity of rainfall (zero) − (500−wavelength) × β / (500-380)
α and β are values greater than or equal to zero, and are predetermined according to the rainfall. As a result, the emission intensity similar to that shown in FIG.

  FIG. 6 is a flowchart illustrating a procedure in which the control ECU 13 controls the light emission intensity of the variable color headlamp 14 for each wavelength range.

  The control ECU 13 is activated when the ignition is turned on (S10), and waits until the headlamp switch 11 is turned on (S20).

  When the headlamp switch 11 is turned on (Yes in S20), the control ECU 13 acquires the rainfall information detected by the raindrop sensor 12 (S30).

  If the rainfall is not zero, the emission intensity control means 21 extracts the emission intensity for each wavelength region from the emission intensity map 22 according to the rainfall (S40), and the emission intensity of the variable color headlamp 14 based on the extracted emission intensity. Is controlled for each wavelength region (S50).

  The control ECU 13 repeats the above processing every predetermined cycle time until the headlamp switch 11 is turned off (S60).

  As described above, according to the vehicle lighting device 100 of the present embodiment, it is possible to reduce the glare that is felt by the driver of the oncoming vehicle when it rains. Further, by reducing the light emission intensity in the short wavelength region and increasing the light emission intensity in the long wavelength region, it is possible to prevent the driver of the host vehicle from feeling a decrease in the light amount.

  Since it is often the driver of the oncoming vehicle that feels a glare, it is not necessary to control the irradiation characteristics of the variable color headlamp 14 if the oncoming vehicle is not approaching. In the present embodiment, a vehicle lighting device 100 that controls the irradiation characteristics of the variable color headlamp 14 in accordance with the presence or absence of an oncoming vehicle and the relative distance from the oncoming vehicle will be described.

  FIG. 7 shows an example of a block diagram of the vehicular lighting device 100 of the present embodiment. In FIG. 7, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted. The vehicle lighting device 100 of FIG. 7 is different from that of FIG. The oncoming vehicle detection means 15 detects that there is an oncoming vehicle in a traveling lane in the direction opposite to the traveling lane of the host vehicle. More preferably, it is possible to detect not only the presence of an oncoming vehicle but also the distance to the oncoming vehicle.

  The oncoming vehicle detection means 15 is configured as a millimeter wave radar device, for example, and is disposed in the front grille in the front of the vehicle or in the bumper at the rear of the vehicle, and the millimeter waves are reflected back to the oncoming vehicle in front of the host vehicle. The distance to the oncoming vehicle is detected based on the time until and the relative speed with respect to the oncoming vehicle is detected based on the frequency change of the reflected wave.

  Further, the oncoming vehicle detection means 15 detects an oncoming vehicle within a predetermined detection angle and a predetermined distance on the left and right with respect to the vehicle traveling direction. Since the millimeter wave radar apparatus has a plurality of receiving antennas, the direction of the other vehicle is determined from the reception intensity of each antenna, and it is detected whether or not the other vehicle is traveling in a lane other than the own lane. When the own lane is not traveling in the lane adjacent to the opposite lane, there is a risk of detecting another vehicle in the other lane in the same traveling direction. In this case, the relative speed with the other vehicle is compared with the vehicle speed of the own vehicle. Thus, it is possible to determine whether the vehicle is in the same traveling direction or another vehicle in the opposite lane (a vehicle having a relative speed higher than the vehicle speed of the host vehicle becomes another vehicle in the opposite lane).

  Further, the oncoming vehicle detection means 15 may be constituted by a camera. With a stereo camera, it is possible to detect the relative distance and direction to the oncoming vehicle based on the parallax of a pair of image data in front of the vehicle, and it is difficult to obtain distance information with a monocular camera. Can be detected. Further, the presence / absence of an oncoming vehicle and the relative distance may be detected by combining the detection result of the millimeter wave radar device with the detection result of the stereo camera or the monocular camera.

[Control of light emission intensity when an oncoming vehicle is detected]
FIG. 8 is a flowchart showing a procedure by which the control ECU 13 controls the light emission intensity of the variable color headlamp 14 for each wavelength region when there is an oncoming vehicle. In FIG. 8, the same steps as those in FIG.

  The control ECU 13 is activated when the ignition is turned on (S10), and waits until the headlamp switch 11 is turned on (S20).

  When the headlamp switch 11 is turned on (Yes in S20), the control ECU 13 determines whether an oncoming vehicle is detected (S25). When the oncoming vehicle is not detected (No in S25), the driver of the oncoming vehicle does not feel a glare, so the emission intensity of the variable color headlamp 14 is not controlled.

  When the oncoming vehicle is detected (Yes in S25), the light emission intensity control means 21 acquires the rainfall information detected by the raindrop sensor 12 (S30).

  If the rainfall is not zero, the emission intensity control means 21 extracts the emission intensity for each wavelength region from the emission intensity map 22 according to the rainfall (S40), and the emission intensity of the variable color headlamp 14 based on the extracted emission intensity. Is controlled for each wavelength region (S50).

  The control ECU 13 repeats the above processing every predetermined cycle time until the headlamp switch 11 is turned off (S60).

  The road shown in FIG. 8 is frequently passed on a road with a relatively large amount of traffic. Therefore, the control as shown in FIG. 8 may cause the driver to feel uncomfortable, regardless of whether there is an oncoming vehicle as in the first embodiment. It is preferable to control the emission intensity for each wavelength region. However, on roads with relatively little traffic, it is unlikely to pass by a corresponding vehicle, so by controlling the emission intensity for each wavelength range only when passing by an oncoming vehicle, it is the same as in the case of rain (zero) even in rainy weather It is possible to illuminate the front with a light emission intensity that forms a natural field of view.

[Control of light emission intensity according to the distance to the oncoming vehicle]
In the present embodiment, when there is an oncoming vehicle, the emission intensity is controlled for each wavelength region in the same manner as in the first embodiment. However, even when the oncoming vehicle is detected, the oncoming vehicle is traveling far away. Since the driver of the oncoming vehicle rarely feels glare, the emission intensity may be controlled according to the relative distance from the oncoming vehicle. In this case, the emission intensity map 22 is a map that defines the emission intensity for each wavelength region according to the rainfall and relative distance.

  FIG. 9 shows an example of a light emission intensity map 22 that defines the light emission intensity for each wavelength region according to the rainfall and relative distance. The light emission intensity map 22 of FIG. 9 is the light emission intensity map 22 in the case of heavy rainfall, but further defines the light emission intensity in the case of heavy rain according to the relative distance. If the relative distance to the oncoming vehicle is large even with the same amount of rainfall (high), it will be close to the emission intensity of rain (zero). become. By storing such a light emission intensity map 22 for each rainfall, the light emission intensity can be controlled for each wavelength region in accordance with the rainfall and the relative distance.

  FIG. 10 is a flowchart illustrating a procedure in which the control ECU 13 controls the light emission intensity of the variable color headlamp 14 for each wavelength range according to the relative distance when there is an oncoming vehicle. In FIG. 10, the same steps as those in FIG.

  The control ECU 13 is activated when the ignition is turned on (S10), and waits until the headlamp switch 11 is turned on (S20).

  When the headlamp switch 11 is turned on (Yes in S20), the control ECU 13 determines whether or not an oncoming vehicle is detected (S25). When the oncoming vehicle is not detected (No in S25), the driver of the oncoming vehicle does not feel a glare, so the emission intensity of the variable color headlamp 14 is not controlled.

  When the oncoming vehicle is detected (Yes in S25), the light emission intensity control unit 21 acquires the relative distance information of the oncoming vehicle detected by the oncoming vehicle detection unit 15 (S26). Next, the light emission intensity control means 21 acquires the rainfall information detected by the raindrop sensor 12 (S30).

  If the rainfall is not zero, the emission intensity control means 21 extracts the emission intensity for each wavelength region from the emission intensity map 22 according to the rainfall and relative distance (S45), and the variable color headlamp 14 is based on the extracted emission intensity. Is controlled for each wavelength region (S50).

  The control ECU 13 repeats the above processing every predetermined cycle time until the headlamp switch 11 is turned off (S60).

  As shown in the flowchart of FIG. 10, by controlling the light emission intensity according to the relative distance, the light emission intensity gradually changes depending on the relative distance from the oncoming vehicle, thereby reducing the uncomfortable feeling that the driver feels when the irradiation characteristics change. can do.

  By the way, if it is preferable to reduce the light emission intensity in the short wavelength region in order to reduce the glare, the presence of the vehicle can be made conspicuous by increasing the light emission intensity in the short wavelength region. . For example, when the host vehicle slips, when the host vehicle is at a vehicle speed higher than a predetermined level, or when some abnormality has occurred in the in-vehicle device (hereinafter referred to as an alert state requiring attention), the presence of the host vehicle is made conspicuous. It is possible to alert the driver of other vehicles. The glare sensation is not as dazzling to the driver of the oncoming vehicle as the high beam, so it can be alerted without causing discomfort. The brake ECU can detect that the host vehicle has slipped by comparing the wheel speed of each wheel, the host vehicle speed can be acquired from the vehicle speed sensor, and each ECU detects that an abnormality has occurred.

  For light in the short wavelength range that gives a feeling of glare, the road surface reflectivity increases as the amount of rain increases. However, when calling attention, it is preferable to increase the emission intensity in the short wavelength range regardless of the amount of rain. Therefore, in the state requiring attention, the light emission intensity control means 21 maximizes the light emission intensity in the short wavelength region regardless of the rainfall, the presence or absence of an oncoming vehicle, or the relative distance from the oncoming vehicle.

  FIG. 11 is a flowchart illustrating a procedure in which the control ECU 13 increases the light emission intensity of the variable color headlamp 14 in the short wavelength region when the host vehicle is in a state requiring attention. In FIG. 11, the same steps as those in FIG.

  The control ECU 13 is activated when the ignition is turned on (S10), and waits until the headlamp switch 11 is turned on (S20).

  When the headlamp switch 11 is turned on (Yes in S20), the light emission intensity control means 21 determines whether an oncoming vehicle is detected (S25). When the oncoming vehicle is not detected (No in S25), the driver of the oncoming vehicle does not feel a glare, so the emission intensity of the variable color headlamp 14 is not controlled.

  When the oncoming vehicle is detected (Yes in S25), the light emission intensity control unit 21 acquires the relative distance information of the oncoming vehicle detected by the oncoming vehicle detection unit 15 (S26). Next, the light emission intensity control means 21 acquires the rainfall information detected by the raindrop sensor 12 (S30).

  Then, the light emission intensity control means 21 determines whether or not the host vehicle is in a state requiring attention (S35). In the state requiring attention (Yes in S35), the light emission intensity control means 21 controls the light emission intensity in the short wavelength region to the maximum in order to increase the glare feeling (S70). As a result, even when a rainy weather and an oncoming vehicle are detected, if the amount of the vehicle is in a state that requires attention, the driver of the oncoming vehicle can be alerted by increasing the glare.

  When it is not in a state requiring attention (No in S35), the light emission intensity control means 21 extracts the light emission intensity for each wavelength region from the light emission intensity map 22 according to the rainfall and relative distance (S45), and varies based on the extracted light emission intensity. The emission intensity of the color headlamp 14 is controlled for each wavelength region (S50).

  The control ECU 13 repeats the above processing every predetermined cycle time until the headlamp switch 11 is turned off (S60).

  According to the present embodiment, the presence of the vehicle can be noticeable when it is in a state requiring attention, and if it is not in the state requiring attention, the driver can be prevented from feeling glare without reducing the amount of light. it can.

  As described above, the vehicular illumination device 100 according to the present embodiment can reduce the glare feeling felt by the driver of the oncoming vehicle during night illumination without causing a decrease in the amount of light. Moreover, the presence can be made conspicuous in a state where attention should be paid to the driver of the oncoming vehicle.

It is an example of the figure which showed the relationship between the wavelength range of light, and a road surface reflectance for every rainfall. It is a figure which shows an example of the block diagram of a dual use illuminating device. It is a figure which shows an example of schematic sectional drawing of a variable color headlamp. It is a figure which shows an example of the light emission intensity map. It is a figure which shows an example of the light emission intensity map which increased the light emission intensity of a long wavelength range while reducing the light emission intensity of a short wavelength area. It is a flowchart figure which shows the procedure in which control ECU controls the emitted light intensity of a variable color headlamp for every wavelength range. It is a figure which shows an example of the block diagram of the illuminating device for vehicles. It is a flowchart figure which shows the procedure in which control ECU controls the emitted light intensity of a variable color headlamp for every wavelength range, when an oncoming vehicle exists. It is a figure which shows an example of the light emission intensity map which prescribes | regulates light emission intensity for every wavelength range according to a relative distance. It is a flowchart figure which shows the procedure in which control ECU controls the light emission intensity | strength of a variable color headlamp for every wavelength range according to relative distance, when an oncoming vehicle exists. It is a flowchart figure which shows the procedure in which control ECU increases the light emission intensity | strength of the short wavelength range of a variable color headlamp, when the own vehicle is a state requiring attention.

Explanation of symbols

11 Head lamp switch 12 Raindrop sensor 13 Control ECU
DESCRIPTION OF SYMBOLS 14 Variable color head lamp 15 Oncoming vehicle detection means 21 Light emission intensity control means 22 Light emission intensity map 31 LED light source 100 Vehicle illumination device

Claims (9)

A vehicle lighting device that controls the mode of light emitted from a headlamp,
Rain detection means for detecting rainfall;
A light emission intensity control means for lowering the light emission intensity of the headlamp on a shorter wavelength side than the predetermined wavelength A when the rain detection means detects rain;
A vehicular lighting device comprising: The light emission intensity control means, when the rain detection means detects rain,
Increasing the emission intensity of the headlamp on the longer wavelength side than the wavelength B equal to or greater than the wavelength A than when no rain is detected,
The vehicular illumination device according to claim 1. The light emission intensity control means, when the rain detection means detects rain,
Reducing the emission intensity of the headlamp on the shorter wavelength side than the predetermined wavelength A than when no rain is detected, and
Increasing the emission intensity on the longer wavelength side than the wavelength B equal to or greater than the wavelength A by an amount corresponding to the reduced emission intensity on the shorter wavelength side than when no rain is detected,
The vehicular illumination device according to claim 1 or 2. The emission intensity control means controls the emission intensity of the headlamp according to the amount of rainfall measured by the rainfall detection means.
The vehicular illumination device according to any one of claims 1 to 3. The emission intensity control means decreases the emission intensity of the headlamp on the shorter wavelength side than the wavelength A, as the amount of rainfall increases.
The vehicular illumination device according to claim 4. Having oncoming vehicle detection means for detecting an oncoming vehicle,
The emission intensity control means includes
Only when the oncoming vehicle detection means detects an oncoming vehicle, the emission intensity of the headlamp on the shorter wavelength side than the wavelength A is reduced as compared with the case where no rain is detected.
The vehicle illumination device according to claim 1, wherein The emission intensity control means controls the emission intensity of the headlamp according to the relative distance from the oncoming vehicle measured by the oncoming vehicle detection means;
The vehicular illumination device according to claim 6. Vehicle status detection means for detecting a vehicle status to alert other vehicles of the presence of the host vehicle,
When the vehicle situation detection means detects the vehicle situation, the emission intensity control means increases the emission intensity on the shorter wavelength side than the predetermined wavelength A even if the rain detection means detects rain,
The vehicular illumination device according to claim 1. An irradiation control method for controlling the mode of light emitted from a headlamp,
A step in which the rain detection means detects the rain;
If rain is detected, the emission intensity control means lowers the emission intensity of the headlamp on the shorter wavelength side than the predetermined wavelength A than when no rain is detected;
A lighting control method comprising:

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