JP2020026144A - Lighting fixture for vehicle - Google Patents

Abstract

To improve visibility for a frontward direction of a vehicle at snow fall.SOLUTION: A light distribution controller 140 generates a light distribution pattern PTN which contains a shading part adding a margin area around a circumference of a snow particle. A light distribution variable lamp 110 is capable of generating beam including intensity distribution according to the light distribution pattern PTN. In a lighting fixture 100 for a vehicle, at least one of the size and shape of the margin area is variable.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicular lamp.

  Vehicle lights play an important role in driving safely at night or in tunnels. If the driver's visibility is given priority and the front of the vehicle is brightly illuminated over a wide area, glare will be given to the driver or pedestrian of the preceding vehicle or oncoming vehicle (hereinafter referred to as the front vehicle) existing in front of the vehicle. There's a problem.

  2. Description of the Related Art In recent years, an ADB (Adaptive Driving Beam) technology for dynamically and adaptively controlling a light distribution pattern based on a surrounding state of a vehicle has been proposed. The ADB technology detects the presence or absence of a preceding vehicle or a pedestrian and dims or turns off an area corresponding to the preceding vehicle or a pedestrian, thereby reducing glare applied to a driver or a pedestrian of the preceding vehicle. is there.

  When the headlamp is turned on during snowfall (or during rainfall), there is a problem that a beam is reflected on snow particles to give glare to the driver, and it becomes rather difficult to see the front. In order to solve this problem, the present inventors have studied a control for detecting snow particles and shielding the surroundings.

  In a system capable of ultra-high-speed control, it is possible to make the light-blocking area as close as possible to the size of snow particles. However, such systems are very expensive and impractical. Therefore, in a realistic system, a range in which the periphery of the snow particle is extended must be used as a light shielding portion. When the light-shielding portion is large, the beam does not irradiate the object overlapping behind the snow particles, and thus there is a problem that the visibility is reduced.

  The present invention has been made in view of such circumstances, and one of exemplary purposes of one embodiment thereof is to improve visibility in front of a vehicle during snowfall.

  One embodiment of the present invention relates to a vehicular lamp. The vehicle lighting device includes a light distribution controller that generates a light distribution pattern including a light-shielding portion with a margin area added around snow particles, and a light distribution variable lamp that can generate a beam having an intensity distribution according to the light distribution pattern. , Is provided. At least one of the size and shape of the margin area is variable.

  Note that any combination of the above-described components, and any conversion of the expression of the present invention among methods, apparatuses, systems, and the like, are also effective as embodiments of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the visibility of the vehicle front at the time of snowfall can be improved.

It is a block diagram of the vehicular lamp concerning an embodiment. FIGS. 2A and 2B are diagrams illustrating the operation of the vehicle lamp of FIG. 3A to 3C are enlarged views of a light shielding portion. 9 is a flowchart illustrating control of a margin area based on a position. It is a photograph taken from a vehicle running during snowfall. FIGS. 6A and 6B are diagrams illustrating an improvement in the visibility of the watched object. It is a block diagram of the vehicular lamp concerning one example.

(Outline of Embodiment)
A vehicular lamp according to an embodiment disclosed in the present specification has a light distribution controller that generates a light distribution pattern including a light-shielding portion with a margin area added around snow particles, and an intensity corresponding to the light distribution pattern. A variable light distribution lamp capable of generating a beam having a distribution. In such a lamp, when the margin area is increased, the followability to snow particles is enhanced, but the periphery of the snow particles is also darkened, and visibility is reduced. Conversely, when the margin area is reduced, the beam can be radiated around the snow particles, so that the visibility is improved, but the ability to follow the snow particles is reduced. Therefore, by controlling the margin area according to the situation, it is possible to balance the tracking performance and the visibility.

  At least one of the size and the shape of the margin area may be set according to the position. The trajectory of the running snow particles moves radially from the vanishing point. The closer the vehicle is to the vehicle, in other words, the further away from the vanishing point, the longer the apparent length of the trajectory of snow particles (movement amount per unit time). Therefore, the margin area may be increased as the snow particles move away from the vanishing point. Thus, the ability to follow snow particles close to the host vehicle can be improved.

  Since the snow falls from the sky, the vanishing point of the snow particles is located above the image. Therefore, the size of the margin region may be smaller as the position of the snow grain is higher, and may be larger as the position of the snow particle is lower. Thereby, control can be simplified.

  The size and shape of the margin area may reflect the vehicle speed. As a result, the ability to follow snow particles during high-speed running can be improved, and visibility can be improved during low-speed running or when the vehicle is stopped.

  The output of the raindrop sensor may be reflected in the size and shape of the margin area. It is difficult to accurately detect the size of snow particles. Therefore, assuming that there is a correlation between the output of the raindrop sensor and the size of the snow particles, and adjusting the margin area, the size of the snow particles can be reflected in the size of the light-shielded portion.

  In a range in which an object to be watched (hereinafter referred to as a watched object) such as a preceding vehicle, an oncoming vehicle, or a pedestrian exists, it may be preferable to give priority to the visibility of the watched object over the ability to follow snow particles. . On the other hand, in a range where the watched object does not exist, for example, in a background where the background is sky or where the object is located in a distant place, there is no problem even if the followability is prioritized. Therefore, the size of the margin area may be reduced in the range where the gaze object exists.

(Embodiment)
The above is the outline of the vehicular lamp. Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and the repeated description will be omitted as appropriate. Further, the scale and shape of each part shown in each drawing are set for the sake of convenience in order to facilitate the description, and are not to be construed as limiting unless otherwise noted. In addition, when terms such as “first” and “second” are used in the present specification or claims, the terms do not indicate any order or importance, and certain configurations may be different from other configurations. It is for distinguishing.

  FIG. 1 is a block diagram of a vehicular lamp according to an embodiment. The vehicular lamp 100 includes a variable light distribution lamp 110 and a light distribution controller 140.

  The variable light distribution lamp 110 is a white light source, receives data indicating a light distribution pattern PTN from the light distribution controller 140, emits a beam L3 having an intensity distribution (beam profile) corresponding to the light distribution pattern PTN, and An illuminance distribution corresponding to the light distribution pattern PTN is formed ahead. The configuration of the variable light distribution lamp 110 is not particularly limited, and may include, for example, a semiconductor light source such as an LD (laser diode) or an LED (light emitting diode), and a lighting circuit for driving and lighting the semiconductor light source. The light distribution variable lamp 110 may include a matrix type pattern forming device such as a DMD (Digital Mirror Device) or a liquid crystal device for forming an illuminance distribution according to the light distribution pattern PTN. The variable light distribution lamp 110 has a resolution enough to shield only snow particles.

  The light distribution controller 140 dynamically and adaptively controls a light distribution pattern PTN supplied to the variable light distribution lamp 110. The light distribution pattern PTN is grasped as a two-dimensional illuminance distribution of a white light irradiation pattern 902 formed on the virtual vertical screen 900 in front of the own vehicle by the variable light distribution lamp 110. The light distribution controller 140 can be constituted by a digital processor, and may be constituted by, for example, a combination of a microcomputer including a CPU and a software program, or constituted by an FPGA (Field Programmable Gate Array) or an ASIC (Application Specified IC). You may.

  In the present embodiment, the light distribution controller 140 detects snow particles and generates a light distribution pattern PTN in which a portion corresponding to the snow particles is shielded from light. "Shading a certain portion" includes not only the case where the luminance (illuminance) of the portion is completely zero, but also the case where the luminance (illuminance) of the portion is reduced.

  The method for detecting snow particles is not limited. The light distribution controller 140 can detect snow particles by image processing based on a camera image IMG obtained by a camera (not shown). The algorithm for detecting snow particles is not particularly limited. The light distribution controller 140 may detect snow particles based on a plurality of continuous frames of the camera image IMG.

  2A and 2B are diagrams for explaining the operation of the vehicular lamp 100 of FIG. FIG. 2A shows a camera image IMG, and FIG. 2B shows a light distribution pattern PTN corresponding to the camera image of FIG. 2A. The camera image IMG shows a snow grain 6, a person 8, and a vehicle 10. The light distribution controller 140 detects the snow particles 6 from the camera image IMG, and shields a corresponding part (referred to as a light shielding part) 7 of the light distribution pattern PTN from light.

  The light distribution controller 140 may perform so-called ADB control. In this case, when detecting a target that should not give glare, such as the vehicle 10, the corresponding portion 11 is also shielded from light.

  The light distribution pattern PTN is updated at, for example, a rate of 30 fps or more, and the light shielding portion 7 can be moved to follow the snow particles 6. Thereby, the reflected light of the snow particles 6 can be reduced, and the visibility in the front can be improved.

  FIGS. 3A to 3C are enlarged views of the light shielding portion 7. The light shielding portion 7 includes a portion X of the snow grain 6 and a margin region Y added around the portion X. The light-shielding portion 7 can be formed in a rectangular shape in which the direction of movement of the snow particles (indicated by an arrow in the figure) is long and the direction perpendicular thereto is short. In the present embodiment, at least one of the size and the shape of the margin area Y is variable, and is dynamically and / or adaptively controlled. 3A, the size of the margin area Y is the smallest, and increases in the order of FIGS. 3B and 3C. 3A to 3C, the width W of the margin region Y in the short direction is fixed, and the length L of the margin region Y in the long direction is variable.

  Hereinafter, specific control of the margin area Y will be described.

1. Control Based on Position At least one of the size and the shape of the margin area Y can be made variable according to the position of the snow particle (light-shielded object).

  FIG. 4 is a flowchart illustrating control of a margin area based on a position. The camera is photographed in front of the vehicle (S100). Then, snow particles are detected based on the camera image (S102). Then, the size and shape of the margin area Y are set for each snow particle according to the position (S104). Then, the light shielding area is set, and the light distribution pattern is updated (S106). This operation is repeated.

  FIG. 5 is a photograph taken from a vehicle running during snowfall. Snow particles move radially from a certain vanishing point DP. In the photograph, snow particles are observed as a trajectory at the exposure time. The length of the trajectory is the apparent moving distance (apparent speed) of the snow particles per unit time, and it can be said that the shorter the distance to the vanishing point DP, the longer the distance farther from the vanishing point DP. Therefore, the margin area Y may be increased as the snow particles move away from the vanishing point. Thereby, followability can be improved.

  The vanishing point DP may be detected by image processing according to the traveling situation. Alternatively, since the snow falls from the sky, the vanishing point DP of the snow grains may be fixedly handled. Then, the position of the snow particle may be considered to be closer to the vanishing point DP as the position is higher in the image, and to be farther from the vanishing point DP as the position is lower. Based on this assumption, the size of the margin area Y may be smaller as the position of the snow particle is higher, and may be larger as the position of the snow particle is lower. Thereby, control can be simplified.

  In a range in which an object to be watched (hereinafter referred to as a watched object) such as a preceding vehicle, an oncoming vehicle, or a pedestrian exists, it may be preferable to give priority to the visibility of the watched object over the ability to follow snow particles. . On the other hand, in a range where the watched object does not exist, for example, in a background where the background is sky or where the object is located in a distant place, there is no problem even if the followability is prioritized. Therefore, the size of the margin area may be reduced in the range where the gaze object exists.

  FIGS. 6A and 6B are diagrams illustrating an improvement in the visibility of the watched object. FIG. 6A shows a camera image IMG, and FIG. 6B shows a light distribution pattern PTN. The gaze object OBJ is likely to exist in the area B including the road. Conversely, since the background of the region A above the region B is the sky (or far away), it can be said that the possibility of the presence of the watched object is low.

  Thus, the light distribution controller 140 divides the area into a region B where a gazeable object may exist and a region A where the gaze object does not exist, controls the margin region according to the position of the snow grain in the region A, and excludes the region B from the control. May be. Regarding the area B, it is preferable that the size of the margin area is smaller. Furthermore, the region B may be excluded from the light blocking control based on the snow particles.

2. Control based on running state In addition to the position of the snow particles, the running state can be reflected in the control of the margin area. As an example, the apparent speed of the snow particles increases as the vehicle speed v increases, and decreases as the vehicle speed v decreases. Therefore, the length L of the margin area may be controlled according to the vehicle speed v. When the y-coordinate of the snow particles is y and the vehicle speed is v, the length L of the margin area can be expressed by a function f (y, v).
L = f (y, v)
The light distribution controller 140 may calculate the value of the function f (y, v) or may have a look-up table.

  The output of the raindrop sensor may be reflected in the control of the margin area in addition to or instead of the vehicle speed. When the output of the raindrop sensor is large, that is, when the amount of snowfall is large, the length L of the margin area may be relatively increased. It is difficult to accurately detect the size of snowflakes based only on the camera image IMG. Therefore, assuming that there is a correlation between the output of the raindrop sensor and the size of the snow particles, and adjusting the margin area, the size of the snow particles can be reflected in the size of the light-shielded portion.

  When the amount of snowfall is large, that is, when the number of snow particles is large, setting the light-shielding portion 7 for each of them increases the calculation cost. Therefore, when the output of the raindrop sensor is large, by expanding the length L (and / or the width W) of the margin area, it is possible to collectively process a plurality of snow particles in one light shielding portion 7. There are advantages too.

  Next, a method for detecting snow particles will be described. FIG. 7 is a block diagram of a vehicle lamp 100A according to one embodiment. The vehicle lamp 100A includes an infrared light 120 and an infrared camera 130. The infrared illumination 120 and the infrared camera 130 may be built in the housing (lamp body) of the vehicle lamp 100 or may be externally attached. The infrared illumination 120 may be built in the housing, and the infrared camera 130 may be mounted on the back side of the room mirror.

  The infrared illumination 120 is a probe light source that emits infrared probe light L1 forward of the vehicle. The probe light L1 may be near-infrared light or light having a longer wavelength. The infrared camera 130 captures the reflected light L2 of the probe light L1 from the object 2 in front of the vehicle. The infrared camera 130 only needs to have sensitivity in at least the wavelength range of the probe light L1, and is preferably insensitive to visible light.

  The light distribution controller 140 detects snow particles by image processing based on the camera image IMG obtained by the infrared camera 130.

  The advantages of the vehicle lamp 100A will be described. When white (visible) probe light is used for detecting snow particles, the snow particles shine white and glare each time the probe light is irradiated, resulting in poor visibility. According to the present embodiment, since infrared light is used as the probe light, there is an advantage that glare can be prevented.

  In addition, since infrared light is used as probe light, there is an advantage that even if the probe light is continuously irradiated, it is difficult for the driver to recognize the probe light. Therefore, it is possible to detect a snow particle that moves at high speed by following it.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and that such modifications are also within the scope of the present invention. is there. Hereinafter, such modified examples will be described.

(Modification 1)
In the embodiment, the light-shielding control for snow particles has been described, but rain-drops may also be subjected to light-shielding control.

(Modification 2)
In the embodiment, only the length L of the margin area is variable. However, the width W may be variable, and the shape of the margin area may be variable.

(Modification 3)
In the embodiment, the infrared light is used as the probe light, but is not limited thereto. Using the beam L3 emitted from the variable light distribution lamp 110 as probe light, it is also possible to detect snow particles. In this case, if the irradiation time of the probe light is long, the driver may be glare. Therefore, the emission time of the probe light may be shortened to such an extent that the driver cannot detect the reflected light L2.

(Modification 4)
Although the present invention has been described using specific words and phrases based on the embodiments, the embodiments are merely illustrative of one aspect of the principles and applications of the present invention. Many modifications and changes in arrangement are permitted without departing from the spirit of the present invention defined in the scope.

REFERENCE SIGNS LIST 100 vehicle lamp 110 variable light distribution lamp 120 infrared illumination 130 infrared camera 140 light distribution controller L1 probe light L2 reflected light L3 beam

Claims (7)

A light distribution controller that generates a light distribution pattern including a light-shielding portion with a margin area added around snow particles,
A light distribution variable lamp capable of generating a beam having an intensity distribution according to the light distribution pattern,
With
A vehicular lamp wherein at least one of a size and a shape of the margin area is variable.   The vehicular lamp according to claim 1, wherein at least one of a size and a shape of the margin region is determined according to a position thereof.   3. The vehicular lamp according to claim 2, wherein the margin area is smaller as the position of the snow particle is higher and larger as the position is lower.   The vehicular lamp according to claim 2, wherein the margin area is larger as the snow particles move away from the vanishing point.   5. The vehicular lamp according to claim 1, wherein at least one of the size and the shape of the margin area reflects a vehicle speed. 6.   The vehicular lamp according to any one of claims 1 to 5, wherein at least one of the size and the shape of the margin area reflects an output of a raindrop sensor.   7. The light distribution controller according to claim 1, wherein the light distribution controller detects the snow particles based on an image captured by an infrared camera of reflected light obtained according to the probe light irradiated by the infrared illumination. A vehicle lighting device according to any of the claims.