JP7544702B2 - Vehicle lighting system, vehicle lighting control device, and vehicle lighting control method - Google Patents

Description

The present invention relates to a vehicle lighting system, a vehicle lighting control device, and a vehicle lighting control method, and more particularly to a vehicle lighting system used in automobiles, a vehicle lighting control device, and a vehicle lighting control method.

Conventionally, adaptive driving beam (ADB) control has been proposed that dynamically and adaptively controls the light distribution pattern of high beams based on the conditions around the vehicle (see, for example, Patent Documents 1 to 3). ADB control uses a camera to detect the presence or absence of an object that should be avoided from being illuminated with high-intensity light in front of the vehicle, and dims or turns off the light in the area corresponding to the object.

JP 2015-064964 A JP 2012-227102 A JP 2008-094127 A

According to the above-mentioned ADB control, it is possible to improve the visibility of the driver of the vehicle while avoiding glare to vehicles ahead, such as a preceding vehicle or an oncoming vehicle. The improved visibility allows the driver to more reliably recognize obstacles ahead, improving driving safety. On the other hand, there is always a demand to further improve the driver's visibility in order to further improve safety.

The present invention has been made in view of the above circumstances, and one of the objects thereof is to provide a technique for improving visibility for a driver.

In order to solve the above problems, one aspect of the present invention is a vehicle lighting system, which includes a light source unit capable of generating a beam with a variable intensity distribution, a visible light imaging unit that images the area in front of the vehicle, a far-infrared imaging unit that images the area in front of the vehicle, a target analysis unit that detects a window of a vehicle in front of the vehicle based on the output of the visible light imaging unit and the output of the far-infrared imaging unit, a pattern determination unit that determines a light distribution pattern in which a portion corresponding to the window is shaded, and a light source control unit that controls the light source unit to generate a beam having an intensity distribution according to the determined light distribution pattern.

Another aspect of the present invention is a control device for a vehicle lamp, the control device including: a target analysis unit that detects a window of a vehicle in front of the vehicle based on an output of a visible light imaging unit that images the area in front of the vehicle and an output of a far-infrared imaging unit that images the area in front of the vehicle, a pattern determination unit that determines a light distribution pattern in which a portion corresponding to the window is shaded, and a light source control unit that controls a light source unit capable of generating a beam with a variable intensity distribution so as to generate a beam having an intensity distribution according to the determined light distribution pattern.

Another aspect of the present invention is a method for controlling a vehicle lamp, the method including the steps of: detecting a window of the vehicle in front of the vehicle based on an output of a visible light imaging unit that images the area in front of the vehicle and an output of a far-infrared imaging unit that images the area in front of the vehicle, determining a light distribution pattern in which a portion corresponding to the window is shaded, and controlling a light source unit capable of generating a beam with a variable intensity distribution so as to generate a beam having an intensity distribution according to the determined light distribution pattern.

Any combination of the above components and any conversion of the present invention into a method, device, system, etc. are also valid aspects of the present invention.

According to the present invention, the visibility for the driver can be improved.

1 is a diagram showing a schematic configuration of a vehicle lighting system according to an embodiment; Fig. 2A is a front view showing a schematic configuration of an optical deflection device, and Fig. 2B is a cross-sectional view of the optical deflection device shown in Fig. 2A taken along line AA. FIG. 2 is a diagram showing a schematic view of the state in front of the vehicle; 11 is a diagram showing the relationship between a detected luminance value and a set illuminance value in luminance uniformization control. FIG. Fig. 5A is a diagram showing the relationship between the detected luminance value and the coefficient in high contrast control, and Fig. 5B is a diagram showing the relationship between the detected luminance value and the set illuminance value in high contrast control. 6A and 6B are flowcharts showing an example of ADB control executed in the vehicle lighting system according to the embodiment.

One aspect of the present invention is a vehicle lighting system that includes a light source unit capable of generating a beam with a variable intensity distribution, a visible light imaging unit that images the area in front of the vehicle, a far-infrared imaging unit that images the area in front of the vehicle, a target analysis unit that detects a window of a vehicle in front of the vehicle based on an output from the visible light imaging unit and an output from the far-infrared imaging unit, a pattern determination unit that determines a light distribution pattern in which a portion corresponding to the window is shaded, and a light source control unit that controls the light source unit to generate a beam having an intensity distribution according to the determined light distribution pattern.

In the above aspect, the target analysis unit may have a light spot detection unit that detects light spots in the visible light image information obtained from the visible light imaging unit, and a low gradation area detection unit that detects a low gradation area of a predetermined shape in the far-infrared image information obtained from the far-infrared imaging unit, and may detect a low gradation area located above the light spot corresponding to the light of the vehicle as a window part based on the detection result of the light spot detection unit and the detection result of the low gradation area detection unit. Also, in the above aspect, the low gradation area detection unit may detect the low gradation area by limiting it to an area above the position corresponding to the light spot of the light in the far-infrared image information. In addition, in any of the above aspects, the vehicle lighting system may include a luminance analysis unit that detects the luminance of each of a plurality of individual areas lined up in front of the vehicle based on the output of the visible light imaging unit, and a tracking unit that detects the displacement of the window portion, wherein the light source unit is capable of independently adjusting the illuminance of light to be irradiated to each of the plurality of individual areas, the pattern determination unit determines an illuminance value of light to be irradiated to each individual area, including a specific illuminance value for the position of the window portion, based on the detection result of the luminance analysis unit and the detection result of the tracking unit, and the light source control unit may control the light source unit based on the illuminance value determined by the pattern determination unit.

Another aspect of the present invention is a control device for a vehicle lamp, the control device including: a target analysis unit that detects a window of a vehicle ahead of the vehicle based on an output from a visible light imaging unit that images an area ahead of the vehicle and an output from a far-infrared imaging unit that images an area ahead of the vehicle, a pattern determination unit that determines a light distribution pattern in which a portion corresponding to the window is shaded, and a light source control unit that controls a light source unit capable of generating a beam with a variable intensity distribution so as to generate a beam having an intensity distribution according to the determined light distribution pattern.

Another aspect of the present invention is a method for controlling a vehicle lamp, the method including the steps of: detecting a window of the vehicle in front of the vehicle based on an output of a visible light imaging unit that images the area in front of the vehicle and an output of a far-infrared imaging unit that images the area in front of the vehicle, determining a light distribution pattern in which a portion corresponding to the window is shaded, and controlling a light source unit capable of generating a beam with a variable intensity distribution so as to generate a beam having an intensity distribution according to the determined light distribution pattern.

The present invention will be described below with reference to the drawings based on preferred embodiments. 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 each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the scale and shape of each part shown in each drawing are set for convenience to facilitate explanation, and are not to be interpreted as being limiting unless otherwise specified. In addition, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. In addition, some of the members that are not important in explaining the embodiment in each drawing are omitted.

Fig. 1 is a diagram showing a schematic configuration of a vehicle lighting system according to an embodiment. In Fig. 1, some of the components of the vehicle lighting system 1 are depicted as functional blocks. These functional blocks are realized as a hardware configuration by elements and circuits including a computer CPU and memory, and as a software configuration by a computer program or the like. Those skilled in the art will understand that these functional blocks can be realized in various forms by combining hardware and software.

The vehicle lighting system 1 is applied to a vehicle headlamp device having a pair of headlamp units arranged on the left and right sides in front of the vehicle. The pair of headlamp units have substantially the same configuration except for having a symmetrical structure, so Fig. 1 shows the structure of one of the headlamp units as the vehicle lamp 2.

The vehicle lamp 2 included in the vehicle lamp system 1 includes a lamp body 4 having an opening on the vehicle front side, and a translucent cover 6 attached so as to cover the opening of the lamp body 4. The translucent cover 6 is formed of a translucent resin, glass, or the like. A light source unit 10, a visible light imaging unit 35, a far-infrared imaging unit 52, and a control device 50 are housed within a lamp chamber 8 formed by the lamp body 4 and the translucent cover 6.

The light source unit 10 is a device capable of generating a beam with a variable intensity distribution. Moreover, the light source unit 10 of this embodiment is capable of independently adjusting the illuminance (intensity) of light irradiated to each of a plurality of individual regions R (see FIG. 3) arranged in front of the vehicle. The light source unit 10 has a light source 22, a reflective optical member 24, a light deflection device 26, and a projection optical member 28. Each part is attached to the lamp body 4 by a support mechanism (not shown).

The light source 22 may be a semiconductor light emitting element such as an LED (Light emitting diode), an LD (Laser diode), or an EL (Electroluminescence) element, or a light bulb, an incandescent lamp (halogen lamp), a discharge lamp, or the like. The reflective optical member 24 is configured to guide the light emitted from the light source 22 to the reflective surface of the optical deflection device 26. The reflective optical member 24 is configured as a reflector whose inner surface is a predetermined reflective surface. The reflective optical member 24 may be a solid light guide, or the like. In addition, when the light emitted from the light source 22 can be directly guided to the optical deflection device 26, the reflective optical member 24 may not be provided.

The light deflection device 26 is disposed on the optical axis of the projection optical member 28 and is configured to selectively reflect the light emitted from the light source 22 to the projection optical member 28. The light deflection device 26 is configured, for example, with a DMD (Digital Mirror Device). That is, the light deflection device 26 is configured by arranging a plurality of micromirrors in an array (matrix). By controlling the angles of the reflecting surfaces of the plurality of micromirrors, respectively, the reflection direction of the light emitted from the light source 22 can be selectively changed. That is, the light deflection device 26 can reflect a portion of the light emitted from the light source 22 toward the projection optical member 28 and reflect the remaining light in a direction that is not effectively used by the projection optical member 28. Here, the direction that is not effectively used can be, for example, a direction that is incident on the projection optical member 28 but hardly contributes to the formation of a light distribution pattern, or a direction toward a light absorbing member (light blocking member) not shown.

Fig. 2(A) is a front view showing a schematic configuration of an optical deflection device. Fig. 2(B) is a cross-sectional view taken along line A-A of the optical deflection device shown in Fig. 2(A). The optical deflection device 26 has a micromirror array 32 in which a plurality of minute mirror elements 30 are arranged in a matrix, and a transparent cover member 34 arranged in front of the reflective surface 30a of the mirror elements 30 (to the right of the optical deflection device 26 shown in Fig. 2(B)). The cover member 34 is made of, for example, glass, plastic, or the like.

The mirror element 30 is substantially square, and has a rotation axis 30b extending in the horizontal direction and dividing the mirror element 30 into substantially equal parts. Each mirror element 30 of the micromirror array 32 is configured to be switchable between a first reflection position (position shown by a solid line in FIG. 2B) at which the light emitted from the light source 22 is reflected toward the projection optical member 28 so as to be used as part of a desired light distribution pattern, and a second reflection position (position shown by a dotted line in FIG. 2B) at which the light emitted from the light source 22 is reflected so as not to be effectively used. Each mirror element 30 rotates around the rotation axis 30b and is individually switched between the first reflection position and the second reflection position. Each mirror element 30 takes the first reflection position when it is on, and takes the second reflection position when it is off.

FIG. 3 is a diagram showing a schematic view of the state in front of the vehicle. As described above, the light source unit 10 has a plurality of mirror elements 30 as individual irradiating units capable of irradiating light independently of each other toward the front of the lamp. The light source unit 10 can irradiate light to a plurality of individual regions R arranged in front of the vehicle by the mirror elements 30. Each individual region R corresponds to one pixel or a set of multiple pixels of the visible light imaging unit 35, specifically, for example, the high-speed camera 36. In this embodiment, each individual region R and each mirror element 30 are in one-to-one correspondence. Note that in FIG. 2(A) and FIG. 2(B), for convenience of illustration, some of the mirror elements 30 are thinned out.

Furthermore, the number of mirror elements 30 and individual regions R is not particularly limited. For example, the resolution of the micromirror array 32 (in other words, the number of mirror elements 30 and individual regions R) is 1,000 to 300,000 pixels. Furthermore, the time required for the light source unit 10 to form one light distribution pattern is, for example, 0.1 to 5 ms. That is, the light source unit 10 can change the light distribution pattern every 0.1 to 5 ms.

1, the projection optical member 28 is, for example, a free-form lens whose front and rear surfaces have free-form shapes. The projection optical member 28 projects a light source image formed on a rear focal plane including its rear focal point as an inverted image in front of the lamp. The projection optical member 28 is disposed so that its rear focal point is located on the optical axis of the vehicle lamp 2 and in the vicinity of the reflecting surface of the micromirror array 32. The projection optical member 28 may be a reflector.

Light emitted from the light source 22 is reflected by the reflective optical member 24 and irradiated onto the micromirror array 32 of the optical deflection device 26. The optical deflection device 26 reflects the light toward the projection optical member 28 by a predetermined mirror element 30 located at a first reflection position. This reflected light passes through the projection optical member 28 and travels forward of the lamp, and is irradiated onto each individual region R corresponding to each mirror element 30. As a result, a light distribution pattern of a predetermined shape, which is constituted by a plurality of partial illumination regions, is formed in front of the lamp.

The visible light imaging unit 35 is a device that images the area in front of the vehicle. The visible light imaging unit 35 includes a high-speed camera 36 and a low-speed camera 38. The high-speed camera 36 has a relatively high frame rate, for example, 200 fps or more and 10,000 fps or less (0.1 to 5 ms per frame). On the other hand, the low-speed camera 38 has a relatively low frame rate, for example, 30 fps or more and 120 fps or less (approximately 8 to 33 ms per frame). Therefore, the high-speed camera 36 has a higher frame rate than the low-speed camera 38. In addition, the high-speed camera 36 has a relatively low resolution, for example, 300,000 pixels or more and less than 5 million pixels. On the other hand, the low-speed camera 38 has a relatively high resolution, for example, 5 million pixels or more. Therefore, the low-speed camera 38 has a higher resolution than the high-speed camera 36. The high-speed camera 36 and the low-speed camera 38 capture all the individual regions R. The resolutions of the high-speed camera 36 and the low-speed camera 38 are not limited to the above values, and can be set to any value within a technically compatible range.

The far-infrared imaging unit 52 is a device that images the area in front of the vehicle. The far-infrared imaging unit 52 includes a far-infrared camera 54. The far-infrared camera 54 captures heat generated by an object as an image. The far-infrared camera 54 has a frame rate of, for example, 5 fps to 10,000 fps (0.1 to 200 ms per frame) and a resolution of, for example, 300,000 pixels to less than 5 million pixels. The far-infrared camera 54 captures images of all the individual regions R.

The control device 50 has a luminance analysis unit 14, a target analysis unit 16, a lamp control unit 18, and a light source control unit 20. Each unit operates when an integrated circuit constituting the unit executes a program stored in a memory. Visible light image information generated by the visible light imaging unit 35 is sent to the luminance analysis unit 14 and the target analysis unit 16. Furthermore, far-infrared image information generated by the far-infrared imaging unit 52 is sent to the target analysis unit 16.

The luminance analysis unit 14 detects the luminance of each individual region R based on the output (visible light image information) of the visible light imaging unit 35. The luminance analysis unit 14 is a high-speed, low-precision analysis unit that executes image analysis with lower accuracy than the target analysis unit 16 and outputs analysis results at high speed. The luminance analysis unit 14 of this embodiment detects the luminance of each individual region R based on information obtained from the high-speed camera 36. The luminance analysis unit 14 detects the luminance of each individual region R, for example, every 0.1 to 5 ms. The detection result of the luminance analysis unit 14, i.e., a signal indicating the luminance information of the individual region R, is transmitted to the lamp control unit 18.

The target analysis unit 16 detects a target present in front of the vehicle based on the output of the visible light imaging unit 35 and the output of the far-infrared imaging unit 52 (far-infrared image information). The target analysis unit 16 of this embodiment detects a target based on image information obtained from the far-infrared camera 54 and the low-speed camera 38. Therefore, the target analysis unit 16 is a low-speed high-precision analysis unit that performs image analysis with higher accuracy than the luminance analysis unit 14 and outputs the analysis result at a low speed. The target analysis unit 16 detects a target, for example, every 50 ms. A target is an object located in front of the vehicle that should be avoided from being illuminated with high-luminance light. The targets detected by the target analysis unit 16 of this embodiment include a window portion 101 of a vehicle 100 in front of the vehicle. The vehicle 100 in front of the vehicle is, for example, at least one of a preceding vehicle and an oncoming vehicle. Furthermore, when the vehicle 100 is a preceding vehicle, the window portion 101 is a rear window, and when the vehicle 100 is an oncoming vehicle, the window portion 101 is a front window.

For example, the target analysis unit 16 aligns the visible light image information obtained from the low-speed camera 38 and the far-infrared image information obtained from the far-infrared camera 54 by trimming and scaling them. In addition, the target analysis unit 16 inverts the gradation of both image information as necessary. In some cases, binarization processing may be performed together with the gradation inversion.

The target analyzing unit 16 has a light spot detecting unit 46 and a low gradation area detecting unit 48. The light spot detecting unit 46 detects a predetermined light spot in the visible light image information obtained from the low speed camera 38 of the visible light imaging unit 35. The size and shape of the light detected as the light spot 104 by the light spot detecting unit 46 can be appropriately set based on experiments and simulations by a designer. The low gradation area detecting unit 48 detects a low gradation area of a predetermined shape in the far-infrared image information obtained from the far-infrared camera 54 of the far-infrared imaging unit 52. The "predetermined shape" is a shape similar to the window portion 101 of the vehicle 100, for example, a rectangular shape that is long in the horizontal direction.

Then, based on the detection results of the light spot detection unit 46 and the low gradation area detection unit 48, the target analysis unit 16 detects the low gradation area 106 located above the two light spots 104 corresponding to the lights 102 of the vehicle 100 as the window portion 101.

Specifically, the target analysis unit 16 uses a conventionally known method including algorithm recognition and deep learning to identify the light points 104 corresponding to the lights 102 of the vehicle 100 from among the light points 104 detected by the light point detection unit 46. For example, the target analysis unit 16 holds information on characteristic points indicating the light points 104 corresponding to the lights 102 in advance. Then, the target analysis unit 16 detects the light points 104 that satisfy the characteristic points among the light points 104 detected by the light point detection unit 46 as the light points 104 corresponding to the lights 102. The "characteristic points" mentioned above refer to, for example, the points appearing in an estimated presence area of a headlight or taillight of the vehicle 100 ahead of the vehicle itself and having a predetermined luminous intensity or higher.

Next, the target analysis unit 16 detects the low gradation region 106 corresponding to the window portion 101 of the vehicle 100 based on the detection result of the low gradation region 106 by the low gradation region detection unit 48. For example, the target analysis unit 16 detects the low gradation region 106 included in a predetermined upper region UR located above the light spot 104 corresponding to the light 102 as the window portion 101.

The low gradation area detection unit 48 of the present embodiment acquires the detection result of the light spot detection unit 46, and determines an upper area UR located above the light spot 104 of the light 102 in the far-infrared image information. Then, the low gradation area 106 is detected only in the upper area UR. That is, the low gradation area detection unit 48 executes the detection process of the low gradation area 106 only for the upper area UR in the far-infrared image information, and does not execute the detection process of the low gradation area 106 for other areas. The "above the light spot 104" where the low gradation area 106 corresponding to the window portion 101 is located, and the "upper area UR" where the detection process of the low gradation area 106 is performed are, for example, a horizontal x vertical range a x b defined by a horizontal distance a between two light spots 104 corresponding to the light 102 and a vertical distance b having a predetermined ratio to the horizontal distance a.

When the target object analysis unit 16 detects the low gradation area 106 in the upper region UR, the target object analysis unit 16 detects the low gradation area 106 as the window portion 101. The detection result of the target object analysis unit 16, i.e., a signal indicating the position information of the window portion 101 in front of the vehicle, is transmitted to the lamp control unit 18.

The luminaire control unit 18 uses the detection results of the luminance analysis unit 14 and/or the target analysis unit 16 to detect the displacement of the target, set the specific individual region R1, set the illuminance value of the light to be irradiated to each individual region R, and the like. As an example, the luminaire control unit 18 includes a tracking unit 40 and a pattern determination unit 42.

The tracking unit 40 detects the displacement of the window unit 101 based on the detection result of the luminance analysis unit 14. Specifically, the tracking unit 40 integrates the detection result of the luminance analysis unit 14 and the detection result of the target analysis unit 16. Then, among the luminances of the individual regions R detected by the luminance analysis unit 14, the luminance of the individual region R in which the light spot 104 corresponding to the light 102 is located is associated with the window unit 101. Since the positional relationship between the light spot 104 corresponding to the light 102 and the window unit 101 is fixed, the luminance of the individual region R in which the light spot 104 is located can be associated with the window unit 101. The tracking unit 40 can detect the displacement of the window unit 101 by recognizing the position of the luminance associated with the window unit 101 in the detection result of the luminance analysis unit 14 acquired thereafter. The tracking unit 40 executes a displacement detection process (tracking) of the window unit 101, for example, every 0.1 to 5 ms.

The tracking unit 40 may perform tracking based on far-infrared image information. In this case, the far-infrared camera 54 is preferably a camera with a high speed similar to that of the high-speed camera 36, and has a frame rate of, for example, 200 fps to 10,000 fps (0.1 to 5 ms per frame). The far-infrared image information is sent to the lamp control unit 18 via the target analysis unit 16, for example, every 0.1 to 5 ms. The tracking unit 40 can detect the displacement of the window unit 101 by recognizing the position of the low gradation area 106 corresponding to the window unit 101 in the far-infrared image information acquired sequentially. When tracking the position of the window unit 101 using the far-infrared image information, the detection of the window unit 101 by the target analysis unit 16 is equivalent to tracking the window unit 101. Therefore, the target analysis unit 16 may also function as the tracking unit 40.

The pattern determination unit 42 determines a light distribution pattern in which the portion corresponding to the window portion 101 is shaded. That is, the pattern determination unit 42 determines the illuminance value of the light to be irradiated to each individual region R, including the specific illuminance value for the position where the window portion 101 is present, based on the detection result of the luminance analysis unit 14 and the detection result of the tracking unit 40.

First, the pattern determination unit 42 determines an individual region R overlapping with the position of the low gradation region 106 corresponding to the window portion 101 as a specific individual region R1. Then, the pattern determination unit 42 determines a specific illuminance value for the specific individual region R1. That is, the pattern determination unit 42 determines a specific illuminance value for the position of the window portion 101. The specific illuminance value is an illuminance value corresponding to "light blocking", and may be "0" or a predetermined low illuminance value. The degree to which the illuminance is reduced can be appropriately set based on experiments and simulations performed by the designer.

In addition, the pattern determination unit 42 also determines the illuminance value for the other individual regions R except the specific individual region R1. For example, the pattern determination unit 42 sets the target luminance value to the same value for the individual regions R except the specific individual region R1. That is, the luminance uniformization control is executed. The target luminance value means the luminance to be detected by the luminance analysis unit 14 in a state in which a light distribution pattern is formed. FIG. 4 is a diagram showing the relationship between the detected luminance value and the set illuminance value in the luminance uniformization control. As shown in FIG. 4, in the luminance uniformization control, for the individual regions R except the specific individual region R1, a relatively high illuminance value is set for the individual regions R whose luminance detected by the luminance analysis unit 14 is relatively low, and a relatively low illuminance value is set for the individual regions R whose luminance detected is relatively high. The luminance uniformization control forms a luminance uniformization light distribution pattern that uniforms the brightness in front of the vehicle.

4, the set illuminance value is changed continuously and linearly with respect to the detected luminance value, but the relationship is not limited to this, and the set illuminance value may be changed stepwise with respect to the detected luminance value. Also, the set illuminance value may be changed curvilinearly with respect to the detected luminance value.

The pattern determination unit 42 may execute high contrast control instead of or in addition to the brightness uniformity control. In the case where both the brightness uniformity control and the high contrast control are executable, for example, the driver can select which control to execute via a light switch (not shown). The high contrast control is a control in which, for the individual regions R except the specific individual region R1, a relatively low illuminance value is set for the individual regions R whose detected luminance is relatively low, and a relatively high illuminance value is set for the individual regions R whose detected luminance is relatively high. A high contrast light distribution pattern is formed by the high contrast control. That is, the high contrast light distribution pattern is a light distribution pattern in which the bright individual regions R become brighter and the dark individual regions R become darker.

For example, the pattern determination unit 42 sets an illuminance value for an individual region R having a lower luminance than a predetermined threshold value, which is lower than the illuminance value set for an individual region R having a higher luminance than the threshold value. On the other hand, for an individual region R having a higher luminance than the threshold value, which is higher than the illuminance value set for an individual region R having a lower luminance than the threshold value. The degree of high or low illuminance value to be set can be appropriately set based on the results of experiments or simulations, taking into consideration the degree of improvement in the detection accuracy of the target object, etc. As a result, the illuminance value of an individual region R having a relatively low luminance becomes lower than the illuminance value of an individual region R having a relatively high luminance.

Also, for example, the pattern determination unit 42 sets an illuminance value lower than the currently set illuminance value for individual regions R having a luminance lower than the threshold value. On the other hand, the pattern determination unit 42 sets an illuminance value higher than the currently set illuminance value for individual regions R having a luminance higher than the threshold value. Note that, without using a threshold value, for example, the luminance of the brightest individual region R may be used as a reference, and the illuminance value to be set may be decreased as the luminance decreases.

In the above-mentioned high contrast control, the newly set relatively low illuminance value is lower than the currently set illuminance value, and the newly set relatively high illuminance value is higher than the currently set illuminance value. Therefore, when the formation of the high contrast light distribution pattern is repeated, positive feedback is applied and the set illuminance value is eventually polarized between 0 and the maximum value. When the illuminance value is polarized, it may be difficult to ensure the visibility of the driver in the individual region R where the illuminance value 0 is set.

In response to this, the deterioration of visibility for the driver due to the polarization can be avoided by using the reference illuminance value M and coefficients as follows: Fig. 5(A) is a diagram showing the relationship between the detected luminance value and the coefficients in high contrast control; Fig. 5(B) is a diagram showing the relationship between the detected luminance value and the set illuminance value in high contrast control.

As shown in FIG. 5A, the pattern determination unit 42 has a predetermined coefficient that is set in advance according to the magnitude of the detection luminance value. A relatively large coefficient is set for a relatively large detection luminance value, and a relatively small coefficient is set for a relatively small detection luminance value. The value of the coefficient can be appropriately set based on the results of experiments and simulations, taking into consideration the degree of improvement in the detection accuracy of the target. Here, as an example, a coefficient of 1.0 is set for the threshold value of the detection luminance value, a coefficient of 1.5 is set for the maximum luminance value, and a coefficient of 0.5 is set for the minimum luminance value. The pattern determination unit 42 sets a coefficient for each individual region R except for the specific individual region R1 based on the detection result of the luminance analysis unit 14.

In addition, as shown in FIG. 5B, the pattern determination unit 42 has a predetermined reference illuminance value M set in advance. The pattern determination unit 42 multiplies the reference illuminance value M by a coefficient set for each individual region R to set the illuminance value of the individual region R. As a result, a low illuminance value is set for the individual region R with a low detection luminance value, and a high illuminance value is set for the individual region R with a high detection luminance value. This makes it possible to avoid a decrease in visibility for the driver due to polarization of illuminance values. Note that the decrease in visibility for the driver due to polarization of illuminance values can also be avoided by using the currently set illuminance value of each individual region R, the coefficient, and the lower and upper limits of the illuminance value instead of the reference illuminance value M.

For example, the pattern determination unit 42 generates a beam having an intensity distribution according to a constant illuminance light distribution pattern by the light source unit 10 at the beginning of the high contrast control. The constant illuminance light distribution pattern is a light distribution pattern in which the illuminance of all individual regions R except the specific individual region R1 is constant. The luminance of each individual region R obtained by irradiating this constant illuminance light distribution pattern is used to form a high contrast light distribution pattern. When another lamp unit is provided in addition to the light source unit 10, a normal light distribution pattern may be formed by this lamp unit. The normal light distribution pattern is, for example, a well-known light distribution pattern for high beams. In the example shown in FIG. 5B, the set illuminance value is changed continuously and linearly with respect to the detected luminance value, but the relationship is not particularly limited to this, and the set illuminance value may be changed stepwise with respect to the detected luminance value. The set illuminance value may be changed curvedly with respect to the detected luminance value.

The pattern determination unit 42 recognizes the displacement of the specific individual region R1 based on the detection result of the tracking unit 40, and updates the position information of the specific individual region R1. Then, it updates the illuminance value of each individual region R, including the specific illuminance value for the specific individual region R1. The processing by the tracking unit 40 and the processing by the pattern determination unit 42 are executed in parallel at least at one time. The pattern determination unit 42 transmits a signal indicating the illuminance value of each individual region R to the light source control unit 20. The pattern determination unit 42 sets the illuminance value, for example, every 0.1 to 5 ms.

The light source control unit 20 controls the light source unit 10 based on the illuminance value determined by the pattern determination unit 42. The light source control unit 20 controls the turning on and off of the light source 22 and the on/off switching of each mirror element 30. The light source control unit 20 adjusts the on time ratio (width and density) of each mirror element 30 based on the illuminance value of the light irradiated to each individual region R. As a result, a beam having an intensity distribution according to the determined light distribution pattern is generated by the light source unit 10. The light source control unit 20 transmits a drive signal to the light source 22 and/or the optical deflection device 26, for example, every 0.1 to 5 ms.

The vehicle lighting system 1 executes ADB (Adaptive Driving Beam) control to form an optimal light distribution pattern according to the positions of the window portion 101 and other targets in front of the vehicle. For example, the pattern determination unit 42 sets a specific illuminance value of "0" for the specific individual region R1 that overlaps with the window portion 101, and sets an illuminance value of "1" for the other individual regions R. This setting is defined as first illuminance information. Furthermore, the pattern determination unit 42 sets illuminance values for all individual regions R including the specific individual region R1 in accordance with luminance uniformity control or high contrast control. This setting is defined as second illuminance information.

Then, the pattern determination unit 42 performs an AND operation on the first illuminance information and the second illuminance information. This generates illuminance information in which the specific illuminance value for the specific individual region R1 is "0" and the illuminance values for the other individual regions R are illuminance values determined according to the luminance uniformization control or high contrast control. That is, the specific individual region R1 is shaded, and a luminance uniformization light distribution pattern or a high contrast light distribution pattern is formed in each individual region R except for the specific individual region R1.

6(A) and 6(B) are flow charts showing an example of ADB control executed in the vehicle lighting system according to the embodiment. This flow is repeatedly executed at a predetermined timing when, for example, an instruction to execute ADB control is given by a light switch (not shown) and the ignition is on, and ends when the instruction to execute ADB control is released (or an instruction to stop the ADB control is given) or the ignition is turned off. The flow shown in FIG. 6(A) is a low-speed process repeated, for example, every 50 ms, and the flow shown in FIG. 6(B) is a high-speed process repeated, for example, every 0.1 to 5 ms. The low-speed process and the high-speed process are executed in parallel.

As shown in Fig. 6A, in the low-speed processing, first, the low-speed camera 38 and the far-infrared camera 54 capture an image of the area in front of the vehicle (S101). Next, the target analyzing unit 16 determines whether or not there is a window portion 101 as a target in front of the vehicle based on the image information of the low-speed camera 38 and the far-infrared camera 54 (S102). If there is a target (window portion 101) (Y in S102), the pattern determining unit 42 sets a specific individual region R1 based on the location of the target (S103), and this routine ends. If there is no target (N in S102), this routine ends. In the above flow chart, the specific individual region R1 is set in the low-speed processing, but the setting may be performed in the high-speed processing.

As shown in Fig. 6B, in the high-speed processing, first, the high-speed camera 36 captures an image of the area in front of the vehicle (S201). Next, the brightness analysis unit 14 detects the brightness of each individual area R based on the image information of the high-speed camera 36 (S202). Next, the tracking unit 40 determines whether a specific individual area R1 has been set (S203). If a specific individual area R1 has been set (Y in S203), the tracking unit 40 tracks the target and detects the position (displacement) of the specific individual area R1. The pattern determination unit 42 updates the setting (position information) of the specific individual area R1 based on the detection result of the tracking unit 40 (S204).

Next, the pattern determination unit 42 sets the illuminance value of the light to be irradiated to each individual region R (S205). A specific illuminance value is set for the specific individual region R1. An illuminance value conforming to the luminance uniform light distribution pattern or the high contrast light distribution pattern is set for the remaining individual regions R. Next, the light source control unit 20 drives the light source unit 10, and light of a determined illuminance is irradiated from the light source unit 10 (S206), and this routine ends. If the specific individual region R1 is not set (N in S203), the pattern determination unit 42 sets the illuminance value of the light to be irradiated to the individual region R (S205). In this case, the specific illuminance value is not included in the illuminance values to be set. After that, the process of step S206 is executed, and this routine ends.

In step S204, if the disappearance of the target is detected by tracking, the setting of the specific individual region R1 is also disappeared. Therefore, the specific illuminance value is not included in the illuminance values set in step S205. Furthermore, in step S203 in the next routine, it is determined that the specific individual region R1 has not been set (N in S203) until the processing of step S103 is executed.

As described above, the vehicle lighting system 1 according to this embodiment includes the light source unit 10 capable of generating a beam with a variable intensity distribution, the visible light imaging unit 35 that images the area ahead of the vehicle, the far-infrared imaging unit 52 that images the area ahead of the vehicle, the target analysis unit 16 that detects the window portion 101 of the vehicle 100 ahead of the vehicle based on the output of the visible light imaging unit 35 and the output of the far-infrared imaging unit 52, the pattern determination unit 42 that determines a light distribution pattern in which a portion corresponding to the window portion 101 is shaded, and the light source control unit 20 that controls the light source unit 10 to generate a beam having an intensity distribution according to the determined light distribution pattern.

The target analysis unit 16 of this embodiment has a light spot detection unit 46 that detects light spots 104 in the visible light image information obtained from the visible light imaging unit 35, and a low gradation area detection unit 48 that detects a low gradation area 106 of a predetermined shape in the far-infrared image information obtained from the far-infrared imaging unit 52. Then, the target analysis unit 16 detects the low gradation area 106 located above the light spot 104 corresponding to the light 102 of the vehicle 100 as the window portion 101 based on the detection result of the light spot detection unit 46 and the detection result of the low gradation area detection unit 48.

In this manner, in this embodiment, the shading area provided to avoid glare on the vehicle 100 ahead of the vehicle itself is limited to the window portion 101 of the vehicle 100. This makes it possible to reduce the area in which the visibility of the driver of the vehicle and the visible light imaging unit 35 is reduced due to shading. This makes it possible to improve the visibility of the driver and the visible light imaging unit 35.

Moreover, the low gradation region detection unit 48 of the present embodiment detects the low gradation region 106 in the far-infrared image information, limited to an upper region UR that spreads above the position corresponding to the light spot 104 of the light 102. This reduces the control load on the target analysis unit 16 and, in turn, the control device 50. The low gradation region detection unit 48 may detect the low gradation region 106 in the entire far-infrared image information, and specify the window portion 101 from the detected low gradation region 106 based on the position of the light spot 104 of the light 102.

The vehicle lighting system 1 of the present embodiment also includes a luminance analysis unit 14 that detects the luminance of each of a plurality of individual regions R lined up in front of the vehicle based on the output of the visible light imaging unit 35, and a tracking unit 40 that detects the displacement of the window unit 101. The light source unit 10 can independently adjust the illuminance of the light irradiated to each of the plurality of individual regions R. The pattern determination unit 42 determines the illuminance value of the light to be irradiated to each individual region R including the specific individual region R1 relative to the position of the window unit 101 based on the detection result of the luminance analysis unit 14 and the detection result of the tracking unit 40. The light source control unit 20 controls the light source unit 10 based on the illuminance value determined by the pattern determination unit 42.

The target analysis unit 16 can detect targets with high accuracy, but the analysis speed is poor because image processing requires a relatively long time. Therefore, when ADB control is performed based only on the analysis result of the target analysis unit 16, it is possible to form a light distribution pattern that narrows the shading area and improves the visibility of the driver of the vehicle, but it is difficult to make the shading area follow the displacement of the target with high accuracy. On the other hand, the brightness analysis unit 14, which performs simple brightness detection, requires a relatively short time for image processing, so it is possible to perform high-speed analysis. However, since the detection accuracy of the target is low, it is difficult to accurately grasp the location of the target. Therefore, when ADB control is performed based only on the analysis result of the brightness analysis unit 14, it is necessary to set the shading area of the light distribution pattern to be wide, which sacrifices the visibility of the driver of the vehicle.

In contrast, in the vehicle lighting system 1 of the present embodiment, the target analysis unit 16, which is a slow but advanced image analysis means, and the luminance analysis unit 14, which is a simple but high-speed image analysis means, are combined to grasp the position of the window portion 101 with high accuracy and determine the light distribution pattern. This makes it possible to improve the accuracy of light irradiation in the vehicle lighting unit 2, in other words, the accuracy of forming the light distribution pattern. As a result, it is possible to achieve both avoidance of glare given to the driver of the vehicle 100 ahead of the vehicle and ensuring visibility for the driver of the vehicle at a higher level.

The above describes the embodiments of the present invention in detail. The above-mentioned embodiments merely show specific examples of implementing the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as changes, additions, and deletions of components are possible within the scope of the invention as defined in the claims. A new embodiment with design changes has the effects of the combined embodiments and modifications. In the above-mentioned embodiments, the contents for which such design changes are possible are emphasized by adding notations such as "in this embodiment" and "in this embodiment", but design changes are permitted even in contents without such notations. Any combination of the above-mentioned components is also effective as an aspect of the present invention. The hatching on the cross section of the drawing does not limit the material of the object to which the hatching is added.

In each embodiment, the visible light imaging unit 35, the far-infrared imaging unit 52, the luminance analysis unit 14, the target analysis unit 16, the lamp control unit 18, and the light source control unit 20 are provided in the lamp chamber 8, but each of them may be provided outside the lamp chamber 8 as appropriate. For example, the low-speed camera 38 of the visible light imaging unit 35 can be an existing camera installed in the vehicle cabin. It is preferable that the visible light imaging unit 35 and the light source unit 10, and the far-infrared imaging unit 52 and the light source unit 10 have the same angle of view.

Furthermore, if the high-speed camera 36 has a resolution equivalent to that of the low-speed camera 38, the low-speed camera 38 may be omitted. This allows the vehicle lighting system 1 to be compact. In this case, the target analysis unit 16 detects the target using image data from the far-infrared imaging unit 52 and the high-speed camera 36. Instead of the light deflection device 26, which is a DMD, the light source unit 10 may include a scanning optical system that scans the area ahead of the vehicle with light from a light source, or an LED array in which LEDs corresponding to each individual region R are arranged.

The invention according to the above-described embodiment may be specified by the items described below.
[Item 1]
a target analysis unit (16) for detecting a window portion (101) of a vehicle (100) ahead of the vehicle based on an output of a visible light imaging unit (35) for imaging an area ahead of the vehicle and an output of a far-infrared imaging unit (52) for imaging an area ahead of the vehicle;
a pattern determination unit (42) for determining a light distribution pattern in which a portion corresponding to the window portion (101) is shaded;
a light source control unit (20) for controlling a light source unit (10) capable of generating a beam having a variable intensity distribution so as to generate a beam having an intensity distribution according to the determined light distribution pattern;
A control device (50) for a vehicle lamp (2) comprising:
[Item 2]
Detecting a window portion (101) of a vehicle (100) ahead of the vehicle based on an output of a visible light imaging unit (35) that images the area ahead of the vehicle and an output of a far-infrared imaging unit (52) that images the area ahead of the vehicle;
determining a light distribution pattern in which a portion corresponding to the window portion (101) is shaded;
A light source unit (10) capable of generating a beam having a variable intensity distribution is controlled so as to generate a beam having an intensity distribution according to the determined light distribution pattern.
A method for controlling a vehicle lamp (2), comprising:

The present invention can be used in a vehicle lighting system, a control device for a vehicle lighting device, and a control method for a vehicle lighting device.

1 Vehicle lighting system, 2 Vehicle lighting device, 10 Light source unit, 14 Brightness analysis unit,
16 target analysis unit, 20 light source control unit, 35 visible light imaging unit, 40 tracking unit, 42 pattern determination unit, 46 light spot detection unit, 48 low gradation area detection unit, 50 control device, 52 far-infrared imaging unit.

Claims (5)

a light source unit capable of generating a beam having a variable intensity distribution;
A visible light imaging unit that images an image in front of the vehicle;
A far-infrared imaging unit that images the area in front of the vehicle;
a target analysis unit that detects a window of a vehicle ahead of the host vehicle based on an output of the visible light imaging unit and an output of the far-infrared imaging unit;
a pattern determination unit that determines a light distribution pattern in which a portion corresponding to the window portion is shaded;
a light source control unit that controls the light source unit to generate a beam having an intensity distribution according to the determined light distribution pattern;
Equipped with
The target analysis unit includes:
a light spot detection unit that detects light spots in visible light image information obtained from the visible light imaging unit;
a low gradation area detection unit that detects a low gradation area of a predetermined shape in far-infrared image information obtained from the far-infrared imaging unit;
A vehicle lighting system characterized in that the low gradation area located above the light spot corresponding to the vehicle light is detected as the window area based on the detection results of the light spot detection unit and the low gradation area detection unit . The vehicle lighting system according to claim 1 , wherein the low gradation area detection unit detects the low gradation area by limiting the area to an area above a position corresponding to the light spot of the light in the far-infrared image information. The vehicle lighting system includes a luminance analysis unit that detects luminance of each of a plurality of individual areas arranged in front of the vehicle based on an output of the visible light imaging unit;
a tracking unit that detects a displacement of the window unit,
The light source unit is capable of independently adjusting an illuminance of light irradiated onto each of a plurality of individual regions;
The pattern determination unit determines an illuminance value of light to be irradiated to each individual region, including a specific illuminance value for a position where the window portion is present, based on the detection result of the luminance analysis unit and the detection result of the tracking unit;
The vehicle lighting system according to claim 1 , wherein the light source control unit controls the light source unit based on an illuminance value determined by the pattern determination unit. a target analyzing unit that detects a window of a vehicle ahead of the host vehicle based on an output from a visible light imaging unit that images an image ahead of the host vehicle and an output from a far-infrared imaging unit that images an image ahead of the host vehicle;
a pattern determination unit that determines a light distribution pattern in which a portion corresponding to the window portion is shaded;
a light source control unit that controls a light source unit capable of generating a beam having a variable intensity distribution so as to generate a beam having an intensity distribution according to the determined light distribution pattern;
Equipped with
The target analysis unit includes:
a light spot detection unit that detects light spots in visible light image information obtained from the visible light imaging unit;
a low gradation area detection unit that detects a low gradation area of a predetermined shape in far-infrared image information obtained from the far-infrared imaging unit;
A control device for a vehicle lighting fixture, characterized in that the low gradation area located above the light spot corresponding to the vehicle light is detected as the window area based on the detection results of the light spot detection unit and the low gradation area detection unit. Detecting a window portion of a vehicle ahead of the host vehicle based on an output from a visible light imaging unit that images an image ahead of the host vehicle and an output from a far-infrared imaging unit that images an image ahead of the host vehicle;
determining a light distribution pattern in which a portion corresponding to the window portion is shaded;
controlling a light source unit capable of generating a beam having a variable intensity distribution so as to generate a beam having an intensity distribution according to the determined light distribution pattern;
Including,
The detection of the window portion includes:
Detecting a light spot in visible light image information obtained from the visible light imaging unit;
Detecting a low gradation area of a predetermined shape in far-infrared image information obtained from the far-infrared imaging unit;
A method for controlling a vehicle lamp, comprising detecting the low-tone area located above the light spot corresponding to the vehicle light as the window portion based on the detection results of the light spot and the low-tone area .

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