Light distribution control device, vehicle lamp system, and light distribution control method

Abstract

The light distribution control device (6) controls the light distribution variable light (2) in a manner to irradiate the near distance target object with light corresponding to the illuminance of the attribute of the near distance target object when the first upper limit number (N1) is the number (T1) of the near distance target object or more, controls the light distribution variable light (2) in a manner to irradiate the far distance target object with light of the illuminance corresponding to the attribute of the far distance target object when the residual number (M) obtained by subtracting the number (T1) of the near distance target object from the first upper limit number (N1) is the number (T2) of the far distance target object or more, controls the light distribution variable light (2) in a manner to form the light distribution pattern (PTN) independent of the near distance target object and the far distance target object when the first upper limit number (N1) is less than the number (T1) of the near distance target object, and controls the light distribution variable light (2) in a manner to form the light distribution pattern (PTN) independent of the far distance target object when the residual number (M) is less than the number (T2) of the far distance target object.

Description

TECHNICAL FIELD

[0001] The present application relates to a light distribution control device, a vehicle lamp system, and a light distribution control method. BACKGROUND

[0002] A scheme of dynamically and adaptively controlling an ADB (Adaptive Driving Beam) control of a light distribution pattern according to a state of the surroundings of a vehicle is proposed. The ADB control is to detect a preceding vehicle for which irradiation of high-intensity light is to be avoided by a camera, and to shield a region corresponding to the preceding vehicle (for example, refer to Patent Literature 1). By shielding the region corresponding to the preceding vehicle, glare to a driver of the preceding vehicle can be reduced, and at the same time, the visibility of a driver of the host vehicle can be improved.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2016-088224 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In the conventional ADB control, a preceding vehicle is mainly studied as an object of light distribution control. However, in order to achieve further improvement of the visibility of a driver, it is expected that a target object other than the preceding vehicle is also an object of light distribution control. For example, reflected light of a light-reflecting object such as a road sign, a sight guide mark (road marking), a signboard, and the like can cause glare to a driver of the host vehicle. Therefore, it is expected that the object of light distribution control is determined, and the light of a region corresponding to the light-reflecting object is reduced. In addition, it is expected that a pedestrian, an obstacle on a travel road (falling object, and the like), a road sign, and the like are more early recognized by a driver of the host vehicle. Therefore, it is expected that the object of light distribution control is determined, and the light of a region corresponding to the pedestrian and the like is increased.

[0008] On the other hand, when the object of light distribution control is increased, the light distribution pattern is frequently switched. If the light distribution pattern is frequently changed, a driver of the host vehicle can feel visual disturbance. The visual disturbance can cause a decrease in the visibility of the driver.

[0009] The present application is obtained in view of such a situation, and one of the objects thereof is to provide a technology of reducing visual disturbance to a driver by light distribution control.

[0010] To solve the above technical problem, one aspect of the present application is a light distribution control device that controls light distribution of a light distribution variable lamp according to objects existing in a front region of a vehicle. The objects include near distance objects located within a prescribed distance from the vehicle, and far distance objects located outside the prescribed distance. The light distribution control device controls the light distribution variable lamp in a manner to irradiate light of an illuminance corresponding to attributes of the near distance objects to the near distance objects when a first upper limit number N1 of the objects that can be an object of light distribution control is T1 or more, controls the light distribution variable lamp in a manner to irradiate light of an illuminance corresponding to attributes of the far distance objects to the far distance objects when a remaining number M obtained by subtracting T1 from the first upper limit number N1 is T2 or more, controls the light distribution variable lamp in a manner to form a light distribution pattern that is independent of the near distance objects and the far distance objects when the first upper limit number N1 is less than T1, and controls the light distribution variable lamp in a manner to form a light distribution pattern that is independent of the far distance objects when the remaining number M is less than T2.

[0011] Another aspect of the present application is a vehicle lamp system. The vehicle lamp system includes a light distribution variable lamp that can irradiate a visible light beam having a variable intensity distribution to a front region, and the light distribution control device of the above aspect.

[0012] Further, another aspect of the present application is a light distribution control method that controls light distribution of a light distribution variable lamp according to objects existing in a front region of a vehicle. The objects include near distance objects located within a prescribed distance from the vehicle, and far distance objects located outside the prescribed distance. The light distribution control method controls the light distribution variable lamp in a manner to irradiate light of an illuminance corresponding to attributes of the near distance objects to the near distance objects when a first upper limit number N1 of the objects that can be an object of light distribution control is T1 or more, controls the light distribution variable lamp in a manner to irradiate light of an illuminance corresponding to attributes of the far distance objects to the far distance objects when a remaining number M obtained by subtracting T1 from the first upper limit number N1 is T2 or more, controls the light distribution variable lamp in a manner to form a light distribution pattern that is independent of the near distance objects and the far distance objects when the first upper limit number N1 is less than T1, and controls the light distribution variable lamp in a manner to form a light distribution pattern that is independent of the far distance objects when the remaining number M is less than T2.

[0013] Further, any combination of the above-described elements, or a scheme that converts the aspects of the present application between a method, a device, a system, and the like is also effective as an aspect of the present application.

[0014] Effects of Invention

[0015] According to the present application, reduction of visual disturbance to the driver can be achieved by light distribution control. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a block diagram of a vehicle lamp system according to an embodiment.

[0017] Figure 2 is a diagram showing a state of a front region of the vehicle.

[0018] Figure 3 is a flowchart illustrating a procedure of light distribution control performed by the light distribution control device.

[0019] Figure 4 is a flowchart illustrating a procedure of light distribution control performed by the light distribution control device.

[0020] Figure 5 (A) of Figure 5 (B) of DETAILED DESCRIPTION

[0021] Hereinafter, the present application will be described based on preferred embodiments with reference to the accompanying drawings. The embodiments do not limit the application but exemplify, and all features or combinations thereof described in the embodiments do not necessarily represent the essence of the application. Identical or similar components, parts, processes shown in each drawing are denoted by the same reference numerals, and repeated explanation is appropriately omitted. Further, the scale or shape of each part shown in each drawing is set for convenience of explanation, and is not limited unless specifically mentioned. In addition, in the present specification or claims, in the case where the terms such as "first", "second" and the like are used, the terms do not mean any order or importance, but are used to distinguish one component from another. In addition, in each drawing, a part of unimportant components is omitted for display in explaining the embodiments.

[0022] Figure 1 is a block diagram of a vehicle lamp system 1 according to an embodiment. In Figure 1 , a part of the components of the vehicle lamp system 1 is depicted as a functional block. These functional blocks are realized as hardware components by elements or circuits such as a CPU or a memory of a computer, or as software components by a computer program or the like. Those skilled in the art can understand that these functional blocks can be realized in various forms by a combination of hardware and software.

[0023] The vehicle lamp system 1 includes a light distribution variable lamp 2, a camera 4, and a light distribution control device 6. They can all be built in the same housing, and some components can also be provided outside the housing. For example, the light distribution variable lamp 2, the camera 4, and the light distribution control device 6 are housed in a lamp chamber. The lamp chamber is divided by a lamp body having an opening portion on the front side of the vehicle and a light-transmissive cover installed to cover the opening portion of the lamp body. The camera 4 and the light distribution control device 6 can be disposed outside the lamp chamber, for example, on the side of the vehicle. At this time, the camera 4 can also be a vehicle-mounted camera. Further, the light distribution control device 6 can also be constituted, for example, by the entire or a part of the vehicle ECU.

[0024] The light distribution variable lamp 2 is capable of irradiating a visible light beam L1 having a variable intensity distribution to the front region of the host vehicle. The light distribution variable lamp 2 is capable of individually changing the illuminance of light irradiated to a plurality of individual regions R arranged in the front region. The plurality of individual regions R are arranged, for example, in a matrix. The light distribution variable lamp 2 receives information indicating a light distribution pattern PTN from the light distribution control device 6 and emits a visible light beam L1 having an intensity distribution corresponding to the light distribution pattern PTN. Thereby, the light distribution pattern PTN is formed in front of the host vehicle. The light distribution pattern PTN can also be understood as a two-dimensional illuminance distribution of an irradiation pattern 902 formed by the light distribution variable lamp 2 on an imaginary vertical screen 900 in front of the host vehicle.

[0025] The configuration of the light distribution variable lamp 2 is not particularly limited, and includes, for example, a plurality of light sources arranged in a matrix, a lighting circuit that individually drives and lights each light source. As a preferable example of the light source, a semiconductor light source such as an LED (Light Emitting Diode), an LD (Laser Diode), an organic or inorganic EL (Electro Luminescence), and the like is cited. Each individual region R is associated with each light source, and light is individually irradiated to each individual region R from each light source. The resolution of the light distribution variable lamp 2, in other words, the light distribution resolution is, for example, 1000 pixels to 2 million pixels. The resolution of the light distribution variable lamp 2 indicates the number of unit regions in which the illuminance can be individually changed in the light distribution pattern PTN.

[0026] Further, in order to form an illuminance distribution corresponding to the light distribution pattern PTN, the light distribution variable lamp 2 can include a matrix-type pattern forming device such as a DMD (Digital Mirror Device) or a liquid crystal device, or a scanning optical-type pattern forming device that scans the front of the host vehicle with light source light.

[0027] The camera 4 has sensitivity in the visible light region and repeatedly photographs the front region of the host vehicle. The camera 4 photographs reflected light L2 of the visible light beam L1 caused by an object in front of the vehicle or light irradiated by a preceding vehicle, and the like. The camera 4 can have sensitivity at least in the wavelength region of the visible light beam L1. The image IMG generated by the camera 4 is transmitted to the light distribution control device 6.

[0028] The image IMG acquired by the light distribution control device 6 can be RAW image data, or can be image data subjected to prescribed image processing by the imaging device 4 or another processing section. In the following description, "the image IMG based on the imaging device 4" indicates either of RAW image data and data subjected to image processing. Further, the two kinds of image data are sometimes expressed as "the image IMG" without distinction.

[0029] The light distribution control device 6 performs ADB control, and dynamically and adaptively controls the light distribution of the light distribution variable lamp 2 according to the target object present in the front region. The light distribution control device 6 can be constituted by a digital processor, for example, can be constituted by a combination of a microcomputer including a CPU and a software program, or can be constituted by an FPGA (Field Programmable Gate Array) or an ASIC (Application Specified IC) or the like. The light distribution control device 6 has, as one example, a target object analysis section 8, a pattern determination section 10. Each section operates by executing a program held in a memory by a constituting integrated circuit. The formation control of the light distribution pattern by the light distribution control device 6 will be described below.

[0030] Figure 2 is a view showing the state of the front region of the host vehicle V. The target object analysis section 8 classifies the target objects present in the front region. Specifically, the target objects present in the front region are classified into the front vehicle 12 including the oncoming vehicle and the preceding vehicle, and target objects other than the same. The target objects other than the front vehicle 12 include pedestrians, road signs, sight line guide marks, billboards, road surface marks, obstacles, and the like. Further, the target object analysis section 8 divides the target objects other than the front vehicle 12 into the near distance target object 14 located within a prescribed distance from the host vehicle, and the far distance target object 16 located outside the prescribed distance. Moreover, the target object analysis section 8 calculates the number S of the front vehicle 12, the number T1 of the near distance target object 14, and the number T2 of the far distance target object 16.

[0031] For example, the target object analysis section 8 holds a prescribed distance threshold value in advance, and classifies the target objects present at a distance less than the prescribed distance threshold value as the near distance target object 14, and classifies the target objects present at a distance equal to or more than the distance threshold value as the far distance target object 16. The distance threshold value is determined, for example, in accordance with the braking distance of the host vehicle V. Therefore, the distance threshold value varies in correspondence with the vehicle speed of the host vehicle V. That is, the near distance target object 14 is a target object before which the host vehicle V cannot stop, and the far distance target object 16 is a target object before which the host vehicle V can stop. The distance threshold value can be appropriately set in accordance with experiments or simulations.

[0032] Further, the target object analysis section 8 grasps the attributes of the close-range target object 14 and the long-range target object 16 respectively. The target object analysis section 8 of the present embodiment grasps the brightness and the position of each target object as the attributes of the target object.

[0033] As one example, the target object analysis section 8 performs the classification of the target object and the grasping of the attributes using the image IMG based on the imaging device 4. The target object analysis section 8 is able to judge the kind of the target object, that is, whether it is the preceding vehicle 12 or a target object other than the preceding vehicle 12, by implementing a known image processing or image analysis on the image IMG. Further, it is able to detect the distance of each target object from the ground position of each target object in the image IMG. Thereby, it is able to classify the close-range target object 14 and the long-range target object 16. Further, it is able to grasp the attributes of each target object, that is, the position and the brightness from the image IMG.

[0034] Further, the target object analysis section 8 can also perform the separation of the target object and the grasping of the attributes using the target object information obtained from a distance measuring sensor or the like. The measurement direction of the distance measuring sensor is oriented toward the front region, and the information of the front region is obtained. The distance measuring sensor can be constituted by a millimeter wave radar or a LiDAR (Light Detection and Ranging: or Laser Imaging Detection and Ranging), for example.

[0035] Further, the target object analysis section 8 transmits the classification result of the target object including the number of each target object, and the information related to the attributes of each target object to the pattern decision section 10.

[0036] Figure 3 , Figure 4 , Figure 5 (A) of FIG. 10 and Figure 5 (B) of FIG. 10 are flowcharts that explain the flow of the light distribution control (ADB control) performed by the light distribution control device 6. Figure 3 The connecting symbol A of Figure 4 is connected to the connecting symbol A of Figure 3 . The connecting symbol B of Figure 4 is connected to the connecting symbol B of . The flow is instructed by the light distribution control execution instruction by the unillustrated light switch, for example, and is repeatedly executed at a prescribed timing when the ignition is on.

[0037] Figure 3As shown, first, the pattern determination section 10 determines whether or not an indication of the light distribution pattern PTN to be formed is received from the vehicle ECU (S101). In the case where the light distribution pattern PTN indication from the vehicle ECU is present (Y of S101), the pattern determination section 10 controls the light distribution variable light 2 in such a manner that the light distribution pattern PTN is formed in accordance with the indication of the vehicle ECU (S102), and ends the routine. Further, in the case where the light distribution pattern PTN indication from the vehicle ECU is present, the target object analysis by the target object analysis section 8 can be omitted. Further, the processing of step S101 can be omitted in the case where the light distribution control device 6 is constituted by the vehicle ECU.

[0038] In the case where the light distribution pattern PTN indication from the vehicle ECU is not present (N of S101), the pattern determination section 10 determines whether or not a target object is present in the front region of the host vehicle V in accordance with the information obtained from the target object analysis section 8 (S103). The pattern determination section 10 determines the presence or absence of a target object including the preceding vehicle 12, the close-range target object 14, and the long-range target object 16. In the case where no target object is present in the front region (N of S103), the pattern determination section 10 defines the light distribution pattern PTN in which the visibility of the driver of the host vehicle V is given priority as the light distribution pattern PTN to be formed. In the present embodiment, as one example, the well-known high beam light distribution pattern Hi is defined as the light distribution pattern PTN to be formed. Further, the light distribution variable light 2 is controlled in such a manner that the high beam light distribution pattern Hi is formed (S104), and the routine is ended.

[0039] In the case where a target object is present in the front region (Y of S103), the pattern determination section 10 determines whether or not the second upper limit number N2 is equal to or greater than the number S of the preceding vehicles 12 (S105). The second upper limit number N2 is held in advance in the pattern determination section 10. The second upper limit number N2, as one example, is the maximum number of target objects that can be the object of light distribution control in the light distribution control device 6. The second upper limit number N2 is appropriately set based on, for example, the relationship between the switching frequency of the light distribution pattern that can be performed in accordance with the ADB control and the visual disturbance felt by the driver of the host vehicle V, or the performance of the light distribution control device 6, or the like, by experiment or simulation. The second upper limit number N2 is a value larger than the first upper limit number N1 described later.

[0040] In the case where the second upper limit number N2 is smaller than the number S of the preceding vehicles 12 (N of S105), the pattern determination section 10 determines the light distribution pattern PTN that is independent of the presence of the preceding vehicles 12, the presence and attributes of the close-range target object 14, and the presence and attributes of the long-range target object 16 as the light distribution pattern PTN to be formed. In the present embodiment, as one example, the well-known low beam light distribution pattern Lo is defined as the light distribution pattern PTN to be formed. Further, the light distribution variable light 2 is controlled in such a manner that the low beam light distribution pattern Lo is formed (S106), and the routine is ended.

[0041] In a case where the second upper limit number N2 is equal to or greater than the number S of the preceding vehicle 12 (Y in S105), the pattern determination portion 10 controls the light distribution variable lamp 2 in such a manner that the light shielding portion is formed with respect to the preceding vehicle 12. In the present embodiment, as the light distribution pattern PTN to be formed, the first light distribution pattern PTN1 including the light shielding portion with respect to the preceding vehicle 12 is determined (S107). Thereby, at least the ADB control with respect to the preceding vehicle 12 is performed. As one example, the illuminance of the light shielding portion is substantially zero. Further, the illuminance of the light shielding portion can also be higher than zero, which can be appropriately set according to experiments or simulations. Moreover, the pattern determination portion 10 subtracts the number S of the preceding vehicle 12 from the second upper limit number N2, and calculates the first upper limit number N1 (N1=N2-S) (S108). The first upper limit number N1 indicates the number of target objects other than the preceding vehicle 12 that can be an object of the light distribution control in the light distribution control device 6. Figure 4

[0042] Next, the pattern determination portion 10 determines whether the first upper limit number N1 is equal to or greater than the number T1 of the close-range target object 14 (S109). When the first upper limit number N1 is less than the number T1 of the close-range target object 14 (N in S109), the pattern determination portion 10 determines the light distribution pattern PTN that is independent of the presence and the attribute of the close-range target object 14 and independent of the presence and the attribute of the far-range target object 16 as the light distribution pattern PTN to be formed. In the present embodiment, the first light distribution pattern PTN1 is specified as the light distribution pattern PTN to be formed. Moreover, the light distribution variable lamp 2 is controlled in such a manner that the first light distribution pattern PTN1 is formed (S110), and the present routine ends.

[0043] When the first upper limit number N1 is equal to or greater than the number T1 of the close-range target object 14 (Y in S109), the pattern determination portion 10 controls the light distribution variable lamp 2 in such a manner that the light having the illuminance corresponding to the attribute of the close-range target object 14 is irradiated to the close-range target object 14. The pattern determination portion 10 of the present embodiment performs the determination processing of the second light distribution pattern PTN2 in order to determine the illuminance corresponding to the attribute of the close-range target object 14 (S111). Thereby, at least the ADB control with respect to the preceding vehicle 12 and the close-range target object 14 is performed.

[0044] As Figure 5 ​In the determination process of the second light distribution pattern PTN2, the pattern determination section 10 first determines whether there is a high-luminance close-range object 14 (S201) as shown in (A). For example, the pattern determination section 10 holds a predetermined luminance threshold value in advance. Further, based on the information obtained from the object analysis section 8, a close-range object 14 equal to or higher than the predetermined luminance threshold value is defined as a high-luminance close-range object 14. The luminance threshold value can be appropriately set according to experiments or simulations. For example, the luminance threshold value is set to a value capable of distinguishing between light-reflecting objects including road signs, sight-guiding signs, billboards, and the like, and objects other than the same. As an example of the light-reflecting object is an object having a retro-reflective surface at least in a portion recognized from the host vehicle.

[0045] In the case where there is a high-luminance close-range object 14 (Y in S201), the pattern determination section 10 controls the light distribution variable light 2 in such a manner as to reduce the illuminance of light irradiated to the high-luminance close-range object 14. That is, the pattern determination section 10 adds a light-reducing section for the high-luminance close-range object 14 to the first light distribution pattern PTN1 (S202). The illuminance of the light-reducing section is, for example, higher than that of the light-shielding section and lower than that before the light adjustment, and is an illuminance capable of suppressing glare caused to the driver of the host vehicle V by the light-reflecting object. The illuminance of the light-reducing section can be appropriately set according to experiments or simulations. In the case where there is no high-luminance close-range object 14 (N in S201), the pattern determination section 10 skips step S202.

[0046] Next, the pattern determination section 10 determines whether there is a low-luminance close-range object 14 in the road on which the host vehicle V travels, that is, in the travel lane (S203). The low-luminance close-range object 14 is a close-range object 14 having a luminance lower than the luminance threshold value. In the case where there is a low-luminance close-range object 14 in the travel lane (Y in S203), the pattern determination section 10 controls the light distribution variable light 2 in such a manner as to increase the illuminance of light irradiated to the low-luminance close-range object 14 in the travel lane. That is, the pattern determination section 10 adds a light-increasing section for the low-luminance close-range object 14 in the travel lane to the first light distribution pattern PTN1 (S204). The illuminance of the light-increasing section is higher than that before the light adjustment, and is an illuminance capable of guiding the line of sight of the driver of the host vehicle V toward the close-range object 14 in the travel lane. The illuminance of the light-increasing section can be appropriately set according to experiments or simulations. In the case where there is no low-luminance close-range object 14 in the travel lane (N in S203), the pattern determination section 10 skips step S204.

[0047] By the above processing, the pattern determination portion 10 determines the second distribution pattern PTN2, which, with respect to the first distribution pattern PTN1, increases the light reduction portion for the near distance object 14 if there is a near distance object 14 of high luminance, and increases the light increase portion for the near distance object 14 if there is a near distance object 14 of low luminance within the travel lane (S205). Further, with respect to the near distance object 14 of low luminance existing outside the travel lane, the light of the illuminance before the dimming is maintained. Next, as shown in FIG. 6, the pattern determination portion 10 subtracts the number T1 of the near distance objects 14 from the first upper limit number N1, and calculates the remaining number M (M=N1-T1) (S112). The remaining number M indicates the number of objects other than the preceding vehicle 12 and the near distance objects 14, which can be the target of the distribution control in the distribution control device 6. Figure 4

[0048] Next, the pattern determination portion 10 determines whether the remaining number M is equal to or greater than the number T2 of the far distance objects 16 (S113). When the remaining number M is less than the number T2 of the far distance objects 16 (N of S113), the pattern determination portion 10 determines the distribution pattern PTN that does not depend on the existence and the attribute of the far distance objects 16 as the distribution pattern PTN to be formed. In the present embodiment, the second distribution pattern PTN2 is defined as the distribution pattern PTN to be formed. Further, the distribution variable light 2 is controlled in such a manner that the second distribution pattern PTN2 is formed (S114), and the present routine is ended.

[0049] When the remaining number M is equal to or greater than the number T2 of the far distance objects 16 (Y of S113), the pattern determination portion 10 controls the distribution variable light 2 in such a manner that the light of the illuminance corresponding to the attribute of the far distance objects 16 is irradiated to the far distance objects 16. The pattern determination portion 10 of the present embodiment executes the determination processing of the third distribution pattern PTN3 in order to determine the illuminance corresponding to the attribute of the far distance objects 16 (S115). By this, the ADB control with respect to the preceding vehicle 12, the near distance objects 14, and the far distance objects 16 is executed.

[0050] Figure 5 ​​As shown in (B), in the determination process of the third light distribution pattern PTN3, the pattern determination portion 10 first determines whether there is a high-luminance distant object 16 (S301). The method of determining whether there is a high-luminance distant object 16 is the same as the method of determining whether there is a high-luminance close object 14. When there is a high-luminance distant object 16 equal to or higher than a prescribed luminance threshold (Y in S301), the pattern determination portion 10 controls the light distribution variable light 2 in such a manner that the illuminance of light irradiated to the high-luminance distant object 16 is reduced. That is, the pattern determination portion 10 adds a light-reducing portion for the high-luminance distant object 16 in the second light distribution pattern PTN2 (S302). The setting method of the illuminance of the light-reducing portion is the same as the setting method of the illuminance of the light-reducing portion in the determination process of the second light distribution pattern PTN2. When there is no high-luminance distant object 16 (N in S301), the pattern determination portion 10 skips step S302.

[0051] Next, the pattern determination portion 10 determines whether there is a low-luminance distant object 16 in the road on which the host vehicle V is traveling, that is, in the travel lane (S303). The low-luminance distant object 16 is a distant object 16 whose luminance is less than the luminance threshold. When there is a low-luminance distant object 16 in the travel lane (Y in S303), the pattern determination portion 10 controls the light distribution variable light 2 in such a manner that the illuminance of light irradiated to the low-luminance distant object 16 in the travel lane is increased. That is, the pattern determination portion 10 adds a light-increasing portion for the low-luminance distant object 16 in the travel lane in the second light distribution pattern PTN2 (S304). The setting method of the illuminance of the light-increasing portion is the same as the setting method of the illuminance of the light-increasing portion in the determination process of the second light distribution pattern PTN2. When there is no low-luminance distant object 16 in the travel lane (N in S303), the pattern determination portion 10 skips step S304.

[0052] Through the above process, the pattern determination portion 10 determines the third light distribution pattern PTN3, for the second light distribution pattern PTN2, adds a light-reducing portion for a high-luminance distant object 16 if there is such an object, and adds a light-increasing portion for a low-luminance distant object 16 in the travel lane if there is such an object (S305). Further, for a distant object 16 whose luminance is outside the travel lane, light whose illuminance before dimming is maintained is irradiated. Next, as shown in (C), the pattern determination portion 10 controls the light distribution variable light 2 in such a manner that the determined third light distribution pattern PTN3 is formed (S116), and ends the present routine. Figure 4

[0053] ​The light distribution variable lamp 2 is driven in a manner in which the light distribution pattern PTN decided by the light distribution pattern deciding section 10 is formed. For example, in a case where the light modulation method of the light source is analog light modulation, the light distribution variable lamp 2 adjusts the direct current level of the driving current flowing in the light source. Further, in a case where the light modulation method of the light source is PWM (Pulse Width Modulation) light modulation, the light distribution variable lamp 2 adjusts the average level of the driving current by switching the current flowing in the light source on and off, thereby adjusting the ratio of the on period. Further, in a case where the light distribution variable lamp 2 includes a DMD, the on / off switching of each mirror element constituting the DMD can also be controlled. In a case where the light distribution variable lamp 2 has a liquid crystal device, the light transmittance of the liquid crystal device can also be controlled. Thereby, the light distribution pattern PTN is formed in front of the host vehicle.

[0054] As explained above, the light distribution control device 6 of the present embodiment controls the light distribution variable lamp 2 in a manner in which the near distance target object 14 is irradiated with light of an illuminance corresponding to the attribute of the near distance target object 14 when the first upper limit number N1 of the target objects that can be the object of light distribution control is T1 or more. Further, the light distribution control device 6 controls the light distribution variable lamp 2 in a manner in which the far distance target object 16 is irradiated with light of an illuminance corresponding to the attribute of the far distance target object 16 when the remaining number M after subtracting the number T1 of the near distance target objects 14 from the first upper limit number N1 is T2 or more.

[0055] That is, in the present embodiment, the number of objects of ADB control is set with an upper limit (the first upper limit number N1) with respect to the near distance target object 14 and the far distance target object 16. And first, if the number T1 of the near distance target objects 14 is N1 or less, the near distance target objects 14 are subjected to ADB control. Next, if the number T2 of the far distance target objects 16 is M or less after the number of objects allocated to the near distance target objects 14, the far distance target objects 16 are subjected to ADB control. Therefore, the near distance target objects 14 are given priority over the far distance target objects 16 as the object of ADB control. The possibility that the near distance target objects 14 have an influence on the running of the host vehicle V is higher than that of the far distance target objects 16. Therefore, by giving priority to the near distance target objects 14 in performing ADB control, the visibility of the driver of the host vehicle V with respect to the near distance target objects 14 is improved, and the safety of vehicle running can be improved.

[0056] Further, the light distribution control device 6 determines the illuminance of the light irradiated to the near distance target object 14 and the far distance target object 16 independently of these target objects when the number T1 of the near distance target objects 14 exceeds the first upper limit number N1. That is, the ADB control to the near distance target object 14 and the far distance target object 16 is abandoned. Further, the light distribution control device 6 determines the illuminance of the light irradiated to the far distance target object 16 independently of the far distance target object 16 when the number T2 of the far distance target objects 16 exceeds the residual number M. That is, the ADB control to the far distance target object 16 is abandoned. Thus, even if the number of the target objects as the object of the ADB control increases, the light distribution pattern can be suppressed from frequently switching. Therefore, the possibility that the driver of the host vehicle V feels a visual disturbance can be reduced, and the visibility of the driver can be suppressed from decreasing.

[0057] Further, in the present embodiment, a second upper limit number N2 larger than the first upper limit number N1 is set as the target object that can be the object of the light distribution control. Also, when the second upper limit number N2 is equal to or more than the number S of the preceding vehicle 12, the light distribution control device 6 controls the light distribution variable light 2 in such a manner that the light shielding portion is formed to the preceding vehicle 12. Also, the number S of the preceding vehicle 12 is subtracted from the second upper limit number N2, and the first upper limit number N1 is calculated. Therefore, the preceding vehicle 12 is more preferentially made the object of the ADB control than the near distance target object 14 and the far distance target object 16. Thus, the glare to the driver of the preceding vehicle 12 can be more reliably reduced, and the safety of the vehicle driving can be improved.

[0058] Further, the light distribution control device 6 determines the illuminance of the light irradiated to the near distance target object 14 and the far distance target object 16 independently of these target objects when the number T1 of the near distance target objects 14 exceeds the first upper limit number N1. That is, the ADB control to the near distance target object 14 and the far distance target object 16 is abandoned. Further, the light distribution control device 6 determines the illuminance of the light irradiated to the far distance target object 16 independently of the far distance target object 16 when the number T2 of the far distance target objects 16 exceeds the residual number M. That is, the ADB control to the far distance target object 16 is abandoned. Thus, even if the number of the target objects as the object of the ADB control increases, the light distribution pattern can be suppressed from frequently switching. Therefore, the possibility that the driver of the host vehicle V feels a visual disturbance can be reduced, and the visibility of the driver can be suppressed from decreasing.

[0059] Further, the light distribution control device 6 of the present embodiment controls the light distribution variable light 2 in such a manner that the illuminance of the irradiated light is reduced to the near distance target object 14 of high luminance in a case where the light of the illuminance corresponding to the attribute of the near distance target object 14 is irradiated to the near distance target object 14. Thus, the glare to the driver of the host vehicle V by the near distance target object 14 of high luminance can be suppressed, and the safety of the vehicle driving can be improved. Further, the light distribution variable light 2 is controlled in such a manner that the illuminance of the irradiated light is increased to the near distance target object 14 of low luminance located on the road on which the host vehicle V travels. Thus, the driver of the host vehicle V easily recognizes the near distance target object 14 of low luminance present in the traffic lane, and the safety of the vehicle driving can be improved.

[0060] The low-luminance close-range object 14 outside the lane has a lower possibility of affecting the running of the host vehicle V than the high-luminance close-range object 14 or the low-luminance close-range object 14 inside the lane. Therefore, the ADB control is not performed on the low-luminance close-range object 14 outside the lane. In this way, by selectively choosing the close-range object 14 to be the subject of the ADB control, it is possible to reduce the possibility of the driver of the host vehicle V feeling visually disturbed, and it is possible to suppress the decrease in the driver's visibility.

[0061] Further, the light distribution control device 6 of the present embodiment controls the light distribution variable light 2 in such a manner as to reduce the illuminance of the irradiated light on the high-luminance long-range object 16 in the case where the light of the illuminance corresponding to the attribute of the long-range object 16 is irradiated to the long-range object 16. Thereby, it is possible to suppress the glare of the high-luminance long-range object 16 on the driver of the host vehicle V, and it is possible to improve the safety of the vehicle running. Further, the light distribution variable light 2 is controlled in such a manner as to increase the illuminance of the irradiated light on the low-luminance long-range object 16 on the road on which the host vehicle V runs. Thereby, the driver of the host vehicle V easily recognizes the low-luminance long-range object 16 inside the lane, and it is possible to improve the safety of the vehicle running.

[0062] The low-luminance long-range object 16 outside the lane has a lower possibility of affecting the running of the host vehicle V than the high-luminance long-range object 16 or the low-luminance long-range object 16 inside the lane. Therefore, the ADB control is not performed on the low-luminance long-range object 16 outside the lane. In this way, by selectively choosing the long-range object 16 to be the subject of the ADB control, it is possible to reduce the possibility of the driver of the host vehicle V feeling visually disturbed, and it is possible to suppress the decrease in the driver's visibility.

[0063] The foregoing has described the embodiments of the present application in detail. The foregoing embodiments merely show specific examples in implementing the present application. The contents of the embodiments are not intended to limit the technical scope of the present application, and various design changes such as changes, additions, and deletions of the constituent elements can be made within the scope of the idea of the present application defined by the claims. The new embodiments to which the design changes are applied have the effects of the combined embodiments and the variations each. In the foregoing embodiments, the contents to which such design changes can be made are emphasized by the expressions such as "of the present embodiment" and "in the present embodiment", and the design changes are allowed even if such expressions are not used. Any combination of the foregoing constituent elements is also effective as the scheme of the present application. The hatching of the cross-sectional marks of the drawings is not intended to limit the material of the object to which the hatching is applied.

[0064] The foregoing embodiments of the present application can be determined in accordance with the items described below.

[0065] [Item 1]

[0066] A light distribution control device (6) is a light distribution control device (6) that controls light distribution of a light distribution variable lamp (2) in accordance with an object present in a front region of a vehicle (V),

[0067] The object includes a near distance object (14) located within a prescribed distance from the vehicle (V) and a far distance object (16) located outside the prescribed distance,

[0068] When a first upper limit number N1 of the object that can be an object of light distribution control is T1 or more, the light distribution variable lamp (2) is controlled in a manner to irradiate the near distance object (14) with light of an illuminance corresponding to the attribute of the near distance object (14),

[0069] When a remaining number M obtained by subtracting the number T1 of the near distance object (14) from the first upper limit number N1 is T2 or more, the light distribution variable lamp (2) is controlled in a manner to irradiate the far distance object (16) with light of an illuminance corresponding to the attribute of the far distance object (16),

[0070] When the first upper limit number N1 is less than the number T1 of the near distance object (14), the light distribution variable lamp (2) is controlled in a manner to form a light distribution pattern (PTN, PTN1) that is independent of the near distance object (14) and the far distance object (16), and when the remaining number M is less than the number T2 of the far distance object (16), the light distribution variable lamp (2) is controlled in a manner to form a light distribution pattern (PTN, PTN2) that is independent of the far distance object (16).

[0071] [Item 2]

[0072] The light distribution control device (6) according to Item 1,

[0073] The object includes a preceding vehicle (12),

[0074] When a second upper limit number N2 of the object that can be an object of light distribution control, which is larger than the first upper limit number N1, is S or more, the light distribution variable lamp (2) is controlled in a manner to form a light shielding portion with respect to the preceding vehicle (12), and the first upper limit number N1 is calculated by subtracting the number S of the preceding vehicle (12) from the second upper limit number N2,

[0075] When the second upper limit number N2 is less than the number S of the preceding vehicle (12), the light distribution variable lamp (2) is controlled in a manner to form a light distribution pattern (PTN, Lo) that is independent of the preceding vehicle (12), the near distance object (14), and the far distance object (16).

[0076] [Item 3]

[0077] The light distribution control device (6) according to any one of Items 1 to 2,

[0078] In a case where the light of the illuminance corresponding to the attribute of the near distance target object (14) is irradiated to the near distance target object (14),

[0079] When the brightness of the near distance target object (14) is the prescribed value or more, the light distribution variable light (2) is controlled in a manner to reduce the illuminance of the light irradiated to the near distance target object (14),

[0080] When the brightness of the near distance target object (14) is less than the prescribed value and the near distance target object (14) is located on a road on which the vehicle (V) travels, the light distribution variable light (2) is controlled in a manner to increase the illuminance of the light irradiated to the near distance target object (14).

[0081] [Item 4]

[0082] The light distribution control device (6) according to any one of Items 1 to 3,

[0083] In a case where the light of the illuminance corresponding to the attribute of the far distance target object (16) is irradiated to the far distance target object (16),

[0084] When the brightness of the far distance target object (16) is the prescribed value or more, the light distribution variable light (2) is controlled in a manner to reduce the illuminance of the light irradiated to the far distance target object (16),

[0085] When the brightness of the far distance target object (16) is less than the prescribed value and the far distance target object (16) is located on a road on which the vehicle (V) travels, the light distribution variable light (2) is controlled in a manner to increase the illuminance of the light irradiated to the far distance target object (16).

[0086] [Item 5]

[0087] A vehicle lamp system (1) includes:

[0088] a light distribution variable light (2) capable of irradiating a visible light beam (L1) of which intensity distribution is variable to a front region, and

[0089] The light distribution control device (6) according to any one of Items 1 to 4.

[0090] [Item 6]

[0091] A light distribution control method is a light distribution control method of controlling a light distribution of a light distribution variable light (2) according to a target object existing in a front region of a vehicle (V),

[0092] The target objects include near distance target objects (14) located within a prescribed distance from the vehicle (V), and far distance target objects (16) located outside the prescribed distance,

[0093] When the first upper limit number N1 of the target objects that can be the object of the light distribution control is equal to or greater than the number T1 of the near distance target objects (14), the light distribution variable light (2) is controlled in a manner to irradiate the near distance target objects (14) with light of an illuminance corresponding to the attribute of the near distance target objects (14),

[0094] When the remaining number M obtained by subtracting the number T1 of the near distance target objects (14) from the first upper limit number N1 is equal to or greater than the number T2 of the far distance target objects (16), the light distribution variable light (2) is controlled in a manner to irradiate the far distance target objects (16) with light of an illuminance corresponding to the attribute of the far distance target objects (16),

[0095] When the first upper limit number N1 is less than the number T1 of the near distance target objects (14), the light distribution variable light (2) is controlled in a manner to form a light distribution pattern (PTN, PTN1) that is independent of the near distance target objects (14) and the far distance target objects (16), and when the remaining number M is less than the number T2 of the far distance target objects (16), the light distribution variable light (2) is controlled in a manner to form a light distribution pattern (PTN, PTN2) that is independent of the far distance target objects (16).

[0096] Industrial applicability

[0097] The present application can be used in a light distribution control device, a vehicle lamp system, and a light distribution control method.

[0098] Explanation of reference numerals

[0099] 1 vehicle lamp system, 2 light distribution variable light, 6 light distribution control device, 12 preceding vehicle, 14 near distance target object, 16 far distance target object.

Claims

1. A light distribution control device that controls light distribution of a light distribution variable lamp in accordance with an object existing in a front region of a vehicle, the object includes a near distance object located within a prescribed distance from the vehicle, and a far distance object located outside the prescribed distance, when a first upper limit number Nl of objects that can be an object of light distribution control is Tl or more, the light distribution variable lamp is controlled in a manner to irradiate the near distance object with light of an illuminance corresponding to a property of the near distance object, when a remaining number M obtained by subtracting Tl from the first upper limit number Nl is T2 or more, the light distribution variable lamp is controlled in a manner to irradiate the far distance object with light of an illuminance corresponding to a property of the far distance object, when the first upper limit number Nl is less than Tl, the light distribution variable lamp is controlled in a manner to form a light distribution pattern that is independent of the near distance object and the far distance object, and when the remaining number M is less than T2, the light distribution variable lamp is controlled in a manner to form a light distribution pattern that is independent of the far distance object.

2. The light distribution control device according to claim 1, the object includes a preceding vehicle, when a second upper limit number N2 of objects that can be an object of light distribution control, which is larger than the first upper limit number Nl, is S or more, the light distribution variable lamp is controlled in a manner to form a light shielding portion for the preceding vehicle, and the first upper limit number Nl is calculated by subtracting S from the second upper limit number N2, when the second upper limit number N2 is less than S, the light distribution variable lamp is controlled in a manner to form a light distribution pattern that is independent of the preceding vehicle, the near distance object, and the far distance object.

3. The light distribution control device according to claim 1 or 2, in a case where the near distance object is irradiated with light of an illuminance corresponding to a property of the near distance object, when a brightness of the near distance object is a prescribed value or more, the light distribution variable lamp is controlled in a manner to reduce the illuminance of the light irradiating the near distance object, when the brightness of the near distance object is less than the prescribed value and the near distance object is located on a road on which the vehicle travels, the light distribution variable lamp is controlled in a manner to increase the illuminance of the light irradiating the near distance object.

4. The light distribution control device according to claim 1 or 2, in a case where the far distance object is irradiated with light of an illuminance corresponding to a property of the far distance object, when a brightness of the far distance object is a prescribed value or more, the light distribution variable lamp is controlled in a manner to reduce the illuminance of the light irradiating the far distance object, when the brightness of the far distance object is less than the prescribed value and the far distance object is located on a road on which the vehicle travels, the light distribution variable lamp is controlled in a manner to increase the illuminance of the light irradiating the far distance object.

5. The light distribution control device according to claim 3, when the brightness of the distant target object is equal to or higher than a predetermined value, the light distribution variable light is controlled in a manner to reduce the intensity of the light irradiated to the distant target object, when the brightness of the distant target object is lower than a predetermined value and the distant target object is located on a road on which the vehicle travels, the light distribution variable light is controlled in a manner to increase the intensity of the light irradiated to the distant target object.

6. A vehicle lamp system comprising: a light distribution variable light capable of irradiating a visible light beam having a variable intensity distribution to the front region, and the light distribution control device according to claim 1 or 2.

7. A vehicle lamp system comprising: a light distribution variable light capable of irradiating a visible light beam having a variable intensity distribution to the front region, and the light distribution control device according to claim 3.

8. A vehicle lamp system comprising: a light distribution variable light capable of irradiating a visible light beam having a variable intensity distribution to the front region, and the light distribution control device according to claim 4.

9. A vehicle lamp system comprising: a light distribution variable light capable of irradiating a visible light beam having a variable intensity distribution to the front region, and the light distribution control device according to claim 5.

10. A light distribution control method of controlling a light distribution of a light distribution variable light in accordance with a target object existing in a front region of a vehicle, the target object includes a near target object located within a predetermined distance from the vehicle and a distant target object located outside the predetermined distance, when a first upper limit number N1 of the target objects that can be an object of light distribution control is equal to or higher than a number T1 of the near target objects, the light distribution variable light is controlled in a manner to irradiate light having an intensity corresponding to a property of the near target object to the near target object, when a remaining number M obtained by subtracting the number T1 of the near target objects from the first upper limit number N1 is equal to or higher than a number T2 of the distant target objects, the light distribution variable light is controlled in a manner to irradiate light having an intensity corresponding to a property of the distant target object to the distant target object, when the first upper limit number N1 is lower than the number T1 of the near target objects, the light distribution variable light is controlled in a manner to form a light distribution pattern that is independent of the near target object and the distant target object, and when the remaining number M is lower than the number T2 of the distant target objects, the light distribution variable light is controlled in a manner to form a light distribution pattern that is independent of the distant target object. ​

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