Patent Publication Number: US-10767828-B2

Title: Vehicular headlamp

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2017-254053, filed on Dec. 28, 2017, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The present invention relates to a vehicular headlamp. More particularly, the present invention relates to a vehicular headlamp that can achieve lighting appearance other than lighting appearance at the time of forming a light distribution pattern for a headlamp is provided. 
     BACKGROUND 
     There is known a vehicular headlamp which includes a plurality of low beam optical systems each including a low beam lens and a low beam light source, and a plurality of high beam optical systems each including a high beam lens and a high beam light source (see, for example, Patent Document 1 ( FIG. 1 , etc.)). 
     In Patent Document 1, a low beam light distribution pattern can be formed by turning off the high beam light sources and turning on the low beam light sources. In addition, a high beam light distribution pattern can be formed by simultaneously turning on the high beam light sources and the low beam light sources. 
     PRIOR ART 
     [Patent Document 1] Japanese Laid-open Patent Publication No. 2017-47815 
     SUMMARY 
     However, in Patent Document 1, there is a problem in that lighting appearance other than lighting appearance at the time of forming a light distribution pattern for a headlamp (e.g. the low beam light distribution pattern or the high beam light distribution pattern) cannot be achieved. 
     The present invention has been made in light of the above circumstances, and it is an object of the present invention to provide a vehicular headlamp that can achieve lighting appearance other than lighting appearance at the time of forming a light distribution pattern for a headlamp. 
     According to an aspect of the embodiments, a vehicular headlamp comprising: a front lens body extending in a predetermined direction; a plurality of optical systems disposed along the predetermined direction behind the front lens body; and a control means, wherein the plurality of optical systems each includes: a rear lens unit disposed behind the front lens body; and a light source which is disposed behind the rear lens unit and emits light which is irradiated forward permeating the rear lens unit and the front lens body in that order to form a light distribution pattern for a headlamp, and the control means individually controls lighting states of the light sources in each of the plurality of optical systems. 
     According to this aspect, there can be provided a vehicular headlamp that can achieve lighting appearance other than lighting appearance at the time of forming a light distribution pattern for a headlamp. 
     This is because the vehicular headlamp includes the control means individually controls lighting states of the light sources in each of the plurality of optical systems. 
     A preferred aspect of the above-mentioned invention is characterized in that the vehicular headlamp further includes a detection means which detects a predetermined state, wherein the control means individually controls the lighting states of the light sources in each of the plurality of optical systems, when the detection means detects the predetermined state. 
     In addition, a preferred aspect of the above-mentioned invention is characterized in that, in the case of forming the light distribution pattern, the control means controls the lighting states of the light sources in each of the plurality of optical systems at a first power and, when the detection means detects the predetermined state, the control means individually controls the lighting states of the light sources in each of the plurality of optical systems at a second power lower than the first power. 
     In addition, a preferred aspect of the above-mentioned invention is characterized in that the predetermined state is reception of a locking signal for locking a vehicle door, or an unlocking signal for unlocking a vehicle door. 
     In addition, a preferred aspect of the above-mentioned invention is characterized in that, the control means individually controls the lighting states of the light sources in each of the plurality of optical systems according to a predetermined lighting pattern, when the detection means detects the predetermined state. 
     In addition, a preferred aspect of the above-mentioned invention is characterized in that the lighting pattern is a sequential lighting pattern. 
     In addition, a preferred aspect of the above-mentioned invention is characterized in that the plurality of optical systems includes an ADB optical system, the ADB optical system includes: an ADB rear lens unit disposed behind the front lens body; and N number of ADB light sources which are disposed behind the ADB rear lens body and each emits light which is irradiated forward permeating the ADB rear lens unit and the front lens body in that order to form a light distribution pattern for ADB, and the control means individually controls each of the N number of ADB light sources at a power which is 1/N of the second power, when the detection means detects the predetermined state. 
     In addition, a preferred aspect of the above-mentioned invention is characterized in that the front lens body includes: a light incident surface extending in the predetermined direction and a light exiting surface extending in the predetermined direction on a side opposite to the light incident surface; and the light incident surface is a surface at which light from the plurality of optical systems enters the front lens body, and the light exiting surface is a surface at which light from the plurality of optical systems which has entered from the light incident surface exits, and at least one of the light incident surface and the light exiting surface is a cylindrical surface in which a cylindrical axis extends in the predetermined direction. 
     In addition, a preferred aspect of the above-mentioned invention is characterized in that the plurality of optical systems includes at least one of a low beam optical system, a high beam optical system and an ADB optical system, the low beam optical system includes a low beam rear lens unit disposed behind the front lens body and a low beam light source which is disposed behind the low beam rear lens unit and emits light which is irradiated forward permeating the low beam rear lens unit and the front lens body in that order to form a light distribution pattern for low beam, the high beam optical system includes a high beam rear lens unit disposed behind the front lens body and a high beam light source which is disposed behind the high beam rear lens unit and emits light which is irradiated forward permeating the high beam rear lens unit and the front lens body in that order to form a light distribution pattern for high beam, and the ADB optical system includes an ADB rear lens unit disposed behind the front lens body and a plurality of ADB light source which is disposed behind the ADB rear lens body and emits light which is irradiated forward permeating the ADB rear lens unit and the front lens body in that order to form a light distribution pattern for ADB. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of the vehicular light  10 . 
         FIG. 2  is a top view of the vehicular light  10 . 
         FIG. 3  is a front view of the vehicular light  10 . 
         FIG. 4  is a longitudinal sectional diagram (sectional diagram taken along the line A-A in  FIG. 2 ) of the low beam optical system  30 . 
         FIG. 5A  is a longitudinal sectional view (view taken along the line B-B in  FIG. 2 ) of the ADB optical system  40  and  FIG. 5B  is a front view of a substrate K 2  mounted with ADB light sources  42   a  to  42   d.    
         FIG. 6A  is a diagram for illustrating a state where a dark portion D at which light from the low beam rear lens unit  31  and the ADB rear lens unit  41  does not pass through a portion of the front lens body  20  corresponding to the interval S 3  is generated.  FIG. 6B  is a diagram for illustrating a state where the dark portion D has been eliminated. 
         FIGS. 7A and 7B  are examples of a positioning mechanism. 
         FIG. 8  is an example of an abutting surface  60  configured to support the structure  50 . 
         FIG. 9A  is an example of a low beam light distribution pattern P Lo .  FIG. 9B  is an example of an ADB light distribution pattern P ADB .  FIG. 9C  is an example of a high beam light distribution pattern P Hi .  FIG. 9D  is an example of the high beam light distribution pattern P Hi . 
         FIG. 10  is an example of the light emitting regions A 1  and A 2  formed in the front lens body  20 . 
         FIGS. 11A and 11B  are examples of the light emitting regions A 1  and A 2  formed in the front lens body  20 . 
         FIG. 12  shows examples of the light emitting regions A 1  and A 2  formed in the front lens body  20  when the ADB optical system  40  is disposed behind the low beam optical system  30 . 
         FIG. 13  shows an example of the light emitting region A 2  formed in the front lens body  20  when ADB optical systems  40  are disposed adjacent to each other. 
         FIG. 14  is an example of the control means  1 . 
         FIG. 15  is a flow chart for explaining an example of control by the control means  1 . 
         FIG. 16  is a diagram (front view) for explaining a modification example of the vehicular lamp  10 . 
         FIGS. 17A-17C  are examples of an ADB light distribution pattern P ADB . 
         FIG. 18  is an example of a light diffusing element  21   a  set in the front lens body  20 . 
         FIG. 19  is an example of a light diffusing element  21   b  set in the front lens body  20 . 
         FIG. 20  is an example of a light diffusing element  21   c  set in the front lens body  20 . 
         FIG. 21  is an example of a light diffusing element  21   d  set in the front lens body  20 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A vehicular lamp  10  (corresponding to a vehicular headlamp according to the present invention) according to an embodiment of the present invention is described below with reference to the attached drawings. Corresponding components in each drawing are denoted by the same reference symbols and overlapping descriptions are omitted. 
       FIG. 1  is a perspective view of the vehicular lamp  10 .  FIG. 2  is a top view of the vehicular lamp  10 .  FIG. 3  is a front view of the vehicular lamp  10 . 
     The vehicular lamp  10  shown in  FIGS. 1 to 3  is a vehicular headlamp (headlamp) and is mounted to, for example, the left and right sides on the front end of a vehicle such as an automobile. Because the vehicular lamp  10  to be mounted to both the left and right sides has a symmetrical configuration, a vehicular lamp  10  mounted to the left side at the front of a vehicle (left side facing the front of the vehicle) is described as a representative example of the vehicular lamp  10 . Although not illustrated, the vehicle lamp  10  is arranged in a lamp chamber constituted by an outer lens and a housing and is attached to the housing or the like. 
     As illustrated in  FIGS. 1 to 3 , the vehicular lamp  10  includes a front lens body  20 , low beam optical systems  30   a  to  30   h  and Adaptive Driving Beam (ADB) optical systems  40   a  to  40   c  (or high beam optical systems to be described later). The low beam optical systems  30   a  to  30   h  all have the same configuration. The ADB optical systems  40   a  to  40   c  also all have the same configuration. The low beam optical systems  30   a  to  30   h  are collectively referred to as “low beam optical system  30 ” in the following description if the low beam optical systems  30   a  to  30   h  do not need to be distinguished from each other. Likewise, the ADB optical systems  40   a  to  40   c  are collectively referred to as “ADB optical system  40 ” if the ADB optical systems  40   a  to  40   c  do not need to be distinguished from each other. The low beam optical system  30  corresponds to a second optical system according to the present invention, and the ADB optical system  40  corresponds to a first optical system according to the present invention. 
     The front lens body  20  is a lens unit that extends in a predetermined direction (also referred to as a first direction herein). The front lens body  20  is primarily responsible for condensing light from a rear lens unit (a low beam rear lens unit  31  and an ADB rear lens unit  41 ) which permeates the front lens body  20  in a second direction orthogonal to the first direction. 
     The front lens body  20  is formed through injection molding a transparent resin such as acrylic or polycarbonate. The predetermined direction is, for example, when viewed from above, a direction inclined by a receding angle θ 1  with respect to a reference axis AX 1  which extends in a vehicle width direction as illustrated in  FIG. 2 , and, when viewed from the front, a direction inclined by a splice angle θ 2  with respect to the reference axis AX 1  which extends in the vehicle width direction as illustrated in  FIG. 3 . The angles θ 1  and θ 2  are any angles from between 0° to 90°. 
     As illustrated in  FIG. 2 , the front lens body  20  includes a light incident surface  21  extending in the first direction and a light exiting surface  22  extending in the first direction on a side opposite to the light incident surface  21 . 
     The light incident surface  21  is, for example, a flat surface (for example, a vertical surface). The light exiting surface  22  is formed as a semi-cylindrical surface (cylindrical surface) having a cylindrical axis extending (in a line) in the first direction for condensing, in the second direction orthogonal to the first direction, the light from the low beam optical system  30  and the ADB optical system  40  which exits from the light exiting surface  22 . 
     The low beam optical system  30  and the ADB optical system  40  are disposed next to each other along the first direction behind the front lens body  20 . 
       FIG. 4  is a longitudinal sectional diagram (sectional diagram taken along the line A-A in  FIG. 2 ) of the low beam optical system  30 . 
     As illustrated in  FIG. 4 , the low beam optical system  30  includes the low beam rear lens unit  31  disposed behind the front lens body  20 , and a low beam light source  32  disposed behind the low beam rear lens unit  31  and emits light which is horizontally irradiated forward at a second diffusion angle θ 4  (see  FIG. 10 ) larger than a first diffusion angle θ 3  to be described later, permeating the low beam rear lens unit  31  and the front lens body  20  in that order to form a low beam light distribution pattern. The second diffusion angle θ 4  is, for example, an angle from 30° to 40°. The second diffusion angle θ 4  can be adjusted by, for example, altering the surface shape of a light exiting portion  31   b  of the low beam rear lens unit  31 . The low beam rear lens unit  31  corresponds to a second rear lens unit according to the present invention. 
     In a general vehicular lamp, one projection lens is responsible for condensing light in the first direction and light in the second direction orthogonal to the first direction. In contrast, in this embodiment, two lenses (the front lens body  20  and the low beam rear lens unit  31 ) which make up a projection lens are responsible for condensing light in the first direction and light in the second direction orthogonal to the first direction. More specifically, in this embodiment, the low beam rear lens unit  31  is mainly responsible for condensing light in the first direction and the front lens body  20  is mainly responsible for condensing light in the second direction. 
     The low beam light source  32  is a semiconductor light emitting element such as an LED or LD having a rectangular (for example, a 1 mm 2 ) light emitting surface and is mounted to a substrate K 1  with the light emitting surface facing forward (to the front). The substrate K 1  is mounted to the housing (not shown) using a screw or another means. 
     The low beam rear lens unit  31  includes a light incident portion  31   a  (rear end portion), the light exiting portion  31   b  (front end portion) on the side opposite to the light incident portion  31   a , an edge portion  31   c  provided between the light incident portion  31   a  and the light exiting portion  31   b , a reflection surface  31   d  extending toward the rear from the edge portion  31   c , and an extension surface  31   e  extending downward from the edge portion  31   c . The low beam rear lens unit  31  is mainly responsible for condensing, in the first direction, light from the low beam light source  32  which permeates the low beam rear lens unit  31 . 
     The light from the low beam light source  32  which has entered the low beam rear lens unit  31  from the light incident portion  31   a  is condensed toward the edge portion  31   c  in at least the vertical direction (up/down direction in  FIG. 4 ). As a result, a low beam light distribution pattern becomes relatively bright around a cutoff line. 
     The light exiting portion  31   b  is formed as, for example, a semi-cylindrical surface (cylindrical surface) having a cylindrical axis extending in the second direction so as to condense, in the first direction, light from the low beam light source  32  which exits the light exiting portion  31   b.    
     The edge portion  31   c  is formed into a shape corresponding to the cutoff line of the low beam light distribution pattern. Although not shown in the drawings, the edge portion  31   c  has, for example, a Z-shaped step portion. 
     In the low beam optical system  30  having the above-described configuration, when the low beam light source  32  is turned on, the light from the low beam light source  32  enters the low beam rear lens unit  31  from the light incident portion  31   a  and is partially blocked (shaded) by the reflection surface  31   d . Then, the light exits from the light exiting portion  31   b  together with light reflected off the reflection surface  31   d . At this time, the light exiting portion  31   b  acts to condense, in the first direction, the light from the low beam light source  32  which exits the light exiting portion  31   b . Then, the light from the low beam light source  32  which has exited the light exiting portion  31   b  passes through a space S 1  between the low beam rear lens unit  31  and the front lens body  20 , further enters the front lens body  20  from the light incident surface  21  and is irradiated forward after exiting the light exiting surface  22 . At this time, the light exiting surface  22  acts to condense, in the second direction, the light from the low beam light source  32  which exits the light exiting surface  22 . Thereby, the low beam light distribution pattern is formed. 
     In other words, the light intensity distribution is formed in the vicinity of the edge portion  31   c  by the light from the low beam light source  32  that has entered the low beam rear lens unit  31 . The low beam rear lens unit  31  (the light exiting portion  31   b ) and the front lens body  20  (which are functioning as a projection lens) project the light intensity distribution forward. Thereby, a low beam light distribution pattern is formed. 
       FIG. 9A  is an example of a low beam light distribution pattern P Lo .  FIG. 9A  illustrates an example of the low beam light distribution pattern P Lo  formed on an imaginary vertical screen (disposed approximately 25 m ahead of the front of the vehicle) opposing the front of the vehicle. 
     The low beam light distribution pattern P Lo  includes a cutoff line CL defined by the edge portion  31   c  on an upper edge. 
     As described above, the light from the low beam light source  32  which permeates the low beam rear lens unit  31  and the front lens body  20  in that order forms a second light emitting region A 2  which at least partially overlaps with a first light emitting region A 1  to be described later in the front lens body  20 . 
       FIGS. 10 and 11  are examples of the light emitting regions A 1  and A 2  formed in the front lens body  20 .  FIG. 10  shows the light emitting regions A 1  and A 2  formed in the front lens body  20  from above.  FIG. 11A  shows the light emitting regions A 1  and A 2  formed in the front lens body  20  from the front. The symbol “E” in  FIGS. 10 and 11A  denotes a region in which the first light emitting region A 1  and the second light emitting region A 2  overlap. 
     In  FIG. 10 , the light from the low beam light source  32  which permeates the low beam rear lens unit  31  and the front lens body  20  in that order is irradiated in the range of the second diffusion angle θ 4 . 
       FIG. 5A  is a longitudinal sectional view (view taken along the line B-B in  FIG. 2 ) of the ADB optical system  40  and  FIG. 5B  is a front view of a substrate K 2  mounted with ADB light sources  42   a  to  42   d.    
     As illustrated in  FIG. 5A , the ADB optical system  40  includes an ADB rear lens unit  41  disposed behind the front lens body  20 , and the plurality of ADB light sources  42   a  to  42   d  which are disposed behind the ADB rear lens unit  41  and emits light which is irradiated forward in the horizontal direction at the first diffusion angle θ 3  (see  FIG. 10 ) permeating the ADB rear lens unit  41  and the front lens body  20  in that order to form an ADB light distribution pattern. The first diffusion angle θ 3  is, for example, an angle around 20°. The first diffusion angle θ 3  can be adjusted by, for example, altering the surface shape of a light exiting surface  41   b  of the ADB rear lens unit  41 . The ADB rear lens unit  41  corresponds to a first rear lens unit according to the present invention. 
     In a general vehicular lamp, one projection lens is responsible for condensing light in the first direction and light in the second direction orthogonal to the first direction. In contrast, in this embodiment, two lenses (the front lens body  20  and the ADB rear lens unit  41 ) which make up a projection lens are responsible for condensing light in the first direction and light in the second direction orthogonal to the first direction. More specifically, in this embodiment, the ADB rear lens unit  41  is mainly responsible for condensing light in the first direction and the front lens body  20  is mainly responsible for condensing light in the second direction. 
     The ADB light sources  42   a  to  42   d  are each a semiconductor light emitting element such as an LED or LD having a rectangular (for example, a 1 mm 2 ) light emitting surface and, as illustrated in  FIG. 5A , are mounted to the substrate K 2  with the light emitting surface facing forward (to the front). The ADB light sources  42   a  to  42   d  are arranged in a row in the horizontal direction. The substrate K 2  is mounted to the housing (not shown) using a screw or another means. 
     The ADB rear lens unit  41  includes a light incident surface  41   a  and a light exiting surface  41   b  on a side opposite to the light incident surface  41   a . The ADB rear lens unit  41  is mainly responsible for condensing, in the first direction, light from the ADB light sources  42   a  to  42   d  which permeates the ADB rear lens unit  41 . 
     The light incident surface  41   a  is a surface at which the light from the ADB light sources  42   a  to  42   d  enters the ADB rear lens unit  41 . 
     The light exiting surface  41   b  is formed as, for example, a semi-cylindrical surface (cylindrical surface) having a cylindrical axis extending in the second direction so as to condense, in the first direction, the light from the ADB light source  42  exiting the light exiting surface  41   b.    
     In the ADB optical system  40  with the above-described configuration, when the ADB light sources  42   a  to  42   d  are turned on, the light from the ADB light sources  42   a  to  42   d  enters the ADB rear lens unit  41  from the light incident surface  41   a  and then exits from the light exiting surface  41 . At this time, the light exiting surface  41   b  acts to condense, in the first direction, the light from the ADB light sources  42   a  to  42   d  exiting from the light exiting surface  41   b . Then, the light from the ADB light sources  42   a  to  42   d  which has exited the light exiting surface  41   b  passes through a space S 2  between the ADB rear lens unit  41  and the front lens body  20 , further enters the front lens body  20  from the light incident surface  21  and is irradiated forward after exiting from the light exiting surface  22 . At this time, the light exiting surface  22  acts to condense, in the second direction, the light from the ADB light sources  42   a  to  42   d  which has exited the light exiting surface  22 . With this configuration, an ADB light distribution pattern is formed. 
     In other words, the low beam rear lens unit  31  (the light exiting portion  31   b ) and the front lens body  20  (which are functioning as a projection lens) project light source images (the light intensity distribution) of the ADB light sources  42   a  to  42   d  forward. Thereby, a low beam light distribution pattern is formed. 
       FIG. 9B  is an example of an ADB light distribution pattern P ADB .  FIG. 9B  illustrates an example of the ADB light distribution pattern P ADB  formed on the imaginary vertical screen. 
     The ADB light distribution pattern P ADB  includes a plurality of irradiation patterns PA 1  to PA 4  which are individually turned on/off through the ADB light sources  42   a  to  42   d  being individually turned on/off. 
     As described above, the light from the ADB light sources  42   a  to  42   b  which permeates the ADB rear lens unit  41  and the front lens body  20  in that order forms, as illustrated in  FIGS. 10 and 11A , the first light emitting region A 1  in the front lens body  20 . In  FIG. 10 , the light from the ADB light sources  42   a  to  42   b  which permeates the ADB rear lens unit  41  and the front lens body  20  in that order is irradiated in the range of the first diffusion angle θ 3 . 
     In the vehicular lamp  10  having the above-described configuration, a high beam light distribution pattern, which is a combination of the low beam light distribution pattern P Lo  and the ADB light distribution pattern P ADB , is formed by simultaneously turning on the low beam light sources  32  and the ADB light sources  42   a  to  42   d.    
       FIG. 9C  is an example of a high beam light distribution pattern P Hi .  FIG. 9C  illustrates an example of the high beam light distribution pattern P Hi  formed on the imaginary vertical screen. 
     As illustrated in  FIG. 11A , the light emitting regions A 1  and A 2  are formed when the low beam light sources  32  and the ADB light sources  42   a  to  42   d  are simultaneously turned on.  FIG. 11A  shows examples of the light emitting regions A 1  and A 2  formed when the low beam light sources  32  forming the low beam optical systems  30   a  and  30   b  and the ADB light sources  42   a  to  42   d  forming the ADB optical system  40   a  are simultaneously turned on. Although not shown, a light emitting region similar to the light emitting regions A 1  and A 2  illustrated in  FIG. 11A  is formed even when the low beam light sources  32  forming the low beam optical systems  30   c  to  30   h  and the ADB light sources  42   a  to  42   d  forming the ADB optical systems  40   b  to  40   c  are simultaneously turned on. With this configuration, the front lens body  20  can be visually recognized as if the entire front lens body  20  is emitting light. 
     On the other hand, when the low beam light sources  32  are turned on and the ADB light sources  42   a  to  42   d  are turned off, as illustrated in  FIG. 11B , the light emitting region A 2  is formed without the light emitting region A 1  being formed. 
     However, as illustrated in  FIG. 11B , because the second light emitting region A 2  at least partially overlaps with the first light emitting region A 1 , the user visually recognizes the region as if the first light emitting region A 1  is emitting light. In other words, the front lens body  20  is visually recognized as if the entire front lens body  20  is emitting light, even though the ADB light sources  42   a  to  42   d  are turned off. 
     The width of the portion at which the first light emitting region A 1  and the second light emitting region A 2  overlap is preferably ⅓ or more the width of the first light emitting region A 1 . In addition, the width of the area in which only the second light emitting region A 2  emits light is preferably ⅘ or more the width when both the first light emitting region A 1  and the second light emitting region A 2  are emitting light. 
     As illustrated in  FIG. 10 , when the front lens body  20  is disposed while being inclined by the receding angle θ 1  with respect to the reference axis AX 1  extending in the vehicle width direction when viewed from above, the ADB optical system  40  is preferably disposed in front of and adjacent to the low beam optical system  30 . The reason for this is described below. 
     First, as illustrated in  FIG. 12 , when the ADB optical system  40  is disposed behind the low beam optical system  30 , compared to a case where the ADB optical system  40  is disposed in front of the low beam optical system  30  (see  FIG. 10 ), the region E in which the first light emitting region A 1  and the second light emitting region A 2  overlap becomes narrower. Therefore, the ADB optical system  40  is preferably disposed in front of the low beam optical system  30  in terms of expanding the region E in which the first light emitting region A 1  and the second light emitting region A 2  overlap.  FIG. 12  shows examples of the light emitting regions A 1  and A 2  formed in the front lens body  20  when the ADB optical system  40  is disposed behind the low beam optical system  30 . 
     As illustrated in  FIG. 13 , when a plurality of the ADB optical systems  40  are arranged adjacent to each other, the first diffusion angle θ 3  is smaller than the second diffusion angle θ 4 , and hence a non-light emitting region F is formed between the light one emitting region A 2  and the other light emitting region A 2 . Therefore, in order to prevent a non-light emitting region from being generated between two light emitting regions, the ADB optical system  40  is preferably disposed adjacent to the low beam optical system  30 .  FIG. 13  shows an example of the light emitting region A 2  formed in the front lens body  20  when ADB optical systems  40  are disposed adjacent to each other. 
     As a result, as illustrated in  FIG. 10 , the ADB optical system  40  is preferably disposed in front of and adjacent to the low beam optical system  30 . 
     As illustrated in  FIG. 2 , the plurality of ADB optical systems  40   a  to  40   c  are preferably disposed in a dispersed manner instead of being disposed adjacent to each other (see  FIG. 13 ). In addition, the low beam optical systems  30   a  to  30   h  are preferably disposed between the dispersed ADB optical systems  40  and other ADB optical systems  40 . One low beam optical system  30  or a plurality of low beam optical systems  30  may be disposed between the dispersed ADB optical systems  40  and other ADB optical systems  40 . 
     As illustrated in  FIG. 2 , among the plurality of low beam rear lens units  31  forming each of the low beam optical systems  30   a  to  30   h  and the plurality of ADB rear lens units  41  forming each of the ADB optical systems  40   a  to  40   c , the low beam rear lens units  31  and the ADB rear lens units  41  disposed adjacent to each other are formed by injection molding a transparent resin such as acrylic or polycarbonate to form rear lens bodies L 1  to L 3 . 
     For example, the rear lens body L 1  is formed by integrally molding two low beam rear lens units  31  forming the low beam optical systems  30   a  and  30   b  and one ADB rear lens unit  41  forming the ADB optical system  40   a.    
     The rear lens body L 2  is formed by integrally molding three low beam rear lens units  31  forming the low beam optical systems  30   c  to  30   e  and one ADB rear lens unit  41  forming the ADB optical system  40   b.    
     The rear lens body L 3  is formed by integrally molding three low beam rear lens units  31  forming the low beam optical systems  30   f  to  30   h  and one ADB rear lens unit  41  forming the ADB optical system  40   c.    
     As illustrated in  FIG. 2 , the rear lens bodies L 1  to L 3  are disposed along a predetermined direction with intervals S 3  therebetween behind the front lens body  20 . 
       FIG. 6A  is a diagram for illustrating a state where a dark portion D at which light from the low beam rear lens unit  31  and the ADB rear lens unit  41  does not pass through a portion of the front lens body  20  corresponding to the interval S 3  is generated. 
     As illustrated in  FIG. 6A , when the low beam light sources  32  and the ADB light sources  42   a  to  42   d  are simultaneously turned on, the dark portion D is generated according to the size of the interval S 3 . The dark portion D is generated because the light Ray Lo  from the low beam rear lens unit  31  and the light Ray ADB  from the ADB rear lens unit  41  do not pass through the portion of the front lens body  20  corresponding to the space S 3 . As a result, there is a problem that the light emitting region divided by the dark portion D is formed in the front lens body  20 , that is, an even light emission feeling of the front lens body  20  can not be achieved. 
       FIG. 6B  is a diagram for illustrating a state where the dark portion D has been eliminated. 
     In this embodiment, in order to prevent the dark portion D from being generated in the front lens body  20 , the low beam rear lens unit  31  and the ADB rear lens unit  41  arranged adjacent to the interval S 3  each include a light exiting region A. From the light exiting region A, as illustrated in  FIG. 6B , horizontal diffused light RayD which passes through the portion (dark portion D) of the front lens body  20  corresponding to the interval S 3  exits. Note that the light exiting region A may be provided in both or one of the low beam rear lens unit  31  and the ADB rear lens unit  41  disposed adjacent to the interval S 3 . 
     The light exiting region A is formed by, for example, adjusting the curvature of a partial region in the light exiting portion  31   b  of the low beam rear lens unit  31  or a partial region in the light exiting surface  41   b  of the ADB rear lens unit  41   b  disposed adjacent to the interval S 3  (for example, making the curvature of the partial region smaller than the curvature of other regions). 
       FIG. 7  is an example of a positioning mechanism. 
     The front lens body  20  and the rear lens bodies L 1  to L 3  each include a positioning mechanism which determines the relative positional relationship between these two components. 
     As illustrated in  FIG. 7A , the front lens body  20  includes, as the positioning mechanism, a protrusion  23  which is inserted into a recess  51  provided in a structure  50  such as a housing to which the front lens body  20  is attached. As illustrated in  FIG. 7B , protrusions  23  are disposed along a straight line Li 1  inclined by the receding angle θ 1  with respect to the reference axis AX 1  extending in the vehicle width direction when viewed from above (two places in  FIG. 7B ). When viewed from the front, the straight line Li 1  extends in a direction inclined by the splice angle θ 2  with respect to the reference axis AX 1  extending in the vehicle width direction. 
     The rear lens bodies L 1  to L 3  each include, as the positioning mechanism, a protrusion La which is inserted into a recess  52  provided in the structure  50  such as a housing to which the rear lens bodies L 1  to L 3  are attached. As illustrated in  FIG. 7B , protrusions La are disposed along a straight line Li 2  inclined by the receding angle θ 1  with respect to the reference axis AX 1  extending in the vehicle width direction (two places in  FIG. 7B ). When viewed from the front, the straight line Li 2  extends in a direction inclined by the splice angle θ 2  with respect to the reference axis AX 1  extending in the vehicle width direction. 
       FIG. 8  is an example of an abutting surface  60  which supports the structure  50 . 
     As illustrated in  FIG. 8 , the abutting surface  60  which supports the structure  50  is provided parallel to a straight line Li 3  inclined by the splice angle θ 2  with respect to the reference axis AX 1  extending in the vehicle width direction when viewed from the front. 
     Next, a control means  1  which individually controls lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   c  is described. 
       FIG. 14  is an example of the control means  1 . 
     As illustrated in  FIG. 14 , the control means  1  is configured of, for example, a lighting control circuit  2  and a control unit  3  such as an Electronic Control Unit (ECU). 
     The low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  are connected to each other in series. A drive voltage is applied to both ends of the low beam light sources  32  connected in series. In addition, switching elements SW Lo1  to SW Lo8  such as bipolar transistors are connected in parallel to each of the low beam light sources  32 . The switching elements SW Lo1  to SW Lo8  are included in, for example, the lighting control circuit  2 . The switching elements SW Lo1  to SW Lo8  all have the same configuration. Herein, the switching elements SW Lo1  to SW Lo8  are collectively referred to as “switching elements SW Lo ” when the switching elements SW Lo1  to SW Lo8  do not need to be distinguished from each other. 
     The switching elements SW Lo  are turned on/off using a D 1  duty cycle PWM (Pulse Width Modulation) signal. The PWM signal is supplied from the control unit  3 . When the switching elements SW Lo  are turned on, the low beam light sources  32  connected in parallel to the switching elements SW Lo  turn off. On the other hand, when the switching elements SW Lo  are turned off, the low beam light sources  32  connected in parallel to the switching elements SW Lo  turn on. 
     Similarly, the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   c  are connected to each other in series. A drive voltage is applied to either end of the ADB light sources  42   a  to  42   d  connected in series. In addition, switching elements SW ADB1  to SW ADB12  such as bipolar transistors are connected in parallel to each of the ADB light sources  42   a  to  42   d . The switching elements SW ADB1  to SW ADB12  are included in, for example, the lighting control circuit  2 . The switching elements SW ADB1  to SW ADB12  all have the same configuration. Herein, the switching elements SW ADB1  to SW ADB12  are collectively referred to as “switching elements SW ADB ” when the switching elements SW ADB1  to SW ADB12  do not need to be distinguished from each other. 
     The switching elements SW ADB  are turned on/off using the D 1  duty cycle PWM signal. The PWM signal is supplied from the control unit  3 . When the switching elements SW ADB  are turned on, the ADB light sources  42   a  to  42   d  connected in parallel to the switching elements SW ADB  turn off. On the other hand, when the switching elements SW ADB  are turned off, the ADB light sources  42   a  to  42   d  connected in parallel to the switching elements SW ADB  turn on. 
     Because the low beam light sources  32  and the ADB light sources  42   a  to  42   d  are connected to each other as described above, the control unit  3  can individually control the lighting states of the low beam light sources  32  and the ADB light sources  42   a  to  42   d  by applying the D 1  duty cycle PWM signal to the switching elements SW Lo  and SW ADB . 
     A receiver  4  is connected to the control unit  3 . The receiver  4  receives a locking signal for locking a vehicle door or an unlocking signal for unlocking the vehicle door. These signals are transmitted using a car key carried by the user, for example, a driver. 
     When the low beam light distribution pattern is to be formed, the control unit  3  controls the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  at a first power. Similarly, when a high beam light distribution pattern is to be formed, the control unit  3  controls the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   h  at the first power. 
     If a predetermined state is detected, for example, if reception of the locking signal for locking the vehicle door or the unlocking signal for unlocking the vehicle door is detected (or if the vehicle door has actually been locked or unlocked on the basis of receiving the locking signal for locking the vehicle door or the unlocking signal for unlocking the vehicle door), the control unit  3  individually controls the lighting states of low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   h  at a second power lower than the first power. The control unit  3  corresponds to a detection means according to the present invention. 
     Next, an example of control by the control means  1  is described. 
       FIG. 15  is a flow chart for explaining an example of control by the control means  1 . 
     The following processing is executed by, for example, running a control program that a CPU in the control means  1  (control unit  3 ) reads from a ROM to a RAM (neither shown). 
     First, the control unit  3  determines whether or not the receiver  4  has received the locking signal or the unlocking signal transmitted from the car key carried by the user (Step S 10 ). 
     If the result of this determination indicates that no locking signal or unlocking signal has been received (Step S 10 : No), the control unit  3  determines if a headlamp switch (not shown) in the vehicle has been switched to a low beam setting or a high beam setting (Step S 11 ). 
     If the result of this determination indicates that the headlamp switch has been switched to the low beam setting (Step S 11 : Low beam), the control unit  3  turns on the low beam light sources  32  and turns off the ADB light sources  42   a  to  42   d  (Step S 12 ). For example, the control unit  3  applies a 100% duty cycle PWM signal to each of the switching elements SW Lo1  to SW Lo8  and supplies each of the low beam light sources  32  with the first power to simultaneously turn on the low beam light sources  32 . In addition, the control unit  3  applies a 0% duty cycle PWM signal to each of the switching elements SW ADB1  to SW ADB12  and does not supply the ADB light sources  42   a  to  42   d  with power, to thereby turn off the ADB light sources  42   a  to  42   d.    
     As a result, the low beam light distribution pattern P Lo  (see  FIG. 9A ) is formed. 
     On the other hand, if the result of the determination in S 11  indicates that the headlamp switch has been switched to the high beam setting (Step S 11 : High beam), the control unit  3  simultaneously turns on the low beam light sources  32  and the ADB light sources  42   a  to  42   d  (Step S 13 ). For example, the control unit  3  applies a 100% duty cycle PWM signal to each of the switching elements SW Lo1  to SW Lo8  and supplies each of the low beam light sources  32  with the first power W 1  to turn on the low beam light sources  32 . In addition, the control unit  3  applies a 25% duty cycle PWM signal to each of the switching elements SW ADB1  to SW ADB12  and supplies the ADB light sources  42   a  to  42   d  with power equivalent to ¼ of the first power W 1  to turn on the ADB light sources  42   a  to  42   d . With this configuration, the ADB light sources  42   a  to  42   d  can be turned on at the same brightness as the low beam light sources  32 . Note that the “4” in the expression “¼ of the first power W 1 ” indicates the number of ADB light sources  42   a  to  42   d  and corresponds to “N” according to the present invention. 
     As a result, the high beam light distribution pattern P Hi  (see  FIG. 9C ) which is a combination of the low beam light distribution pattern P Lo  and the ADB light distribution pattern P ADB  is formed. 
     Alternatively, if the result of the determination in S 10  indicates that a locking signal or an unlocking signal has been received (Step S 10 : Yes), the control unit  3  individually controls the lighting states of the low beam light sources  32  and the ADB light sources  42   a  to  42   d  according to a preset lighting pattern (Step S 14 ). 
     The preset lighting pattern is, for example, a sequential lighting pattern such as that described below. 
     As illustrated in  FIG. 1 , when the low beam optical systems  30   a  to  30   h  and the ADB optical systems  40   a  to  40   c  are disposed, all the light sources  32  and  42   a  to  42   d  of the low beam optical systems  30   a  to  30   h  and the ADB optical systems  40   a  to  40   c  are first turned off. Then, only the ADB light sources  42   a  to  42   d  of the ADB optical system  40   a  are simultaneously turned on. Next, the ADB light sources  42   a  to  42   d  of the ADB optical system  40   a  are turned off and only the low beam light source  32  of the low beam optical system  30   a  is turned on. Then, the low beam light source  32  of the low beam optical system  30   a  is turned off and only the low beam light source  32  of the low beam optical system  30   b  is turned on. Through repeating a similar on/off pattern, there can be achieved a sequential lighting pattern which is visually recognized as if the lit portion moves from left to right in  FIG. 1 . 
     By viewing this lighting pattern, the user can grasp that the vehicle door has been locked or unlocked. 
     As described above, through individually controlling the lighting states of the light sources  32  and  42   a  to  42   d  of the low beam optical systems  30   a  to  30   h  and the ADB optical systems  40   a  to  40   c , a reply (notification) can be sent indicating that the vehicle door has been locked or unlocked. 
     Note that if the low beam light sources  32  are to be turned on in S 14 , the control unit  3  preferably applies, for example, a 50% duty cycle PWM signal to the switching elements SW Lo  and supplies the low beam light sources  32  with the second power W 2  which is lower than the first power W 1 , to thereby turn on the low beam light sources  32  (in other words, turn on the low beam light sources  32  at a brightness lower than that when forming the low beam light distribution pattern). In addition, if the ADB light sources  42   a  to  42   d  are to be turned on in S 14 , the control unit  3  preferably applies, for example, a 12.5% duty cycle PWM signal to the switching elements SW ADB  and supplies the ADB light sources  42   a  to  42   d  with a power that is ¼ of the second power W 2 , to thereby turn on the ADB light sources  42   a  to  42   d  (in other words, turn on the ADB light sources  42   a  to  42   d  at a brightness lower than that when forming the ADB light distribution pattern). 
     Next, an example of setting a light diffusing element (also referred to as a “dimple”) in the front lens body  20  is described. 
     [Case where no light diffusing element is set in front lens body  20 ] As illustrated in  FIG. 3 , if no light diffusing element is set in front lens body  20  extending in the direction inclined by the splice angle θ 2  with respect to the reference axis AX 1  which extends in the vehicle width direction, the ADB light distribution pattern P ADB  illustrated in  FIG. 17A  is formed on the imaginary vertical screen when, for example, one light source among the ADB light sources  42   a  to  42   d  which form the ABD optical system  40   a  is turned on. 
     In contrast, in order to improve the feel of light distribution, the inventors of the present invention investigated blurring the ADB light distribution pattern P ADB  in the horizontal direction and the vertical direction by setting a light diffusion element in the front lens body  20 . 
     [Case where light diffusing element is set in front lens body  20 ]  FIG. 18  is an example of a light diffusing element  21   a  set in the front lens body  20 . 
     As illustrated in  FIG. 18 , the inventors of the present invention divided a region of the front lens body  20  (for example, a partial region of the light incident surface  21 ) permeated by light from the ADB optical system  40  into a plurality of rectangular regions using a plurality of horizontal straight lines L H  and a plurality of vertical straight lines L V . One light diffusing element  21   a  was set in each of the plurality of rectangular regions. The light diffusing element  21   a  is a light diffusing element (for example, a convex lens which protrudes toward the rear of the vehicle) which diffuses the light from the ADB optical system  40  in horizontal and vertical directions. 
     The inventors of the present invention conducted a simulation and found that, when the light diffusing element  21   a  is disposed as illustrated in  FIG. 18 , the ADB light distribution pattern P ADB  does not blur in the horizontal and vertical directions and instead, as illustrated in  FIG. 17B , blurs in directions inclined relative to the horizontal and vertical directions (see the arrows in  FIG. 17B ). 
     As a result, the inventors of the present invention eagerly studied how to blur the ADB light distribution pattern P ADB  in the horizontal direction and the vertical direction. 
       FIG. 19  is an example of a light diffusing element  21   b  set in the front lens body  20 . 
     As a result, the inventors of the present invention found that, as illustrated in  FIG. 19 , the ADB light distribution pattern P ADB  can be blurred in the horizontal and vertical directions (see the arrows in  FIG. 17C ) as illustrated in  FIG. 17C  by dividing a region of the front lens body  20  (for example, a partial region of the light incident surface  21  or the light exiting surface  22 ) permeated by light from the ADB optical system  40  into a plurality of rectangular regions with a plurality of straight lines LA extending in the first direction (direction inclined by the splice angle θ 2  with respect to the reference axis AX 1 ) and a plurality of straight lines LB extending in the second direction orthogonal to the first direction, and setting one light diffusing element  21   b  in each rectangular region. The light diffusing element  21   b  is a light diffusing element (for example, a convex lens which protrudes toward the rear of the vehicle) which diffuses the light from the ADB optical system  40  in the first and second directions. 
     The cross-sectional shape of the light diffusing element  21   b  (rectangular region) when cut along a plane orthogonal to the first direction and a plane orthogonal to the second direction is a continuous curved shape. For example, the cross-sectional shape of the light diffusing element  21   b  (rectangular region) is a curved shape (for example, a convex curved shape protruding toward the rear of the vehicle) slightly expanded toward the center from either end of the cross-sectional shape, or a curved shape (for example, a concave curved shape recessed toward the rear of the vehicle) slightly recessed toward the center from either end of the cross-sectional shape. 
       FIG. 20  is an example of a light diffusing element  21   c  set in the front lens body  20 . 
     Further, as illustrated in  FIG. 20 , the inventors of the present invention found that vertical edges (see the vertical edges e 1  and e 4  in  FIG. 9B ) of the ADB light distribution pattern P ADB  can be blurred in the horizontal direction by dividing a region of the front lens body  20  (for example, a partial region of the light incident surface  21  or the light exiting surface  22 ) permeated by light from the ADB optical system  40  into a plurality of long and thin regions with the plurality of straight lines LB extending in the second direction orthogonal to the first direction and setting one light diffusing element  21   c  in each long and thin region. The light diffusing element  21   c  is a light diffusing element (for example, a cylindrical surface extending in the second direction) which diffuses the light from the ADB optical system  40  in the first direction. 
     The cross-sectional shape of the light diffusing element  21   c  (long and thin region) when cut along a plane orthogonal to the second direction is a continuous curved shape. For example, the cross-sectional shape of the light diffusing element  21   c  (long and thin region) is a curved shape (for example, a convex curved shape protruding toward the rear of the vehicle) slightly expanded toward the center from either end of the cross-sectional shape or a curved shape (for example, a concave curved shape recessed toward the rear of the vehicle) slightly recessed toward the center from either end of the cross-sectional shape. 
       FIG. 21  is an example of a light diffusing element  21   d  set in the front lens body  20 . 
     Further, as illustrated in  FIG. 21 , the inventors of the present invention found that the cutoff line CL (see  FIG. 9A ) of the low beam light distribution pattern P Lo  can be blurred in the vertical direction by dividing a region of the front lens body  20  (for example, a partial region of the light incident surface  21  or the light exiting surface  22 ) permeated by light from the low beam optical system  30  into a plurality of long and thin regions with the plurality of straight lines LA extending in the first direction and setting one light diffusing element  21   d  in each long and thin region. The light diffusing element  21   d  is a light diffusing element (for example, a cylindrical surface extending in the first direction) which diffuses the light from the low beam optical system  30  in the second direction. 
     The cross-sectional shape of the light diffusing element  21   d  (long and thin region) when cut along a plane orthogonal to the first direction is a continuous curved shape. For example, the cross-sectional shape of the light diffusing element  21   d  (long and thin region) is a curved shape (for example, a convex curved shape protruding toward the rear of the vehicle) slightly expanded toward the center from either end of the cross-sectional shape or a curved shape (for example, a concave curved shape recessed toward the rear of the vehicle) slight recessed toward the center from either end of the cross-sectional shape. 
     As described above, according to this embodiment, there can be provided the vehicular lamp  10  which can achieve lighting appearance (for example, a sequential lighting pattern) other than lighting appearance at the time of forming a light distribution pattern for a headlamp (e.g. the low beam light distribution pattern or the high beam light distribution pattern). 
     This is because the vehicular lamp  10  includes the control means  1  which individually controls the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   c.    
     In addition, according to this embodiment, there can be provided a vehicular lamp  10  in which a light emitting region does not change (or hardly changes) both when the ADB light sources  42   a  to  42   d  (or high beam light sources to be described later) are turned off and the low beam light sources  32  are turned on, and when both the ADB light sources  42   a  to  42   d  (or high beam light sources to be described later) and the low beam light sources  32  are simultaneously turned on. 
     This is because, when the ADB light sources  42   a  to  42   d  (or high beam light sources to be described later) are turned off and the low beam light sources  32  are turned on, the second light emitting region A 2  which at least partially overlaps with the first light emitting region A 1  is formed in the front lens body  20  by horizontally diffusing the light from the low beam light sources  32 , which permeates the low beam rear lens unit  31  and the front lens body  20  in that order, at the second diffusion angle θ 4  which is larger than the first diffusion angle θ 3 . 
     Further, according to this embodiment, there can be provided the vehicle lamp  10  which has a good line-shaped appearance. 
     This is because, as illustrated in  FIG. 2 , one front lens body  20  extends in the predetermined direction without being segmented, and a plurality of optical systems (the low beam rear lens unit  31  and the ADB rear lens unit  41 ) are disposed along the predetermined direction behind the front lens body  20  which extends in the predetermined direction without being segmented. 
     Further, according to this embodiment, because a plurality of rear lens units (the low beam rear lens unit  31  and the ADB rear lens unit  41 ) are integrally molded in units of rear lens bodies, such as the rear lens bodies L 1  to L 3 , molding is made easier compared to a case where all of the plurality of rear lens units are molded integrally. 
     In addition, according to this embodiment, even when, for example, the rear lens body L 1  (corresponding to a first rear lens body according to the present invention) and the rear lens body L 2  (corresponding to a second rear lens body according to the present invention) are disposed with the interval S 3  (see  FIG. 6A ) therebetween, the dark portion D through which light does not pass can be prevented from being generated at the portion of the front lens body  20  corresponding to the interval S 3  (see  FIG. 6B ). 
     This is because, as illustrated in  FIG. 6B , the rear lens units (low beam rear lens unit  31  and ADB rear lens unit  41 ) arranged adjacent to the interval S 3  include the light exiting region A, and horizontal diffused light which passes through the portion of the front lens body  20  corresponding to the interval S 3  exits from the light exiting region A. 
     In addition, according to this embodiment, the relative positional relationship between the front lens body  20  and the rear lens bodies L 1  to L 3  can be determined because the front lens body  20  and the rear lens bodies L 1  to L 3  each include the positioning mechanism which determines the relative positional relationship between these components. 
     Next, a modification example is described. 
     In the above-described embodiment, a flat surface (for example, a vertical surface) is used for the light incident surface  21  of the front lens body  20  and a semi-cylindrical surface (cylindrical surface) having a cylindrical axis extending in the first direction is used for the light exiting surface  22  of the front lens body  20 , but the present invention is not limited to this example. 
     For example, a semi-cylindrical surface (cylindrical surface) having a cylindrical axis extending in the first direction may be used for the light incident surface  21  of the front lens body  20  and a flat surface (for example, a vertical surface) may be used for the light exiting surface  22  of the front lens body  20 . 
     Further, in the above-described embodiment, a semi-cylindrical surface (cylindrical surface) having a cylindrical axis extending in the second direction is used for the light exiting portion  31   b  of the low beam rear lens unit  31 , but the present invention is not limited to this example. 
     For example, a convex lens surface protruding toward the front of the vehicle may be used for the light exiting portion  31   b  of the low beam rear lens unit  31 . The same applies to the light exiting surface  41   b  of the ADB rear lens unit  41 . 
     Further, in the above-described embodiment, the ADB optical system  40  is used for the first optical system, but the present invention is not limited to this example. 
     For example, a high beam optical system may be used for the first optical system. 
     Note that, although not shown, the high beam optical system includes, for example, a high beam rear lens unit disposed behind the front lens body  20  and a high beam light source disposed behind the high beam rear lens unit and emits light which is horizontally irradiated forward at the first diffusion angle θ 3  permeating the high beam rear lens unit and the front lens body  20  in that order to form a high beam light distribution pattern. 
       FIG. 9D  is an example of the high beam light distribution pattern P Hi .  FIG. 9D  shows an example of the high beam light distribution pattern P Hi  formed on the imaginary vertical screen. 
     Further, in the above-described embodiment, a plurality of rear lens units (the low beam rear lens unit  31  and the ADB rear lens unit  41 ) are integrally molded in units of rear lens bodies, such as the rear lens bodies L 1  to L 3 , but the present invention is not limited to this example. The plurality of rear lens units (the low beam rear lens unit  31  and the ADB rear lens unit  41 ) may be molded so as to be physically independent from each other without being molded integrally. 
     In addition, in the above-described embodiment, the front lens body  20  includes, as a positioning mechanism, the protrusion  23  which is inserted into the recess  51  provided in the structure  50  such a housing, but the present invention is not limited to this example. For example, although not shown, the front lens body  20  may include, as the positioning mechanism, a recess into which a protrusion formed on the structure  50  such as a housing is inserted. 
     Similarly, in the above-described embodiment, the rear lens bodies L 1  to L 3  each include, as a positioning mechanism, the protrusion La inserted into the recess  52  provided in the structure  50  such a housing, but the present invention is not limited to this example. For example, although not shown, the rear lens bodies L 1  to L 3  may each include, as the positioning mechanism, a recess into which a protrusion formed on the structure  50  such as a housing is inserted. 
     In addition, in the above-described embodiment, the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   c  are individually controlled, but the present invention is not limited to this example. 
       FIG. 16  is a diagram (front view) for explaining a modification example of the vehicular lamp  10 . 
     For example, as illustrated in  FIG. 16 , a vehicular lamp  70  different to the vehicular lamp  10  may be disposed adjacent to the vehicular lamp  10  and the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h , the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   c  and the light source of the vehicular lamp  70  (not shown) may be individually controlled. The vehicular lamp  70  is, for example, a DRL lamp, a position lamp or an indicator lamp. The light source of the vehicular lamp  70  is a semiconductor light emitting element such as an LED and, although not shown in the drawings, is connected to the lighting control circuit  2  in a manner similar to the low beam light source  32  and other components. 
     With the above configuration, the following sequential lighting pattern, for example, can be achieved. 
     That is, all the light sources  32  and  42   a  to  42   d  of each of the low beam optical systems  30   a  to  30   h  and the ADB optical systems  40   a  to  40   c  and the light source of the vehicular lamp  70  (not shown) are first turned off. Then, only the ADB light sources  42   a  to  42   d  of the ADB optical system  40   a  are simultaneously turned on. Next, the ADB light sources  42   a  to  42   d  of the ADB optical system  40   a  are turned off and only the low beam light source  32  of the low beam optical system  30   a  is turned on. Then, the low beam light source  32  of the low beam optical system  30   a  is turned off and only the low beam light source  32  of the low beam optical system  30   b  is turned on. Through repeating a similar on/off pattern and finally turning on and off the light source of the vehicular lamp  70  (not shown), there can be achieved a sequential lighting pattern which is visually recognized as if the lit portion moves from left to right in  FIG. 16 . 
     In addition, in the above-described embodiment, the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   c  are individually controlled according to a preset lighting pattern (sequential lighting pattern), but the present invention is not limited to this example. 
     For example, the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   c  may be, for example, individually controlled based on a random lighting pattern or may be individually controlled based on various lighting patterns other than a sequential lighting pattern. 
     In addition, in the above-described embodiment, the preset lighting pattern is a sequential lighting pattern, but the present invention is not limited to this example. 
     For example, the preset lighting pattern may be a lighting pattern including a pattern in which, at a certain timing, some of the low beam light sources  32  among the plurality of low beam light sources  32  which make up the plurality of low beam optical systems  30   a  to  30   h  are turned on and the remainder of the low beam light sources  32  are turned off. 
     Further, in the above-described embodiment, when the locking signal or the unlocking signal has been received (Step S 10 : Yes), the control unit  3  individually controls the lighting states of the low beam light sources  32  and the ADB light sources  42   a  to  42   d  according to the preset lighting pattern, but the present invention is not limited to this example. For example, the control unit  3  may individually control the lighting states of the low beam light sources  32  and the ADB light sources  42   a  to  42   d  according to a preset lighting pattern at another predetermined timing. 
     Further, in the above-described embodiment, when a low beam light distribution pattern is to be formed (or a high beam light distribution pattern is to be formed), the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   h  are controlled at the first power, whereas when a predetermined state has been detected, the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   h  are individually controlled at the second power which is lower than the first power. However, the present invention is not limited to this example. 
     For example, when forming a low beam light distribution pattern (and when forming a high beam light distribution pattern) and a predetermined state is detected (for example, when reception of the locking signal for locking a vehicle door or the unlocking signal for unlocking a vehicle door has been detected), the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   d  of each of the ADB optical systems  40   a  to  40   h  may be controlled at the same power (for example, the first power). 
     Further, in the above-described embodiment, the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  are connected to each other in series and the ADB light sources  42   a  to  42   c  of each of the ADB optical systems  40   a  to  40   c  are connected to each other in series. As a result, the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   c  of each of the ADB optical systems  40   a  to  40   c  are individually controlled, but the present invention is not limited to this example. 
     For example, the lighting states of the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  and the ADB light sources  42   a  to  42   c  of each of the ADB optical systems  40   a  to  40   c  may be individually controlled by connecting the low beam light sources  32  of each of the low beam optical systems  30   a  to  30   h  to each other in parallel and connecting the ADB light sources  42   a  to  42   c  of each of the ADB optical systems  40   a  to  40   c  to each other in parallel. 
     In addition, in the above-described embodiment, a step (Step S 11 ) for determining whether or not a headlamp switch has been switched to a low beam setting or a high beam setting is provided after a step (Step S 10 ) in which the controls means  1  detects a predetermined state, but these steps may be performed in the opposite order. Alternatively, a step for determining whether the engine is operating or the vehicle is travelling may be provided before the step (Step S 10 ) for detecting a predetermined state. If it is determined that the engine is operating or the vehicle is travelling, the step (Step S 10 ) for detecting the predetermined state may be omitted. 
     It goes without saying that the numbers in the above-described embodiment are merely examples and other appropriate numbers may be used. 
     The various aspects of the above-described embodiment are merely exemplary and the description of the embodiment is not intended to limit the scope of the present invention. The present invention may be implemented in numerous other ways without departing from the gist or main technical characteristics of the present invention.