below , preferred embodiments of the present invention will be described in detail referring to the drawings . fig1 is a perspective view of a light device 1 for a vehicle ( hereinafter shown merely as a light device ) in relation with an embodiment of the present invention . fig2 is a plan view of the light device 1 , and fig3 is an exploded perspective view of the light device 1 . the light device 1 has the light source of an led ( light emitting diode ), and is a light device applied as a blinker device for a motorcycle , for example . the light device 1 has a configuration of accommodating base plates 4 , 5 that mount the light sources and a reflector 7 in a space formed between a housing 2 and a lens 3 . the housing 2 is formed of a black resin and the like , and the lens 3 is formed of a colorless transparent or colored transparent resin . the reflector 7 that engages the inside of the housing 2 is formed of a resin and the like , and a reflecting surface by plating , metal vapor deposition and the like is arranged thereon . in the light device 1 in relation with the present embodiment , the base plate mounting the light sources is formed of the first base plate 4 that mounts the first light sources 8 and the second base plate 5 that mounts the second light sources 11 ( refer to fig4 ). both of the first base plate 4 and the second base plate 5 are formed into a bottomed cylindrical shape , and are fixed to a support column 6 arranged in the reflector 7 using a fastening member 10 , such as a screw , with the bottom surfaces thereof abutting on each other back to back . thus , the bottom sections of the first base plate 4 and the second base plate 5 are fixed so as to be oriented to the direction perpendicular to the irradiation direction a of the light device 1 . the first light sources 8 and the second light sources 11 are mounted on the bottom sections of the first base plate 4 and the second base plate 5 . therefore , the light axis of the first light sources 8 comes to be oriented to the same direction as the irradiation direction a , and the light axis of the second light sources 11 comes to be oriented in a direction opposite to the irradiation direction a . fig4 is a cross - sectional view taken from line iv - iv of fig2 . also , fig5 is a front view of the light device 1 . the first base plate 4 mounts the first light sources 8 of eight pieces in total at equal intervals in a ring shape in a copper foil section 12 arranged on the bottom section of the bottomed cylindrical shape thereof . an extension section 4 a corresponding to the side face of the bottomed cylindrical shape stands toward the irradiation direction a side so as to surround the first light sources 8 by bending the end of the first base plate 4 . the extension section 4 a is extended to a position adjacent to the rear surface side of the lens 3 , a projection section 9 of a ring shape abutting on the extension section 4 a is formed on the rear surface side of the lens 3 , and therefore the extension section 4 a abuts on the rear surface side of the lens 3 . thus , irradiation light 8 a of the first light sources 8 is prevented from leaking sideways , and reduction of the light quantity of the light emitting section by the first light sources 8 can be prevented . with the configuration described above , when the light device 1 is lit , as shown in the front view of fig5 , a portion where the extension section 4 a exists comes to appear clearly as a profile r 1 of a ring shape . in other words , the light emitting section by the first light sources 8 and the light emitting section by the second light sources 11 are separated from each other clearly by arranging the extension section 4 a . thus , a peculiar visual effect is given by a simple structure and viewability of the light device 1 is improved without increasing the light quantity itself . also , in the present embodiment , the second base plate 5 is also formed into a bottomed cylindrical shape having a diameter equal to that of the first base plate 4 , and the second light sources 11 of eight pieces in total are mounted at equal intervals in a ring shape in a copper foil section 13 arranged on the bottom section thereof . a second extension section 5 a corresponding to the side face of the bottomed cylindrical shape stands toward the opposite side of the irradiation direction a so as to surround the second light sources 11 by bending the end of the second base plate 5 . thus , irradiation light 11 a of the second light sources 11 comes to be reflected to the irradiation direction a side by the reflector 7 without leaking sideways , and generation of the difference between the light quantity of the irradiation light 11 a and the irradiation light 8 a can be prevented . also , by being formed of a resin that hardly reflects the irradiation light and being coated with low reflectance ratio on the surface , the extension sections 4 a , 5 a can prevent reflection to the side and can improve directivity to the irradiation direction a . further , the edge on the outside in the radial direction of the reflector 7 may be formed into a shape same to that of the outer peripheral part of the housing 2 as shown in fig1 - 3 , and may be configured to be stored in the inside of the joint of the housing 2 and the lens 3 as shown in fig4 . in the example shown in fig4 , an offset amount b is arranged between the front ends of an outer edge 7 a of the reflector 7 and the second extension section 5 a , which means that the front ends of the outer edge 7 a of the reflector 7 and the second extension section 5 a are configured to overlap with each other in the irradiation direction a , thereby the dimension in the irradiation direction a of the light device 1 is made small , and the light device 1 is made compact . although the light device 1 has a feature that the profile r 1 clearly appears by lighting both of the first light sources 8 and the second light sources 11 , it is also possible to light either one of the first light sources 8 or the second light sources 11 . therefore , an operation of blinkering the ring section by the second light sources 11 while the small circle section by the first light sources 8 emits the light and so on is possible . in this case also , because the small circle section and the ring section are clearly separated from each other in emitting the light , high viewability can be secured . fig6 is a front view of a light device 30 for a vehicle ( hereinafter referred to merely as a light device ) in relation with the second embodiment of the present invention . also , fig7 is a perspective view of the light device 30 , and fig8 is a cross - sectional view taken from line viii - viii of fig6 . the light device 30 applied to a tail light device of a motorcycle is configured to accommodate a base plate 34 that mounts the light sources and a reflector 39 in a space formed between a housing 31 and a lens 33 . the housing 31 is formed of a black resin and the like , and the lens 33 is formed of a colorless transparent or colored transparent resin . in the present embodiment , a colorless transparent or colored transparent outer lens 32 is arranged outside the lens 33 . also , the reflector 39 that engages with the inside of the housing 31 is formed of a resin and the like , and a reflecting surface by plating , metal vapor deposition and the like is arranged thereon . in the light device 30 , first light sources 36 and second light sources 38 are mounted on the front and rear surfaces of the single base plate 34 , respectively . the base plate 34 formed into a bottomed cylindrical shape is fastened along with the reflector 39 to the housing 31 using a fastening member 37 , such as a screw . thus , the bottom section of the base plate 34 is fixed so as to be oriented to the direction perpendicular to the irradiation direction a of the light device 30 . the first light sources 36 and the second light sources 38 are mounted on the front and rear surfaces of the base plate 34 . therefore , the light axis of the first light sources 36 comes to be oriented to the direction same to the irradiation direction a , and the light axis of the second light sources 38 comes to be oriented to the direction opposite to the irradiation direction a . the base plate 34 mounts at least two pieces of the first light sources 36 at equal intervals in a ring shape in a copper foil section 40 arranged on the bottom section of the bottomed cylindrical shape thereof . an extension section 34 a corresponding to the side face of the bottomed cylindrical shape stands toward the irradiation direction a side so as to surround the first light sources 36 by bending the end of the base plate 34 . the extension section 34 a is extended to a position abutting on the rear surface side of the lens 33 . thus , irradiation light 36 a of the first light sources 36 is prevented from leaking sideways , and reduction of the light quantity of the light emitting section by the first light sources 36 can be prevented . also , in the present embodiment , the edge of the reflector 39 is extended toward the irradiation direction a side , and extends to a position adjacent to the side of the second light sources 38 . thus , irradiation light 38 a of the second light sources 38 is reflected to the irradiation direction a side by the reflector 39 without leaking sideways . also , the lens 33 is supported by a cylindrical cover 35 that is fixed to the housing 31 side . this cylindrical cover 35 is formed of a resin colored in an optional color and so on , and has a function of preventing the base plate 34 and the like from being viewed from the outside in addition to preventing the irradiation light 38 a of the second light sources 38 from leaking sideways . with the configuration described above , when the light device 30 is lit , as shown in the front view of fig6 , a portion where the extension section 34 a exists comes to appear clearly as a profile r 2 of a ring shape . in other words , the light emitting section by the first light sources 36 and the light emitting section by the second light sources 38 are separated from each other clearly by arranging the extension section 34 a . thus , a peculiar visual effect is given by a simple structure and viewability of the light device 30 is improved without increasing the light quantity itself . also , in the present embodiment , by increasing the thickness of an edge 33 b of the lens 33 corresponding to the outside of the extension section 34 a , a recess 33 a of a cylindrical shape is formed inside the extension section 34 a . thus , the difference in viewability between the inside and outside of the extension section 34 a is enlarged further . also , a wave - like lens cut is arranged on the rear surface side of the recess 33 a , and variation in the appearance is further given to the light emitting section inside the extension section 34 a . in the present embodiment , the unevenness is not arranged in the outer lens 32 outside the lens 33 , and it is configured to obtain only the visual effect by arranging the recess 33 a without giving variation in the smooth profile of the light device 30 . as described above , according to the light device for a vehicle in relation with the present invention , because the base plate supporting the led light sources is disposed perpendicularly to the irradiation direction of the light device and the extension section surrounding the first light sources and standing so as to be oriented to the irradiation section is arranged , the irradiation light of the first light sources is kept inside the profile formed by the extension section and the irradiation light of the second light sources is emitted outside the profile formed by the extension section , and therefore such visual effect can be secured that the inside and outside of the extension section are viewed separately and the profile of the extension section appears so as to be emphasized within the irradiation range of the light device . thus , viewability of the light device for a vehicle can be improved by a simple structure without increasing the light quantity itself . also , the shape and structure of the light device for a vehicle , the use and lighting method of the light device , the shape and structure of the base plate and the extension section , the form , disposal position and number of pieces of the light source , the shape of the lens and the housing , and so on are not limited to the embodiments described above , and various alterations are possible . for example , the extension section of the base plate can be configured so as to be integral with or separate from the bottom section of the base plate , and can be formed into a polygonal shape or an optional shape in the front view of the light device . the light device for a vehicle in relation with the present invention can be applied to various light devices such as a head light , tail light device , position light and the like in addition to the blinker device . 1 , 30 . . . light device for a vehicle ( light device ) 8 a , 36 a . . . irradiation light of first light sources 11 a , 38 a . . . irradiation light of second light sources