Patent Publication Number: US-9404631-B2

Title: Light emitting apparatus and automotive lamp

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a light emitting apparatus using light emitting devices, such as LEDs (light-emitting diodes), and an automotive lamp. 
     2. Description of the Related Art 
     In the conventional practice there are known automotive lamps using LEDs as the light source (See Patent Document 1 in the following Related Art Documents, for instance). 
     RELATED ART DOCUMENTS 
     Patent Documents 
     [Patent Document 1] Japanese Patent Application Publication No. 2011-40495. 
     For automotive lamps using the LEDs, it is desirable that the light emitted from the LEDs be effectively utilized. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the foregoing circumstances, and a purpose thereof is to provide a light emitting apparatus and an automotive lamp capable of improving the utilization efficiency of light emitted from LEDs. 
     In order to resolve the above-described problems, a light emitting apparatus according to one embodiment of the present invention includes: a mounting part that mounts a light emitting device thereon; and a light condenser that condenses light emitted from the light emitting device, the light condenser including (1) an incident part through which the light emitted from the light emitting device enters, (2) a reflector that reflects light entering from the incident part, and (3) an emission part that emits light reflected by the reflector. In this light emitting apparatus, a phosphor layer, which converts a wavelength of the light emitted from the light emitting device and emits the wavelength-converted light, is formed in the incident part, and the light condenser is arranged such that the phosphor layer is located on a light emission surface of the light emitting device. 
     The light condenser may be of a frame shape having a first opening, a second opening disposed counter to the first opening, and a side surface part disposed in between the first opening and the second opening, and the first opening may functions as the incident part, the second opening may function as the emission part, and the reflector may be formed such that a metallic film is formed on an inner surface of the side surface part. The phosphor layer may be formed by filling the first opening with a resin containing a fluorescent material. 
     The mounting part may be arranged such that a plurality of light emitting devices are able to be mounted side by side, and the light condenser may further include a light shielding part provided in such a manner as to demarcate the adjacent light emitting devices. 
     The light condenser may include a molded body made of transparent material having a first surface part, a second surface part disposed counter to the first surface part, and a side surface part disposed in between the first surface part and the second surface part. In this light condenser, the first surface part may function as the incident part, the second surface part may function as the emission part, and the reflector may be formed such that a metallic film is formed on an outer surface of the side surface part. The phosphor layer may be formed by embedding a part of plate-shaped phosphor in the first surface part. 
     The mounting part may be arranged such that a plurality of light emitting devices are able to be mounted side by side, the molded body made of transparent material may be arranged for each of the plurality of light emitting devices and, in each molded body made of transparent material, a metallic film is formed on an adjacent surface facing an adjacent molded body made of transparent material as well as the outer surface of the side surface part. 
     Another embodiment of the present invention relates to an automotive lamp. The automotive lamp includes: the above-described light emitting apparatus; and an optical member that controls the light emitted from the light emitting apparatus so as to emit the light therefrom toward a front area of the automotive lamp. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will now be described by way of examples only, with reference to the accompanying drawings which are meant to be exemplary, not limiting and wherein like elements are numbered alike in several Figures in which: 
         FIG. 1  is a cross-sectional view of an automotive lamp according to an embodiment of the present invention; 
         FIG. 2A  to  FIG. 2C  are diagrams for explaining a structure of a light emitting apparatus according to a first embodiment; 
         FIG. 3A  and  FIG. 3B  are diagrams for explaining a structure of a light emitting apparatus according to a second embodiment; 
         FIG. 4A  to  FIG. 4C  are diagrams for explaining a structure of a light emitting apparatus according to a third embodiment; 
         FIG. 5A  and  FIG. 5B  are diagrams for explaining a structure of a light emitting apparatus according to a fourth embodiment; 
         FIG. 6A  to  FIG. 6C  are diagrams for explaining modifications of the light emitting apparatus according to the third embodiment; and 
         FIG. 7  is a diagram for explaining a structure of a light emitting apparatus according to a fifth embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, a detailed description is given of embodiments of the present invention with reference to drawings. 
       FIG. 1  is a cross-sectional view of an automotive lamp  100  according to an embodiment of the present invention. The automotive lamp  100  is a so-called projector-type automotive headlamp having a projection lens. 
     As shown in  FIG. 1 , the automotive lamp  100  includes a lamp body  12  having a recess that is open toward a front part of the lamp, and a cover  14  for blocking the opening surface of the lamp body  12 . And an internal space formed by the lamp body  12  and the cover  14  is formed as a lamp chamber  16 . 
     A lamp unit  10  is placed within the lamp chamber  16 . As shown in  FIG. 1 , the lamp unit  10  is mounted in an approximately central part of a bracket  18 . Here, the bracket  18  is formed of a metal such as aluminum. A first aiming screw  21  is mounted on an upper portion of the bracket  18 , whereas a second aiming screw  22  is mounted on a lower portion of the bracket  18 . The bracket  18  is directly supported by the first aiming screw  21 , the second aiming screw  22  and a support portion (not shown) holding a pivot attached to the bracket  18 . Also, the bracket  18  is indirectly supported by the lamp body  12  in a freely tiltable manner. The lower second aiming screw  22  is provided with an aiming actuator  24 . As the aiming actuator  24  is driven, the bracket  18  is tilted, which thereby causes the lamp unit  10  to be tilted. As a result, the light axis of the illuminating light is variably controlled. 
     The lamp unit  10  includes a light emitting apparatus  20 , a projection lens  30 , a lens support member  32 , a heatsink  26 , and a fan  28 . 
     The light emitting apparatus  20  is provided at a front side of the bracket  18 . The light emitting apparatus  20 , which includes a white-light LED, emits white light toward the projection lens  30 . A detailed structure of the light emitting apparatus  20  will be discussed later. 
     The projection lens  30  is an optical member that projects the light emitted from the light emitting apparatus  20  toward a front area of the automotive lamp  100 . The projection lens  30  is a plano-convex aspheric lens wherein the incident surface of the projection lens  30  is formed with a plane surface and the emission surface thereof is formed with a convex surface. The projection lens  30  is supported, by the lens support member  32 , in front of the light emitting apparatus  20 . A light axis Ax of the projection lens  30  is approximately parallel to the front-back direction of a vehicle. 
     The heatsink  26  is provided on a back side of the bracket  18 . The heatsink  26 , which is formed of aluminum or other metal having a high thermal conductivity, radiates the heat generated by the light emitting apparatus  20 . The fan  28 , which is disposed at the back of the heatsink  26 , is used to effect a forced air cooling of the heatsink  26 . 
       FIG. 2A  to  FIG. 2C  are diagrams for explaining a structure of a light emitting apparatus according to a first embodiment.  FIG. 2A  is a front view of the light emitting apparatus.  FIG. 2B  is a cross-sectional view (horizontal cross-sectional view) taken along the line X-X of  FIG. 2A .  FIG. 2C  is a cross-sectional view (vertical cross-sectional view) taken along the line Y-Y of  FIG. 2A . 
     As shown in  FIG. 2B  and  FIG. 2C , the light emitting apparatus  20  is mounted in an approximately central part of a base  27 , which is formed integrally with the bracket  18  by an aluminum die casting. The light emitting apparatus  20  includes an LED substrate  36  provided on top of the base  27 , four LED chips  37  mounted on top of the LED substrate  36 , and a light condenser  25  placed on these LED chips  37 . 
     The LED chips  37  are a blue-color LED of a square with the side length of 1 mm, a blue-color LED of a square with the side length of 0.3 mm, a blue-color LED of a square with the side length of 0.5 mm, and so forth, for instance. The four LED chips  37  are arranged horizontally in a series on the LED substrate  36 . The LED substrate  36 , formed of aluminum nitride or the like, is so formed as to be able to mount the four LED chips  37  thereon. The LED substrate  36 , which is provided with a power feeding pattern, a power feeding connector and so forth, has a function of supplying the current to the LED chips  37 . For example, a so-called “split light distribution pattern” can be illuminated if the LED chips  37  on the both ends are turned on and the remaining two inner LED chips  37  are turned off. The split light distribution pattern is a light distribution pattern where a split region, in which no light is illuminated, is provided in part of a high-beam light distribution pattern. The split light distribution pattern is a light distribution pattern that can suppress the irradiation of light to a driver&#39;s own lane and an oncoming traffic lane and at the same time can ensure an excellent field of view outside the driver&#39;s own lane and the oncoming traffic lane. 
     The light condenser  25  has a function of condensing the light emitted from the LED chips  37  and a phosphor layer  38  and having the condensed light directed toward the projection lens  30 . Provision of such a small-sized light condenser  25  nearest the LED chips  37  as in the present embodiment allows the traveling direction of light emitted from both the LED chips  37  and the phosphor layer  38  to be preferably controlled and thereby enables the light emitted therefrom to efficiently enter the projection lens  30 . 
     The light condenser  25  is of a frame shape having an opening through which the light emitted from the LED chips  37  is passed, and the light condenser  25  has this opening in an approximately central part thereof. The light condenser  25  has a first opening  25   a , a second opening  25   b  disposed counter to the first opening  25   a , and a side surface part  25   c  disposed between the first opening  25   a  and the second opening  25   b.    
     The first opening  25   a  and the second opening  25   b  are each a rectangular opening. The second opening  25   b  is larger in size than the first opening  25   a . In the light condenser  25 , the first opening  25   a  functions as an incident part through which the light emitted from the LED chips  37  enters, and the second opening  25   b  functions as an emission part that emits the light. 
     The side surface part  25   c  has four inner surfaces provided for each side of the first opening  25   a  and the second opening  25   b  of rectangle shapes. Here, the four inner surfaces are parabolic in cross section. A metallic film is formed on each of the inner surfaces of the side surface part  25   c , and the side surface part  25   c  functions as a reflector that reflects the light entering through the first opening  25   a.    
     The light condenser  25  may be formed in a manner such that a frame body is shaved out of aluminum materials of a rectangular parallelepiped shape and then the inner surface of the frame body is subjected to aluminum evaporation. 
     In the present embodiment, a resin a fluorescent material containing a fluorescent material is filled into the first opening  25   a  of the light condenser  25  and thereby the phosphor layer  38  are formed. The phosphor layer  38  has a function of wavelength-converting blue light emitted from the LED chips  37  into yellow light so as to be emitted. The light condenser  25  where the phosphor layer  38  is formed is arranged such that the phosphor layer  38  is located on light emission surfaces of the four LED chips  37 . A light incident surface of the phosphor layer  38  is in contact with the light emission surfaces of the LED chips  37 . Also, the phosphor layer  38  is optically coupled via a not-shown transparent material. 
     Illuminating the LED chips  37  in the light emitting apparatus  20  configured as above allows the blue light, which has transmitted through the phosphor layer  38 , and the yellow light, whose wavelength has been converted by the phosphor layer  38 , to be mixed together. As a result, white light is obtained. 
     As described above, in the light emitting apparatus  20  according to the present embodiment, the phosphor layer  38  filled with phosphors is formed in the first opening  25   a  that is the incident part of the light condenser  25 . And the light condenser  25  is arranged such that the phosphor layer  38  covers the light emission surfaces of the four LED chips  37 . With this structure, no gaps exists in between the side surface of the phosphor layer  38  and the light condenser  25 . Thus, this structure allows most of light emitted from the LED chips  37  to enter the light condenser  25 . As a result, the projection lens  30  can direct more light and therefore the utilization efficiency of light emitted therefrom can be improved in the automotive lamp  100 . If the inner surface of the side surface part  25   c  of the light condenser  25  has the shape of a compound parabolic concentrator (CPC), the light emitted through the first opening  25   a  can be emitted in a fixed direction. In this case, therefore, much light can be directed onto the projection lens  30  more efficiently. Also, since the gaps is nonexistent or very small, a dark region caused by the gaps is reduced and a uniform light distribution is obtained in the light distribution pattern formed on a road surface in front of a driver&#39;s own vehicle. 
       FIG. 3A  and  FIG. 3B  are diagrams for explaining a structure of a light emitting apparatus according to a second embodiment.  FIG. 3A  is a front view of a light emitting apparatus.  FIG. 3B  is a cross-sectional view (horizontal cross-sectional view) taken along the line X-X of  FIG. 3A . A light emitting apparatus  20  according to the second embodiment is applicable to the automotive lamp  100  as well. 
     In the light emitting apparatus  20  according to the second embodiment, the same or corresponding components as or to those of the light emitting apparatus according to the first embodiment shown in  FIG. 2A  to  FIG. 2C  are denoted with the same reference numerals as those thereof, and the repeated description thereof will be omitted as appropriate. 
     The light emitting apparatus  20  according to the second embodiment differs from the above-described light emitting apparatus according to the first embodiment in that the light condenser  25  has three light shielding parts  40 . The three light shielding parts  40  are plate-like or membrane-like members, which extend from the first opening  25   a  to the second opening  25   b  within the light condenser  25 , in such a manner as to demarcate the phosphor layer  38  corresponding to the emission surface of a pair of adjacent LED chips  37 . The light shielding part  40  is not limited to any particular one as long as it absorbs, reflects, diffuses and blocks the light. The light shielding part  40  as used herein may be a colored resin board, a resin board containing light reflective material, a light-blocking inorganic material, a metal, a multi-layer film where films having different refractive indices are laminated, and so forth, for instance. 
     In the case where no shielding parts is provided as in the first embodiment, there are cases where a desired light distribution pattern cannot be appropriately formed by controlling the turning on and off of each LED chip  37  when the light emitted from each LED chip  37  is diffused inside the light condenser  25 . In the case where the light shielding parts  40  are provided in the light condenser  25  as in the second embodiment, on the other hand, the range where the light emitted from each LED chip  37  diffuses is limited, so that a desired light distribution pattern can be appropriately formed. 
       FIG. 4A  to  FIG. 4C  are diagrams for explaining a structure of a light emitting apparatus according to a third embodiment.  FIG. 4A  is a front view of the light emitting apparatus.  FIG. 4B  is a cross-sectional view (horizontal cross-sectional view) taken along the line X-X of  FIG. 4A .  FIG. 4C  is a cross-sectional view (vertical cross-sectional view) taken along the line Y-Y of  FIG. 4A . A light emitting apparatus  20  according to the third embodiment is applicable to the automotive lamp  100  as well. 
     In the light emitting apparatus  20  according to the third embodiment, the same or corresponding components as or to those of the light emitting apparatus according to the first embodiment shown in  FIG. 2A  to  FIG. 2C  are denoted with the same reference numerals as those thereof, and the repeated description thereof will be omitted as appropriate. 
     The light emitting apparatus  20  according to the third embodiment differs in the structure of the light condenser, placed on the LED chips  37 , from the above-described light emitting apparatus according to the first embodiment. The light condenser  45  according to the third embodiment is constituted by a molded body (compact) made of transparent material. The transparent material as used herein may be an inorganic material, an organic thermoplastic resin, or a thermosetting resin, as long as it transmits light. Such a transparent inorganic material as used herein may preferably be molten silica or fused quartz, calcium aluminate glass, lithium niobate, chalcide, titanium oxide, strontium titanate, alumina, lithium fluoride, yttrium oxide, magnesium oxide, zirconia, magnesium fluoride, calcium fluoride, sodium fluoride, barium fluoride, lead fluoride, sodium iodide, sodium chloride, potassium chloride, silver chloride, thallium chloride, thallium chloride-bromide, potassium bromide, silver bromide, thallium bromide, potassium iodide, cesium bromide, cesium iodide, quartz glass or soda-lime glass, oxide glass (e.g., optical glass), fluoride glass, chalcogen glass, or the like, for instance. Such a transparent thermoplastic resin as used herein may be polystyrene, acrylonitrile-styrene copolymer resin, transparent acrylonitrile-butadiene-styrene (ABS) resin, styrene-butadiene copolymer, styrene-maleic anhydride based resin, methacrylic resin, cellulose acetate, polyester carbonate, polymethylpentene, polyarylate, polyethersulfone, polyether ether ketone, polycarbonate, transparent nylon, polysulfone resin, polyolefin, polyvinyl butyral, or the like, for instance. Among those transparent thermoplastic resins listed above, preferable in terms of heat resistance are methacrylic resin, polyester carbonate, polymethylpentene, polyarylate, polyethersulfone, polyether ether ketone, polycarbonate, transparent nylon, polysulfone resin. Such a transparent thermosetting resin as used herein may be silicone resin, epoxy resin, phenol resin, phenol aralkyl resin, unsaturated polyester resin, polyimide resin, silica-based sol-gel agent, alumina-based sol-gel agent, titania-based sol-gel agent, zirconia-based sol-gel agent, or the like, for instance. Among those transparent thermosetting resins listed above, silicone resin and epoxy resin are preferable in terms of transparency. 
     The light condenser  45  is formed in an approximately rectangular parallelepiped shape and has a first surface part  45   a , a second surface part  45   b  disposed counter to the first surface part  45   a , and a side surface part  45   c  disposed in between the first surface part  45   a  and the second surface part  45   b.    
     The first surface part  45   a  and the second surface part  45   b  are each formed in a rectangular shape. The second surface part  45   b  is larger in size than the first surface part  45   a . In the light condenser  45 , the first surface part  45   a  functions as an incident part through which the light emitted from the LED chips  37  enters, and the second surface part  45   b  functions as an emission part that emits the light. 
     The side surface part  45   c  has four outer surfaces provided for each side of the first surface part  45   a  and the second surface part  45   b  of rectangle shapes. Here, the four outer surfaces are parabolic in cross section. A metallic film is formed on each of the outer surfaces of the side surface part  45   c , and the side surface part  45   c  functions as a reflector that reflects the light entering from the first surface part  45   a.    
     In the third embodiment, a plate-shaped phosphor  46  is partially embedded in the first surface part  45   a  of the light condenser  45 . More specifically, the phosphor  46  is embedded in the first surface part  45   a  of the light condenser  45  in a manner such that one of the rectangular surfaces of the phosphor  46 , which serves as a light incident surface, is exposed to outside. The phosphor  46  is one obtained when a yellow phosphor, which converts blue light into yellow light, is turned into ceramics and then formed in a rectangular-plate shape. The phosphor  46  may be a sintered plate formed of yttrium aluminum garnet (YAG). The light condenser  45  where the phosphor  46  is embedded is arranged such that the phosphor  46  is located on the light emission surfaces of the four LED chips  37 . An exposed surface (light incident surface) of the phosphor  46  is in contact with the light emission surfaces of the LED chips  37 . Also, the phosphor  46  is optically coupled via a not-shown transparent material. 
     Illuminating the LED chips  37  in the light emitting apparatus  20  configured as above allows the blue light, which has transmitted through the phosphor  46 , and the yellow light, whose wavelength has been converted from the blue light by the phosphor  46 , to be mixed together. As a result, white light is obtained. 
     As described above, in the light emitting apparatus  20  according to the third embodiment, the plate-shaped phosphor  46  is embedded in the first surface part  45   a , which is the incident part of the light condenser  45 . And the light condenser  45  is arranged such that the light incident surface of the phosphor  46  covers the light emission surfaces of the four LED chips  37 . Such a structure as this allows most of light emitted from the LED chips  37  and the phosphor  46  to enter the light condenser  45 . As a result, the projection lens  30  can direct more light and therefore the utilization efficiency of light emitted therefrom can be improved in the automotive lamp  100 . 
       FIG. 5A  and  FIG. 5B  are diagrams for explaining a structure of a light emitting apparatus according to a fourth embodiment.  FIG. 5A  is a front view of a light emitting apparatus.  FIG. 5B  is a cross-sectional view (horizontal cross-sectional view) taken along the line X-X of  FIG. 5A . A light emitting apparatus  20  according to the fourth embodiment is applicable to the automotive lamp  100  as well. 
     In the light emitting apparatus  20  according to the fourth embodiment, the same or corresponding components as or to those of the light emitting apparatus according to the third embodiment shown in  FIG. 4A  to  FIG. 4C  are denoted with the same reference numerals as those thereof, and the repeated description thereof will be omitted as appropriate. 
     The light emitting apparatus  20  according to the fourth embodiment is configured such that the light condenser in the third embodiment is divided into four portions and such that each portion of the thus divided light condensers  45  is provided on top of the LED chips  37  corresponding respectively to the divided light condensers  45 . A phosphor  46  is embedded in each light condenser  45 . 
     In the molded body, which is made of transparent material (hereinafter referred to as “transparent molded body” also), of each light condenser  45  according to the fourth embodiment, a metallic film is formed on an adjacent surface  45   d  facing an adjacent transparent molded body as well as the outer surface of the side surface part. As a result, similar to the light emitting apparatus according to the above-described second embodiment, the range where the light emitted from each LED chip  37  diffuses is limited, so that a desired light distribution pattern can be appropriately formed. 
       FIG. 6A  to  FIG. 6C  are diagrams for explaining modifications of the light emitting apparatus according to the third embodiment. 
       FIG. 6A  shows a first modification where asperities  60  are formed on the second surface part  45   b  (light emission surface) of the light condenser  45 . The asperities  60  may be formed by spraying sand particles onto the light emission surface of the light condenser  45  using a sandblasting method. Or alternatively, the asperities  60  may be formed, at the time of the formation of the transparent molded body, by transcribing a fine asperity structure into the incident part using a mold having fine asperities. Forming such asperities  60  as described above onto the light emission surface of the light condenser  45  can enhance the extraction efficiency of light by reducing the total reflection. 
       FIG. 6B  shows a second modification where a thin film  61  made of a low refractive index material is formed on top of the second surface part  45   b  (light emission surface) of the light condenser  45 . The refractive index of the thin film  61  is lower than that of the transparent molded body constituting the light condenser  45 . If, for example, the transparent molded body is formed of dimethyl silicone (the refractive index: 1.41), a silica-based sol-gel material (the refractive index: 1.35) may be used as the low refractive index material. The formation of such a thin film  61  as aforementioned on the light emission surface of the light condenser  45  can improve the utilization efficiency of light as well. 
       FIG. 6C  shows a third modification where a thin film  62 , which is structured such that a low refractive index material and a high refractive index material are alternately stacked therein, is formed on the second surface part  45   b  (light emission surface) of the light condenser  45 . If, for example, the transparent molded body is formed of dimethyl silicone (the refractive index: 1.41), silica may be used as the low refractive index material and titanium oxide may be used as the high refractive index material. The formation of such a thin film  62  as aforementioned on the light emission surface of the light condenser  45  can improve the utilization efficiency of light as well. 
       FIG. 7  is a diagram for explaining a structure of a light emitting apparatus according to a fifth embodiment.  FIG. 7  is a vertical cross-sectional view of a light emitting apparatus  20 . The light emitting apparatus  20  according to the fifth embodiment is applicable to the automotive lamp  100  as well. 
     In the light emitting apparatus  20  according to the fifth embodiment, the same or corresponding components as or to those of the light emitting apparatus according to the first embodiment shown in  FIG. 2A  to  FIG. 2C  are denoted with the same reference numerals as those thereof, and the repeated description thereof will be omitted as appropriate. 
     In the light emitting apparatus  20  shown in  FIG. 7 , a reflector frame body  70  is provided on the LED substrate  36 . The reflector frame body  70  is provided on the LED substrate  36  in such a manner as to surround the side surfaces of the LED chips  37 . The phosphor layer  38  is provided on the light emission surfaces of the LED chips  37 . 
     The light condenser  25  is provided on a top face  70   a  of the reflector frame body  70 . In the state where the light condenser  25  is being provided on a top face  70   a  of the reflector frame body  70 , the phosphor layer  38  is located within the first opening  25   a  (the incident part of the light condenser  25 ) of the light condenser  25 . The light condenser  25  and the reflector frame body  70  may be formed integrally with each other. Or alternatively, the light condenser  25  and the reflector frame body  70  may be formed separately and mounted using an adhesive or the like. 
     The reflector frame body  70  has light-reflecting surfaces  70   b  that face the side surfaces of the LED chips  37 . Provision of the reflector frame body  70  in such a manner as to surround the LED chips  37  allows the light emitted from the side surfaces of the LED chips  37  to be reflected toward the light condenser  25 . As a result, the utilization efficiency of light emitted from the LED chips  37  can be improved. The reflector frame body  70  may be formed of a metal or may be formed by reflection-coating the inner surface of the frame body that is molded with a resin material. 
     The present invention has been described based upon illustrative embodiments. These embodiments are intended to be illustrative only and it will be obvious to those skilled in the art that various modifications to constituting elements and processes could be developed and that such modifications are also within the scope of the present invention. 
     Although, in the above-described embodiments, the LEDs are used as the light source, other light sources such as laser beams may naturally be used instead. 
     Although, in the above-described embodiments, white light is produced using the blue-color LED and the phosphor of YAG, the white light may be produced using a near-ultraviolet light emitting LED and a phosphor that emits visible light by absorbing the near-ultraviolet light.