Patent Publication Number: US-7712935-B2

Title: Lamp unit

Description:
FIELD OF THE PRESENT INVENTION 
     Apparatuses consistent with the present invention relate to a lamp unit adapted to be incorporated into a lamp, and more particularly, to a lamp unit for use in a vehicle and having a light emitting element as a light source. 
     DESCRIPTION OF THE RELATED ART 
     In recent years, related art lamp units having a light emitting element as a light source, e.g., a light emitting diode, are increasingly being used in lamps such as vehicle headlamps. 
     For example, there has been proposed a reflector-type lamp unit having a light emitting element disposed on an optical axis extending in a front-and-rear direction of the lamp unit, and a reflector disposed above the light emitting element. The light emitting element is oriented orthogonally upward with respect to the optical axis, and light from the light emitting element is reflected in a forward direction by the reflector (see, e.g., JP 2004-095480 A). 
     However, in such a related art reflector-type lamp unit having a light emitting element that is oriented in a direction orthogonal to the optical axis, some light from the light emitting element is directed toward a region in front of the reflector without being incident on the reflector. This direct light from the light emitting element is irradiated in the forward direction as diffusion light, and does not contribute much to forming a light distribution pattern. 
     In order to address the above disadvantages, there has been proposed a related art reflector-type lamp unit having a light emitting element that is oriented upward but is inclined rearward with respect to a direction orthogonal to an optical axis (see, e.g., JP 2005-056704 A). According to this configuration, an amount of light incident on the reflector from the light emitting element increases, whereby a luminous flux of the light emitting element can be effectively utilized. Thus, it is possible to improve lamp efficiency. 
     However, there still remain some disadvantages. For example, in such a related art reflector-type lamp unit, light reflected by a portion of a reflecting surface near a front edge of the reflector generally forms a small and bright image of a light source, and therefore, is suitable for forming a hot zone (i.e., a high luminous intensity region) of a light distribution pattern. However, the light emitting from the light emitting element has a strong directivity, and the light emitting element has a luminous intensity distribution such that the luminous intensity is high in a direction orthogonal to a light emitting surface of the light emitting element. Thus, in a case where the light emitting element is inclined rearward, the direction orthogonal to the light emitting surface of the light emitting element is largely deviated to a rear side of the portion of the reflecting surface near the front edge of the reflector. Therefore, it becomes difficult to form a sufficiently bright hot zone in the light distribution pattern by the light reflected from the portion of the reflecting surface near the front edge of the reflector. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments of the present invention address the above disadvantages and other disadvantages not described above. However, the present invention is not required to overcome the disadvantages described above, and thus, an exemplary embodiment of the present invention may not overcome any of the problems described above. 
     One or more exemplary embodiments of the present invention provide a reflector-type lamp unit having a light emitting element as a light source. Lamp efficiency of the lamp unit is improved while ensuring a sufficient brightness of a hot zone in a light distribution pattern. 
     According one or more exemplary embodiments of the present invention, a lamp unit includes a light emitting element disposed on an optical axis extending in a front-and-rear direction of the lamp unit, the light emitting element being oriented to face in a direction substantially orthogonal to the optical axis, a first reflector facing the light emitting element to forwardly reflect light from the light emitting element, and a direct light control member disposed in front of the light emitting element for controlling direct light from the light emitting element, the direct light being directed toward a region in front of the first reflector without being incident on the first reflector. The direct light control member includes a first lens portion which deflects a first portion of the direct light in a direction approaching the optical axis, and an extended portion extending from the first lens portion toward a rear side of the first lens portion. The extended portion controls a second portion of the direct light differently from the first lens portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a lamp unit according to a first exemplary embodiment of the present invention; 
         FIG. 2  is a sectional view taken along the line II-II in  FIG. 1 ; 
         FIG. 3  is a perspective view showing two light distribution patterns projected, from the lamp unit of  FIG. 1 , on an imaginary vertical screen disposed at a position 25 m in front of the lamp unit; 
         FIG. 4  is a sectional view showing a lamp unit according to a second exemplary embodiment of the present invention; 
         FIG. 5  is a perspective view showing three light distribution patterns projected, from the lamp unit of  FIG. 4 , on an imaginary vertical screen disposed at a position 25 m in front of the lamp unit; and 
         FIG. 6  is a sectional view showing a lamp unit according to a third exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION 
     Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. The following exemplary embodiments do not limit the scope of the invention. 
     First Exemplary Embodiment 
       FIG. 1  is a front view of a lamp unit  10  according to a first exemplary embodiment of the present invention, and  FIG. 2  is a sectional view taken along the line II-II in  FIG. 1 . 
     As shown in  FIGS. 1 and 2 , the lamp unit  10  is a reflector-type lamp unit including a light emitting element  12  as a light source. The lamp unit  10  may be adapted to be incorporated in a vehicle headlamp (not shown), for example, on a left side of a front end portion of a vehicle. The lamp unit  10  is arranged such that an optical axis Ax thereof extends in a front-and-rear direction of the lamp unit  10  so as to irradiate light to form a portion of a low-beam light distribution pattern. The front-and-rear direction of the lamp unit  10  may be or may not coincide with a front-and-rear direction of a vehicle. 
     The light emitting element  12  is disposed on the optical axis Ax, and is oriented inward in a width direction. The lamp unit  10  further includes a first reflector  14  disposed on an inner side of the light emitting element  12  in the width direction, a direct light control member  16  disposed just in front of the light emitting element  12 , a metallic bracket  18  supporting the light emitting element  12 , the first reflector  14  and the direct light control member  16 , and a frame-like fixing member  20  fixing and positioning the light emitting element  12  to the metallic bracket  18 . The first reflector  14  reflects light from the light emitting element  12  in a forward direction, while the direct light control member  16  controls light that is directed toward a region in front of the first reflector  12  from the light emitting element  12  without being incident on the first reflector  14 . 
     The metallic bracket  18  has an L-shape when viewed in a plan view. The metallic bracket  18  includes a vertical wall  18 A extending in the forward direction, another vertical wall  18 B extending toward the inner side in the width direction of the vehicle, an upper wall  18 C formed on upper edges of the vertical walls  18 A,  18 B, and a lower wall  18 D formed on lower edges the vertical walls  18 A,  18 B. A wall surface  18   a  of the vertical wall  18 A on the inner side of the width direction extends along a vertical plane including the optical axis Ax. 
     The light emitting element  12  is a white light emitting diode, and includes a light emitting chip  12   a  having a square light emitting surface, a substrate  12   b  supporting the light emitting chip  12   a , and a sealing resin hemispherically covering the light emitting chip  12   a . Dimensions of the light emitting surface is, for example, about 1 mm by about 1 mm. 
     A recessed portion  18   b  is formed on the wall surface  18   a  of the vertical wall  18 A. The light emitting element  12  is disposed inside the recessed portion  18   b , and is fixedly supported on the metallic bracket  18 . The fixing member  20  engages with a circumferential edge portion of the substrate  12   b , and presses the substrate  12   b  from the inner side in the width direction, thereby positioning the light emitting element  12  with respect to the metallic bracket  18 . An annular stepped portion  18   c  is formed around the recessed portion  18   b  of the vertical wall  18 A for positioning the fixing member  20  therein. 
     The first reflector  14  has a reflecting surface  14   a . The reflecting surface  14   a  includes a plurality of reflecting elements  14   s  that are arranged to form a vertical stripe pattern along a reference surface. The reference surface is a paraboloid of revolution having the optical axis Ax as a center axis, and a light emitting center of the light emitting element  12  as a focal point. Each of the reflecting elements  14   s  diffusely reflects the light from the light emitting element  12  such that the light is diffused in the width direction and is directed slightly downward. A diffusing angle of each of the reflecting elements  14   s  is set to become smaller toward the inner side of the width direction. In other words, the reflecting element  14   s  disposed closer to the optical axis Ax has a larger diffusing angle than the reflecting element  14   s  disposed farther from the optical axis Ax. 
     The first reflector  14  has such an external shape that upper and lower potions thereof are cut in parallel to have an upper end surface and a lower end surface having an equal distance from the optical axis Ax. The first reflector is supported on the metallic bracket  18  at the upper and lower end surfaces and an end surface facing outward in the width direction. 
     The direct light control member  16  is a resin molded member, and is transparent and colorless. The direct light control member  16  is configured to control the light that is directed toward the region in front of the first reflector  14  without being incident on the first reflector  14 . 
     More specifically, the direct light control member  16  includes a first lens portion  16 A operable to deflect the light in a direction approaching the optical axis Ax, an extended portion  16 B extending toward the inner side of the width direction from the first lens portion  16 A, and a base portion  16 C for positioning and fixing the direct light control member  16  to the metallic base  18 . The extended portion  16 B is operable to control the light in a different manner from the first lens portion  16 A. When seen in a front view, the direct light control member  16  has a hemispherical shape disposed on the inner side of the vertical plane including the optical axis Ax with respect to the width direction. 
     When seen in a plan view, the first lens portion  16 A and the extended portion  16 B extend substantially in an arc shape so as to surround the light emitting center of the light emitting element  12 . An angle formed by the optical axis Ax and a straight line connecting the light emitting center of the light emitting element  12  and a boundary point between the first lens portion  16 A and the extended portion  16 B is about 40° to about 50°. A rear edge of the extended portion  16 B is positioned on or near a straight line L connecting the light emitting center of the light emitting element  12  and a front edge  14   b  of the reflecting surface  14   a  of the first reflector  14 . 
     The first lens portion  16 A includes a front surface having a spherical shape, and a rear surface having a freely curved shape whose curvature is smaller than that of the front surface. The first lens portion  16 A downwardly deflects the light from the light emitting element  12  in the direction approaching the optical axis Ax. 
     A thickness of the extended portion  16 B is substantially constant. The extended portion  16 B is formed so as to circumferentially surround the first lens portion  16 A with respect to the optical axis Ax. A rear surface  16   a  of the extended portion  16 B is subjected to an engraving treatment. According to this configuration, the light incident on the rear surface  16   a  of the extended portion  16 B from the light emitting element  12  is randomly diffused in the forward direction. 
     The base portion  16 C extends in the forward direction in a shape of a flat plate from an end portion of the first lens portion  16 A on the outer side in the width direction. The base portion  16 C is fixedly supported on the metallic bracket  18  such that a flat surface of the base portion  16 C on the outer side in the width direction is in contact with the wall surface  18   a  of the vertical wall  18 A. 
     A protruded portion  18   d  is provided at a front end portion of the wall surface  18   a  of the vertical wall  18 A for positioning the direct light control member  16 . 
     A plurality of radiator fins  18   e , each extending in a vertical direction, are formed on a rear surface of the vertical wall  18 B of the metallic bracket  18 . 
       FIG. 3  a perspective view showing two light distribution patterns PA, PB projected, from the lamp unit  10  according to the first exemplary embodiment, on an imaginary vertical screen disposed at a position 25 m in front of the lamp unit  10 . 
     As shown  FIG. 3 , the light distribution patterns PA, PB form a part of a low-beam light distribution pattern PL indicated by a chain double-dashed line. The low-beam light distribution pattern PL is formed by combining the light distribution patterns PA, PB and other light distribution pattern(s) formed by light irradiated from other lamp unit(s) (not shown). 
     The low-beam light distribution pattern PL is for a left-hand traffic, and has a horizontal cut-off line CL 1  and an oblique cut-off line CL 2  along an upper edge thereof An elbow point E, at which the two cut-off lines CL 1 , CL 2  intersect, is disposed about 0.5° to about 0.6° below a vanishing point H-V in the forward direction of the lamp. The low-beam light distribution pattern PL includes a hot zone HZL, which is a high luminous intensity region, surrounding the elbow point E. A section of the hot zone HZL on a left side of the elbow point E is larger that a section of the hot zone HZL on a right side of the elbow point E. 
     The light distribution pattern PA is formed by the light that is reflected by the first reflector  14 , and an upper edge thereof is substantially coincident with the horizontal cut-off line CL 1 . 
     The light distribution pattern PA is formed so as to straddle the line V-V, and is a bright light distribution pattern having a narrow vertical width and a small horizontal diffuse angle as compared with the light distribution pattern PB. The light distribution pattern PA includes a particularly bright hot zone HZA near the elbow point E. This hot zone HZA contributes to the hot zone HZL of the low-beam light distribution pattern PL. 
     The hot zone HZA is formed due to the reflecting element  14   s  that is disposed away from the optical axis Ax. More specifically, the diffuse angle of the light reflected by the reflecting elements  14   s  disposed away from the optical axis Ax is smaller than the diffuse angle of the light reflected by the reflecting element  14   s  disposed near the optical axis Ax, i.e., the light reflected by the reflecting elements  14   s  disposed away from the optical axis Ax forms a relatively small image of the light source. Moreover, because the reflecting elements  14   s  disposed away from the optical axis Ax are arranged around the direction orthogonal to the light emitting surface of the light emitting chip  12   a  of the light emitting element  12 , the amount of light incident thereon is larger than that on the reflecting element  14   s  disposed near the optical axis Ax. 
     The light distribution pattern PB is formed by the light that is downwardly deflected in the direction approaching the optical axis Ax by the first lens portion  16 A of the direct light control member  16 , and is formed below the horizontal cut-off line CL 1  on a right side of the line V-V. 
     The light distribution pattern PB is formed by controlling the light that is incident on the first lens portion  16 A directly from the light emitting element  12 , and a contour thereof is more vague (i.e., less sharp and well-defined) as compared with a contour of the light distribution pattern PA. Therefore, the light distribution pattern PB is suitable for forming a right inner diffuse area of the low-beam light distribution pattern PL. 
     As described above, the lamp unit  10  according to the first exemplary embodiment has the optical axis Ax extending in the front-and-rear direction, and the light emitting element  12  is disposed on the optical axis Ax such that the light emitting surface of the light emitting chip  12   a  faces the inner side in the width direction. The first reflector  14  is disposed on the inner side of the light emitting element  12  with respect to the width direction to forwardly reflect the light from the light emitting element  12 . Therefore, the light emitting element  12  is arranged such that the direction orthogonal to the light emitting surface of the light emitting chip  12   a  is not largely deviated from the front edge portion of the reflecting surface  14   a . Accordingly, a small and bright image of the light source can be formed by the light that is reflected by the reflecting surface  14   a  of the first reflector  14 , whereby the light distribution pattern PA having the sufficiently bright hot zone HZA can be formed. 
     The lamp unit  10  according to the first exemplary embodiment further includes the direct light control member  16  just in front of the light emitting element  12 , i.e., on a front side of the light emitting element  12  but on a rear side of the front edge  14   b  of the first reflector  14 . The direct light control member  16  controls the light that is directed toward the region in front of the first reflector  14  from the light emitting element  12  without being incident on the first reflector  14 . The direct light control member includes the first lens portion  16 A operable to deflect the light in the direction approaching the optical axis Ax and the extended portion  16 B extending toward the inner side from the first lens portion  16 A in the width direction to control the light in a different way from the first lens portion  16 A. Accordingly, the following advantages can be obtained. 
     The light distribution pattern PB can be formed in addition to the light distribution pattern PA by deflecting the light that is directly incident on the first lens portion  16  from the light emitting element  12  in the direction approaching the optical axis Ax. Thus, it possible to make effective use of the luminous flux of the light source, thereby improving the lamp efficiency. 
     In the related art, the light directed toward a region in front of the reflector from the light emitting element creates a disadvantageous effect in that this light generates a glare light rather than contributing to the light distribution pattern. However, in the first exemplary embodiment, the rear edge of the extended portion  16 B is disposed substantially on the straight line L connecting the light emitting center of the light emitting element  12  and the front edge  14   b  of the reflecting surface  14   a  of the first reflector  14 . Therefore, almost all the light directed toward the region in front of the first reflector  14  from the light emitting element  12  can be controlled by the direct light control member  16 . 
     On an edge portion of the direct light control member  16  on the inner side in the width direction, it is difficult to precisely deflect the light from the light emitting element  12  in the direction approaching the optical axis Ax as compared with a portion of the direct light control member  16  that is closer to the optical axis Ax. However, because the edge portion of the direct light control member  16  on the inner side in the width direction is configured as the extended portion  16 B that is operable to control the light differently from the first lens portion  16 A, the light directly incident from the light emitting element  12  can be suitably controlled by the entire portion of the direct light control member  16 . 
     Further, although the direct light control member  16  is provided just in front of the light emitting element  12  to provide a compact configuration, most of the light directed toward the region in front of the first reflector  14  from the light emitting element  12  can be captured to be incident on the direct light control member  16 . Because the direct light control member  16  has such a compact configuration, the amount of light that is reflected by the first reflector  14  but is shielded by the direct light control member  16  can be made small. Further, the light reflected by the first reflector  14  but shielded by the direct light control member  16  is originally the light emitted in a rearward direction from the light emitting element  12  so that luminous intensity thereof is not high. Thus, the loss of luminous flux resulting from presence of the direct light control member  16  can be made sufficiently low. 
     Although the lamp unit  10  according to the first exemplary embodiment is configured as a reflector-type lamp unit having the light emitting element  12  as the light source, the lamp efficiency thereof can be improved while ensuring sufficient brightness for the hot zone HZA of the light distribution pattern PA formed by the light irradiated from the lamp unit  10 . 
     In a case where the light deflection control is not precisely performed by the entire portion of the direct light control member  16 , stray light may be generated. The stray light may be harmful when it is irradiated in the region in front of the first reflector  14 . However, in the first exemplary embodiment, the engraving treatment is applied to the rear surface  16   a  of the extended portion  16 B of the direct light control member  16 . Therefore, the light that is incident on the rear surface  16   a  from the light emitting element  12  can be randomly diffused in the forward direction. According to this configuration, it is possible to prevent stray light from being generated and from being irradiated to the region in front of the first reflector  14 . The light passed through the extended portion  16 B becomes almost perfectly diffused light. Thus, glare light is prevented from being generated. 
     While the rear surface  16   a  of the extended portion  16 B is subjected to the engraving treatment in the first exemplary embodiment, other kinds of surface treatment, e.g., a frost treatment or a light screening paint, may be applied to the rear surface  16   a  of the extended portion  16 B to obtain similar advantages. 
     Further, while the light emitting surface of the light emitting chip  12   a  has a square shape in the first exemplary embodiment, the light emitting surface of the light emitting chip  12   a  may have other shapes, e.g., a rectangular shape whose dimensions are about 1 mm by about 2 mm. Furthermore, the light emitting element may be a light emitting diode or a laser diode in so far as it includes a surface emitting chip like the light emitting chip  12   a.    
     Further, while the lamp unit  10  irradiates light to form a part of the low-beam light distribution pattern PL in the first exemplary embodiment, the lamp unit  10  may be used to irradiate light for forming a part of a high-beam light distribution pattern. 
     Further, while the light emitting element  12  is oriented to face the inner side in the width direction and the first reflector  14  is disposed on the inner side of the light emitting element  12  in the lamp unit  10  according to the first exemplary embodiment, similar functions and advantages can be obtained in so far as the light emitting element  12  is oriented to face in a direction that is substantially orthogonal to the optical axis Ax. For example, the light emitting element  12  may be oriented to face the outer side in the width direction and the first reflector  14  may be disposed on the outer side of the light emitting element  12 . Similarly, the light emitting element  12  may be oriented to face upward and the first reflector  14  may be disposed above the light emitting element  12 . Of course, the light emitting element  12  may be oriented to face downward and the first reflector  14  may be disposed below the light emitting element  12 . 
     Further, while in the first exemplary embodiment, the lamp unit  10  is incorporated in a left side vehicle headlamp, the lamp unit  10  may also be incorporated into a right side vehicle headlamp. In a case where the lamp unit  10  is incorporated into the right side vehicle headlamp, the lamp unit  10  may have a configuration that is transversely reverse to the configuration of the first exemplary embodiment, or the lamp unit  10  may simply be shifted parallel so as to be incorporated into the right side vehicle headlamp. 
     Second Exemplary Embodiment 
     Next, a second exemplary embodiment of the present invention will be described. 
       FIG. 4  is a sectional view showing a lamp unit  110  according to a second exemplary embodiment. 
     As shown in  FIG. 4 , a configuration of the lamp unit  110  is similar to that of the lamp unit  10  in the first exemplary embodiment. However, the lamp unit  110  is different from the lamp unit  10  in the first exemplary embodiment in that a configuration of an extended portion  116 B of a direct light control member  116  is different, and in that a second reflector  124  is provided. 
     The extended portion  116 B of the direct light control member  116 , i.e., the portion of the direct light control member  116  on the inner side with respect to the width direction, is configured as a second lens portion which deflects light directly incident thereon from the light emitting element  12  in a direction away from the optical axis Ax. 
     A rear surface of the extended portion  116 B is formed to have a convex curve in a cross section taken along a plane including the optical axis Ax. The extended portion  116 B extends in a circumferential direction around the optical axis Ax. The extended portion  116 B is operable to irradiate the light from the light emitting element  12  as substantially parallel light. 
     The second reflector  124  is disposed at a front of the first reflector  14 , and reflects the light passing through the extended portion  116 B from the light emitting element  12  in a direction toward the optical axis Ax. 
     The second reflector  124  has a reflecting surface  124   a  extending in the forward direction from a position at the inner side of the front edge  14   b  of the reflecting surface  14   a  of the first reflector  14  with respect to the width direction. The light incident on the reflecting surface  124   a  is downwardly reflected by the reflecting surface  124   a.    
     The second reflector  124  extends in a circumferential direction along the front edge  14   b  of the first reflector  14 . The first reflector  14  and the second reflector  124  are formed in a one-piece structure. 
       FIG. 5  is a perspective view showing three light distribution patterns PA, PB, PC projected, from the lamp unit  100 , on an imaginary vertical screen disposed at a position  25  m in front of the lamp unit  110 . 
     As shown in  FIG. 5 , according to light irradiation from the lamp unit  110 , the light distribution pattern PC is formed in addition to the light distribution patterns PA, PB. 
     The light distribution pattern PC is formed by the light that is emitted from the light emitting element  12 , transmitted through the extended portion  116 B and then reflected by the second reflector  124 . The light reflected by the second reflector  124  is downwardly irradiated in a leftward direction. Therefore, the light distribution pattern PC is formed on the left side of the line V-V where the light distribution pattern PC partially overlaps a left lower end portion of the low-beam light distribution pattern PL. 
     According to the configuration of the second exemplary embodiment, the light distribution pattern PC can be additionally formed to irradiate a left part of a near zone in front of the lamp unit. Thus, for example, in the case where the lamp unit is used in a vehicle headlamp, a left shoulder of a road can be brightly illuminated to enhance visibility of pedestrians. 
     The light incident on the extended portion  116 B from the light emitting element  12  includes the light that is incident on the portion of the direct light control member  116  on the inner side with respect to the width direction, the light having a relatively high luminous intensity. Therefore, the light distribution pattern PC can be made bright. 
     A shape of the reflecting surface  124   a  of the second reflector  124  may be modified to change an irradiating area, a shape, or a size of the light distribution pattern PC. 
     Third Exemplary Embodiment 
     Next, a third exemplary embodiment of the present invention will be described. 
       FIG. 6  is a sectional view showing a lamp unit  210  according to a third exemplary embodiment. 
     As shown in  FIG. 6 , a configuration of a lamp unit  210  is similar to that of the lamp unit  10  in the first exemplary embodiment. However, the lamp unit  210  according to the third exemplary embodiment is different from the lamp unit  10  of the first exemplary embodiment in that a configuration of an extended portion  216 B of a direct light control member  216  is different, and in that third and fourth reflectors  234 ,  244  are provided. 
     A rear surface  216   a  of the extended portion  216 B of the direct light control member  216  is subjected to a mirror finishing by means of, e.g., aluminum deposition or chrome deposition. The rear surface  216   a  of the extended portion  216 B reflects the light directly incident thereon from the light emitting element  12  toward the rear side of the light emitting element  12  in a direction approaching the optical axis Ax. 
     The third reflector  234  is disposed on the rear side of the light emitting element  12 . The third reflector  234  reflects the light reflected by the rear surface  216   a  of the extended portion  216 B toward the region in front of the first reflector  14 . The light reflected by the third reflector  234  is substantially parallel light in a plane including the optical axis Ax. 
     The third reflector  234  extends toward the inner side in the width direction from a rear end portion of the fixing member  20  in a shape of a cup. The third reflector  234  and the fixing member  20  are formed in a one-piece structure. A reflecting surface  234   a  of the third reflector  234  is formed by applying a mirror finishing to a surface of the third reflector facing the forward direction. 
     The fourth reflector  244  is disposed in front of the first reflector  14 . The light reflected by the rear surface  216   a  of the extended portion  216 B and the third reflector  234  in this order is reflected by the fourth reflector  244  in a direction toward the optical axis Ax. 
     The fourth reflector  244  has a reflecting surface  244   a  extending in the forward direction from a position at the inner side of the front edge  14   b  of the reflecting surface  14   a  of the first reflector  14  with respect to the width direction. The light incident on the reflecting surface  244   a  is downwardly reflected by the reflecting surface  244   a.    
     The fourth reflector  244  extends in a circumferential direction along the front edge  14   b  of the first reflector  14 . The first reflector  14  and the fourth reflector  244  are formed in a one-piece structure. 
     According to the configuration of the third exemplary embodiment, an additional light distribution pattern similar to the light distribution pattern PC in the second exemplary embodiment can be formed to irradiate a left part of a near zone in front of the lamp unit. Thus, for example in the case where the lamp unit is used in a vehicle headlamp, a left shoulder of a road can be brightly illuminated to enhance visibility of pedestrians. 
     The light incident on the extended portion  216 B from the light emitting element  12  includes the light that is incident on the portion of the direct light control member  216  on the inner side with respect to the width direction of the vehicle, the light having a relatively high luminous intensity. Therefore, the additional light distribution pattern can be made bright. 
     A shape of the reflecting surface  244   a  of the fourth reflector  244  may be modified to change an irradiating area, a shape, or a size of the additional light distribution pattern. 
     In the exemplary embodiments described above, the extended portion may have any configuration in so far as the extended portion controls the second portion of the direct light differently from the first lens portion. 
     Further, while exemplary embodiments have been described with particular reference to an application in a vehicle lamp, the present inventive concept may also be applied to other vehicle lamps such as a headlamp, a fog lamp, or a cornering lamp, and to lamps other than vehicle headlamps, such as a spotlight or any other reflector type lamp which uses a light emitting element as a light source. 
     While description has been made in connection with exemplary embodiments of the present invention, those skilled in the art will understand that various changes and modification may be made therein without departing from the present invention. For example, numerical values in the above description of the exemplary embodiments may, of course, be set to different values as is advantageous. It is aimed, therefore, to cover in the appended claims all such changes and modifications falling within the true spirit and scope of the present invention.