Patent Publication Number: US-2011075437-A1

Title: Vehicle headlight apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a vehicle headlight apparatus, more particularly to vehicle headlight apparatus capable of emitting parallel light beams. 
     2. Description of the Related Art 
     Referring to  FIG. 1 , a conventional vehicle headlight  1  disclosed in Taiwanese Patent Publication No. 1258549 comprises a main body  11 , and a plurality of lamp devices  12  mounted on the main body  11 . Each of the lamp devices  12  has an optical axis (X) (see  FIG. 2 ), an LED lamp  121 , a reflector  122 , and a convex lens  123  disposed in front of the lamp device  121 . The reflector  122  reflects light beams that are generated by the lamp device  121 . The light beams reflected from the reflector  122  are transmitted into and refracted in the convex lens  123 . However, since the brightness of the LED lamps  121  is insufficient, the conventional vehicle headlight  1  must employ a large number of the lamp devices  12  to satisfy illumination demand. Accordingly, the manufacturing cost of the conventional vehicle headlight  1  is increased. 
     Referring to  FIG. 2 , the convex lens  123  has a pair of first and second focal points (f, f′). Light beams generated by the LED lamp  121  that are parallel to the optical axis (X) are transmitted into and refracted in the lens  123 . The refracted light beams are converged toward the second focal point (f′). In fact, once the light beams generated by the LED lamp  121  do not pass through the first focal point (f), the refracted light beams will be focused at some positions on the optical axis (X) including the second focal point (f′). 
     As a result, the refracted light beams cause discomforting glare for oncoming drivers. 
     SUMMARY OF THE INVENTION 
     Therefore, the object of the invention is to provide a vehicle headlight apparatus capable of alleviating the above drawbacks of the prior art. 
     Accordingly, a vehicle headlight apparatus of the present invention comprises a lamp device having an optical axis and generating light beams. A lens device has a plurality of lenses disposed in front of the lamp device. A reflector unit has a plurality of reflecting surfaces. Any two adjacent ones of the reflecting surfaces are spaced apart from each other along a transverse direction perpendicular to the optical axis. The reflecting surfaces reflect the light beams generated by the lamp device, and face respectively the lenses. The light beams reflected from each of the reflecting surfaces intersect at a focal point of a corresponding one of the lenses, and are subsequently transmitted into the lenses so that the light beams are parallel after they pass through the corresponding one of the lenses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: 
         FIG. 1  is a partly exploded perspective view of a conventional vehicle headlight; 
         FIG. 2  is a schematic view of a convex lens of the conventional vehicle headlight, illustrating how the light beams generated by a lamp device are transmitted into and refracted in the convex lens; 
         FIG. 3  is a perspective view of a vehicle headlight apparatus of a first preferred embodiment of the present invention; 
         FIG. 4  is a schematic sectional view of the vehicle headlight apparatus of the first preferred embodiment; 
         FIG. 5  is a schematic sectional view of a vehicle headlight apparatus of a second preferred embodiment according to the present invention; 
         FIG. 6  is a schematic sectional view of a vehicle headlight apparatus of a third preferred embodiment of the present invention; and 
         FIG. 7  is a schematic sectional view of a vehicle headlight apparatus of a fourth preferred embodiment according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before the invention is described in greater detail with reference to the accompanying embodiments, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure. 
     Referring to  FIGS. 3 and 4 , a first preferred embodiment of a vehicle headlight apparatus according to the present invention comprises a lamp device  3 , a lens device  4 , and a reflector unit  5 . 
     The lamp device  3  has an optical axis (X) and generates light beams. In this preferred embodiment, the lamp device  3  is a high pressure gas discharge lamp. 
     The lens device  4  has three lenses  41 ,  42 ,  43  that are disposed in front of the lamp device  3  and that have equal focal distances d 1 , d 2 , d 3 . The focal points f 1 , f 2 , f 3  of the lenses  41 ,  42 ,  43  located respectively behind the lenses  41 ,  42 ,  43  are spaced apart from each other along an axial direction (A) parallel to the optical axial (X), and along a transverse direction (T) perpendicular to the optical axis (X). The lenses  41 ,  42 ,  43  are also spaced apart from each other along the axial direction (A). 
     The reflector unit  5  has three reflecting surfaces  51 ,  52 ,  53 . Any two adjacent ones of the reflecting surfaces  51 ,  52 ,  53  are spaced apart from each other along the transverse direction (T). The reflecting surfaces  51 ,  52 ,  53  reflect the light beams generated by the lamp device  3 , and face respectively the lenses  41 ,  42 ,  43 . In this preferred embodiment, the lenses  41 ,  42 ,  43  are convex lenses. Each of the reflecting surfaces  51 ,  52 ,  53  is a parabolic surface. 
     The light beams reflected from each of the reflecting surfaces  51 ,  52 ,  53  intersect at the focal point f 1 , f 2 , f 3  of a corresponding one of the lenses  41 ,  42 ,  43 , and are subsequently transmitted into the lenses  41 ,  42 ,  43  so that the light beams are parallel after they pass through the corresponding one of the lenses  41 ,  42 ,  43 . 
     As shown in  FIG. 5 , a second preferred embodiment of the vehicle headlight apparatus according to the present invention has a structure similar to that of the first embodiment. The main difference between this embodiment and the first embodiment resides in the following. The lenses  41 ,  42 ,  43  have different focal distances d 1 , d 2 , d 3 , and the focal points f 1 , f 2 , f 3  of the lenses  41 ,  42 ,  43  are spaced apart from each other along the axial direction (A). The lenses  41 ,  42 ,  43  are arranged along the transverse direction (T). The second preferred embodiment has the same advantages as those of the first preferred embodiment. 
     As shown in  FIG. 6 , a third preferred embodiment of the vehicle headlight apparatus according to the present invention has a structure similar to that of the first embodiment. The main difference between this embodiment and the first embodiment resides in the following. The lenses  41 ,  42 ,  43  have equal focal distances d 1 , d 2 , d 3 , and are arranged along the transverse direction (T), and the focal points f 1 , f 2 , f 3  of the lenses  41 ,  42 ,  43  are also arranged along the transverse direction (T). The third preferred embodiment has the same advantages as those of the first preferred embodiment. 
     As shown in  FIG. 7 , a fourth preferred embodiment of the vehicle headlight apparatus according to the present invention has a structure similar to that of the first embodiment. The main difference between this embodiment and the first embodiment resides in the following. The lenses  41 ,  42 ,  43  have different focal distances d 1 , d 2 , d 3 , and the focal points f 1 , f 2 , f 3  of the lenses  41 ,  42 ,  43  are arranged along the transverse direction (T). The fourth preferred embodiment has the same advantages as those of the first preferred embodiment. 
     To sum up, the advantages of the vehicle headlight apparatus according to the present invention are as follows. In the present invention, although only one lamp device  3  and only one reflecting unit  5  are employed by the vehicle headlight apparatus, the arrangement of the reflecting surfaces  51 ,  52 ,  53  and the lenses  41 ,  42 ,  43  provides a broader illumination area than the conventional vehicle headlight  1 . The light beams generated by the lamp device  3  are reflected from the reflecting surfaces  51 ,  52 ,  53 , intersect at the focal points f 1 , f 2 , f 3  of the lenses  41 ,  42 ,  43 , and are subsequently transmitted into the lenses  41 ,  42 ,  43 , so that the light beams are parallel after they pass through the lenses  41 ,  42 ,  43 . Therefore, the light beams are not be focused in front of the lens device  4  so as to prevent occurrence of glare, thus ensuring driving safety of oncoming drivers. 
     While the invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.