Patent Publication Number: US-9410671-B2

Title: Head lamp for vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Application No. 10-2014-0035655 filed Mar. 27, 2014, the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a head lamp for a vehicle. More particularly, it relates to a head lamp for a vehicle which serves to improve sharpness of a cut-off line formed between a signal beam region and a low beam region of light emitted from the head lamp. 
     2. Description of Related Art 
     As well known, a head lamp for a vehicle is one of the essential components for safe driving, which illuminates a front side of a vehicle when the vehicle travels during the day and night, and simultaneously serves to give a warning to an oncoming vehicle on the opposite lane. 
     Referring to  FIG. 1 , a head lamp  10  in the related art includes a lens  11 , a body  12  which is mounted on a rear side of the lens  11 , a reflector  13  which is mounted on a rear side of the body  12 , a light source  14  which is installed at the rear of the reflector  13 , and a shield  15  and a signal plate  16  which are provided in the body  12 . 
     According to the head lamp  10  in the related art, in the case of a low beam, light emitted from the light source  14  is reflected by the reflector  13 , and thereafter, goes straight forward while passing through an opening portion  17  of the shield  15 , and in the case of a signal beam, light emitted from the light source  14  is reflected by the reflector  13 , and then passes through the opening portion  17  of the shield  15 , and the light is reflected again by the signal plate  16 , and then proceeds upward in a diagonal direction. 
     The low beam and the signal beam emitted from the head lamp mainly illuminate a predetermined region as illustrated in  FIG. 2 , and a boundary of light, that is, a cut-off line is formed between a low beam region illuminated by the low beam and a signal beam region illuminated by the signal beam due to the shield  15  disposed in front of the light source  14 . 
     That is, a part of the light emitted from the light source  14  is shut off by the shield  15 , and the remaining light, which is not shut off, exits through the lens  11 , such that the cut-off line is formed between the low beam region and the signal beam region. 
     According to the head lamp  10  in the related art as described above, since the light reflected by the reflector  13  is reflected again by the signal plate  16 , intensity of illumination of the light exiting the lens  11  is low, the signal beam region is narrow because a size of the signal plate  16  is small, and as a result, there is a problem in that there is a great difference in brightness between the low beam region and the signal beam region, and the cut-off line is clearly seen. 
     Therefore, in order to improve sharpness of the cut-off line, it is necessary to reduce the difference in brightness between the low beam region and the signal beam region. 
     However, the aforementioned head lamp  10  in the related art adopts an assembly structure in which the shield  15  and the signal plate  16  are separately manufactured, the signal plate  16  is attached to the shield  15 , and the shield  15  is mounted in the body  12 , and as a result, it is difficult to reduce the difference in brightness between the low beam region and the signal beam region because assembly dispersion among the shield  15 , the signal plate  16  and the body  12  needs to be considered in addition to the design of the shield  15  and the signal plate  16 . 
     The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY 
     Various aspects of the present invention are directed to providing a head lamp for a vehicle, capable of improving sharpness of a cut-off line formed between a signal beam region and a low beam region. 
     According to various aspects of the present invention, a head lamp for a vehicle may include a reflector coupled to a light source, and reflecting light emitted from the light source, a body coupled to the reflector, and disposed in front of the reflector, a lens coupled to the body, and disposed in front of the light source, a shield formed integrally with the body, positioned between the reflector and the lens, and shuts off a part of the light from the light source which is reflected by the reflector, and a signal reflective surface which is formed integrally with an inner circumferential surface of the reflector, and reflects the light emitted from the light source to an upper end portion of the lens. 
     The shield may include a center plate having a predetermined gradient at a center thereof, and one end of the center plate, which is directed toward the lens, may be positioned at a higher position than another end which is directed toward the light source. 
     An open portion, through which the light reflected by the signal reflective surface passes, may be formed at a lower portion of a center plate of the shield. 
     The shield may be formed at an opened rear side of the body so as to have a height equal to or less than a height of the light source, or have a height equal to or less than a height of a central axis of the light source. 
     The signal reflective surface may be formed in a shape having a curved surface with a predetermined curvature, and positioned below the light source. 
     The head lamp according to the present invention allows light to be reflected just once by the signal reflective surface formed integrally with the reflector so as to emit a signal beam such that light has a higher intensity of illumination than light reflected by a signal plate that is separately attached to the existing shield, and a size of the signal reflective surface may be adjusted to be greater than that of the existing signal plate such that the signal beam is emitted to an upper end of the low beam region, as a result, there is an effect in that a difference in brightness of light between the low beam region and the signal beam region may be reduced, sharpness of the cut-off line may be improved, and consumer complaints may be reduced. 
     According to various aspects of the head lamp for a vehicle of the present invention, the signal reflective surface is formed integrally with the reflector, and the shield is formed integrally with the body, thereby decreasing the number of components and material costs. 
     It is understood that the term “vehicle” or “vehicular” or other similar terms as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuel derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example, both gasoline-powered and electric-powered vehicles. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view illustrating an exemplary head lamp in the related art. 
         FIG. 2  is a view for explaining a cut-off line between a low beam region and a signal beam region illuminated by the head lamp in the related art. 
         FIGS. 3A and 3B  are front views illustrating an exemplary head lamp according to the present invention. 
         FIG. 4  is a cross-sectional view taken along line A-A of  FIG. 3 . 
         FIGS. 5A and 5B  are views illustrating a body of the exemplary head lamp according to the present invention. 
         FIG. 6  is a view illustrating a reflector of the exemplary head lamp according to the present invention. 
         FIG. 7  is a view for explaining an operating state when the exemplary head lamp is turned on, according to the present invention. 
         FIG. 8  is a view for explaining an effect of improving sharpness of a cut-off line between a low beam region and a signal beam region when the exemplary head lamp is turned on, according to the present invention. 
     
    
    
     It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
     As illustrated in  FIGS. 3A, 3B, 4, 5A, 5B and 6 , a head lamp  100  according to various embodiments of the present invention includes a light source  110 , a reflector  120  which is coupled to the light source  110 , a body  130  which is disposed in front of the reflector  120 , a shield  140  which is formed integrally with the body  130 , a signal reflective surface  150  which is formed integrally with the reflector  130 , and a lens  160  which is coupled to the body  130 . 
     The light source  110  emits light by being supplied with electric power, and emits light in a state in which the light source  110  is inserted into the reflector  130 . For example, the light source  110  may be a directional light source that emits light in a predetermined direction. 
     The reflector  120  has a shape having a semi-circular curved surface with an opened side so as to reflect light emitted from the light source  110 . For example, the reflector  120  may have a shape having an elliptical curved surface or a free curved surface, and one side of the light source  110 , which is inserted into the reflector  120 , may be positioned at a focal point of the reflector  120 . 
     The body  130  may have an approximately cylindrical shape, be coupled to the reflector  120  by a connecting bracket  121 , and be disposed in front of the reflector  120 . 
     The connecting bracket  121 , which has a shape that protrudes forward, is formed integrally with the reflector  120  at an edge of an opened front side that faces the body  130 , and the reflector  120  is integrally connected to the body  130  by coupling the connecting bracket  121  to an edge of a rear side of the body  130 . 
     The shield  140  is formed integrally with an opened rear side of the body  130 , positioned between the reflector  120  and the lens  160  so as to shut off a part of light from the light source  110  which is reflected by the reflector  120 , and forms a cut-off line between a low beam region and a signal beam region by shutting off a part of the light. 
     As illustrated in  FIGS. 4, 5A and 5B , a plate-shaped center plate  141  having a predetermined gradient is formed at a center of the shield  140 , and one end of the center plate  141  which is directed toward the lens  160  is positioned at a higher position than the other end which is directed toward the light source  110 . 
     An open portion  142  through which light reflected by the signal reflective surface  150  passes is formed at a lower portion of the center plate  141  of the shield  140 . 
     The shield  140  is formed to be disposed at the opened rear side of the body  130  so as to have a height equal to or less than a height of the light source  110 , or have a height equal to or less than a height of a central axis of the light source  110 . 
     That is, most of a lower end portion of the opened rear side of the body  130  is blocked by the shield  140  such that light cannot pass therethrough, and light passing through an upper end portion of the rear side is directed to a lower end portion of the lens  160 . 
     As illustrated in  FIG. 6 , the signal reflective surface  150  is formed integrally with an inner circumferential surface (a reflective surface) of the reflector  120  so as to reflect a part of light emitted from the light source  110  toward an upper end portion of the lens  160 , and formed in an approximately fan-shaped region on the basis of the light source  110 . 
     The signal reflective surface  150  is formed in a shape having a curved surface with a predetermined curvature, and positioned below the light source  110 . The light reflected by the signal reflective surface  150  passes through the open portion  142 , and then proceeds toward the upper end portion of the lens  160 . 
     The lens  160  projects the light reflected by the reflector  120  to the outside of the head lamp  100 , is mounted on a front side of the body  130 , is disposed in front of the light source  110 , and may be a convex lens type aspherical lens, but the present invention is not limited thereto. 
     A proceeding direction of light may be changed when light entering the lens  160  is refracted by the lens  160 . For example, when a region of the lens  160  is divided into an upper hemisphere region and a lower hemisphere region on the basis of a front spherical surface of the lens  160 , light, which horizontally enters the lower hemisphere region, may be refracted by the lens  160  and diverge upward, and light, which horizontally enters the upper hemisphere region, may be refracted by the lens  160  and diverge downward. 
     Hereinafter, a movement route and an illumination range of light when the head lamp  100  is turned on will be described with reference to  FIGS. 7 and 8 . 
     As illustrated in  FIG. 7 , light emitted from the light source  110  of the head lamp  100  may be reflected at an inner circumferential surface of the reflector  120 , may pass through the body  130 , and may enter the lens  160 . 
     Specifically, a part of the light emitted from the light source  110  is reflected by the signal reflective surface  150 , passes through the open portion  142  of the shield  140 , and enters the lens  160 , and the light entering the lens  160  exits as a signal beam through the upper hemisphere region of the lens  160 . 
     The light reflected at the inner circumferential surface of the reflector  120  except for the signal reflective surface  150  passes through the upper end portion of the rear side of the body  130 , that is, an upper side of the shield  140 , and enters the lens  160 , and the light entering the lens  160  exits as a low beam through the lower hemisphere region of the lens  160 . 
     In a case in which the light exiting the head lamp  100  is projected on a screen, the signal beam region is partially superimposed on an upper end portion of the low beam region, as illustrated in  FIG. 8 . 
     The head lamp  100  allows light to be reflected just once by the signal reflective surface  150  formed integrally with the reflector  120  so as to emit a signal beam such that light has a higher intensity of illumination than light reflected by a signal plate that is separately attached to the existing shield, and a size of the signal reflective surface  150  may be adjusted to be greater than that of the existing signal plate such that the signal beam is emitted to an upper end of the low beam region, as a result, there is an effect in that a difference in brightness of light between the low beam region and the signal beam region may be reduced, and sharpness of the cut-off line may be improved. 
     For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.