Abstract:
An LED lamp includes a bracket, a plurality of first LED modules mounted on a center of the bracket, a second LED module mounted on a foreside of the bracket and spaced from the first LED modules, and a driving circuit board mounted on a rear end of the bracket and electrically connecting with the second LED module and the first LED modules. The driving circuit board comprises a chip automatically monitoring operating status of the first LED modules and automatically controlling activation of the second LED module when failure occurs on at least one of the first LED modules.

Description:
BACKGROUND 
       [0001]    1. Field of the Disclosure 
         [0002]    The present disclosure generally relates to LED (light emitting diode) lamps, and more particularly to an LED lamp having complementary light sources for compensating light. 
         [0003]    2. Description of Related Art 
         [0004]    An LED lamp is a type of solid-state lighting that utilizes LEDs as a source of illumination. The LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamp due to its long-term reliability, environment friendliness, and low power consumption. 
         [0005]    A conventional LED lamp comprises a plurality of LED modules, each of which includes a plurality of LEDs. With prolonged use, the LEDs thereof are easily damaged, resulting in significantly diminished brightness of the LED lamp. 
         [0006]    What is needed, therefore, is an LED lamp having complementary light sources to maintain the brightness of the LED lamp. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0008]      FIG. 1  is an assembled, isometric view of an LED lamp in accordance with an exemplary embodiment of the present disclosure. 
           [0009]      FIG. 2  is an exploded view of the LED lamp of  FIG. 1 . 
           [0010]      FIG. 3  is an inverted view of  FIG. 2 . 
           [0011]      FIG. 4  is an exploded, enlarged view of a second LED module and a heat-absorbing member of the LED lamp of  FIG. 3 . 
           [0012]      FIG. 5  is an exploded, enlarged view of a first LED module of the LED lamp of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIGS. 1-2 , an LED lamp in accordance with an exemplary embodiment of the present disclosure comprises a bracket  10 , a lamp shell  20  on a bottom side of the bracket  10 , a heat sink  40  on a top side of the bracket  10 , a plurality of first light source modules  50  on a bottom side of the heat sink  40 , a second light source module  30  sandwiched between the bracket  10  and the lamp shell  20 , and a transparent envelope  60  on bottom side of the lamp shell  20  covering the first light source modules  50  and the second light source module  30 . 
         [0014]    Particularly referring to  FIG. 2 , the bracket  10 , integrally formed as a single piece, comprises a substantially elliptic fixing frame  11  and a lamp holder  12  located at a rear end of the fixing frame  11 . A rectangular opening  110  is defined in a center of the fixing frame  11 . A plurality of parallel fins  13  spaced from each other and a convex portion  14  are located at two opposite sides of the rectangular opening  110 . The convex portion  14  is located between the rectangular opening  110  and the lamp holder  12 , which connects the LED lamp to a supporting structure, such as a post. 
         [0015]    Referring to  FIG. 3  also, the lamp shell  20 , integrally formed as a single piece, comprises a mounting frame  21 . The mounting frame  21  has the same profile as the fixing frame  11  of the bracket  10 . The mounting frame  21  defines a rectangular window  210  corresponding to the rectangular opening  110  of the fixing frame  11 . A triangular opening  22  corresponding to the fins  13 , and a recess  23  depressed downwardly opposite to the convex portion  14  of the bracket  10 , are located at two opposite sides of the rectangular window  210 . The recess  23  and a chamber (not labeled) enclosed by the convex portion  14  of the bracket  10  cooperatively define a slot (not labeled) receiving a driving circuit board  70  therein. The driving circuit board  70  electrically connects the second light source module  30  and the first light source modules  50 . 
         [0016]    Referring to  FIGS. 2-4 , the second light source module  30  is sandwiched between the bracket  10  and the lamp shell  20  opposite to the fins  13  of the bracket  10  and in the triangular opening  22  of the lamp shell  20 . A heat-absorbing member  36 , to which the second light source module  30  is attached, is attached onto a surface  130  at a bottom of the fins  13 . The heat-absorbing member  36  is planar and made of materials having high thermal conductivity. The second light source module  30 , substantially triangular, comprises a second LED module  32  and a second reflector  34  fixed to the second LED module  32 . The second LED module  32  comprises a triangular printed circuit board  320  and a plurality of spaced LEDs  322  evenly mounted on a bottom side of the printed circuit board  320  and facing the envelope  60 . The second reflector  34  comprises a substantially triangular base plate  340  and a sidewall  342  extending downwardly from a peripheral edge of the base plate  340 . The base plate  340  of the second reflector  34 , the printed circuit board  320  of the second LED module  32  and the heat-absorbing member  36  are sequentially connected by fasteners (not shown), which further engage the surface  130  of the bracket  10 , securing the second light source module  30  and the heat-absorbing member  36  thereto. A rim  344  extends outwardly and horizontally from a top end of the sidewall  342 , abutting a bottom of the lamp shell  20  near the triangular opening  22  thereof, thereby positioning the second LED module  32  therein. The base plate  340  defines a plurality of through holes  346  receiving the LEDs  322  therein. The LEDs  322  face downwardly. The light emitted from the LEDs  322  is reflected by the second reflector  34  to project downwardly. 
         [0017]    Referring to  FIGS. 2-3 , the heat sink  40 , integrally formed of materials having high thermal conductivity, comprises a substantially rectangular plate  42 , a plurality of spaced parallel fins  44  extending upwardly from a top face of the plate  42 , and a plurality of mounting members  46  extending downwardly from a center of a bottom face of the plate  42 . Two opposite sides of the plate  42  present two opposite curved configurations corresponding to two middle parts of the profile of the fixing frame  11  of the bracket  10 . The plate  42  covers the rectangular opening  110  of the bracket  10 , thereby abutting the bottom face thereof to the bracket  10  near a peripheral edge of the rectangular opening  110 , and the mounting members  46  extend downwardly through the rectangular opening  110 . A plurality of fasteners (not shown) extends through a plurality of holes  420  defined in the two opposite sides of the plate  42 , and a plurality of threaded holes  112 , defined in the fixing frame  11  and corresponding to the holes  420 , mounting the heat sink  40  on the fixing frame  11  of the bracket  10 . 
         [0018]    The mounting members  46  are symmetrical about a longitudinal central line (not shown) of the bottom face of the plate  42 . The mounting members  46  are parallel and spaced. Each mounting member  46  comprises a rectangular extending plate  460  extending downwardly from the bottom face of the plate  42  and a rectangular mounting plate  462  extending slantwise from a bottom end of the extending plate  460 . The first light source modules  50  are on bottom faces of the mounting plates  462 , respectively. The mounting members  46  are the same length and parallel to each fin  44  of the heat sink  40 . Height of the extending plates  460  gradually decreases toward two opposite sides of the plate  42 , wherein a pair of extending plates  460  at a central portion of the plate  42  are the same height as each other and larger than other extending plates  460  located near the two opposite sides of the plate  42 . Each mounting plate  462  is disposed at an acute angle with respect to the bottom face of the plate  42 . The angles between the mounting plates  462  and the bottom face of the plate  42  gradually increase from a central two of the mounting plates  462  toward the two opposite lateral sides of the plate  42 , such that a pair of mounting plates  462  at the central portion of the plate  42  forms the same acute angles with the bottom face of the plate  42 , less than the angles between the other mounting plates  462  and the bottom face of the plate  42 . Thus, light generated by the first light source modules  50  is radiated from the central portion of the plate  42  toward the two opposite lateral sides thereof to increase the illumination angle of the LED lamp. 
         [0019]    Referring also to  FIG. 5 , each of the first light source modules  50  comprises an elongated rectangular first LED module  52  and a first reflector  54  fixed thereon. The first LED module  52  comprises a rectangular printed circuit board  520  and a plurality of spaced LEDs  522  evenly mounted on a bottom side of the printed circuit board  520  and facing the transparent envelope  60 . The LEDs  522  are arranged into two rows. The first reflector  54  comprises a top wall  540  and two sidewalls  542  extending upwardly from two ends of the top wall  540 , respectively. A top face of the top wall  540  is depressed toward the printed circuit board  520  to form a plurality of reflecting walls  544  each of which defines an extending hole  546  in a bottom thereof close to the printed circuit board  520 . The extending holes  546  are corresponding to the LEDs  522  and receive the LEDs  522  therein. The first LED modules  52  are secured on the inclined mounting plates  462  of the mounting members  46  to present a wide illumination. 
         [0020]    Referring to  FIGS. 2-3 , the envelope  60 , integrally formed of transparent materials such as glass or plastic, comprises a convex portion  62  and a mounting portion  64  extending outwards and horizontally from a peripheral edge of the convex portion  62 . The envelope  60  corresponds to the first light source modules  50  and the second light source module  30 , and abuts a bottom of the mounting frame  21  of the lamp shell  20 . A mounting strip  80 , having the same profile as the mounting portion  64  of the envelope  60 , abuts the mounting portion  64  of the envelope  60  to mount the envelope  60  on the mounting frame  21  of the lamp shell  20 . 
         [0021]    Referring to  FIG. 2 , the driving circuit board  70  comprises a power interface  72  connecting to a power supply (not shown), two light source interfaces  74  connecting the first light source modules  50  and the second light source module  30 , respectively, and a chip  76  automatically controlling a brightness of the LED lamp. The chip  76  monitors operational status of the first light source modules  50 , and activates the second light source module  30  in response to the operating status of the first light source modules  50 . If one of the first LED modules  52  of the first light source modules  50  fails, the chip  76  outputs a signal activating the second light source module  30 , thereby compensating for intensity loss of the first light source modules  50  upon failure, and accordingly normalizing overall brightness of the LED lamp. 
         [0022]    It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.