Abstract:
An LED lamp includes a lamp frame, a reflector received in the lamp frame, a plurality of LED modules received in the lamp frame and an envelope covering an opening of the lamp frame. The lamp frame is made of a material with a good heat conductivity and thermally connects the LED modules. The reflector includes a plurality of interconnecting reflecting cells, each reflecting cell separating a corresponding LED module from others. Each LED module faces to a corresponding reflecting cell and light emitted therefrom is reflected by the reflecting cell to radiate out of the envelope.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to an LED (light emitting diode) lamp and, more particularly, to an improved LED lamp having an even illumination and a large illumination area. 
         [0003]    2. Description of Related Art 
         [0004]    An LED lamp as a new type of light source can generate brighter light, and have many advantages, e.g., energy saving, environment friendly and longer life-span, compared to conventional light sources. Therefore, the LED lamp has a trend of substituting for conventional lamps. 
         [0005]    A conventional LED lamp comprises a plate-shaped heat sink and an LED module attached to a bottom of the heat sink. In use of the LED lamp, light generated by the LED module directly irradiates to an outside of the LED lamp. Since LEDs of the LED module are conventionally arranged on a PCB of the LED module in a discrete matrix manner, the light emitted by the LEDs cannot radiate to an ambient environment uniformly and illumination area of the LED lamp is not large, which cause some troublesome problems, e.g., light beams with different light intensities, light glare. In addition, due to being mounted on the bottom of the heat sink, the light produced by the LED module can only project from the bottom of the heat sink and cannot illuminate other places around the LED lamp, whereby an application of the LED lamp is prohibited in some fields which need a large light illumination area, such as navigation light. 
         [0006]    What is needed, therefore, is an LED lamp which can overcome the limitations described. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Many aspects of the present embodiments 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 embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0008]      FIG. 1  is an isometric, assembled view of an LED lamp in accordance with an embodiment of the disclosure. 
           [0009]      FIG. 2  is an inverted view of the LED lamp of  FIG. 1 . 
           [0010]      FIG. 3  is an exploded view of the LED lamp of  FIG. 1 . 
           [0011]      FIG. 4  is an inverted view of the LED lamp of  FIG. 3 . 
           [0012]      FIG. 5  is a cross-sectional view of  FIG. 1 , taken along a line V-V thereof. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIGS. 1-4 , an LED lamp in accordance with an embodiment of the disclosure includes a casing  10 , a lamp frame  20  mounted on the casing  10 , a plurality of heat sinks  30  attached to a bottom of the lamp frame  20  and surrounding the casing  10 , a reflector  40  and a plurality of LED modules  50  received in the lamp frame  20 . A plurality of fixing brackets  60  fix the LED modules  50  in the lamp frame  20 . An envelope  70  covers the lamp frame  20 . 
         [0014]    Also referring to  FIG. 5 , the casing  10  is cubic and includes six interconnecting rectangular plates  12  cooperatively defining a chamber  14 . A driving module  16  is received in the chamber  14  and fastened on the plate  12  at a bottom of the casing  10  via screws  18 . The plate  12  at a top of the casing  10  is fastened on a center of the bottom of the lamp frame  20  and defines a plurality of through holes  120 . The driving module  16  has lead wires (not shown) extending through the through holes  120  and electrically connecting the LED modules  50  to provide power supply and controlling signals for the LED modules  50 . 
         [0015]    Particularly referring to  FIG. 3 , the lamp frame  20  is made of metal such as aluminum, copper or an alloy thereof. The lamp frame  20  includes a plurality of interconnecting frame units  22  each having a trapezoid cross section. Each of the frame units  22  includes a rectangular base plate  222 , two folding plates  224  slantwise and upwardly extending from two longer edges of the base plate  222  and two baffle plates  226  vertically extending from two shorter edges of the base plate  222 , whereby a receiving room  220  is defined at an inner side of the frame unit  22  for receiving a corresponding LED module  50  therein. Two adjacent frame units  22  interconnect together via the folding plates  224  thereof. 
         [0016]    The heat sinks  30  each include an elongated heat conducting plate  32  and a plurality of fins  34  vertically extending from a bottom face of the heat conducting plate  32 . Each heat conducting plate  32  is attached to the base plate  222  of a corresponding frame unit  22 . The heat sinks  30  together define a central space corresponding to a central portion of the lamp frame  20  for positioning the casing  10 . The heat sinks  30  absorb heat generated by the LED modules  50  and dissipate the heat into ambient air when the LED lamp is operated. 
         [0017]    The reflector  40  is integrally bent from a flat sheet and has a shape corresponding to that of the lamp frame  20  such that the reflector  40  can be intimately adhered on an inner face of the lamp frame  20 . The reflector  40  includes a plurality of interconnecting reflecting cells  42  each having a trapezoid cross section. Each of the LED modules  50  is received in a corresponding reflecting cell  42 . Each of the reflecting cells  42  includes a rectangular base portion  422  and two folding portions  424  slantwise and upwardly extending from two longer edges of the base portion  422 , whereby the two folding portions  424  of each reflecting cell  42  separate a corresponding LED module  50  from others. Two adjacent reflecting cells  42  interconnect together via the folding portions  424  thereof. The reflector  40  has an inner face coated with a film of reflecting material, by which light emitted from the LED modules  50  can be reflected out of the LED lamp. 
         [0018]    The LED modules  50  each include a rectangular printed circuit board  52  and a plurality of LEDs  54  attached on the printed circuit board  52 . 
         [0019]    The fixing brackets  60  each are bent from a metal sheet and include a rectangular body  62  and two fixing portions  64  vertically extending from two opposite ends of the body  62 . Each of the LED modules  50  is attached to a bottom face of the body  62  of a corresponding fixing bracket  60  to make the LEDs  54  face to a corresponding base portion  422  of the reflector  40  and opposite to the envelope  70 . The fixing portions  64  of each fixing bracket  60  are fastened on the inner faces of the baffle plates  226  of a corresponding frame unit  22 . Heat generated from the LED modules  50  can be transferred to the fixing brackets  60 , the lamp frame  20  and the heat sinks  30  in sequence. 
         [0020]    The envelope  70  is made of transparent or semitransparent material, such as glass etc., to allow light to penetrate therethrough. When the envelope  70  is made of a semitransparent material, the LED lamp in accordance with the disclosure can generate more soft and uniform light. The envelope  70  is a rectangular plate and covers on an opening of the lamp frame  20  to envelop the LED modules  50  and the fixing brackets  60  in the lamp frame  20 . 
         [0021]    In assembly, the heat sinks  30  are fastened on the base plates  222  of the lamp frame  20 . The casing  10  is positioned among the heat sinks  30  and attached to the base plates  222  of the lamp frame  20 . The reflector  40  is adhered on the inner face of the lamp frame  20 . The LED modules  50  are attached to the bottom faces of the fixing brackets  60 . The fixing portions  64  of the fixing brackets  60  are fastened on the inner faces of the baffle plates  226  of the lamp frame  20 . The envelope  70  is covered on an opening of the lamp frame  20 . 
         [0022]    In operation, the LED modules  50  get power from the driving module  16  and generate light. Shown as arrows in the  FIG. 5 , a part of the light directly projects to the base portions  422  of the reflector  40 , another part of the light directly projects to the folding portions  424  of the reflector  40 . When reaching the inner face of the base portions  422  and the folding portions  424  of the reflector  40 , the light is reflected out of the LED lamp. The light emitted from the LED modules  50  is reflected in a multidirectional manner, which increases the illumination area of the LED lamp. 
         [0023]    It is believed that the disclosure and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.