Patent Publication Number: US-2011069484-A1

Title: Illuminating apparatus

Description:
This application claims priority of Taiwan Patent Application No. 98132193, filed on Sep. 24, 2009, the entirety of which is incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an illuminating apparatus comprising at least one reflector. A portion of light beams to be emitted along an optical axis of a light emitting diode is reflected by the reflector, and a remaining portion of light beams of the light emitting diode is emitted directly to an illuminated surface. 
     2. Description of the Related Art 
     Environmental considerations is important in the development of electronic products, such as energy saving. Light emitting diodes offer benefits of a long life span, and energy saving, in addition to benefit for miniaturization and performance, such as non-blinking ability. As a result, low-powered light emitting diodes have become a major developmental focus area for the lighting industry. 
     Meanwhile, highly efficiency light emitting diodes are point light sources. Thus, adapting point light sources to an illuminating apparatus is a major challenge for developers. Accordingly, although there are illuminating apparatuses which utilize light emitting diodes, they are mostly designed for direct light illumination. In other words, the illuminating angle and the projecting area of current light emitting diodes are currently not satisfactorily designed, such that lamp-like LED lamps or illuminating apparatuses cannot provide significant illumination effects. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, the invention provides an illuminating apparatus utilizing a light emitting diode as a light source. The angle of the light beams from the light emitting diode emitted to an illuminated surface is shifted away from an optical axis of the light emitting diode. Therefore, the illuminating apparatus may be employed in refrigerators of convenience stores for illumination of merchandises, wall washers or for other use. 
     The invention provides an illuminating apparatus comprising a light emitting diode. The light emitting diode includes a viewing angle. The viewing angle is the off-axis angle at which the luminous intensity is half the axial luminous intensity. The effective light beams of the light emitting diode are the light beams within the viewing angle of the light emitting diode. A portion of the effective light beams from the light emitting diode is directly emitted, and a remaining portion of the effective light beams from the light emitting diode is reflected by the reflector to be condensed, or substantially parallel to each other or combinations of being converged or substantially parallel to each other, in order to illuminate a first area away from an optical axis of the light emitting diode which is not able to be directly illuminated by the emitted light beams of the light emitting diode. That is, the light beams from the light emitting diode to the illuminated surface is shifted an angle away from the optical axis. 
     The invention provides an illuminating apparatus which comprises at least one light emitting diode and at least one reflector. The reflector corresponding to the light emitting diode is disposed on a side of the light emitting diode. A portion of light beams emitted along an optical axis of the light emitting diode is reflected by the reflector, and a remaining portion of light beams is emitted directly to an illuminated surface such that the illuminated surface is completely illuminated. 
     In a preferred embodiment, the light beams from the light emitting diode to the illuminated surface is shifted an angle away from the optical axis. A portion of effective light beams emitted along the optical axis of the light emitting diode is reflected by the first reflector, and a remaining portion of effective light beams of the light emitting diode is emitted directly, wherein an illumination angle of the effective light beams of the light emitting diode is substantially 120 degrees, that is, the viewing angle is substantially 60 degrees. 
     In a preferred embodiment, effective light beams of the light emitting diode directly illuminate to a first area near the optical axis, and the reflector reflects light beams from the light emitting diode to a second area away from the optical axis 
     Accordingly, the invention provides various illuminating apparatuses comprising all kinds of reflectors. The reflector, corresponding to at least one light emitting diode, is disposed on a side of the light emitting diode. A portion of light beams emitted along an optical axis of the light emitting diode is reflected by the reflector, and a remaining portion of light beams is emitted directly to an illuminated surface. The light beams from the light emitting diode to the illuminated surface is shifted an angle away from the optical axis. Therefore, the illuminating apparatus may be employed in refrigerators of convenience stores for illumination of merchandises, wall washers or for other use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a schematic view of a first embodiment of an illuminating apparatus of the invention; 
         FIG. 2  is a schematic view of a variant embodiment of the illuminating apparatus in  FIG. 1 ; 
         FIG. 3  is a partially enlarged view of the illuminating apparatus in  FIG. 1 ; 
         FIG. 4  is a sectional view of the illuminating apparatus in  FIG. 1 ; 
         FIG. 5  is a schematic view of a variant embodiment of a reflector shown in  FIG. 1 ; 
         FIG. 6  is a schematic view of another variant embodiment of the reflector shown in  FIG. 1 ; 
         FIG. 7  is a schematic view of a second embodiment of the illuminating apparatus of the invention; 
         FIG. 8  is a partially enlarged view of the illuminating apparatus in  FIG. 7 ; 
         FIG. 9  is a schematic view of a variant embodiment of the illuminating apparatus in  FIG. 7 ; and 
         FIG. 10  is a front view of a refrigerator employing the illuminating apparatus of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     First Embodiment 
       FIG. 1  is a schematic view of a first embodiment of an illuminating apparatus of the invention;  FIG. 2  is a schematic view of a variant embodiment of the illuminating apparatus in  FIG. 1 ;  FIG. 3  is a partially enlarged view of the illuminating apparatus in  FIG. 1 ; and  FIG. 4  is a sectional view of the illuminating apparatus in  FIG. 1 . The illuminating apparatus  1  comprises at least one light emitting diode  11  and at least one reflector  12 . The reflector  12  corresponding to the light emitting diode  11  is disposed on a side of the light emitting diode  11 . As shown in  FIG. 2 , the reflector  12  of an illuminating apparatus  1   a  corresponds to five light emitting diodes  11 , but it is not limited thereto. A portion of light beams emitted along an optical axis X of the light emitting diode  11  is reflected by the reflector  12 , and a remaining portion of light beams is emitted directly to an illuminated surface of the light emitting diode A. 
     As shown in  FIG. 4 , the light emitting diode includes a viewing angle (such as 60 degrees) which is an off-axis angle at which a luminous intensity is half an axial luminous intensity, and the light emitting diode includes a plurality of effective light beams which are the light beams within the viewing angle of the light emitting diode  11 . The effective light beams from the light emitting diode  11  to the illuminated surface A is shifted by an angle A from the optical axis X. A common light emitting diode has a viewing angle of substantially 60 degrees as shown in  FIG. 4 , but it is not limited thereto. In detail, a portion of the effective light beams substantially along the optical axis X of the light emitting diode  11  is reflected by the reflector  12 , and a remaining portion of the effective light beams of the light emitting diode  11  is directly emitted. The light emitting diode  11  provides direct effective light beams D illuminating to area A 1  near the optical axis X and the reflector  12  reflects light R from the light emitting diode  11  to area A 2  away from the optical axis X such that the illuminated surface is completely illuminated. 
     As shown in  FIG. 1  to  FIG. 4 , the reflector  12  comprises a curved concave surface disposed on a side of the light emitting diode  11 . The reflector  12  comprises a single curved cross section extending along a first direction Y perpendicular to the optical axis X. The reflector  12  comprises a curved reflecting portion  121 , and the curved reflecting portion  121  comprises the curved concave surface, wherein a cross section of the curved concave surface of the reflector  12  comprises a portion of an elliptical curve (as shown in  FIG. 5 ). The cross section of the curved concave surface extends along the first direction Y perpendicular to the optical axis X. Preferably, the light emitting diode  11  is disposed substantially at or near one of the two focus points of the elliptical curve. The light R is reflected by the reflector  12  and converged to pass through the other one of the two focus points to be projected to the illuminated surface A far away from the optical axis X. Alternatively, a cross section of the curved concave surface of the reflector  12  comprises a portion of a parabolic curve (as shown in  FIG. 6 ). The cross section of the curved concave surface extends along the first direction Y perpendicular to the optical axis X. The light emitting diode  11  is disposed substantially at or near the focus point of the parabolic curve, and the reflected light beams from the curved concave surface are substantially parallel. Alternatively, a cross section of the curved concave surface of the reflector  12  comprises a portion of an elliptical curve connecting to a portion of a parabolic curve, but it is not limited thereto. The cross section can also be any other kinds of curves. Preferably, the reflector comprises plastic material coated with metal or plastic material covered with metal foil, but it is not limited thereto. 
     As shown in  FIG. 3 , the reflector  12  further comprises two end reflecting portions  122  respectively connecting with the two ends of the curved reflecting portion  121  and perpendicular to the curved reflecting portion  121 . The reflector  12  further comprises two fixing portions  123  respectively connecting to the two end reflecting portions  122  to fasten the reflector  12 . 
     As shown in  FIG. 3 , the illuminating apparatus  1  further comprises a circuit board  14 . The light emitting diode  11  and the reflector  12  corresponding thereto are disposed on a surface of the circuit board  14 . The reflector  12  is fastened to the surface of the circuit board  14  by the two fixing portions  123 . The light emitting diode  11  is electrically connected to a printed circuit on the circuit board  14 . The circuit board  14  is strip shaped and extends along the first direction Y. When the illuminating apparatus  1  comprises a plurality of light emitting diodes  11 , the light emitting diodes  11  are arranged linearly on the circuit board  14 . 
     The illuminating apparatus  1  further comprises a supporting frame  16  disposed on another surface of the circuit board  14  to support the light emitting diode  11 , the reflector  12  and the circuit board  14 . The supporting frame  16  comprises metal, and preferably the supporting frame  16  can be steel, iron or aluminum. The supporting frame  16  is also a heat sink and comprises heat-dissipation ability to transfer heat radiated from the light emitting diode  11 . The supporting frame  16  comprises a body  161  and a reflecting portion  162 . The body  161  is preferably L shaped, but it is not limited thereto. The reflecting portion  162  is disposed on the front edge of the body  161  to reflect light beams of the light emitting diode  11 , and to cooperate with the reflector  12  in order to limit an illumination angle of the light emitting diode  11 . The reflecting portion  162  comprises a polished metal reflecting surface. Alternatively, the reflecting portion  162  comprises another reflector (not shown), and this reflector comprises the same material as the reflector  12  (same description is omitted). 
     Second Embodiment 
       FIG. 7  is a schematic view of a second embodiment of the illuminating apparatus of the invention; and  FIG. 8  is a partially enlarged view of the illuminating apparatus in  FIG. 7 . The illuminating apparatus  1   b  is similar to the illuminating apparatus  1  in the first embodiment, and the differences are described as follows. The illuminating apparatus  1   b  comprises a reflector  12   b . The reflector  12   b  comprises a curved reflecting portion  121   b , and the curved reflecting portion  121   b  comprises a first curved portion  1211  and a second curved portion  1212 . The first curved portion  1211  comprises the curved concave surface as shown in the first embodiment (same description is omitted), and the second curved portion  1212  comprises an ellipsoid-like concave surface connected with the curved concave surface. The reflector  12   b  further comprises an end reflecting portion  122 , a first fixing portion  123   a  and a second fixing portion  123   b . The end reflecting portion  122  connects to the first fixing portion  123   a  and is perpendicular to the curved concave surface. The first fixing portion  123   a  connects to the end reflecting portion  122 , and the second fixing portion  123   b  connects to the second curved portion  1212 . The reflector  12   b  is fastened to the circuit board  14  by the first fixing portion  123   a  and the second fixing portion  123   b . The illuminating apparatus  1   b  is preferably a strip lamp. The first curved portion  1211  (the curved concave surface) of the reflector  12   b  is disposed close to a center of the illuminating apparatus, and the second curved portion  1212  (the ellipsoid-like concave surface) is disposed away from the center of the illuminating apparatus. The rest of structure of the illuminating apparatus  1   b  is the same as the illuminating apparatus  1  in the first embodiment, and therefore the relevant descriptions are omitted. 
       FIG. 9  is a schematic view of a variant embodiment of the illuminating apparatus in  FIG. 7 . The illuminating apparatus  1   c  is a strip lamp, and the reflectors  12   b  of the second embodiment are applied on two ends thereof. The rest of the applied reflectors used in the illuminating apparatus  1   c  are reflectors  12  of the first embodiment. The rest of the structure of the illuminating apparatus  1   c  is the same as the illuminating apparatus  1  of the first embodiment, and therefore the relevant descriptions are omitted hereafter. 
       FIG. 10  is a front view of a refrigerator employing the illuminating apparatus of the invention. The illuminating apparatuses  1 ,  1   a ,  1   b  and  1   c  as described can be disposed on a side of the illuminated surface A to illuminate the illuminated surface A. The illuminated surface is, for example, a rectangular surface.  FIG. 10  depicts the illuminating apparatus disposed on two sides of the illuminated surface, but it is not limited thereto. 
     As described, the invention provides various illuminating apparatuses comprising all kinds of reflectors. The reflector, corresponding to at least one light emitting diode, is disposed on a side of the light emitting diode. A portion of the effective light beams of the light emitting diode is reflected by the reflector, and a remaining portion of the effective light beams is emitted directly to an illuminated surface of the light emitting diode. The effective light beams are shifted form the optical axis by an angle to the illuminated surface. Therefore, the illuminating apparatus may be employed in refrigerators of convenience stores for illumination of merchandises, wall washers or for other use. 
     While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.