Abstract:
Disclosed is a thin LED lens including a lens body being an inverted frusto-conical shaped structure, a light exit surface formed on a non-frustum end of the lens body, and an accommodating chamber formed at a frustum end of the lens body, characterized in that the accommodating chamber has a primary accommodating chamber and at least one secondary accommodating chamber disposed around the primary accommodating chamber, such that the primary accommodating chamber and the secondary accommodating chamber are arranged in a concentric and radial shape, and the secondary accommodating chamber is in form of a circular groove. The thin LED lens can be made thinner to achieve the effects of facilitating the manufacture, reducing the material, and providing a better light distribution.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a thin light emitting diode (LED) lens, and more particularly to the thin LED lens with a small thickness to facilitate the manufacture and provides better light distribution. 
         [0003]    2. Description of the Related Art 
         [0004]    Most conventional lens structures are used in light emitting modules. As science and technology advance, the light emitting modules are developed with a thinner, lighter and smaller design while maintaining a good light distribution effect of a light emitting source. In general, the thickness of the LED optical lens or the diameter width of the light exit surface is adjusted to meet the actual requirements of an illumination range and a uniform luminous intensity. 
         [0005]    With reference to  FIGS. 1 to 3  for a ray tracing diagram, a light distribution curve and an irradiance diagram of an embodiment of a conventional LED lens respectively, a conventional lens body  900  is combined with an LED emission light source, and the maximum luminous intensity at the center of the emission light source) (ω=0°) is approximately equal to 2000 cd, and the maximum luminance at the center position on the X-Z plane is approximately equal to 2000 lux. However, the conventional lens has a greater thickness, so that when the lens is applied in a light emitting module, the total thickness is also increased. As a result, the dimensions of the light emitting module are further limited. 
         [0006]    With reference to  FIGS. 4 to 6  for a ray tracing diagram, a light distribution curve and an irradiance diagram of another embodiment of a conventional LED lens respectively,  FIG. 1  and  FIG. 4  are compared, and the comparison result shows that the lens body  800  of this preferred embodiment is thinner than the previous lens body  900 . 
         [0007]    In other words, the previous lens body  900  can be cut thinner to obtain the lens body  800  of this preferred embodiment. 
         [0008]    In  FIGS. 4 to 6 , although the thickness, weight and volume of the lens body  800  are reduced, the maximum luminous intensity at the center of the emission light source) (ω=0°) is approximately equal to 1300 cd, and the maximum luminance at the center position on the X-Z plane is approximately equal to 1400 lux. In other words, if the conventional lens is cut thinner, the thickness, weight and volume of the lens can be reduced, yet the level of difficulty of the design is higher, and thus the required range and effect of the illumination can not be achieved. 
         [0009]    As to the requirements, the design of a thin LED lens uses less material and has a smaller weight and a smaller volume, and meanwhile the thin LED lens combined with LED to emit a better light distribution than the regular lens has become a major subject that demands immediate attention in the market. 
       SUMMARY OF THE INVENTION 
       [0010]    In view of the aforementioned problems of the prior art, it is a primary objective of the present invention to overcome the problems by providing a thin LED lens that uses less material to manufacture the lens while providing a better light distribution. 
         [0011]    To achieve the aforementioned objective, the present invention provides a thin LED lens comprising a lens body which is an inverted frusto-conical shaped structure, a light exit surface formed on a non-frustum end of the lens body, and an accommodating chamber formed at a frustum end of the lens body, characterized in that the accommodating chamber has a primary accommodating chamber and at least one secondary accommodating chamber disposed around the primary accommodating chamber, so that the primary accommodating chamber and the secondary accommodating chamber are arranged in a concentric and radial shape, and the secondary accommodating chamber is in form of a circular groove. 
         [0012]    In a preferred embodiment, the primary accommodating chamber is formed by a sidewall surface connecting around a bottom surface, and the bottom surface is in a planar shape, a convex arc shape or a concave arc shape with respect to the lens body. The thin LED lens further comprises a diffusion portion coupled to the lens body and disposed around the light exit surface, and the diffusion portion has a plurality of ribs formed on a surface of the diffusion portion. The light exit surface has a plurality of bumps distributed in form of a dot pattern. 
         [0013]    In another preferred embodiment, there are two secondary accommodating chambers, and a hollow hole is concavely formed in a central area of the light exit surface and facing towards the lens body. Wherein, the light exit surface at the position of the hollow hole is in a convex arc shape with respect to the lens body and has a plurality of bumps distributed in form of a dot pattern. 
         [0014]    To achieve the aforementioned objective, the present invention further uses a preferred embodiment for the illustration, wherein there are two secondary accommodating chambers in this preferred embodiment and the light exit surface is concaved towards the lens body and has a plurality of bumps formed at a central area of the light exit surface and distributed in form of a dot pattern. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a ray tracing diagram of an embodiment of a conventional LED lens; 
           [0016]      FIG. 2  is a light distribution curve of an embodiment of a conventional LED lens; 
           [0017]      FIG. 3  is an irradiance diagram of an embodiment of a conventional LED lens; 
           [0018]      FIG. 4  is a ray tracing diagram of another embodiment of a conventional LED lens; 
           [0019]      FIG. 5  is a light distribution curve of another embodiment of a conventional LED lens; 
           [0020]      FIG. 6  is an irradiance diagram of another embodiment of a conventional LED lens; 
           [0021]      FIG. 7  is a cross-sectional view of a thin LED lens of a first preferred embodiment of the present invention; 
           [0022]      FIG. 8  is a ray tracing diagram of a thin LED lens of the first preferred embodiment of the present invention; 
           [0023]      FIG. 9  is a light distribution curve of a thin LED lens of the first preferred embodiment of the present invention; 
           [0024]      FIG. 10  is an irradiance diagram of a thin LED lens of the first preferred embodiment of the present invention; 
           [0025]      FIG. 11  is a perspective view of a thin LED lens of a second preferred embodiment of the present invention; 
           [0026]      FIG. 12  is a cross-sectional view of a thin LED lens of the second preferred embodiment of the present invention; 
           [0027]      FIG. 13  is a ray tracing diagram of a thin LED lens of the second preferred embodiment of the present invention; 
           [0028]      FIG. 14  is a light distribution curve of a thin LED lens of the second preferred embodiment of the present invention; 
           [0029]      FIG. 15  is an irradiance diagram of a thin LED lens of the second preferred embodiment of the present invention; 
           [0030]      FIG. 16  is a perspective view of a thin LED lens of a third preferred embodiment of the present invention; 
           [0031]      FIG. 17  is a cross-sectional view of a thin LED lens of the third preferred embodiment of the present invention; 
           [0032]      FIG. 18  is a ray tracing diagram of a thin LED lens of the third preferred embodiment of the present invention; 
           [0033]      FIG. 19  is a light distribution curve of a thin LED lens of the third preferred embodiment of the present invention; 
           [0034]      FIG. 20  is an irradiance diagram of a thin LED lens of the third preferred embodiment of the present invention; 
           [0035]      FIG. 21  is a perspective view of a thin LED lens of a fourth preferred embodiment of the present invention; and 
           [0036]      FIG. 22  is a cross-sectional view of a thin LED lens of the fourth preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]    The technical content of the present invention will become apparent with the detailed description of preferred embodiments and the illustration of related drawings as follows. It is noteworthy that same numerals are used for representing same respective elements in the drawings. 
         [0038]    The thin LED lens of the present invention can be combined with an LED for guiding lights of the LED to produce a better light pattern. 
         [0039]    With reference to  FIGS. 7 to 10  for a cross-sectional view, a ray tracing diagram, a light distribution curve and an irradiance diagram of a thin LED lens  1  of the first preferred embodiment of the present invention respectively, the thin LED lens  1  as shown in  FIG. 7  comprises a lens body  100  which is an inverted frusto-conical shaped structure, a light exit surface  11  formed at a non-frustum end of the lens body  100 , and an accommodating chamber  12  formed at a frustum end of the lens body  100 . 
         [0040]    The accommodating chamber  12  has a primary accommodating chamber  121  and a secondary accommodating chamber  122  disposed around the primary accommodating chamber  121 , so that the primary accommodating chamber  121  and the secondary accommodating chamber  122  are arranged in a concentric and radial shape, and the secondary accommodating chamber  122  is disposed around the primary accommodating chamber  121  to form a circular groove, and the bottom of the groove is in a sharp shape. Wherein, the primary accommodating chamber  121  is formed by a sidewall surface  1211  connecting around a bottom surface  1212 , and the bottom surface  1212  is in a planar shape with respect to the lens body  100 . 
         [0041]    When an LED is installed in the accommodating chamber  12  as shown in  FIGS. 8 and 9 , the light emitted by the LED can be passed through the lens body and refracted or reflected, so that the light path can be shifted to produce a better illumination effect. The maximum luminous intensity at the center of the emission light source) (ω=0°) is approximately equal to 2000 cd, and the luminous intensity is greater and has a full angle approximately equal to 40°. In  FIG. 10 , the maximum luminance at the central position on the X-Z plane is preferably equal to 2000 lux. 
         [0042]    Compared with the conventional lenses  800 ,  900  as shown in  FIGS. 1 and 4 , the thin LED lens  1  of the present invention reduces the use of material of the lens while maintaining the same luminous intensity and luminance. In other words, the thin LED lens  1  of the present invention can reduce the volume of the conventional lens body and fit in the application for any compact or thin lamps to avoid occupying too much space. 
         [0043]    Based on the first preferred embodiment, the present invention further provides a second preferred embodiment and a third preferred embodiment as examples for the illustration the present invention. 
         [0044]    With reference to  FIGS. 11 to 15  for a perspective view, a cross-sectional view, a ray tracing diagram, a light distribution curve and an irradiance diagram of a thin LED lens  2  in accordance with the second preferred embodiment of the present invention respectively, the difference between the thin LED lens  2  of this preferred embodiment as shown in  FIGS. 11 and 12  and the first preferred embodiment resides on that the light exit surface  21  has a plurality of bumps  210  distributed in a dot pattern. The bumps  210  are provided for guiding the light of the LED to diverge a light path and enhance the light uniformity. The primary accommodating chamber  221  is formed by a sidewall surface  2211  connecting around a bottom surface  2212 , and the bottom surface  2212  is in a convex arc shape with respect to the lens body  200 . The thin LED lens  2  further comprises a diffusion portion  201  coupled to the lens body  200  and disposed around the light exit surface  21 , wherein the diffusion portion  201  has a plurality of ribs  2011  disposed on a surface of the diffusion portion  201  and arranged in a whirlpool shape. 
         [0045]    In  FIGS. 13 and 14 , the maximum luminous intensity at the center of the emission light source) (ω=0°) is approximately equal to 900 cd, and the luminous intensity is greater and has a full angle approximately equal to 80° as shown in  FIG. 15 , and the maximum luminance at the central position on the X-Z plane is preferably equal to 900 lux. 
         [0046]    With reference to  FIGS. 16 to 20  for a perspective view, a cross-sectional view, a ray tracing diagram, a light distribution curve and an irradiance diagram of a thin LED lens  3  in accordance with the third preferred embodiment of the present invention respectively, the difference between the thin LED lens  3  of this preferred embodiment as shown in  FIGS. 16 and 17  and the first preferred embodiment resides on that the light exit surface  31  is concaved towards the lens body  300 , and the light exit surface  31  has a plurality of bumps  310  formed in the central area of the light exit surface  31  and distributed in a dot pattern. 
         [0047]    In addition, the accommodating chamber  32  has a primary accommodating chamber  321  and a plurality of secondary accommodating chambers  322 . Each secondary accommodating chambers  322  includes a first secondary accommodating chamber  3221  and a second secondary accommodating chamber  3222 , and the second secondary accommodating chamber  3222  is disposed around the external periphery of the first secondary accommodating chamber  3221 , and the first secondary accommodating chamber  3221  is disposed around the edge of the primary accommodating chamber  321 , so that the primary accommodating chamber  321  and the plurality of secondary accommodating chambers  322  are arranged concentrically and adjacent to each other. 
         [0048]    It is noteworthy that the cup-shaped surface of the lens body  300  can be designed with a mesh form, a cellular honeycomb structure or a frosted glass treatment to diverge the light path of the LED, so as to enhance the light uniformity. 
         [0049]    In  FIGS. 18 and 19 , the maximum luminous intensity at the center of the emission light source) (ω=0°) is approximately equal to  1050  cd and the luminous intensity is greater and has a full angle approximately equal to 88° as shown in  FIG. 20 , and the maximum luminance at the center position on the X-Z plane is preferably equal to 1100 lux. 
         [0050]    Based on the first to the third preferred embodiments, the present invention further uses a fourth preferred embodiment as an example for illustrating the present invention. 
         [0051]    With reference to  FIGS. 21 and 22  for a perspective view and a cross-sectional view of thin LED lens in accordance with a fourth preferred embodiment of the present invention respectively, the thin LED lens  4  of the present invention has a lens body  400  which is substantially an inverted frusto-conical shaped structure, and a light exit surface  41  is formed at a non-frustum end of the lens body  400 , and the central area of the light exit surface  41  is concaved towards the lens body  400  to from a hollow hole  44 , and the light exit surface  41  at the position of the hollow hole  44  is in a convex arc shape with respect to the lens body  400 . When a light exits, the light is received by the surface of the light exit surface  41  and a plurality of bumps  410  is provided and distributed in a dot pattern. 
         [0052]    The frustum end is concavely sunken towards the lens body  400  to form an accommodating chamber  42  including a primary accommodating chamber  421  and a plurality of secondary accommodating chambers  422  disposed around the primary accommodating chamber  421 . Each secondary accommodating chamber  422  includes a first secondary accommodating chamber  4221  and a second secondary accommodating chamber  4222 , and the second secondary accommodating chamber  4222  is disposed around the external periphery of the first secondary accommodating chamber  4221 , and the first secondary accommodating chamber  4221  is disposed around the edge of the primary accommodating chamber  421 , so that the primary accommodating chamber  421  and the secondary accommodating chambers  422  are arranged in a concentric and radial shape. The quantity of the secondary accommodating chambers  422  are two and the secondary accommodating chambers are disposed adjacent to each other and arranged in form of a circular groove. 
         [0053]    The primary accommodating chamber  421  is formed by a sidewall surface  4211  connecting around a bottom surface  4212 , and the bottom surface  4212  is in a concave arc shape with respect to the lens body  400  and capable of guiding and diverging the light of the LED. 
         [0054]    In addition, the cup-shaped surface of the lens body  400  is designed with a mesh form, a cellular honeycomb structure, or a frosted glass treatment to diverge the light path of the LED, so as to enhance the light uniformity.