Wide angle based indoor lighting lamp

Abstract

The present disclosure provides one embodiment of an illumination structure. The illumination structure includes a substrate. A light-emitting diode (LED) is disposed over the substrate. A first lens is disposed over the LED. A second lens is disposed over the first lens. The first lens and the second lens are configured to refract light that is emitted by the LED backward.

What is claimed is: 
     
         1 . An illumination structure comprising:
 a light-emitting diode (LED) device on a mount;   a lens on the mount and over the LED device; and   a gap between the LED device and the lens;   wherein the lens includes an outer side surface having a concave curved cross-sectional profile configured in a manner such that a bottom of the outer side surface protrudes further out from a center of the lens than a top of the outer side surface.   
     
     
         2 . The illumination structure of  claim 1 , wherein the lens is configured to redistribute light emitted from the LED device to a solid angle more than 2π steradian. 
     
     
         3 . The illumination structure of  claim 1 , wherein the lens includes an outer top surface having a concave recess. 
     
     
         4 . The illumination structure of  claim 1 , further comprising a diffuser cap covering the lens. 
     
     
         5 . The illumination structure of  claim 1 , wherein the mount comprises a circuit board upon which the LED device is formed. 
     
     
         6 . The illumination structure of  claim 5 , wherein the mount comprises a heat sink upon which the circuit board is formed. 
     
     
         7 . The illumination structure of  claim 5 , wherein the circuit board comprises MCPCB, FR-4, or ceramic. 
     
     
         8 . The illumination structure of  claim 6 , wherein the heat sink comprises metal. 
     
     
         9 . The illumination structure of  claim 6 , wherein the heat sink is wider than the circuit board. 
     
     
         10 . The illumination structure of  claim 5 , wherein the circuit board is embedded in the heat sink. 
     
     
         11 . The illumination structure of  claim 1 , wherein the lens includes a transparent material selected from the group consisting of polycarbonate (PC) and poly methyl methacrylate (PMMA). 
     
     
         12 . The illumination structure of  claim 1 , wherein the LED device includes a plurality of LED chips. 
     
     
         13 . An illumination structure comprising:
 a light-emitting diode (LED) device on a mount;   a lens on the mount and over the LED device; and   a gap between the LED device and the lens; wherein   the lens includes an outer side surface, an inner side surface opposite to the outer side surface, an outer top surface, and an inner top surface opposite to the outer top surface;   the outer top surface includes a concave recess, a center and a rim surrounding the center and the concave recess;   the outer top surface is spaced away from the mount along a first direction, defining a height H from the rim of the outer top surface to a top surface of the mount along the first direction;   the outer top surface spans from the center to the rim along a second direction perpendicular to the first direction, defining a first radius r;   the concave recess includes a recess depth d defined as a distance from the rim to the center along the first direction; and   a first ratio d/H ranges between 0.5 and 0.8.   
     
     
         14 . The illumination structure of  claim 13 , wherein
 the outer side surface defines a round area on the mount and the round area has a second radius R along the second direction; and   a second ratio r/R ranges between 0.3 and 1.0.   
     
     
         15 . The illumination structure of  claim 13 , wherein
 the inner top surface is spaced away from the mount along the first direction, defining a height h to the top surface of the mount; and   a third ratio h/H ranges between 0.1 and 0.4.   
     
     
         16 . The illumination structure of  claim 13 , wherein the outer side surface having a concave curved cross-sectional profile configured in a manner such that a bottom of the outer side surface protrudes further out from a center of the lens than a top of the outer side surface. 
     
     
         17 . The illumination structure of  claim 13 , wherein the lens is configured to redistribute light emitted from the LED device to a solid angle more than 2π steradian. 
     
     
         18 . The illumination structure of  claim 13 , further comprising a diffuser cap housing the LED device and the lens within. 
     
     
         19 . The illumination structure of  claim 13 , wherein the LED device includes a plurality of LED chips. 
     
     
         20 . The illumination structure of  claim 14 , wherein a lowest point of the concave recess of the outer top surface is a vertex centered around the LED device.