Bat-wing lens design with multi-die
View Patent ↗A batwing beam is produced from an optical emitter having a primary LED lens over a number of LED dies on a package substrate. The LED lens includes a batwing surface formed by rotating a parabolic arc about an end of the parabolic arc over a center of the optical emitter. A center of each of the LED dies is mounted to the package substrate about the focus of a parabola whose arc forms the batwing surface, for example, between about 0.5 to 1.5 of a focal distance from the vertex of the parabola. The batwing surface reflects light from the number of LED dies through total internal reflection (TIR) or through a reflectivity gel coating.
1. A method, comprising:
attaching a plurality of light-emitting devices to a substrate;
forming a lens on the plurality of light-emitting devices directly through a molding process, the lens covering the side surfaces of the plurality of light-emitting devices, wherein the forming of the lens comprises forming an upper surface that is defined by rotating an arc around a vertical axis; and
thereafter curing the lens,
wherein the attaching of the plurality of light-emitting devices and the forming of the lens are performed in a manner such that the plurality of light-emitting devices are symmetrically disposed around the vertical axis.
2. The method of claim 1 , further comprising applying a reflective material to the upper surface.
3. The method of claim 2 , wherein the applying of the reflective material comprises selecting a material that is tuned to reflect a specific wavelength of light emitted by the light-emitting devices.
4. The method of claim 2 , wherein the forming of the lens comprises configuring a shape of the lens such that at least 80% of a light emitted by the light-emitting devices is reflected by the reflective material upon reaching the upper surface of the lens.
5. The method of claim 1 , wherein the molding process includes an injection molding process.
6. The method of claim 1 , wherein the molding process includes a compression molding process.
7. The method of claim 1 , wherein the forming of the lens is comprises forming the lens such that it has a vertex.
8. The method of claim 7 , wherein the forming of the lens is performed in a manner such that the arc is a parabola or a hyperbola.
9. The method of claim 7 , wherein a horizontal distance between the vertex and a focus of the parabola defines a focal distance, and wherein a distance between a center of the light-emitting devices to the vertex is in a range from about 0.5 times the focal distance to about 1.5 times the focal distance.
10. The method of claim 1 , wherein the attaching of the plurality of light-emitting devices comprises forming at least two concentrically-located rings of light-emitting devices.