Transmissive optical elements including transparent plastic shell having a phosphor dispersed therein, and methods of fabricating same
View Patent ↗A transmissive optical element is fabricated by filling a mold with molten liquid that includes a transparent plastic and a phosphor additive, and allowing the molten liquid to solidify to produce the transmissive optical element having phosphor dispersed therein. Accordingly, a separate phosphor coating or phosphor-containing encapsulant need not be used. Transmissive optical elements include a shell made of transparent plastic with a phosphor dispersed therein. The phosphor may be uniformly and/or nonuniformly dispersed in the shell.
1. A method for forming a transmissive optical element comprising:
filling a dome-shaped mold with a molten liquid that comprises a transparent plastic and a phosphor additive;
allowing the molten liquid to solidify to produce a solid dome-shaped transmissive optical element having phosphor dispersed therein and including a dome-shaped inner surface and a dome-shaped outer surface; and
forming a solid transparent dome-shaped shell including a dome-shaped inner surface and a dome-shaped outer surface directly on the dome-shaped inner surface and/or directly on the dome-shaped outer surface of the solid dome-shaped transmissive optical element having phosphor disposed therein.
2. A method according to claim 1 wherein the filling is preceded by forming the solid transparent dome-shaped shell and wherein the filling comprises filling a dome-shaped mold that includes the solid transparent dome-shaped shell with a molten liquid that comprises a transparent plastic and a phosphor additive.
3. A transmissive optical element comprising:
a first solid dome-shaped shell that comprises a transparent plastic including a phosphor dispersed therein, the first solid dome-shaped shell including a dome-shaped inner surface and a dome-shaped outer surface; and
a second solid dome-shaped shell including a dome-shaped inner surface and a dome-shaped outer surface directly on the dome-shaped inner and/or outer surface of the first solid dome-shaped shell.
4. A transmissive optical element according to claim 3 wherein the phosphor is uniformly dispersed in the first solid dome-shaped shell.
5. A transmissive optical element according to claim 3 wherein the phosphor is nonuniformly dispersed in the first solid dome-shaped shell to provide an indicia in the first solid dome-shaped shell.
6. A transmissive optical element according to claim 3 in combination with a semiconductor light emitting device that is configured to emit light into and through the first and second solid dome-shaped shells, to emerge from the first and second solid dome-shaped shells.
7. A transmissive optical clement according to claim 6 in further combination with a mounting substrate that is adjacent the semiconductor light emitting device such that the semiconductor light emitting device is between the mounting substrate and the first and second solid dome-shaped shells.
8. A transmissive optical element according to claim 7 in further combination with an encapsulant between the semiconductor light emitting device and the first and second solid dome-shaped shells.
9. A transmissive optical element according to claim 3 wherein the second solid dome-shaped shell is directly on the inner surface of the first solid dome-shaped shell, the transmissive optical element further comprising a third solid dome-shaped shell directly on the outer surface of the first solid dome-shaped shell.