Anti-reflective coatings for light bulbs
A light bulb having anti-reflective coatings on an inner surface and/or an outer surface of the shell of the light bulb. The anti-reflective coatings reduce light loss due to reflections at the interfaces between the interior of the bulb and the shell and between the shell and the exterior of the bulb. The light source may be either incandescent, fluorescent or LED.
1. An LED bulb comprising:
one or more LEDs;
a shell surrounding said one or more LEDs, wherein the shell has a shell index of refraction;
a liquid inside the shell, the liquid in contact with the one or more LEDs and the shell;
an anti-reflective coating on an inner surface of the shell, wherein the anti-reflective coating has an inner surface index of refraction, and
wherein the shell index of refraction and the inner surface index of refraction in combination matches an index of refraction of the liquid in the visible light spectrum.
2. The LED bulb as set forth in claim 1 , wherein the one or more LEDs and the shell surrounding the one or more LEDs form a cavity, and the liquid partially fills the cavity.
3. The LED bulb as set forth in claim 1 , wherein the shell is glass.
4. The LED bulb as set forth in claim 1 , wherein the shell is plastic.
5. The LED bulb as set forth in claim 1 , wherein the shell is a bulb-shaped shell.
6. An LED bulb comprising:
one or more LEDs;
a shell surrounding said one or more LEDs, wherein the shell has a shell index of refraction;
a liquid inside the shell, the liquid in contact with the one or more LEDs and the shell;
an inner anti-reflective coating on an inner surface of the shell, wherein the inner anti-reflective coating has an inner surface index of refraction; and
an outer anti-reflective coating on an outer surface of the shell, wherein the outer anti-reflective coating has an outer surface index of refraction,
wherein:
the shell index of refraction and the inner surface index of refraction in combination matches an index of refraction of the liquid in the visible light spectrum, and
the shell index of refraction and the outer surface index of refraction in combination matches an index of refraction of an external atmosphere in the visible light spectrum.
7. The LED bulb as set forth in claim 6 , wherein the one or more LEDs and the shell surrounding the one or more LEDs form a cavity, and the liquid partially fills the cavity.
8. The LED bulb as set forth in claim 6 , wherein the shell is glass.
9. The LED bulb as set forth in claim 6 , wherein the shell is plastic.
10. The LED bulb as set forth in claim 6 , wherein the shell is a bulb-shaped shell.