Side-view surface mount white LED
View Patent ↗A light emitting diode is disclosed. The diode includes a package support and a semiconductor chip on the package support, with the chip including an active region that emits light in the visible portion of the spectrum. Metal contacts are in electrical communication with the chip on the package. A substantially transparent encapsulant covers the chip in the package. A phosphor in the encapsulant emits a frequency in the visible spectrum different from the frequency emitted by the chip and in response to the wavelength emitted by the chip. A display element is also disclosed that combines the light emitting diode and a planar display element. The combination includes a substantially planar display element with the light emitting diode positioned on the perimeter of the display element and with the package support directing the output of the diode substantially parallel to the plane of the display element.
1. A light emitting diode comprising:
a package support;
a semiconductor chip on said package support, said chip including an active region that emits radiation in the visible or UV portion of the spectrum;
metal contacts in electrical communication with said chip on said package; a substantially transparent encapsulant covering said chip in said package;
a phosphor in said encapsulant that emits radiation in the visible spectrum different from the radiation emitted by said chip and in response to the wavelength emitted by said chip; and
a diffuser distributed in a pre-form and with said pre-form positioned within said encapsulant adjacent said diode.
2. A light emitting diode according to claim 1 comprising a diode and a phosphor with combined output radiation that produce white light.
3. A light emitting diode according to claim 2 wherein said diode emits in the blue portion of the visible spectrum.
4. A light emitting diode according to claim 2 wherein said phosphor is selected from the group consisting of: YAG:Ce, (Sr,Ba) 2 SiO 4 :Eu, CaGa 2 S 4 :Eu, SrGa 2 S 4 :Eu, and (Sr,Ca)S:Eu, and combinations thereof.
5. A light emitting diode according to claim 1 wherein said phosphor is dispersed within said encapsulant.
6. A light emitting diode according to claim 1 wherein said phosphor is packaged in a pre-form and positioned within said encapsulant.
7. A light emitting diode according to claim 1 further comprising a diffuser dispersed within said encapsulant.
8. A light emitting diode according to claim 1 wherein said encapsulant defines a meniscus with respect to said package and said chip.
9. A display element comprising the combination of a light emitting diode and a planar display element, the combination comprising:
a substantially planar display element;
a light emitting diode positioned on the perimeter of said display element and including;
a reflective package support that directs the output of said diode substantially parallel to the plane of said display element;
a semiconductor chip on said reflective package support, said chip including an active region that emits radiation in the visible or UV portion of the spectrum;
metal contacts in electrical communication with said chip on said reflective package;
a substantially transparent encapsulant covering said chip in said reflective package, said encapsulant forming a negative meniscus; and;
a phosphor in said encapsulant that emits radiation in the visible spectrum different from the radiation emitted by said chip and in response to the wavelength emitted by said chip.
10. display element according to claim 9 comprising a diode and a phosphor with combined output frequencies that produce white light.
11. A display element according to claim 9 comprising a liquid crystal display.
12. A display element according to claim 9 comprising a color filter.
13. A display element according to claim 9 comprising a polarizer.
14. A display element according to claim 9 comprising a plurality of phosphors in said encapsulant that emit radiation at different wavelengths from one another.
15. A light emitting diode comprising:
a package support;
a semiconductor chip on said package support, said chip including an active region that emits radiation in the visible or UV portion of the spectrum;
metal contacts in electrical communication with said chip on said package; a substantially transparent encapsulant covering said chip in said package; and
a phosphor in said encapsulant that emits radiation in the visible spectrum different from the radiation emitted by said chip and in response to the wavelength emitted by said chip, with more than 50 percent of the phosphor positioned in the lower 25 percent of the encapsulant.
16. A light emitting diode according to claim 15 wherein said diode emits in the blue portion of the visible spectrum and the combined output radiation of said diode and said phosphor produces white light.
17. The combination of:
a planar display element; and
a light emitting diode according to claim 15 positioned as a side view surface mount diode on the perimeter of said display element to transmit its radiation beam parallel to the plane of said display element.
18. A light emitting diode comprising:
a package support;
a semiconductor chip on said package support, said chip including an active region that emits radiation in the visible or UV portion of the spectrum;
metal contacts in electrical communication with said chip on said package;
a substantially transparent encapsulant covering said chip in said package;
a phosphor in said encapsulant that emits radiation in the visible spectrum different from the radiation emitted by said chip and in response to the wavelength emitted by said chip; and
a physical spacer element between said chip and said phosphor.
19. A light emitting diode according to claim 18 wherein said diode emits in the blue portion of the visible spectrum and the combined output radiation of said diode and said phosphor produces white light.
20. The combination of:
a planar display element; and
a light emitting diode according to claim 18 positioned as a side view surface mount diode on the perimeter of said display element to transmit its radiation beam parallel to the plane of said display element.