The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 05, 2000
Filed:
Mar. 15, 1999
Jeffrey N Miller, Los Altos Hills, CA (US);
Danny E Mars, Los Altos, CA (US);
Agilent Technologies, Inc., Palo Alto, CA (US);
Abstract
A light emitting device and a method of fabricating the device include a wavelength selective reflector that is formed between a light source and a layer of phosphorescent material. The light emitting device is a phosphor-conversion light emitting diode (LED) that outputs secondary light that is converted from primary light emitted from the light source. In the preferred embodiment, the light source is a Gallium Nitride (GaN) die and the wavelength selective reflector is a distributed Bragg reflector (DBR) mirror. The DBR mirror is comprised of multiple alternating layers of high and low refractive index materials. The high refractive index material may be Titanium Dioxide (TiO.sub.2) and the low refractive index material may be Silicon Dioxide (SiO.sub.2). An encapsulating layer over the GaN die provides a distance between the GaN die and the DBR mirror. Preferably, the encapsulating layer is a dome-shaped structure and the DBR mirror forms a dome-shaped shell over the encapsulating layer. In the most preferred embodiment, the dome-shaped configuration of the encapsulating layer and the DBR mirror is generally hemispheric. The dome-shaped configuration of the DBR mirror reduces the cone-angle average of the primary light from the light source, thereby improving the transmittance characteristic of the DBR mirror with respect to the primary light. Consequently, the amount of output light generated by the LED is significantly improved.