Illumination – Light source and modifier – Including selected wavelength modifier
Patent
1999-03-15
2000-12-05
Sember, Thomas M.
Illumination
Light source and modifier
Including selected wavelength modifier
362800, 362 84, 257 95, 257 97, 257 99, 313113, 313512, 313502, H04N 931
Patent
active
061556998
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.
REFERENCES:
patent: 4822144 (1989-04-01), Vriens
patent: 4882617 (1989-11-01), Vriens
patent: 5557115 (1996-09-01), Shakuda
patent: 5813752 (1998-09-01), Singer et al.
patent: 5813753 (1998-09-01), Vriens et al.
patent: 5962971 (1999-10-01), Chen
patent: 5977612 (1999-11-01), Bour et al.
Mars Danny E.
Miller Jeffrey N.
Agilent Technologie,s Inc.
Sember Thomas M.
LandOfFree
Efficient phosphor-conversion led structure does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Efficient phosphor-conversion led structure, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient phosphor-conversion led structure will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-954943