Green Patents for Sale: Illumitex’s LED Chip and Light Extraction Portfolio
The Pluritas Illumitex sale web page lists six U.S. patents, and the sale overview document says there are five patent families including foreign counterparts in Europe, China, Japan, Taiwan, and South Korea.
One provisional – Application Serial No. 61/587,552, entitled “Hybrid mirror for higher extraction efficiency from bottom-emitting LEDs – is listed as well (comprising the LED micro-mirror family), though it apparently expired in January. Because of the timing of patent application publication, it’s too early to tell whether the provisional has been converted to a formal utility application.
The first patent family relates to LED emitter layer shaping and includes U.S. Patent No. 7,829,358 and its related divisional, U.S. Patent No. 8,263,993, both entitled “System and method for emitter layer shaping” (Layer Shaping Patents).
The Layer Shaping Patents are directed to methods of shaping an emitter layer (80) of an LED to form a shaped portion (81) and an unshaped portion (82). In the shaped portion (81) the Gallium Nitride layer (810) and sidewalls (860) and (865) are shaped to a controlled height to maximize light extraction efficiency.
This allows photons of light from the quantum well region (815) that enter the Gallium Nitride layer (810) through interface (850) to exit through exit face (855) with minimal energy loss.
According to the sale overview document, these shaped emitters achieve the highest possible light extraction efficiencies by minimizing internal reflections and controlling beam shape.
Another family includes U.S. Patent Nos. 7,789,531 and 8,087,960 (’960 Patent), both entitled “LED system and method” (LED Substrate Shaping Patents). The LED Substrate Shaping Patents are directed to methods of making LEDs in which a quantum well region (15) is shaped in conformance with the substrate (10).
More particularly, both the substrate (10) and the quantum well region (15) form sidewall (60), sidewall (65), or other sidewalls. Photons from the quantum well regions (15) may enter the substrate (10) through interface (50).
According to the ’960 Patent, the size and shape of interface (50) and exit face (55), the distance between the two faces, and the shapes of the sidewalls (60, 65) can be optimized to direct light incident on the inner side of the sidewalls to exit face (55) to produce a desired light output profile.
U.S. Patent No. 8,115,217 (’217 Patent) represents a family relating to LED packaging. Entitled “Systems and methods for packaging light-emitting diode devices,” the ’217 Patent is directed to a packaged LED device (100) comprising a housing (130) with an LED chip (120) residing in an interior wall (135) of the housing (130). A phosphor plate (140) is positioned on top of the LED chip (120).
Submount (110) comprises a block of thermally conductive material having a top surface and a bottom surface. The submount (110) also includes cap layers (115) on the bottom surface, a metal layer (150) on the top surface, and embedded electrical connectors (160) connecting the cap layer (115) and the metal layer (150).
Finally, U.S. Patent No. 8,217,399, entitled “Photon tunneling light emitting diodes and methods” (’399 Patent), represents the photon tunneling family. The ’399 Patent is directed to an LED device comprising an LED layer structure (100) bonded to a submount (150).
The submount can include one or more electrodes (151) in contact with or connected to a p-metal layer (145) and one or more electrodes (152) connected to an n-metal contacts (160). The LED device has an n-Gallium Nitride layer (120), a p-Gallium Nitride layer (130), and a quantum well layer (140).
According to the sale overview document, a key feature of the ’399 Patent invention is that the LED layer structure (100) has a thickness less than the wavelength of the light produced. The resulting photon tunneling prevents photons from becoming trapped in the substrate and therefore increases the amount of light emitted.
The sale overview document also features some cool analysis by our friends over at IP Checkups that shows where the Illumitex patents fit in the broader LED patent landscape.
Eric Lane is a patent attorney at McKenna Long & Aldridge LLP in San Diego and the author of Green Patent Blog. Mr. Lane can be reached at email@example.com
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