BridgeLux fires lawsuit right back at Cree
Five weeks after being accused of patent infringement by the major LED manufacturer Cree, BridgeLux has responded with a lawsuit of its own.
BridgeLux has filed a motion to dismiss the action brought by Cree and Boston University, while alleging that the North Carolinan company has infringed US patent 6,869,812.
"We believe in the importance of respecting the intellectual property rights of others, just as we expect that others will respect our rights," insisted BridgeLux CEO Bob Walker.
Of the three patents cited, BridgeLux's is the most recent, having been filed in May 2003. Entitled High power AllnGaN based multi-chip light emitting diode , it is attributed to Heng Liu of Sunnyvale, CA, but does not mention either BridgeLux or eLite Optoelectronics, the firm's former incarnation.
eLite was itself founded in December 2002 by former employees of AXT s LED operation. AXT now concentrates solely on semiconductor manufacturing materials, primarily GaAs substrates.
The Heng Liu patent describes an LED chip design that improves brightness and electro-optic efficiency through the use of a transparent substrate and an elongated chip geometry.
The patent says that this design enhances heat dissipation, and allows the chip to operate at relatively high currents.
Cree has sued BridgeLux over infringement of a number of US patents, including 6,657,236 and 5,686,738. The "˜738 patent, filed back in 1997 and assigned to Boston University, details an MBE-based method for making GaN films. GaN LEDs are generally produced using MOCVD.
The more recent "˜236 patent lists Stephen DenBaars from the University of California, Santa Barbara, as one of three inventors, and is concerned with improving LED light extraction through the use of "optical elements".
These "light-extraction" structures allow photons that would otherwise remain trapped within the LED to escape. They consist of surfaces that reflect or scatter light more favorably, while the patent also mentions random patterning and texturing techniques to aid light extraction.
