MANHASSET, N.Y. Cambridge Display Technology announced Monday (March 14) it would expand its intellectual property (IP) portfolio in the field of organic light emitting diodes (OLEDs) used for display and lighting applications.
Among the patents now allowed in the U.S. is a patent relating to OLEDs which comprises hole transport, electron transport and emissive components, using type II interfaces, in the same molecule. This is believed to be important in the context of the printing of OLED devices. Molecules containing 'type II' interfaces are believed to be important in achieving high efficiency display devices.
According to Cambridge (Cambridge, U.K.), other new U.S. patents allowed include a patent relating to the use of a dielectric barrier layer over the key emissive layer to protect it from damage due to sputtering of a conductive layer. This is expected to have application in top emitting devices in which the light does not have to pass between the transistors but, more efficiently, through a transparent cathode structure.
Another allowed patent is jointly owned with Seiko Epson Corp. and covers certain solvents used in ink formulations for ink jet printing of polymer OLEDs. The companies formed a joint venture
for polymer OLED production in June 2002.
The ability of manufacturers to print displays is seen as key to the ability to produce lower cost, larger displays for OLED televisions. Ink jet printing is viewed as the best current approach to the challenges of manufacture of OLED displays.
Cambridge has a joint program with Toppan Printing
to develop roll printed displays using ink jet printing.