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:
Aug. 15, 2006
Filed:
Mar. 20, 2003
Takatoshi Tsujimura, Fujisawa, JP;
Kohichi Miwa, Yokohama, JP;
Mitsuo Morooka, Kawasaki, JP;
Toppoly Optoelectronics Corp., Chu-Nan, TW;
Abstract
A technique to reduce the rate of increase in threshold voltage, i.e. degradation, of an amorphous silicon TFT driving an OLED. A first supply voltage is supplied to a drain of the TFT when a first control voltage is applied to a gate of the TFT to activate the TFT and drive the OLED. However, a second, lower supply voltage is supplied to the drain of the TFT when a second control voltage is applied to the gate of the TFT to deactivate the TFT and turn off the OLED, whereby a voltage differential between the drain and the source when the second control voltage is applied to the gate is substantially lower said first supply voltage. This reduces degradation of the TFT. According to one feature of the present invention, when the TFT is turned off by the absence of voltage applied to its gate, the voltage at the drain of the TFT is reduced to approximately zero to minimize the voltage differential between the drain and the source.