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:
Apr. 19, 2011
Filed:
Oct. 10, 2007
Charles I. Levey, West Henrietta, NY (US);
John W. Hamer, Rochester, NY (US);
Charles I. Levey, West Henrietta, NY (US);
John W. Hamer, Rochester, NY (US);
Global OLED Technology LLC, Herndon, VA (US);
Abstract
Compensating for changes in the threshold voltage of the drive transistor of an OLED drive circuit, the drive transistor includes a first electrode, second electrode, and gate electrode; connecting a first voltage source to the first electrode, and an OLED device to the second electrode and to a second voltage source; providing a test voltage to the gate electrode and connecting to the OLED drive circuit, a test circuit, that includes an adjustable current mirror causing voltage applied to the current mirror, to be at a first test level; providing a test voltage to the gate electrode of the drive transistor and connecting the test circuit to the OLED device producing a second test level after the drive transistor and the OLED device age; and using the first and second test levels to calculate changes in the voltage applied to the gate electrode of the drive transistor to compensate for drive transistor aging.