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:
Jun. 05, 2012
Filed:
Mar. 04, 2009
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
Subpixels on an electroluminescent (EL) display panel, such as an organic light-emitting diode (OLED) panel, are compensated for initial nonuniformity ('mura') and for aging effects such as threshold voltage Vshift, EL voltage Vshift, and OLED efficiency loss. The drive current of each subpixel is measured at one or more measurement reference gate voltages to form status signals representing the characteristics of the drive transistor and EL emitter of those subpixels. Current measurements are taken in the linear region of drive transistor operation to improve signal-to-noise ratio in systems such as modern LTPS PMOS OLED displays, which have relatively small Vshift over their lifetimes and thus relatively small current change due to channel-length modulation. Various sources of noise are also suppressed to further increase signal-to-noise ratio.