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:
Jul. 20, 2021
Filed:
Apr. 23, 2020
Sharp Kabushiki Kaisha, Osaka, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A pixel circuit for driving a light-emitting device for a display device is operable in an initialization phase, a compensation phase, a data programming phase, and an emission phase. The one horizontal time is minimized while maintaining accurate compensation of the threshold voltage of the drive transistor, and the pixel circuit further employs a varactor to compensate for variations in the threshold voltage of the drive transistor and for parasitic capacitances that arise within the pixel circuit. A capacitance of the varactor varies with a voltage at a node Nconstituting an electrical connection during the compensation phase of the drive transistor, the light-emitting device, a storage capacitor, and the varactor. The use of the capacitance variation of the varactor accounts for a variation in the threshold voltage of the drive transistor and for parasitic capacitances in the pixel circuit. The varactor may be implemented as a thin film transistor that operates as a variable capacitor.