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US 8,044,891 B2Granted
Systems and methods for providing threshold voltage compensation of pixels
AssigneeChimei Innolux Corporation
InventorDu-Zen Peng
Life of this patent
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Abstract
Systems and methods for providing threshold voltage compensation of pixels are provided. A representative system incorporates first switching element and a voltage compensation driver. The first switching element is operative to transfer a data signal. The voltage compensation driver is operative to generate a compensation voltage according to a reference signal and output a driving current according to the data signal and the compensation voltage.
Claims16
A system for providing threshold voltage compensation of pixels comprising:
- a first switching element transferring a data signal;
- and a voltage compensation driver coupled between a power voltage and a display device, inducing a charging voltage on a first node according to a reference signal and generating a compensation voltage according to the charging voltage during a first period, and
- outputting a driving current according to the data signal and the compensation voltage to the display device during a second period following with the first period, wherein the charging voltage is higher than the power voltage, and
- the reference signal is pulled to the power voltage with in the first period and is pulled to ground within the second period, and wherein the power voltage is maintained during the first and the second periods, and
- the voltage compensation driver comprises a key transistor coupled between the power voltage and the display device, generating the driving current according to the data signal and the compensation voltage;
- a first capacitor coupled between the reference signal and the first node;
- and a second capacitor coupled between the first node and the key transistor, storing the compensation voltage, and
- the voltage compensation driver and the first switching element are coupled to a first scan line and a second scan line respectively, and the first scan line is asserted during the first period and the second scan line is asserted ruing the second period later than the first period.
5 more elements
A method for providing threshold voltage compensation of pixels, comprising:
- inducing a charging voltage on a first node according to a reference signal during a first period;
- loading a threshold compensation voltage of a first transistor into a first capacitor according to the charge voltage during the first period;
- loading a first data signal and the loaded threshold compensation voltage into a second capacitor during a second period later than the first period;
- and
- coupling the loaded data signal and the loaded threshold compensation voltage to the first transistor to provide a threshold independent driving current to a display device during the second period, wherein the charge voltage is higher than a power voltage, and the reference signal is pulled to the power voltage within the first period and is pulled to ground within the second period;
- wherein the first transistor is coupled between the power voltage and the display device, and the power voltage is maintained during the first and second periods, and the first capacitor is coupled between the reference signal and the first node, and the second capacitor is coupled between the first node and the first transistor, storing the compensation voltage.
3 more elements
A system for providing threshold voltage compensation of pixels comprising:
- a voltage compensation driver coupled between a power voltage and a display device, inducing a charging voltage on a first node according to a reference signal and generating a compensation voltage according to the charging voltage during a first period, and providing a driving current to the display device according to the compensation voltage during a second period later than the first period, and the charging voltage is higher than the power voltage, and the reference signal is pulled to the power voltage within the first period and is pulled to ground within the second period, wherein the power voltage is maintained during the first and the second periods, wherein the voltage compensation driver comprises:
- a key transistor having a first terminal coupled to the power voltage and a second terminal coupled to the display device;
- a first capacitor coupled between the first node and the reference signal;
- and
- a second capacitor coupled between the first node and a control terminal of the key transistor, storing the compensation voltage according to a first data signal stored during a previous driving operation in the first capacitor and the charging voltage higher than the power voltage, such that the key transistor generates and outputs the driving current according to the compensation voltage and a second data signal from a first switching element.
2 more elements
Dependencies are inferred from the claim text.