Pixel circuits for amoled displays
First Claim
1. A system for controlling a display, the system comprising:
- a reference voltage source;
a programming voltage source;
a pixel circuit includinga light-emitting device,a drive transistor for driving current through the light-emitting device according to a driving voltage across the drive transistor during an emission cycle,a storage capacitor coupled to a gate of said drive transistor for storing said driving voltage,a first switching transistor that controls a coupling of said reference voltage source to said storage capacitor,a second switching transistor that controls a coupling of said programming voltage source to the gate of said drive transistor, the second switching transistor controlled by a signal used to control the first switching transistor of the pixel circuit in an adjacent row of the display, anda controller configured toallow a node between the drive transistor and the light-emitting device to charge to a voltage that is a function of the characteristics of the drive transistor, andcharge a node between said storage capacitor and the gate of said drive transistor to said programming voltage.
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Accused Products
Abstract
A system for controlling a display in which each pixel circuit comprises a light-emitting device, a drive transistor, a storage capacitor, a reference voltage source, and a programming voltage source. The storage capacitor stores a voltage equal to the difference between the reference voltage and the programming voltage, and a controller supplies a programming voltage that is a calibrated voltage for a known target current, reads the actual current passing through the drive transistor to a monitor line, turns off the light emitting device while modifying the calibrated voltage to make the current supplied through the drive transistor substantially the same as the target current, modifies the calibrated voltage to make the current supplied through the drive transistor substantially the same as the target current, and determines a current corresponding to the modified calibrated voltage based on predetermined current-voltage characteristics of the drive transistor.
533 Citations
9 Claims
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1. A system for controlling a display, the system comprising:
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a reference voltage source; a programming voltage source; a pixel circuit including a light-emitting device, a drive transistor for driving current through the light-emitting device according to a driving voltage across the drive transistor during an emission cycle, a storage capacitor coupled to a gate of said drive transistor for storing said driving voltage, a first switching transistor that controls a coupling of said reference voltage source to said storage capacitor, a second switching transistor that controls a coupling of said programming voltage source to the gate of said drive transistor, the second switching transistor controlled by a signal used to control the first switching transistor of the pixel circuit in an adjacent row of the display, and a controller configured to allow a node between the drive transistor and the light-emitting device to charge to a voltage that is a function of the characteristics of the drive transistor, and charge a node between said storage capacitor and the gate of said drive transistor to said programming voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification