Systems and methods for aging compensation in AMOLED displays
First Claim
1. A system for compensating individual pixel circuits in a display array of a multiplicity of pixel circuits, the system comprising:
- each of said pixel circuits being adapted to be programmed according to programming information, during a programming cycle, and driven to emit light according to the programming information, during an emission cycle, each pixel circuit including;
a light emitting device for emitting light during the emission cycle,a driving transistor for conveying current through the light emitting device during the emission cycle,a storage capacitor for being charged with a voltage based at least in part on the programming information, during the programming cycle, andan emission control transistor arranged to selectively connect, during the emission cycle, at least two of the light emitting device, the driving transistor, and the storage capacitor, such that current is conveyed through the light emitting device via the driving transistor according to the voltage on the storage capacitor; and
a driver for programming the pixel circuit via a data line by charging the storage capacitor according to the programming information;
a monitor for extracting a voltage or a current from the pixel circuit indicative of aging degradation of the pixel circuit; and
a controller for operating the monitor and the driver and configured to;
receive an indication of the amount of degradation from the monitor;
receive a data input indicative of an amount of luminance to be emitted from the light emitting device;
determine an amount of compensation to provide to the pixel circuit based on the amount of degradation; and
provide the programming information to the driver to program the pixel circuit, wherein the programming information is based at least in part on the received data input and the determined amount of compensation;
wherein the emission control transistor couples the storage capacitor across a gate terminal and a source terminal of the driving transistor during the emission cycle, the pixel circuit further comprising;
a data switch transistor, operated according to a select line, for coupling the data line to a terminal of the storage capacitor coupled to the gate terminal of the driving transistor; and
a monitoring switch transistor, operated according to the select line, for coupling a monitor line to a terminal of the storage capacitor coupled to the emission control transistor, the monitor line being coupled to the monitor for measuring the current through the drive transistor during the monitoring cycle.
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Accused Products
Abstract
Circuits for programming, monitoring, and driving pixels in a display are provided. Circuits generally include a driving transistor to drive current through a light emitting device according to programming information which is stored on a storage device, such as a capacitor. One or more switching transistors are generally included to select the circuits for programming, monitoring, and/or emission. Circuits advantageously incorporate emission transistors to selectively couple the gate and source terminals of a driving transistor to allow programming information to be applied to the driving transistor independently of a resistance of a switching transistor.
518 Citations
13 Claims
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1. A system for compensating individual pixel circuits in a display array of a multiplicity of pixel circuits, the system comprising:
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each of said pixel circuits being adapted to be programmed according to programming information, during a programming cycle, and driven to emit light according to the programming information, during an emission cycle, each pixel circuit including; a light emitting device for emitting light during the emission cycle, a driving transistor for conveying current through the light emitting device during the emission cycle, a storage capacitor for being charged with a voltage based at least in part on the programming information, during the programming cycle, and an emission control transistor arranged to selectively connect, during the emission cycle, at least two of the light emitting device, the driving transistor, and the storage capacitor, such that current is conveyed through the light emitting device via the driving transistor according to the voltage on the storage capacitor; and a driver for programming the pixel circuit via a data line by charging the storage capacitor according to the programming information; a monitor for extracting a voltage or a current from the pixel circuit indicative of aging degradation of the pixel circuit; and a controller for operating the monitor and the driver and configured to; receive an indication of the amount of degradation from the monitor; receive a data input indicative of an amount of luminance to be emitted from the light emitting device; determine an amount of compensation to provide to the pixel circuit based on the amount of degradation; and provide the programming information to the driver to program the pixel circuit, wherein the programming information is based at least in part on the received data input and the determined amount of compensation; wherein the emission control transistor couples the storage capacitor across a gate terminal and a source terminal of the driving transistor during the emission cycle, the pixel circuit further comprising; a data switch transistor, operated according to a select line, for coupling the data line to a terminal of the storage capacitor coupled to the gate terminal of the driving transistor; and a monitoring switch transistor, operated according to the select line, for coupling a monitor line to a terminal of the storage capacitor coupled to the emission control transistor, the monitor line being coupled to the monitor for measuring the current through the drive transistor during the monitoring cycle. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A pixel circuit for driving a light emitting device, the pixel circuit comprising:
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a driving transistor for driving current through a light emitting device according to a driving voltage applied across the driving transistor; a storage capacitor for being charged, during a programming cycle, with the driving voltage; an emission control transistor for connecting at least two of the driving transistor, the light emitting device, and the storage capacitor, such that current is conveyed through the driving transistor, during the emission cycle, according to voltage charged on the storage capacitor; and at least one switch transistor for connecting a current path through the driving transistor to a monitor for receiving indications of aging information based on the current through the driving transistor, during a monitoring cycle. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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Specification