Display device and method for driving same
First Claim
1. An active matrix display device, comprising:
- a plurality of data wiring lines supplying data signals;
a plurality of scan wiring lines that are each selectively driven;
a plurality of pixel circuits provided at respective intersections between the plurality of data wiring lines and the plurality of scan wiring lines,wherein each of the pixel circuits includes;
an electrooptical element provided between a first power source line that supplies a first power source potential and a second power source line that supplies a second power source potential; and
a driving unit that controls a current flowing through the electrooptical element, the driving unit including a driving transistor provided between the first power source line and the second power source line and connected in series to the electrooptical element, and a driving capacitance element that stores a drive voltage for controlling the driving transistor;
an input unit that supplies to the driving unit a voltage of the data signal supplied by a corresponding data wiring line in response to a corresponding scan wiring line being selected;
a first compensation unit connected to a reverse bias control line that supplies a control potential at least during a first prescribed period, the first compensation unit causing the electrooptical element to be reverse biased between the second power source line and the reverse bias control line during the first prescribed period, receiving a resultant reverse direction current flowing through the electrooptical element, and supplying a compensation signal based on the reverse direction current to the driving capacitance element; and
a light emission control transistor provided between the first power source line and the electrooptical element, the light emission control transistor being in an off state during a second prescribed period that includes the first prescribed period, andwherein the driving unit determines a drive voltage for controlling the driving transistor in accordance with at least a voltage of the data signal and the compensation signal, the driving unit causing the electrooptical element to emit light in accordance with the determined drive voltage after the second prescribed period ends.
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Accused Products
Abstract
In a pixel circuit, during a period during which an organic EL element is not emitting light, a transistor is in an “on” state and a reverse-direction voltage determined by a reverse-direction current that depends on the degree to which degradation of the organic EL element has progressed is written to a capacitor. The transistor then turns off, another transistor turns on, and a compensating current that depends on the reverse-direction voltage flows from another capacitor towards a reverse-biasing power-supply line, causing a drive voltage maintained by the capacitor to change by a compensating voltage change. This makes it possible to minimize decreases in the emission luminance of an electro-optical element such as an organic EL element due to degradation thereof over time.
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Citations
16 Claims
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1. An active matrix display device, comprising:
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a plurality of data wiring lines supplying data signals; a plurality of scan wiring lines that are each selectively driven; a plurality of pixel circuits provided at respective intersections between the plurality of data wiring lines and the plurality of scan wiring lines, wherein each of the pixel circuits includes; an electrooptical element provided between a first power source line that supplies a first power source potential and a second power source line that supplies a second power source potential; and a driving unit that controls a current flowing through the electrooptical element, the driving unit including a driving transistor provided between the first power source line and the second power source line and connected in series to the electrooptical element, and a driving capacitance element that stores a drive voltage for controlling the driving transistor; an input unit that supplies to the driving unit a voltage of the data signal supplied by a corresponding data wiring line in response to a corresponding scan wiring line being selected; a first compensation unit connected to a reverse bias control line that supplies a control potential at least during a first prescribed period, the first compensation unit causing the electrooptical element to be reverse biased between the second power source line and the reverse bias control line during the first prescribed period, receiving a resultant reverse direction current flowing through the electrooptical element, and supplying a compensation signal based on the reverse direction current to the driving capacitance element; and a light emission control transistor provided between the first power source line and the electrooptical element, the light emission control transistor being in an off state during a second prescribed period that includes the first prescribed period, and wherein the driving unit determines a drive voltage for controlling the driving transistor in accordance with at least a voltage of the data signal and the compensation signal, the driving unit causing the electrooptical element to emit light in accordance with the determined drive voltage after the second prescribed period ends. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of driving an active matrix display device including:
- a plurality of data wiring lines that each supply a data signal;
a plurality of scan wiring lines that are each selectively driven; and
a plurality of pixel circuits provided at respective intersections between the plurality of data wiring lines and the plurality of scan wiring lines, each of the pixel circuits including;
an electrooptical element provided between a first power source line that supplies a first power source potential and a second power source line that supplies a second power source potential; and
a driving unit for controlling a current flowing through the electrooptical element, the driving unit having a driving transistor provided between the first power source line and the second power source line and connected in series to the electrooptical element, and a driving capacitance element that stores a drive voltage for controlling the driving transistor, the method comprising;supplying to the driving unit a voltage of the data signal supplied by a corresponding data wiring line in response to a corresponding scan wiring line being selected; supplying to the driving capacitance element a compensation signal based on a reverse direction current flowing through the electrooptical element between the second power source line and a reverse bias control line that supplies a control potential at least during a first prescribed period; determining the drive voltage based on at least a voltage of the data signal and the compensation signal; controlling a light emission timing of the electrooptical element to block current flowing between the first power source line and the electrooptical element during a second prescribed period that includes the first prescribed period; and causing the electrooptical element to emit light in accordance with the determined drive voltage after the second prescribed period ends.
- a plurality of data wiring lines that each supply a data signal;
Specification