Display device and method of driving the same
A display device includes: a plurality of pixels coupled to data lines and sensing lines; a data driver configured to supply one of an image data signal and a sensing data signal to the data lines; a voltage supply configured to supply an initialization voltage to the pixels through the sensing lines; and a sensing circuit configured to receive a sensing value from at least one of the pixels through the sensing lines, and compare the sensing value with a sensing reference value to generate a sensing voltage control signal to control at least one of the sensing data signal or the initialization voltage.
1. A display device comprising:
a plurality of pixels coupled to data lines and sensing lines;
a data driver configured to supply one of an image data signal and a sensing data signal to the data lines;
a voltage supply configured to supply an initialization voltage to the pixels through the sensing lines; and
a sensing circuit configured to receive a sensing value from at least one of the pixels through the sensing lines, and compare the sensing value with a sensing reference value to generate a sensing voltage control signal to control at least one of the sensing data signal or the initialization voltage, the sensing voltage control signal comprising a first control signal to decrease at least one of the sensing data signal or the initialization voltage when the sensing value is greater than the sensing reference value, and a second control signal to increase at least one of the sensing data signal or the initialization voltage when the sensing value is less than the sensing reference value,
wherein the voltage supply is configured to increase or decrease a level of the initialization voltage from a previous initialization voltage level according to the first control signal or the second control signal of the sensing voltage control signal to change a sensing voltage range for detecting the sensing value, and
wherein the sensing voltage control signal is not supplied to the plurality of pixels.
2. The display device according to claim 1 , wherein the sensing circuit comprises:
an analog-to-digital converter coupled to the sensing lines and configured to convert an analog sensing value provided through an input terminal to a digital sensing code.
3. The display device according to claim 2 , wherein the sensing circuit further comprises:
a voltage comparator coupled to the input terminal of the analog-to-digital converter and configured to compare the analog sensing value with a sensing reference voltage to generate the sensing voltage control signal.
4. The display device according to claim 3 , wherein the voltage comparator is configured to:
generate a first sensing voltage control signal in response to the analog sensing value being greater than the sensing reference voltage, and
generate a second sensing voltage control signal in response to the analog sensing value being less than the sensing reference voltage.
5. The display device according to claim 4 , further comprising:
a code comparator configured to receive the digital sensing code, and to compare the digital sensing code with a maximum sensing code or a minimum sensing code to generate the sensing voltage control signal based on a value of the comparing.
6. The display device according to claim 5 , wherein the code comparator is configured to:
generate a first sensing voltage control signal in response to the value of the comparing between the digital sensing code and the maximum sensing code being less than a preset reference range, and
generate a second sensing voltage control signal in response to the value of the comparing between the digital sensing code and the minimum sensing code being less than a preset reference range.
7. The display device according to claim 6 , further comprising:
a timing controller configured to generate compensated image data by reflecting the digital sensing code in input image data, and to provide the compensated image data to the data driver.
8. The display device according to claim 7 , wherein the code comparator is configured to compare the digital sensing code with the maximum sensing code or the minimum sensing code, and in response to the value of the comparing being out of a preset reference range, to provide the digital sensing code to the timing controller.
9. The display device according to claim 8 , wherein the timing controller is configured to receive the sensing voltage control signal, to supply a signal to change the sensing data signal to the data driver based on the sensing voltage control signal, and to supply a signal to change the initialization voltage to the voltage supply based on the sensing voltage control signal.
10. The display device according to claim 1 , wherein the pixels are coupled to scan lines and control lines, and
wherein each of the pixels comprises:
a light-emitting element;
a first transistor including a gate electrode coupled to a first node, a first electrode coupled to a first driving voltage through a first power line, and a second electrode coupled to a first electrode of the light-emitting element;
a second transistor including a gate electrode coupled to one of the scan lines, a first electrode coupled to one of the data lines, and a second electrode coupled to the first node;
a third transistor including a gate electrode coupled to one of the control lines, a first electrode coupled to one of the sensing lines, and a second electrode coupled to the second electrode of the first transistor; and
a storage capacitor coupled between the first node and the second electrode of the first transistor.
11. The display device according to claim 10 , wherein:
the first transistor is a driving transistor, and
a scan signal is supplied to the one of the scan lines and a control signal is supplied to the one of the control lines during a display period.
12. A display device comprising:
a plurality of pixels coupled to data lines and sensing lines;
a data driver configured to supply one of an image data signal and a sensing data signal to the data lines;
a voltage supply configured to supply an initialization voltage to the pixels through the sensing lines; and
a sensing circuit configured to receive an analog sensing value from at least one of the pixels through the sensing lines, to convert the analog sensing value to a digital sensing code reflecting a difference between the analog sensing value and the initialization voltage, to compare the digital sensing code with a maximum sensing code or a minimum sensing code to generate a sensing voltage control signal to control at least one of the sensing data signal or the initialization voltage based on a value of the comparing,
wherein the voltage supply is configured to increase or decrease a level of the initialization voltage from a previous initialization voltage level according to the sensing voltage control signal to widen a sensing voltage range for detecting the analog sensing value, and
wherein the sensing voltage control signal is not supplied to the plurality of pixels.
13. The display device according to claim 12 , wherein the sensing circuit is configured to:
generate a first sensing voltage control signal in response to the value of the comparing between the digital sensing code and the maximum sensing code being less than a preset reference range, and
generate a second sensing voltage control signal in response to the value of the comparing between the digital sensing code and the minimum sensing code being less than a preset reference range.
14. The display device according to claim 13 , further comprising:
a timing controller configured to generate compensated image data by reflecting the digital sensing code in input image data, and to provide the compensated image data to the data driver.
15. The display device according to claim 14 , wherein the sensing circuit is configured to compare the digital sensing code with the maximum sensing code or the minimum sensing code, and in response to the value of the comparing being out of a preset reference range, to provide the digital sensing code to the timing controller.
16. The display device according to claim 15 , wherein the timing controller is configured to receive the sensing voltage control signal, to supply a signal to change the sensing data signal to the data driver based on the sensing voltage control signal, and to supply a signal to change the initialization voltage to the voltage supply based on the sensing voltage control signal.
17. A method of driving a display device including a plurality of pixels coupled to data lines and sensing lines and driven to have a display period for displaying an image and a sensing period for sensing characteristics of a driving transistor included in each of the pixels, the method comprising:
supplying a sensing data signal to the data lines and an initialization voltage to the sensing lines in the sensing period;
receiving an analog sensing value from at least one of the pixels through the sensing lines; and
comparing the analog sensing value with a sensing reference voltage to generate a sensing voltage control signal to control at least one of the sensing data signal or the initialization voltage, the sensing voltage control signal comprising a first control signal to decrease at least one of the sensing data signal or the initialization voltage when the analog sensing value is greater than the sensing reference voltage, and a second control signal to increase at least one of the sensing data signal or the initialization voltage when the analog sensing value is less than the sensing reference voltage,
wherein a level of the initialization voltage is increased or decreased from a previous initialization voltage level according to the first control signal or the second control signal of the sensing voltage control signal to change a sensing voltage range between the sensing data signal and the initialization voltage for detecting the analog sensing value during the sensing period, and
wherein the sensing voltage control signal is not supplied to the plurality of pixels.
18. The method according to claim 17 , wherein generating the sensing voltage control signal comprises:
generating a first sensing voltage control signal in response to the analog sensing value being greater than the sensing reference voltage, and generating a second sensing voltage control signal in response to the analog sensing value being less than the sensing reference voltage.
19. The method according to claim 18 , further comprising:
receiving the analog sensing value and converting the analog sensing value to a digital sensing code.
20. The method according to claim 19 , further comprising:
receiving the digital sensing code, and comparing the digital sensing code with a maximum sensing code or a minimum sensing code to generate the sensing voltage control signal based on a value of the comparing.