Organic light emitting display
An organic light emitting display includes a display panel, on which a plurality of pixels each including an organic light emitting diode and a driving thin film transistor (TFT) controlling a current flowing in the organic light emitting diode are disposed, a timing controller configured to modulate input digital video data to compensate for changes in electric characteristic of the driving TFT, and a driving circuit unit configured to changes in electric characteristic of the driving TFT of each of specific pixels of the plurality of pixels in an image display period of each image frame and sequentially apply image display data to remaining pixels except the specific pixels along one direction in the image display period.
1. An organic light emitting display, comprising:
a display panel, on which a plurality of pixels each including an organic light emitting diode and a driving thin film transistor (TFT), for controlling a current flowing in the organic light emitting diode, are disposed;
a timing controller configured to modulate input digital video data to compensate for changes in electric characteristic of the driving TFT; and
a driving circuit unit configured, in an image display period of each image frame, to:
sense the changes in electric characteristic of the driving TFT of each of specific pixels on one display line selected among display lines of the display panel and apply luminance recovery data to the specific pixels based on the sensed changes, the image display period being a remaining period excluding a vertical blank period from each image frame; and
sequentially apply image display data to pixels on remaining lines among the display lines of the display panel, except the specific pixels along one direction, while not sensing the changes in electric characteristic of the driving TFT of the pixels on the remaining lines,
wherein one image frame assigned to the specific pixels includes:
a first initialization period, in which a source voltage of the driving TFT included in each of the specific pixels is firstly initialized to a reference voltage,
a programming period, in which a sensing data voltage is applied to a gate electrode of the driving TFT in the first initialization state of the source voltage of the driving TFT and sets the driving TFT to a turn-on state,
a sensing period, in which the source voltage of the driving TFT increased by a current flowing in the driving TFT is sensed and stored for a predetermined period of time,
a sampling period, in which the sensed source voltage is sampled and detects the changes in the electric characteristic of the driving TFT,
a second initialization period, in which the source voltage of the driving TFT is secondly initialized to the reference voltage, and
an emission period, in which a luminance recovery data voltage is applied to the gate electrode of the driving TFT in the second initialization state of the source voltage of the driving TFT to turn on the driving TFT, and the organic light emitting diode operates using a luminance recovery driving current applied through the driving TFT to display a luminance recovery image, and
wherein one image frame assigned to the pixels on the remaining lines includes:
an initialization period, in which a source voltage of the driving TFT included in each of the pixels on the remaining lines is initialized to the reference voltage,
a programming period, in which an image display data voltage is applied to the gate electrode of the driving TFT in the initialization state of the source voltage of the driving TFT and turns on the driving TFT, and
an emission period, in which the organic light emitting diode operates using an image display driving current applied through the driving TFT and displays an original image.
2. The organic light emitting display of claim 1 , wherein the one display line is sequentially selected among the display lines of the display panel along the one direction.
3. The organic light emitting display of claim 1 , wherein the one display line is non-sequentially selected among the display lines of the display panel irrespective of the one direction.
4. The organic light emitting display of claim 1 , wherein an emission duty of the organic light emitting diode for displaying the luminance recovery image is the same in all of the display lines of the display panel irrespective of a location of the specific pixels on the display panel.
5. The organic light emitting display of claim 1 , wherein a black display data voltage capable of turning off the driving TFT is applied to the gate electrode of the driving TFT during the sampling period.
6. The organic light emitting display of claim 1 , wherein the luminance recovery data voltage has the same voltage level as the image display data voltage to be applied to a display line next to a display line, to which the luminance recovery data voltage is applied.
7. The organic light emitting display of claim 1 , wherein the change in the electrical characteristic of the driving TFT indicates at least one of change in a threshold voltage of the driving TFT and change in a mobility of the driving TFT.
8. An organic light emitting display, comprising:
a display panel, on which a plurality of pixels each including an organic light emitting diode and a driving thin film transistor (TFT), for controlling a current flowing in the organic light emitting diode, are disposed;
a timing controller configured to modulate input digital video data to compensate for changes in electric characteristic of the driving TFT; and
a driving circuit unit configured to:
sense the changes in electric characteristic of the driving TFT of each of specific pixels in an image display period of each image frame and
sequentially apply image display data to remaining pixels except the specific pixels along one direction in the image display period,
wherein one image frame assigned to the specific pixels includes:
a first initialization period, in which a source voltage of the driving TFT included in each of the specific pixels is firstly initialized to a reference voltage,
a programming period, in which a sensing data voltage is applied to a gate electrode of the driving TFT in the first initialization state of the source voltage of the driving TFT and sets the driving TFT to a turn-on state,
a sensing period, in which the source voltage of the driving TFT increased by a current flowing in the driving TFT is sensed and stored for a predetermined period of time,
a sampling period, in which the sensed source voltage is sampled and detects the changes in the electric characteristic of the driving TFT,
a second initialization period, in which the source voltage of the driving TFT is secondly initialized to the reference voltage, and
an emission period, in which a luminance recovery data voltage is applied to the gate electrode of the driving TFT in the second initialization state of the source voltage of the driving TFT to turn on the driving TFT, and the organic light emitting diode operates using a luminance recovery driving current applied through the driving TFT to display a luminance recovery image, and
wherein one image frame assigned to the remaining pixels includes:
an initialization period, in which a source voltage of the driving TFT included in each of the remaining pixels is initialized to the reference voltage,
a programming period, in which an image display data voltage is applied to the gate electrode of the driving TFT in the initialization state of the source voltage of the driving TFT and turns on the driving TFT, and
an emission period, in which the organic light emitting diode operates using an image display driving current applied through the driving TFT and displays an original image.
9. The organic light emitting display of claim 8 , wherein the image display period is a remaining period excluding a vertical blank period from each image frame.
10. The organic light emitting display of claim 8 , wherein the specific pixels selected in each image frame are pixels on one display line of the display panel.
11. The organic light emitting display of claim 8 , wherein:
the specific pixels are selected as pixels on one display line of the display panel among the plurality of pixels of the display panel in each image frame; and
the display line of the specific pixels is sequentially selected among display lines of the display panel along the one direction.
12. The organic light emitting display of claim 8 , wherein:
the specific pixels are selected as pixels on one display line of the display panel among the plurality of pixels of the display panel in each image frame, and
the display line of the specific pixels is non-sequentially selected among display lines of the display panel irrespective of the one direction.
13. The organic light emitting display of claim 8 , wherein an emission duty of the organic light emitting diode for displaying the luminance recovery image is the same in all of display lines of the display panel irrespective of a location of the specific pixels on the display panel.
14. The organic light emitting display of claim 8 , wherein a black display data voltage capable of turning off the driving TFT is applied to the gate electrode of the driving TFT during the sampling period.
15. The organic light emitting display of claim 8 , wherein the luminance recovery data voltage has the same voltage level as the image display data voltage to be applied to a display line next to a display line, to which the luminance recovery data voltage is applied.
16. The organic light emitting display of claim 8 , wherein the change in the electrical characteristic of the driving TFT indicates at least one of change in a threshold voltage of the driving TFT and change in a mobility of the driving TFT.