Organic light emitting display with threshold voltage compensation and method for driving the same

1. An organic light emitting display comprising:

a display panel;

a data driver configured to supply a data signal to the display panel;

a memory positioned inside or outside the data driver, the memory including at least two banks; and

a sensing circuit unit configured to:

measure a threshold voltage of at least one driving transistor included in a subpixel positioned on one line of the display panel during a first vertical blank period during which an image is not displayed on the display panel, the first vertical blank period immediately preceding display of a first image on the display panel, and

provide compensation data corresponding to the measured threshold voltage of the subpixel positioned on the one line of the display panel to the memory, the compensation data provided during a second vertical blank period during which the image is not displayed on the display panel, the second vertical blank period immediately following display of the first image,

wherein the data driver separately reads previous compensation data and writes new compensation data provided by the sensing circuit unit in the at least two banks of the memory.

2. The organic light emitting display of claim 1 , wherein the sensing circuit unit is configured to sense a first line to a last line of the display panel and is configured to provide corresponding compensation data during a display period of the image or during a vertical blank period.

3. The organic light emitting display of claim 1 , wherein the data driver includes a data signal compensation unit, the data signal compensation unit configured to compensate for the data signal based on the compensation data,

wherein the data signal compensation unit reads the previous compensation data from a first bank of the at least two banks of the memory and writes the new compensation data to a second bank of the at least two banks of the memory,

wherein a position, at which the previous compensation data is read, and a position, at which the new compensation data is written, are changed each time compensation data is newly provided.

4. The organic light emitting display of claim 3 , wherein the data signal compensation unit is configured to read the previous compensation data, so as to compensate for the data signal, to be supplied, during a period, in which an image is displayed on the display panel.

5. The organic light emitting display of claim 1 , wherein the sensing circuit unit includes a circuit unit, the circuit unit configured to control a sensing operation for measuring the threshold voltage of the at least one driving transistor included in the display panel,

wherein the circuit unit outputs a switching control signal, which activates the sensing operation, at a start time point and an end time point of a vertical blank period positioned between frames.

6. The organic light emitting display of claim 1 , wherein when the sensing circuit unit is configured to measure the threshold voltage of the at least one driving transistor included in the display panel and is further configured to provide the compensation data, the sensing circuit unit supplying an initialization voltage through a reference line of a subpixel of the display panel and sensing the threshold voltage of the at least one driving transistor through a sensing transistor of the subpixel.

7. The organic light emitting display of claim 1 wherein

the sensing unit is configured to measure threshold voltages of subpixels positioned in a second line of the display panel during the second vertical blank period, the second line adjacent to and distinct from the one line of the display panel.

8. A method for driving an organic light emitting display comprising:

supplying a data signal to a display panel and displaying an image on the display panel;

measuring, by a sensing circuit unit, a threshold voltage of at least one driving transistor included in the display panel during a first vertical blank period during which the image is not displayed on the display panel, providing compensation data corresponding to the measured threshold voltage of the at least one driving transistor to a memory during a second vertical blank period during which the image is not displayed on the display panel, and separately reading previous compensation data and writing new compensation data in at least two banks of the memory; and

reading the previous compensation data and compensating for the data signal, to be supplied, during a period, during which the image is displayed on the display panel,

wherein the first vertical blank period immediately precedes the display of a first image on the display panel and the second vertical blank period immediately follows the display of the first image.

9. The method of claim 8 , further comprising:

measuring a threshold voltage of a driving transistor included in a subpixel positioned on one line of the display panel and providing compensation data during each vertical blank period, during which the image is not displayed on the display panel; and

sensing a first line to a last line of the display panel and then providing corresponding compensation data during a display period of the image or during a vertical blank period.

10. The method of claim 8 , wherein a position, at which the previous compensation data is read, and a position, at which the new compensation data is written, are changed each time compensation data is newly provided.