Hybrid driving manner organic light emitting diode display apparatus
The present invention provides an organic light emitting diode (OLED) display apparatus displaying a grayscale of one frame with N number of subfields. The OLED display apparatus includes a display panel where pixels are defined by an intersection of data lines and gate lines, a gate driving unit that provides a scan signal to the gate line, and a data driving unit that controls a data voltage in an analog manner. Here, the data voltage is provided to the data line in at least one subfield.
1. An Organic Light Emitting Diode (OLED) display apparatus displaying a frame of an image having a grayscale value with N (N is a natural number larger than 2) number of subfields, the OLED display apparatus comprising:
a display panel where pixels are defined by an intersection of data lines and gate lines;
a power supplying unit that provides a voltage to a driving transistor and an OLED of the pixel;
a gate driving unit that provides a scan signal to the gate line; and
a data driving unit that controls a data voltage in an analog manner, the data voltage provided to the data line in a subfield,
wherein each of the subfields has an associated power supply voltage, and the data voltage is applied to a pixel in least one subfield of the N subfields based on the grayscale value of the image; and
wherein the displayed grayscale of a pixel is a sum of the grayscales of the N subfields and when the grayscale of the image is greater than the sum of the grayscales of the pixel of the N subfields, the data voltage of the pixel in at least one of the subfields in increased; or, when the increase in the data voltage is insufficient to achieve the grayscale of the image, the duration of one of the subfields increased.
2. The OLED display apparatus of claim 1 , wherein N successive grayscale areas are assigned to the subfields respectively, and the grayscale areas displayed in all of the subfields are different.
3. The OLED display apparatus of claim 2 , wherein the data driving unit provides a black data voltage to at least (N−1) number of the subfields.
4. The OLED display apparatus of claim 1 , wherein the power supplying unit provides the high potential voltage or the low potential voltage so that a driving transistor connected to the OLED is driven in a saturation area, and controls to decrease a drain-source voltage of the driving transistor.
5. The OLED display apparatus of claim 4 , wherein the power supplying unit provides the high potential voltage or the low potential voltage so that the drain-source voltage of the driving transistor is lower in a second subfield than the drain-source voltage of the driving transistor in a first subfield, when an area of a grayscale value higher than a grayscale value of an area displayed in the second subfield is displayed in the first subfield.
6. The OLED display apparatus of claim 1 , wherein the power supplying unit does not provide the high potential voltage or the low potential voltage in at least one subfield.