PMOLED displays

FIGURE 6.4.18 Power consumption of AMOLED and PMOLED displays of different resolutions. (Adapted from Haskal, E., SID Int. Symp. Seminar Lecture Notes, M-3/3, 2004. Copyright Society for Information Display. With permission.)... 

The advantage of AMOLED over PMOLED displays arises because emission in a passive matrix occurs one line at a time, so each OLED element operates at high peak currents and low duty-cycle. The duty-cycle in a PMOLED display is approximately equal to the inverse of the number of rows. For example, in an SXGA (1280 X 1024) display, the duty cycle is approximately 0.1%. The peak current of an OLED pixel may be 1 mA or more. High OLED currents lead to reduced power efficiency and operational lifetime and also place greater demands on the current capacity of the row driver circuits, which may have to handle currents of hundreds of miUiamperes on each output (although not simultaneously). 

Figure 6.4.17 illustrates PMOLED and AMOLED display architectures, with only one pixel of the AMOLED display shown for simplicity. The pixel in Figure 6.4.17(b) is the simplest AMOLED pixel, a two TFT pixel. It was proposed in 1975 for use with any electro-optic material that requires the flow of current [45]. Later, we describe AMOLED pixels that are more complicated than the two TFT pixel. 

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