Active matrix driving

Active matrix drive schemes make OLEDs potentially competitive over a much wider range of applications. There is no longer a strict limit on the number of pix-... 

Other device architectures include inverted OLEDs. Here the cathode is in intimate contact with the substrate. The organic layers are then deposited onto the cathode in reverse order, i.e., starting with the electron transport material and ending with the HIL. The device is completed with an anode contact. In this case, as above, one of the electrodes is transparent, and light exits from the device through that contact. For example, Bulovic et al. [38], fabricated a device in which Mg/Ag was the bottom contact and ITO the top electrode. The advantage of this type of architecture is that it allows for easier integration with n-type TFTs (see Section 7.5 for a discussion of active-matrix drive OLED displays). 

Y. Hong, R. Hattori, and J. Kanicki, Novel poly-Si TFT pixel electrode circuits and current programmed active-matrix driving methods for AMOLEDs, SID Tech. Dig., 33, 618-621, 2002. 

Fig. 10.10 E-ink display with soft electronics active matrix driving circuits.

Ohta, S. et al.. Active matrix driving organic light-emitting diode panel using organic thin-fihn transistors, Jpn. J. Appl. Phys. Part 1 44, 3678-3681, 2005. 

The orientations of the molecules of the FLC materials are classified by the presence or absence of a helical structure. The most famous FLC device is the SSFLC (Surface Stabilized FLC) [1], in which the helical structure of the FLC material is unwound. While a variety of molecular orientations have been applied in SSFLC devices, three molecular orientations appear to be the most useful in practical FLC displays.These are the bookshelf-layered structure and the Cl-uniform (CIU) and the C2-uniform (C2U) orientations [2]. Each of these structures shows monostability or bistability, depending on the material and its alignment properties. The monostable orientations are applicable to active matrix FLC displays while the bistable orientations are applicable to passive matrix FLC displays. FLC displays with a helical orientation have also been investigated. One useful FLC mode with the helical orientation is the DHF (deformed-helix ferroelectric) mode [3]. This mode is monostable and is thus suitable for an active matrix drive method. 

Fig. 6.3.6 Rdationship between applied voltage and transmittance for SSFLC active matrix driving.

Alternating Polarization Domains (APD) mode for active matrix driving... 

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