P‐147: Novel Electrode Structure in the Super‐IPS LC Cell for High‐Aperture Ratio

Abstract

In this paper, we propose a novel electrode structure, which exhibits high-aperture ratio, in the super in-plane switching (S-IPS) liquid crystal (LC) cell for high transmittance. Generally, the transmittance of the S-IPS LC cell is not superior to other LC mode using the multi domain effect because of the low aperture ratio. To improve the aperture ratio of the S-IPS cell, we found the method to minimize the black matrix (BM) area by applying the novel electrode structure which can move the disclination from the active area. As a result, we found that the proposed electrode structure could provide higher aperture ratio than that of the conventional type by reducing the BM area, so that we could achieve the high transmittance compared to the conventional structure. We used the commercial software 'TechWiz LCD' for calculation of the director configuration, which applies Q-tensor method.

Enhanced thin-film transistor driven high-aperture in-plane switching liquid crystal displays without common line and black matrix

“…They are well connected to the source electrode and gate line via through holes, and the common electrodes at both ends cover the underlying data lines to prevent electrical noise from being applied to the LC layer. As will be shown later, this noise shield electrode (SE) is what makes the black matrix above the data line unnecessary 9 – 11 , 23 .

Figure 3 Optical and SEM (scanning electron microscopy) images of fabricated ( a , b ) CL and ( c , d ) CLSE pixel structures.

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“…2 b,a for a comparison with the conventional structure). During the holding period (t OFF ) in the conventional structure, regardless of the pixel voltage, Vp (including Vp = 0), nonzero Vgp and Vgc are always applied to keep the TFT off, and these voltages are applied to the LC layer, inducing light leakage as reported in 23 . On the other hand, in the case of the dark state with Vp = 0 in the CL structure, both Vgp and Vgc are zero volt, which does not induce light leakage.…”

“…In the conventional structure, the LC suffers from a continuous DC voltage during the holding (TFT OFF) stage even when the pixel voltage equal to zero, shown as the gray areas in Fig. 2 a, which cause light leakage 23 along the gate line through the gaps between the gate line and pixel/common electrodes. Therefore, in the conventional structure shown in Fig.…”