Fabrication of vertically aligned liquid crystal cell without using a conventional alignment layer

Alignment control technology of liquid crystal molecules

“…Research groups from academic to business proposed recently different types of VA‐LCD self‐alignment . Jeng et al successfully fabricated VA‐LCDs without PI alignment layers by using LC‐mixture with silica‐based nanoparticles, polyhedral oligomeric silsesquioxanes (POSS) .…”

“…However, there was a problem of reliability and image sticking parameters, such as VHR and residual DC voltage. Therefore, Mizusaki et al improved these parameters by exchanging the RM monomer with one of high rigidity, such as acrylic acid 4‐(4′‐octyloxy‐biphenyl‐4‐yloxy)‐butyl ester . The polymer resulting from the high rigidity monomer is easy to separate from the LC layer.…”

“…Research groups from academic to business proposed recently different types of VA-LCD selfalignment. [246][247][248][249][250][251][252]255,256 Jeng et al successfully fabricated VA-LCDs without PI alignment layers by using LCmixture with silica-based nanoparticles, polyhedral oligomeric silsesquioxanes (POSS). 247 They found that the POSS modified by phenethyl groups induced vertical LC-alignment because of the interaction of phenethyl groups with the LC molecules.…”

“…Therefore, Mizusaki et al improved these parameters by exchanging the RM monomer with one of high rigidity, such as acrylic acid 4-(4′-octyloxy-biphenyl-4-yloxy)-butyl ester. 250 The polymer resulting from the high rigidity monomer is easy to separate from the LC layer. Thus, VHR and residual DC voltage were improved owing to the reduction of the radical at the tail end of the polymerized compound.…”

“…251,252,256 Research for a homogeneous self-alignment has also started in the past few years. The reason is that IPS/FFS-LCD operating modes are mostly chosen for mobile, tablet, Light transmission type 244,245 Self-alignment VA 0.1~2 wt% Unpolarized UV irradiation Light transmission type [246][247][248][249][250][251][252] Self-alignment HA 0.1~2 wt% Polarized UV irradiation Light transmission type 253,254 and PC applications. These in-plane type homogeneouslyaligned (HA) modes are characterized by a wide viewing angle and high transmittance.…”