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Haruhiko OKUMURA
2009 Volume E92.C Issue 11 Pages
1333
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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Toshinari OGIWARA, Jun-ichi TAKAHASHI, Hitoshi KUMA, Yuichiro KAWAMURA ...
Article type: INVITED PAPER
2009 Volume E92.C Issue 11 Pages
1334-1339
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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We carried out degradation analysis of a blue phosphorescent organic light emitting diode by both impedance spectroscopy and transient electroluminescence (EL) spectroscopy. The number of semicircles observed in the Cole-Cole plot of the modulus became three to two after the device was operated for 567 hours. Considering the effective layer thickness of the initial and degraded devices did not change by degradation and combining the analysis of the Bode-plot of the imaginary part of the modulus, the relaxation times of emission layer and hole-blocking with electron transport layers changed to nearly the same value by the increase of the resistance of emission layer. Decay time of transient EL of the initial device was coincident with that of the degraded one. These phenomena suggest that no phosphorescence quenching sites are generated in the degraded device, but the number of the emission sites decrease by degradation.
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Doo-Hee CHO, Sang-Hee Ko PARK, Shinhyuk YANG, Chunwon BYUN, Min Ki RYU ...
Article type: INVITED PAPER
2009 Volume E92.C Issue 11 Pages
1340-1346
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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We have fabricated the transparent bottom gate and top gate TFTs using new oxide material of Al-Zn-Sn-O (AZTO) as an active layer. The AZTO active layer was deposited by RF magnetron sputtering at room temperature. Our novel TFT showed good TFT performance without post-annealing. The field effect mobility and the sub-threshold swing were improved by the post-annealing, and the mobility increased with SnO
2 content. The AZTO TFT (about 4 mol% AlOx, 66 mol% ZnO, and 30 mol% SnO
2) exhibited a mobility of 10.3cm
2/Vs, a turn-on voltage of 0.4V, a sub-threshold swing of 0.6V/dec, and an on/off ratio of 10
9. Though the bottom gate AZTO TFT showed good electrical performance, the bias stability was relatively poor. The bias stability was significantly improved in the top gate AZTO TFT. We have successfully fabricated the transparent AMOLED panel using the back-plane composed with top gate AZTO TFT array.
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Byung-Tae CHOI, Hyung Dal PARK, Heung-Sik TAE
Article type: PAPER
2009 Volume E92.C Issue 11 Pages
1347-1352
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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To explain the variation of the address discharge during an address period, the wall voltage variation during an address period was investigated as a function of the address-on-time by using the
Vt closed curves. It was observed that the wall voltage between the scan and address electrodes was decreased with an increase in the address-on-time. It was also observed that the wall voltage variation during an address period strongly depended on the voltage difference between the scan and address electrodes. Based on this result, the modified driving waveform to raise the level of
Vscanw, was proposed to minimize the voltage difference between the scan and address electrodes. However, the modified driving waveform resulted in the increase in the falling time of scan pulse. Finally, the overlapped double scan waveform was proposed to reduce a falling time of scan pulse under the raised voltage level of V
scanw, also.
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Tomokazu SHIGA, Masao ONO, Shinichi HARA, Satoshi KUSAKARI, Yoshifumi ...
Article type: PAPER
2009 Volume E92.C Issue 11 Pages
1353-1357
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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A replacement of an expensive MgO protective layer with relatively inexpensive Lanthanum Hexa Boride (LaB
6) has already been proposed. Since LaB
6 is not transparent, unlike MgO, the LaB
6 panel employs a long sustain gap structure. Since the sustain gap is 2.6 times larger than the distance between sustain and address electrodes, different driving methods from those of the conventional PDPs have to be adopted. For the driving technique of the sustain period, an application of delayed auxiliary pulses on A electrode and the overlap sustain pulse drive are proposed. Luminance degradation with higher sustain frequency driving can be compensated by use of a 2step sustain pulse driving. Low reset luminance and low address voltage are achieved with a square-ramp technique for the reset period. TV operation is successfully realized on AC PDP which incorporated the LaB
6 cathodes.
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Pai-Shan PA
Article type: BRIEF PAPER
2009 Volume E92.C Issue 11 Pages
1358-1361
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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A precision in thickness recycling modus for a displays' color filter surface using a gear-form cathode in microelectrochemical removal is developed in the study. Through the precise removal processes of optical materials of nanostructure of Indium-Tin-Oxide crystallization, the optoelectronic semiconductor industry can effectively recycle defective products, and reducing production costs.
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Takuya OHZONO, Hirosato MONOBE, Yo SHIMIZU
Article type: INVITED PAPER
2009 Volume E92.C Issue 11 Pages
1362-1365
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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The self-organized microwrinkles can serve as a surface alignment layer to align nematic liquid crystals, which is primarily based on the groove mechanism. The azimuthal anchoring energy is discussed and estimated from the groove topography and the actual twist angle in the twisted nematic cell.
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Musun KWAK, Hanrok CHUNG, Hyukmin KWON, Jehyun KIM, Daekyung HAN, Yoon ...
Article type: INVITED PAPER
2009 Volume E92.C Issue 11 Pages
1366-1370
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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Using frictional force microscopy (FFM), the friction surface characteristics were compared between twisted nematic (TN) mode and vertical alignment (VA) mode alignment films (AFs). The friction asymmetry was detected depending on temperature conditions on TN mode AF, but not on VA mode AF. The difference between two modes was explained by leaning intermolecular repulsion caused by the pre-tilt angle uniformity and the density of side chain. No level difference according to temperature conditions appeared when the pre-tilt angle were measured after liquid crystal (LC) injection.
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Tomoyuki KOGANEZAWA, Ichiro HIROSAWA, Hidenori ISHII, Takahiro SAKAI
Article type: INVITED PAPER
2009 Volume E92.C Issue 11 Pages
1371-1375
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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We developed a new method for characterizing molecular distribution in very thin liquid crystal layer (5-40nm) evaporated onto rubbed polyimide film used by grazing-incidence X-ray diffraction (GIXD). The diffraction peaks corresponding to intermolecular correlation perpendicular to longitudinal axis of liquid crystal molecule and the clear anisotropic distribution of liquid crystal molecules in a thin layer were successfully observed. We found that in the vicinity of the alignment film, the intermolecular spacing correlation perpendicular to longitudinal axis of the 5CB molecule was expanded by the alignment film, and that the ordering of the 5CB was not so high. As the distance from the alignment film the spacing came close to the intrinsic intermolecular spacing.
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Ichiro HIROSAWA, Tomoyuki KOGANEZAWA, Hidenori ISHII, Takahiro SAKAI
Article type: PAPER
2009 Volume E92.C Issue 11 Pages
1376-1381
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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We investigated effect of annealing after rubbing by grazing incidence X-ray diffraction, since annealing process is performed in the actual process of liquid crystal display (LCD) fabrication. It was found that rubbed surface polymers were highly crystallized by annealing at 250°C after rubbing, and that the crystallization of surface polymers by annealing occurred in the aligned polymer region induced by rubbing. Crystallization of surface polymers by annealing increasingly occurred as increasing of rubbing strength. Thus, it is considered that annealing process after rubbing should also play an important role to control liquid crystal alignment in LCD.
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Kosuke NISHIMURA
Article type: INVITED PAPER
2009 Volume E92.C Issue 11 Pages
1382-1386
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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A prototype of a novel mobile viewer system consisting of a mobile phone and a 13.1-inch 4096-color electronic paper display has been developed. The basic concept of the system, the technological study for realizing the concept, and the specifications of the prototype are described. Possible applications of the system are also proposed.
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Keiji HIRATA, Yasunori HARADA, Toshihiro TAKADA, Naomi YAMASHITA, Shig ...
Article type: PAPER
2009 Volume E92.C Issue 11 Pages
1387-1395
Published: November 01, 2009
Released on J-STAGE: November 01, 2009
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We propose a 2D display and camera arrangement for video communication systems that supports both spatial information between distant sites and user mobility. The implementation of this arrangement is called the “surrounding back screen method.” The method enables users to freely come from and go into other users' spaces and provides every user with the direct pointing capability, since there is no apparent spatial barrier separating users, unlike the case of conventional video communication systems. In this paper, we introduce two properties (“sharedness” and “exclusiveness”) and three parameters (a distance and two angles) to represent the geometrical relationship between two users. These properties and parameters are used to classify the shared spaces created by a video communication system and to investigate the surrounding back screen method. Furthermore, to demonstrate and explore our surrounding back screen method, we have developed a prototype system, called t-Room. Taking into account practical situations, we studied a practical case where two t-Rooms with different layouts are connected.
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