2.2 Applications 

應用

A remarkable property of azo-dye aligning layers gives a good chance to provide a high photoalignment quality of ferroelectric liquid crystal (FLC) using the azo-dye layer. 

偶氮染料對準層的一個顯著特性提供了一個高光配鐵電液晶（FLC）使用偶氮染料層質(zhì)量的好機會。

The photo-aligned FLC cell appeared to be better than prepared by buffing, if the UV-irradiation time of the azo-dye layer is high enough [27]. The FLC row addressing response time ofτ≈ 100 μ s at the voltage pulse amplitude of U=  ±15V was demonstrated [27, 28]. Large FLC cell gaps of 5 μ m and 7 μ m were used, which is easy in manufacturing. Perfect electrooptical performance of the photo-aligned FLC display with a memorized gray scale was demonstrated. http://ukthesis.org/ygsslwdx/

使用5μm和7微米大的FLC細胞間隙，這是很容易制造的。有記憶的灰度照片對齊FLC顯示完美的電光性能證明。

A prototype of passively addressed passive matrix FLC display based on the photo-alignment technique was developed [28]. Recently photoaligned bistable FLC with dichromatic (two color) [29] and almost achromatic (black/white) [30] switching were realized. 1 60×160 passive matrix addressed bistable 5um FLC display was demonstrated with the driving voltage of ±13V and 5um cell gap [31]. Images can be saved for very long time without any power supply.  VAN-LCD has become very popular for LCD TV applications because of the high contrast and wide viewing angle it affords. In experiment [32] the commercially available polyimide (PI) for homeotropic alignment was used in a combination with azo-dye for varying the pretilt angle fromthe homeotropic direction. The composition of 1% of azo-dye in solution with PI was prepared and the photo-aligning films were illuminated by a slantwise nonpolarized light. 

在實驗 [32] 中，市場可買到的聚酰亞胺（PI）為垂直排列中，從各向同性方向使用偶氮染料的組合與不同的預傾斜角。制備1％的偶氮類染料組合物，在溶液中與PI的光取向膜，由一個傾斜的非偏振光照明。

For comparison the aligning film of a pure PI was prepared by rubbing technique to align the LC molecules in a homeotropic state with some pretilt angle. The measured value of the pretilt angle from the homeotropic alignment was about 1.4°, which is higher than in other photo-alignedVAN LC cell (0.53 ° ). Later the pretilt angles of 2-30 from the homeotropic LC orientation were obtained using the mixture of homeotropic PI and photopolymerized azo-dye SDA-2 [11].  The measured value of the contrast ratio between “off” and “on” states in all the cases exceeds 1000:1 in the monochromatic light. Thus it is concluded that azo-dyes are suitable for the alignment of VA-LCD. 

測量值之間“關(guān)”和“開”的狀態(tài)在所有的情況下，對比度超過1000:1單色光。因此可以得出結(jié)論，偶氮染料適合VA-LCD的取向。#p#分頁標題#e#

We fabricated truly bistable π-BTN display, based on photoaligning technology [33]. The strong anchoring surface was achieved by the usual rubbed polyimide (PI) layer. Such PI layer provides a strong polar anchoring energy of 1.5 x10-3 J/m2. We found that the polar anchoring energy of photo-polymerized azo-dye SDA-1 (SDA-2) can be adjusted to 1.5-2.8 ⋅ 10-4 J/m2, while azimuthal anchoring to 3.6-5.6⋅ 10-5 J/m2by changing the exposure time, which wa s suitable for obtaining  π-BTN bistability by surface anchoring breaking. The π-BTN LCD was switched between –22.50 and 157.50, exhibiting a high contrast ratio (CR>140) and wide viewing angles [33]. π -BTN was also successfully made on flexible plastic substrates using photo-alignment technology [34]. This facilitates the implementation of low-power consumption bistable liquid crystal display into smart cards [34].  

π-BTN液晶在-22.50和157.50之間切換，表現(xiàn)出高對比度（CR>140）和寬視角[33]。 π-BTN也成功用于柔性塑料基板上，使用光取向技術(shù)[34]。這有利于實現(xiàn)低功耗雙穩(wěn)態(tài)液晶顯示器智能卡[34]。

We have also investigated the properties of azo-dye alignment on plastic substrates  [35]. Excellent alignment with a high anchoring energy was achieved with the exposure energy less than 1.0 J/cm2, which corresponds to the azimuthal anchoring energy > 10-4 J/m2. We used a mixture of azo-dye SD-1 with a mentioned above thermo-polymerized azo-dye SDA-2 for the display fabrication. The LC pretilt angle of about 50on the plastic substrate was made by a double exposure method. To demonstrate the alignment quality on plastic substr ates a 9-digit reflective passive matrix TN-LCD mounted in smart card was fabricated. To maintain a uniform cell gap of 8 μ m (second Mauguin minimum of MLC-6809-000 Merck LC mixture), semi-dry adhesive spacers were chosen. The electrooptical performance of the photo-aligned plastic display was very similar to common TN-LCD  http://ukthesis.org/ygsslwdx/  fabricated for comparison by usual rubbing method on glass substrate. 

保持均勻的單元間隙8μ米（第二Mauguin最小的MLC-6809-000默克LC混合物），選擇半干燥粘合間隔物。照片對齊的塑料顯示器的電光性能是非常相似，共同的TN-LCD制造，在玻璃基板上用于比較通常的摩擦方法。