88 research outputs found
High-performance alignment thin films for advanced displays
No full textDisplay technology has gradually but profoundly shaped the lifestyle of human beings. Liquid crystal display (LCD) and organic light-emitting diode (OLED) display are two mainstream displays in the market due to their high-quality performance, which are further being developed to be an ultra-thin, transparent, flexible and even foldable display. An alignment film is an indispensable part in LCDs as well as recently emerging transparent display, and deeply influence their contrast ratio (CR) and light efficiency. Alignment thin film used for LC molecules orientation should be characterized by high aligning order, non-contaminated film and robust photo-tolerance. The employment of an ultra-thin polarizing film is also significant in rigid or flexible OLED display to suppress the reflection from cathode layer so as to improve the CR and outdoor readability. Therefore, development on high-performance thin films either for LC alignment or flexible OLED display are highly demanded. Firstly, polyimide (PI) is a dominating material for LC alignment and is widely used in display devices, one of which is smart window. In general, smart windows are developed either by optimizing the scattering composites or by designing an appropriate electrode pattern, while little investigation has been carried out on the alignment layer. Here, an inhomogeneous vertical alignment thin film with micro-domain structure was proposed and employed on a normally transparent smart window. This inhomogeneity morphology on the thin film can considerably enhance the power-on haziness while provide an ultra-transparent power-off state. In addition, the performance on off-axis viewing, response speed and power consumption are much better than commercialized polymer-dispersed liquid crystal (PDLC) smart window. The proposed smart window can serve as color transparent display using edge-light wave-guiding. In addition to employing vertical polyimide thin film, we can use photoalignment material, azo-dye SD1, to develop a transmittance tunable smart window based on two axis-variable polarizers. Azo-dye SD1 is a very promising material for LC alignment, which gives high order and strong anchoring to LC after absorb a small amount of light dosage (i.e., 150 mJ/cm2). Making use of this advantage, continuously axis-variable alignment thin film was achieved, on top of which a liquid crystal polymer/dichroic dye composited was coated and then photo-polymerized to form a rigid axis-variable polarizer. By horizontally shifting one polarizer relative to the other, varying transmittance with good uniformity is obtained. The tunability on transmittance can be realized by a simple roller instead of conventional electrical-driving. Indeed, the photo-sensitive azo-dye, SD1, does benefit vast varieties of devices, but this azo-dye has to be photo-stabilized when it is used in display panels, such as smartphone. A long-term exposure to the ambient light and the backlight will inevitably destroy the alignment quality so as to deteriorate the contrast ratio. Therefore, a method to stabilize azo-dye while maintain its original alignment performance is needed. Here, we introduced a polymer network into the azo-dye thin film. By thermally cross-linking the polymer network, the azo-dye thin film showed strong robustness against white light and heat. The electro-optical performance was even better than that of pure azo-dye thin film. A high CR (i.e., 2200) and an ultra-low pretilt angle (i.e., 0.025°) achieved by the stabilized film is extremely suitable for in-plane switching (IPS) display, a display mode currently widely used in smartphone. What’s more, photoalignment thin film can even be developed as a polarizer. Another azo-dye AD-1, due to its ultra-high dichroism (i.e., 70~100) and ultra-thin profile (i.e., 150~300nm), is quite prospective as a thin-film polarizer for flexible display. Also, this azo-dye needs to be stabilized. The AD-1 film after stabilization showed quite fascinating performance: the film not only showed strong resistance to intense white light but also processed an extended absorbance over the entire visible region. A dichroic ratio up to 34 and corresponding polarization efficiency up to 99.5% was achieved by this 200nm-thick azo-dye polarizer. When combined with λ/4 waveplate, the reflection of OLED panel can be greatly suppressed and less than 1%.</p
One Step Stabilized Azo Dye Photoalignment for Mass Production
No full textPresented is a novel azo dye stabilization method that only needs a single-shot UV light exposure. The proposed photoalignment layer offers very acceptable thermal and photo-stability, as well as image sticking parameter (1.01). Also, both VHR (99.0%) and RDC (<10mV) are comparable to that of PI rubbing. The ease of processing multi-domain alignment with high resolution (20μm) shows a great potential in a wide range of electro-optical devices
Optical rewritable liquid crystal displays without a front polarizer
No full textA front polarizer-free optically rewritable (ORW) liquid crystal display (LCD) has been made via a hybrid alignment configuration with dye-doped LCs. The hybrid structure consists of one optically active planar and one optically passive homeotropic alignment layer. The rewritability of the device is achieved by photo-reorienting the azo dye molecules in the active planar alignment layer. The dye is doped in LCs to function as a polarizer by following the LCs’ direction via a guest-host effect so that the front polarizer can be eliminated. This makes the device more compact and easier to operate for image erasing and rewriting. The image rewriting time only requires ∼9.0 s, which is determined by the exposure energy and LC parameters. The hybrid-mode dye-doped ORW LCD devices could find applications in E-paper, transparent display, and various photonics devices.</p
A Process Interoperability Method for SMEs
No full textPart 2: Full PapersInternational audienceThis paper starting with the present status of enterprise interoperability, focuses on enterprise interoperability of SMEs (Small and Medium-sized Enterprises), and based on a SMEs oriented framework of enterprise interoperability proposes an approach of process level interoperability. The approach appropriate for SMEs mainly solves two types of interoperability involving processes’ interior in the process level. Life cycle of process level interoperability is redesigned and reorganized. In each phase of the life cycle a comprehensive solution is given. In final, this paper gives a case study to describe and enhance the approach
Bioleaching of Sphalerite by the Native Mesophilic Iron-oxidizing Bacteria from a Lead-Zinc Tailing
No full textAbstractAn isolated native mesophilic iron-oxidizing bacteria, acidithiobacillus ferrooxidans, was used to extract zinc by the bioleaching method from a typical lead-zinc tailing. Experiments were carried out by mixed culture of the mesophilic strain in the shake flasks and the different influencing factors such as pH, temperature, inoculation cell number, as well as slurry concentration on the process of bioleaching were investigated. The results indicated that the extraction efficiency of zinc was relevant with these variables and more than 70% of sphalerite was dissolved on the condition of with pH 2.0, initial ferrous concentration of 10g/L and slurry concentration of 10wt.% during 25 d, while without bacteria, 22% of Zn was merely extracted
A Process Interoperability Method for SMEs
No full textAbstract. This paper starting with the present status of enterprise interoperability, focuses on enterprise interoperability of SMEs (Small and Medium-sized Enterprises), and based on a SMEs oriented framework of enterprise interoperability proposes an approach of process level interoperability. The approach appropriate for SMEs mainly solves two types of interoperability involving processes' interior in the process level. Life cycle of process level interoperability is redesigned and reorganized. In each phase of the life cycle a comprehensive solution is given. In final, this paper gives a case study to describe and enhance the approach
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