Thèses : « Liquid crystal displays (LCD) »

1

Leckner, Sara. « Soft proofing using liquid crystal displays ». Licentiate thesis, KTH, Numerical Analysis and Computer Science, NADA, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1701.

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Development of colour management systems, the level ofstandardisation, as well as the embedding of facilities forcolour management into computer operating systems and software,enables successful future interoperability of colour reproductionin the graphic arts industry. Yet colour reproduction from onemedium to another, still gives rise to inconsistencies.

This thesis investigates colour management and controlprocesses in premedia and press process workflows in graphic artsproduction, including standards, instruments and procedures. Thegoal is to find methods for higher efficiency and control ofcolour print media production processes, aiming at increasingcolour consistency and process automation and of reducingoverheads. The focus is on the control of colour data by displaysin prepress processes producing low quality paper products. Inthis respect the greatest interest of this thesis is on technicaland visual characteristics of displays with respect tp thereproduction of colour, especially desktop Thin Film TransistorLiquid Crystal Displays (TFTLCD) compared to portable TFTLCDs andCathod Ray Tube (CRT) monitors.

In order to reach the desired goal, this thesis is based on aliterature survey and empirical studies. The empirical studiesinclude both qualitative and quantitative methods, organised intothree parts:

Colour process management: Analysed case studies of theimplementation of colour management in entire graphic artsproduction workflow processes.

Display technology: LCD and CRT displays have been examinedthrough measurements to establish their fundamental strengthsand weaknesses in reproducing colours.

Comparison of reproduction: A perceptual experiment hasbeen conducted to determine the ability of the disparatecomponents included in a colour management system to co-operateand match reproduced colour, according to the perceivedpreference of observers.

It was found that in most cases consistent colour fidelitydepends on the knowledge and experience of the actors involved inthe production process, including the utilisation of routines andequipment. Lack of these factors is not necessarily fatal for thefinal low quality paper colour product, but obstructs theautomation. In addition, increased digitalisation will increasethe importance of displays in such processes. The results showthat CRTs and desktop LCDs meet most of the demands of colourreproduction in various areas of low quality paper productionprocesses, e.g. newspaper production. However, some fundamentalaspects, such as low digital input values, viewing angles andcolour temperature, matters that concern characterisation andcalibration, still need to be developed. Concerning softproofing, the matching correspondence between hard and softcopies gives similar results for both CRT and LCDs forhigh-quality paper originals, if the luminance is decreased onthe LCD (to luminance levels of CRTs). Soft proofing of lowquality papers gives equally lower matching agreement for bothCRT and LCD, in this case when the luminance of the LCD is sethigher (e.g. about twice the levels luminance levels ofCRTs).

Keywords:Displays, LCD, CRT, premedia, prepress, softproof, workflows, newspaper, colour management systems, colourcontrol, colour reproduction

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2

Hurley, Shawn Patrick. « Liquid Crystal Displays for Pixelated Glare Shielding Eyewear ». Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1279550994.

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3

Osterman, Jesper. « Investigations of Optical Properties and Photo-Alignment in Bistable Nematic Liquid Crystal Displays ». Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6083.

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4

Mienko, Marek. « Tiled photoluminescent liquid crystal displays using LED illumination ». Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616175.

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5

Li, Shuo. « Multiple-LED color-sequential liquid crystal on silicon projector / ». View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20LIS.

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6

Peters, Stuart Richard. « Competition and technological change in the liquid crystal display (LCD) industry ». Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327114.

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Tavares, Viviane. « Caracterização e processamento de telas de cristal líquido visando a reciclagem ». Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-22032007-150914/.

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As telas de cristal líquido (LCD) são usadas em TVs, calculadoras, telefones celulares, computadores (laptop e palm), vídeo games e agendas eletrônicas. O aumento e a rápida obsolescência tecnológica desses dispositivos eletrônicos causa o descarte excessivo de LCDs usados, diminuindo a vida útil de aterros. Por isso é necessário o desenvolvimento de uma metodologia de reciclagem de LCDs, que deve ser iniciada pela caracterização de LCDs, seguida do processamento das telas com objetivo de separar os materiais, utilizando algumas técnicas de Tratamento de Minérios. Os ensaios realizados para caracterização dos componentes da tela foram: solubilização em solvente; chama; infravermelho; DSC; MEV com EDS; difração de raios-X; e perda ao fogo. A seqüência identificada dos materiais de fora para dentro foi: triacetato de celulose, poli (álcool) vinil dopado com iodo, triacetato de celulose, cristal líquido, vidro com ITO, triacetato de celulose, poli (álcool) vinil dopado com iodo, triacetato de celulose, polímero não identificado com mica. Após a caracterização foi realizada a etapa de liberação de materiais, utilizando-se de moinhos de rolos, de disco, de martelos, de bolas, separação por álcool, imersão em nitrogênio líquido, e solubilização em água, para separação dos materiais recicláveis. A operação de Tratamento de Minérios que apresentou cerca de 98% de separação dos materiais foi com o moinho de martelos. Este material pode ser usado eventualmente como substituto da areia. Para viabilizar a separação dos materiais existe a necessidade de alteração no projeto das LCDs.
Liquid crystal displays (LCD) are used in TVs, calculators, mobiles, computers (laptop and palm), video games and electronic agendas. The increasing and fast technological obsolescence of these electronic devices causes their extreme discard, decreasing the landfills useful life. Therefore it is necessary the development of a LCD recycling methodology which must be started by the LCDs characterization, followed by the displays processing with the objective of separating materials, using some Ore Treatment techniques. The characterization tests of the LDC components: solvent solubilization, flame, infrarred, DSC, MEV with coupled EDS, X-ray diffraction and loss on fire. The sequence of the identified materials were: celulose triacetate, poly vinyl alcohol with iodine, cellulose triacetate, liquid cristal, ITO glass, cellulose triacetate, poly vinyl alcohol with iodine, cellulose triacetate, polymer with muscovite. Following the characterization, the materials releasing step was performed. Firstly the LCDs were grinded using different kinds of mills, then the grinded materials were passed through several separation tests: separation on alcohol, immersion in liquid nitrogen and solubilization in water. Hammer milling present the best results. The project of the LCDs should be improved in order to allow the materials separation.

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Aiken, John Charles. « The development of a colour liquid crystal display spatial light modulator and applications in polychromatic optical data processing ». Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326384.

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9

Leung, Kit Yee. « Single-panel sequential-color LCOS projectors using LED lamps / ». View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20LEUNG.

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10

Jang, Yong-Kyu. « ADVANCED UNDERSTANDING OF THE OPTICAL PROPERTIES IN PHASE COMPENSATED LIQUID CRYSTAL DEVICES ». Kent State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=kent1185484614.

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11

Valyukh, Iryna. « Optical Characterization and Optimization of Display Components Some Applications to Liquid-Crystal-Based and Electrochromics-Based Devices / ». Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-107429.

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ATKURI, HARI MUKUNDA. « METHODS TO ADJUST THE PHYSICAL PROPERTIES OF LIQUID CRYSTALS AND RELATED DEVICES ». Kent State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=kent1343078114.

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13

Springle, Ian David. « Photoluminescent liquid crystal displays ». Thesis, University of Cambridge, 1997. https://www.repository.cam.ac.uk/handle/1810/272071.

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Guarnieri, Gabriele. « High dynamic range images : processing, display and perceptual quality assessment ». Doctoral thesis, Università degli studi di Trieste, 2009. http://hdl.handle.net/10077/3121.

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2007/2008
The intensity of natural light can span over 10 orders of magnitude from starlight to direct sunlight. Even in a single scene, the luminance of the bright areas can be thousands or millions of times greater than the luminance in the dark areas; the ratio between the maximum and the minimum luminance values is commonly known as dynamic range or contrast. The human visual system is able to operate in an extremely wide range of luminance conditions without saturation and at the same time it can perceive fine details which involve small luminance differences. Our eyes achieve this ability by modulating their response as a function of the local mean luminance with a process known as local adaptation. In particular, the visual sensation is not linked to the absolute luminance, but rather to its spatial and temporal variation. One consequence of the local adaptation capability of the eye is that the objects in a scene maintain their appearance even if the light source illuminating the scene changes significantly. On the other hand, the technologies used for the acquisition and reproduction of digital images are able to handle correctly a significantly smaller luminance range of 2 to 3 orders of magnitude at most. Therefore, a high dynamic range (HDR) image poses several challenges and requires the use of appropriate techniques. These elementary observations define the context in which the entire research work described in this Thesis has been performed. As indicated below, different fields have been considered; they range from the acquisition of HDR images to their display, from visual quality evaluation to medical applications, and include some developments on a recently proposed class of display equipment. An HDR image can be captured by taking multiple photographs with different exposure times or by using high dynamic range sensors; moreover, synthetic HDR images can be generated with computer graphics by means of physically-based algorithms which often involve advanced lighting simulations. An HDR image, although acquired correctly, can not be displayed on a conventional monitor. The white level of most devices is limited to a few hundred cd/m² by technological constraints, primarily linked to the power consumption and heat dissipation; the black level also has a non negligible luminance, in particular for devices based on the liquid crystal technology. However, thanks to the aforementioned properties of the human visual system, an exact reproduction of the luminance in the original scene is not strictly necessary in order to produce a similar sensation in the observer. For this purpose, dynamic range reduction algorithms have been developed which attenuate the large luminance variations in an image while preserving as far as possible the fine details. The most simple dynamic range reduction algorithms map each pixel individually with the same nonlinear function commonly known as tone mapping curve. One operator we propose, based on a modified logarithmic function, has a low computational cost and contains one single user-adjustable parameter. However, the methods belonging to this category can reduce the visibility of the details in some portions of the image. More advanced methods also take into account the pixel neighborhood. This approach can achieve a better preservation of the details, but the loss of one-to-one mapping from input luminances to display values can lead to the formation of gradient reversal effects, which typically appear as halos around the object boundaries. Different solutions to this problem have been attempted. One method we introduce is able to avoid the formation of halos and intrinsically prevents any clipping of the output display values. The method is formulated as a constrained optimization problem, which is solved efficiently by means of appropriate numerical methods. In specific applications, such as the medical one, the use of dynamic range reduction algorithms is discouraged because any artifacts introduced by the processing can lead to an incorrect diagnosis. In particular, a one-to-one mapping from the physical data (for instance, a tissue density in radiographic techniques) to the display value is often an essential requirement. For this purpose, high dynamic range displays, capable of reproducing images with a wide luminance range and possibly a higher bit depth, are under active development. Dual layer LCD displays, for instance, use two liquid crystal panels stacked one on top of the other over an enhanced backlight unit in order to achieve a dynamic range of 4 ÷ 5 orders of magnitude. The grayscale reproduction accuracy is also increased, although a “bit depth” can not be defined unambiguously because the luminance levels obtained by the combination of the two panels are partially overlapped and unevenly spaced. A dual layer LCD display, however, requires the use of complex splitting algorithms in order to generate the two images which drive the two liquid crystal panels. A splitting algorithm should compensate multiple sources of error, including the parallax introduced by the viewing angle, the gray-level clipping introduced by the limited dynamic range of the panels, the visibility of the reconstruction error, and glare effects introduced by an unwanted light scattering between the two panels. For these reasons, complex constrained optimization techniques are necessary. We propose an objective function which incorporates all the desired constraints and requirements and can be minimized efficiently by means of appropriate techniques based on multigrid methods. The quality assessment of high dynamic range images requires the development of appropriate techniques. By their own nature, dynamic range reduction algorithms change the luminance values of an image significantly and make most image fidelity metrics inapplicable. Some particular aspects of the methods can be quantified by means of appropriate operators; for instance, we introduce an expression which describes the detail attenuation introduced by a tone mapping curve. In general, a subjective quality assessment is preferably performed by means of appropriate psychophysical experiments. We conducted a set of experiments, targeted specifically at measuring the level of agreement between different users when adjusting the parameter of the modified logarithmic mapping method we propose. The experimental results show a strong correlation between the user-adjusted parameter and the image statistics, and suggest a simple technique for the automatic adjustment of this parameter. On the other hand, the quality assessment in the medical field is preferably performed by means of objective methods. In particular, task-based quality measures evaluate by means of appropriate observer studies the clinical validity of the image used to perform a specific diagnostic task. We conducted a set of observer studies following this approach, targeted specifically at measuring the clinical benefit introduced by a high dynamic range display based on the dual layer LCD technology over a conventional display with a low dynamic range and 8-bit quantization. Observer studies are often time consuming and difficult to organize; in order to increase the number of tests, the human observers can be partially replaced by appropriate software applications, known as model observers or computational observers, which simulate the diagnostic task by means of statistical classification techniques. This thesis is structured as follows. Chapter 1 contains a brief background of concepts related to the physiology of human vision and to the electronic reproduction of images. The description we make is by no means complete and is only intended to introduce some concepts which will be extensively used in the following. Chapter 2 describes the technique of high dynamic range image acquisition by means of multiple exposures. In Chapter 3 we introduce the dynamic range reduction algorithms, providing an overview of the state of the art and proposing some improvements and novel techniques. In Chapter 4 we address the topic of quality assessment in dynamic range reduction algorithms; in particular, we introduce an operator which describes the detail attenuation introduced by tone mapping curves and describe a set of psychophysical experiments we conducted for the adjustment of the parameter in the modified logarithmic mapping method we propose. In Chapter 5 we move to the topic of medical images and describe the techniques used to map the density data of radiographic images to display luminances. We point out some limitations of the current technical recommendation and propose an improvement. In Chapter 6 we describe in detail the dual layer LCD prototype and propose different splitting algorithms for the generation of the two images which drive the two liquid crystal panels. In Chapter 7 we propose one possible technique for the estimation of the equivalent bit depth of a dual layer LCD display, based on a statistical analysis of the quantization noise. Finally, in Chapter 8 we address the topic of objective quality assessment in medical images and describe a set of observer studies we conducted in order to quantify the clinical benefit introduced by a high dynamic range display. No general conclusions are offered; the breadth of the subjects has suggested to draw more focused comments at the end of the individual chapters.
XXI Ciclo
1982

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15

Kim, Wook Sung. « Scattering in liquid crystal displays ». Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526470.

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Jiao, Meizi. « Fast-response liquid crystal displays ». Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4580.

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After about five decades of extensive material research and device development, followed by massive investment in manufacturing technology, thin-film-transistor liquid-crystal-display (TFT-LCD) has finally become the dominant flat panel display technology. Nowadays, LCD performances, such as viewing angle, contrast ratio, and resolution, have reached acceptable levels. The remaining major technical challenges are response time, light efficiency, and sunlight readability. Fast response time is desired to reduce motion blur and to enable field sequential color displays using red (R), green (G), and blue (B) LEDs (light emitting diodes) without noticeable color breakup. Sequential RGB colors would eliminate the commonly used spatial color filters which in turn enhances light efficiency and resolution density by ~ 3X. In this dissertation, several new approaches for achieving fast-response LCDs are explored. From material viewpoint, the most straightforward approach for achieving fast response time is to employ a thin cell gap with high birefringence and low viscosity liquid crystal (LC). We investigated the thin cell approach theoretically and experimentally. Voltage shielding effect and anchoring energy effect of alignment layers are found to play important roles on operating voltage and response time. Simulations are carried out to understand the underlying physics and confirm the experimental results quantitatively. Another approach to realize fast response time is to explore novel device configuration. Here, we proposed a dual fringing-field switching (DFFS) mode in which small LC domains are formed following the distribution of fringing fields. Therefore, it exhibits submillisecond response time without using thin cell or overdrive/undershoot voltage method. The response time of the DFFS mode is ~20X faster than a conventional vertical aligned LCD.; In addition, high optical efficiency is achieved from the complementary top and bottom active LC domains. Two transmissive and one transflective LCDs using DFFS mode are conceived and their electro-optical properties investigated. A shortcoming of DFFS LCDs is their fabrication complexity. To keep the advantages of this fast-response mode while avoiding the requirement of double-TFTs and pixel registration, we modified the device structure to transflective LCD which uses a single TFT in each pixel and vertical aligned positive dielectric anisotropy LC. Two types of electrodes are considered: fringing-field switching (FFS) and in-plane switching (IPS). Besides fast response time and high transmittance, such a transflective LCD shows good sunlight readability. As nematic LC is gradually approaching to its limit in term of response time, polymer-stabilized blue phase (PSBP) LCD is emerging. It has potential to become next-generation display because of following revolutionary features: submillisecond response time, no need for alignment layer, good dark state and symmetric viewing angle, and cell gap insensitivity if IPS electrode is employed. In this dissertation, we studied the material-property correlation of Kerr effect-induced birefringence in nano-structured PSBP LC composites. Furthermore, a new device configuration of BP LCD with corrugated electrodes is proposed to solve two critical technical issues: high driving voltage and relatively low transmittance. The on-state voltage can be reduced from ~35 Vsubscript rms] to ~10 Vsubscript rms] which will enable TFT addressing, and the transmittance is improved from ~65% to ~85%. This new device configuration will accelerate the emergence of PSBP LCD. Wide view is another important requirement for a high-end display. Several new LCD configurations with negative A-plate and biaxial plate as phase compensation films are proposed to achieve wide view and broadband operation.; The underlying working principles are studied and detailed display performances are included in this dissertation.
ID: 030422960; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2010.; Includes bibliographical references (p. 114-122).
Ph.D.
Doctorate
Optics and Photonics

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17

Hong, Qi. « WIDE VIEWING ANGLE LIQUID CRYSTAL DISPLAYS ». Doctoral diss., University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4042.

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In this dissertation, novel phase compensation technologies are applied to the designs of wide viewing angle and high transmittance liquid crystal displays. First, a design of wide viewing angle liquid crystal displays utilizing crossed linear polarizers is proposed. The designed multi-domain vertical-alignment liquid crystal display predicts superb contrast ratio over wide viewing angles. Next, to increase the bright state transmittance while maintain the high contrast. Finally, to reduce the cost and improve the applicability of the broadband and wide-view circular polarizer, the device configuration of the broadband and wide-view circular polarizer is significantly simplified by the application of biaxial compensation films. The produced states of polarization remain close to the ideal circular polarization over a wide range of incident angles within the visual spectrum. With this circular polarizer, the presented wide-view liquid crystal display predicts high contrast ratio as well as high and uniform transmittance over wide viewing angles within the visual spectrum. ratio, wide viewing angle circular polarizers are developed. The produced states of polarization are very close to the ideal circular state of polarization over a wide range of incident angles within the visual spectrum. This guarantees not only high contrast ratio but also high and uniform transmittance.
Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering

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18

Deng, Hui-Fang. « Computer modelling of liquid crystal displays ». Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392171.

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19

Mak, Hin Yu. « New type transflective liquid crystal displays / ». View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20MAKH.

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Li, Yan. « High-efficiency Blue Phase Liquid Crystal Displays ». Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5399.

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Blue phase liquid crystals (BPLCs) have a delicate lattice structure existing between chiral nematic and isotropic phases, with a stable temperature range of about 2 K. But due to short coherent length, these self-assembled nano-structured BPLCs have a fast response time. In the past three decades, the application of BPLC has been rather limited because of its narrow temperature range. In 2002, Kikuchi et al. developed a polymer stabilization method to extend the blue-phase temperature range to more than 60 K. This opens a new gateway for display and photonic applications. In this dissertation, I investigate the material properties of polymer-stabilized BPLCs. According the Gerber's model, the Kerr constant of a BPLC is linearly proportional to the dielectric anisotropy of the LC host. Therefore, in the frequency domain, the relaxation of the Kerr constant follows the same trend as the dielectric relaxation of the host LC. I have carried out experiments to validate the theoretical predictions, and proposed a model called extended Cole-Cole model to describe the relaxation of the Kerr constant. On the other hand, because of the linear relationship, the Kerr constant should have the same sign as the dielectric anisotropy of the LC host; that is, a positive or negative Kerr constant results from positive or negative host LCs, respectively. BPLCs with a positive Kerr constant have been studied extensively, but there has been no study on negative polymer-stabilized BPLCs. Therefore, I have prepared a BPLC mixture using a negative dielectric anisotropy LC host and investigated its electro-optic properties. I have demonstrated that indeed the induced birefringence and Kerr constant are of negative sign. Due to the fast response time of BPLCs, color sequential display is made possible without color breakup. By removing the spatial color filters, the optical efficiency and resolution density are both tripled. With other advantages such as alignment free and wide viewing angle, polymer-stabilized BPLC is emerging as a promising candidate for next-generation displays. However, the optical efficiency of the BPLC cell is relatively low and the operating voltage is quite high using conventional in-plane-switching electrodes. I have proposed several device structures for improving the optical efficiency of transmissive BPLC cells. Significant improvement in transmittance is achieved by using enhanced protrusion electrodes, and a 100% transmittance is achievable using complementary enhanced protrusion electrode structure. For a conventional transmissive blue phase LCD, although it has superb performances indoor, when exposed to strong sunlight the displayed images could be washed out, leading to a degraded contrast ratio and readability. To overcome the sunlight readability problem, a common approach is to adaptively boost the backlight intensity, but the tradeoff is in the increased power consumption. Here, I have proposed a transflective blue phase LCD where the backlight is turned on in dark surroundings while ambient light is used to illuminate the displayed images in bright surroundings. Therefore, a good contrast ratio is preserved even for a strong ambient. I have proposed two transflective blue phase LCD structures, both of which have single cell gap, single gamma driving, reasonably wide view angle, low power consumption, and high optical efficiency. Among all the 3D technologies, integral imaging is an attractive approach due to its high efficiency and real image depth. However, the optimum observation distance should be adjusted as the displayed image depth changes. This requires a fast focal length change of an adaptive lens array. BPLC adaptive lenses are a good candidate because of their intrinsic fast response time. I have proposed several BPLC lens structures which are polarization independent and exhibit a parabolic phase profile in addition to fast response time. To meet the low power consumption requirement set by Energy Star, high optical efficiency is among the top lists of next-generation LCDs. In this dissertation, I have demonstrated some new device structures for improving the optical efficiency of a polymer-stabilized BPLC transmissive display and proposed sunlight readable transflective blue-phase LCDs by utilizing ambient light to reduce the power consumption. Moreover, we have proposed several blue-phase LC adaptive lenses for high efficiency 3D displays.
Ph.D.
Doctorate
Optics and Photonics
Optics and Photonics
Optics

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21

Rao, Linghui. « Low Voltage Blue Phase Liquid Crystal Displays ». Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5448.

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From cell phones, laptops, desktops, TVs, to projectors, high reliability LCDs have become indispensable in our daily life. Tremendous progress in liquid crystal displays (LCDs) has been made after decades of extensive research and development in materials, device configurations and manufacturing technology. Nowadays, the most critical issue on viewing angle has been solved using multidomain structures and optical film compensation. Slow response time has been improved to 2-5 ms with low viscosity LC material, overdrive and undershoot voltage, and thin cell gap approach. Moving image blur has been significantly reduced by impulse driving and frame insertion. Contrast ratio in excess of one million-to-1 has been achieved through local dimming of the segmented LED backlight. The color gamut would exceed 100% of the NTSC (National Television System Committee), if RGB LEDs are used. Besides these technological advances, the cost has been reduced dramatically by investing in advanced manufacturing technologies. Polymer-stabilized blue phase liquid crystal displays (BPLCDs) based on Kerr effect is emerging as a potential next-generation display technology. In comparison to conventional nematic devices, the polymer-stabilized BPLCDs exhibit following attractive features: (1) submillisecond response time, (2) no need for molecular alignment layers, (3) optically isotropic dark state when sandwiched between crossed polarizers, and (4) transmittance is insensitive to cell gap when the in-plane electrodes are employed. However, aside from these great potentials, there are still some tough technical issues remain to be addressed. The major challenges are: 1) the operating voltage is still too high (~50 Volts vs. 5 Volts for conventional nematic LCDs), and the transmittance is relatively low (~65% vs. 85% for nematic LCDs), 2) the hysteresis effect and residual birefringence effect are still noticeable, 3) the mesogenic temperature range is still not wide enough for practical applications (?40 oC to 80 oC), and 4) the ionic impurities in these polymer-stabilized nano-structured LC composites could degrade the voltage holding ratio, which causes image sticking. In this dissertation, the BPLC materials are studied and the new BPLC device structures are designed to optimize display performances. From material aspect, the electro-optical properties of blue phase liquid crystals are studied based on Kerr effect. Temperature effects on polymer-stabilized blue phase or optically isotropic liquid crystal displays are investigated through the measurement of voltage dependent transmittance under different temperatures. The physical models for the temperature dependency of Kerr constant, induced birefringence and response time in BPLCs are first proposed and experimentally validated. In addition, we have demonstrated a polymer-stabilized BPLC mixture with a large Kerr constant K~13.7 nm/V2 at 20 oC at 633 nm. These models would set useful guidelines for optimizing material performances. From devices side, the basic operation principle of blue phase LCD is introduced. A numerical model is developed to simulate the electro-optic properties of blue phase LCDs based on in-plane-switching (IPS) structure. Detailed electrode dimension effect, distribution of induced birefringence, cell gap effect, correlation between operation voltage and Kerr constant, and wavelength dispersion are investigated. Viewing angle is another important parameter. We have optimized the device configurations according to the device physics studied. With proper new device designs, the operating voltage is decreased dramatically from around 50 Volts to below 10 Volts with a reasonably high transmittance (~70%) which enables the BPLCDs to be addressed by amorphous silicon thin-film transistors (TFTs). Moreover, weak wavelength dispersion, samll color shift, and low hysteresis BPLCDs are achieved after their root causes being unveiled. Optimization of device configurations plays a critical role to the widespread applications of BPLCDs. In addition to displays, blue phase liquid crystals can also be used for photonic applications, such as light modulator, phase grating, adaptive lens and photonic crystals. We will introduce the application of blue phase liquid crystal as a modulator to realize a viewing angle controllable display. The viewing angle can be tuned continuously and precisely with a fast response time. The detailed design and performance are also presented in this dissertation.
Ph.D.
Doctorate
Optics and Photonics
Optics and Photonics
Optics

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22

Sun, Gang. « Novel large-area liquid crystal displays : tiled smectic-A displays and photoluminescent displays ». Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615240.

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23

Zhang, Baolong. « Processing, characterizations and optical modeling of color filter liquid-crystal-on-silicon microdisplays / ». View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202006%20ZHANG.

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Au, Ping Tong. « Mechanically stabilized bistable FLCD on flexible substrates / ». View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20AU.

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Li, Xihua. « Bi and multi stable ferroelectric liquid crystal displays / ». View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20LI.

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Tian, Linan. « Liquid crystal blue phase for electro-optic displays ». Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/liquid-crystal-blue-phase-for-electrooptic-displays(0230a0fd-6cbb-4edb-a626-ae981fe75141).html.

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Liquid crystals are a vast and diverse class of materials which ranges from fluids made up of simple rods, polymers and solutions, to elastomers and biological organisms. Liquid crystal phases are neither crystalline, nor a ‘normal’ isotropic liquid, but lie somewhere in between these two common states of matter. Liquid crystals have found enormous use in display devices due to their electro-optic properties. In this thesis, the optical and electro-optical properties of some chiral liquid crystalline phases are studied. The optical and electro-optical behaviour of liquid crystalline blue phases has been investigated via a detailed analysis of the reflection spectrum from thin, vertical field (VF) cells. Spectral analysis in this thesis was performed using a numerical fitting technique based on the Berreman 4x4 matrix method. The validity of the technique was proved through comparisons of independent measurements with the calculated physical parameters. A novel Kerr effect measurement method was proposed in this thesis and a known material was used to verify this new method. The Kerr constant together with its dispersion relation was measured using a white light source. An unusually large Kerr constant, K, is determined in the blue phases of a non-polymer stabilized material, ~ 3x10-9 mV-2 (BPI). The large value of K is attributed to significant pre-transitional values of the dielectric anisotropy and birefringence. K follows an inverse dependence on temperature which is more marked in BPII than BPI, and we consequently suggest that the BPI demonstrates properties best suited to electro-optic devices. The field effects in blue phase include electrostriction and the influence of the Kerr effect was separated from electrostriction phenomena for the first time in this work. Finally in the Kerr effect measurements, the Kerr constant in the optically isotropic dark conglomerate phase of a bent-core material was studied for the first time, with rather low values, ~1x10-11 mV-2. The low Kerr constant can be understood in the context of the physical properties of the material. Supercooling phenomena in the blue phase were studied through an analysis of the optical properties in thin cells. Features including the Bragg reflection peak jump and hysteresis are measured through the reflection spectra. A blue phase sample with a single orientation over an area of millimeters was prepared to help the spectra study of the blue phases. Although some previous reports indicated that there may be a new blue phase in the supercooled region, we find that there is no evidence shows that the supercooled blue phase has a different structure from the BPI.Chiral molecules have been included as dopants in achiral bent-core materials to produce a range of new chiral mixtures. Different host materials and chiral dopants have been used to produce several chiral nematic materials in which the chiral nematic phase, the underlying smectic phase and the blue phases are examined. The order parameter is determined as a function of temperature in the chiral nematic phase, and compared to that determined for several calamitic materials; no discernible difference is found. A study of the pitch divergence in the chiral nematic phase of the bent-core mixtures shows interesting properties at both low temperature (as the smectic phase is approached) and at high temperatures (at the transition to the blue phase). An unusual phase separation of the chiral dopant in the mixtures is reported, and details are deduced through a comparison between different mixtures. It is found that a dopant with similar clearing point to the bent-core material has less likelihood of phase separation. Although the blue phase temperature range is extended in these mixtures in comparison with typical values for calamitic materials, it does not extend beyond 2K in any of the materials. Both blue phase I and the fog phases are observed in these chiral bent core systems, but no BPII is observed in any of the materials studied. The small k33 (~ 2.8 pN at 10 K below clearing point) in the bent-core host material is suggested as one of the reasons that the blue phase range is not enhanced as much as may have been expected from reports by other authors.

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Tanner, Joette Russell Samulski Edward T. « Novel alignment materials for use in liquid crystal displays ». Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,202.

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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.
Title from electronic title page (viewed Oct. 10, 2007). " ... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.

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Hasegawa, Satoshi, Kazuhiro Fujikake, Masako Omori, Masaru Miyao et 克. 宮尾. « Readability of Characters on Mobile Phone Liquid Crystal Displays ». Ablex Publishing Corporation, 2008. http://hdl.handle.net/2237/11136.

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29

Yeung, Fion Sze Yan. « Bistable twisted nematic liquid crystal display using photoalignment technology / ». View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202004%20YEUNG.

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Cheung, Hon Lung. « Multimedia video interface controller for silicon microdisplay application / ». View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202002%20CHEUNG.

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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.
Includes bibliographical references (leaves [61]-[65]). Also available in electronic version. Access restricted to campus users.

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Lee, Chung Yung. « Bistable twised nematic liquid crystal displays by inhomogeneous alignment surfaces / ». View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20LEE.

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Buyuktanir, Ebru Aylin. « Electro-optical Characterization of Bistable Smectic A Liquid Crystal Displays ». Kent State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=kent1207869606.

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Venkataraman, Nithya Leela. « Photosensitive Cholesteric Liquid Crystal Materials ». Kent State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=kent1248110797.

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Kim, Youn Jin. « Developing Image Quality Metrics of Liquid Crystal Displays : Internal Reference Approach ». Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485591.

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Recently, many kinds of mobile displays have become increasingly popular. They are widely used under a variety of ambient illumination levels, including bright outdoor viewing conditions. Manufacturers of mobile displays require new data and computational models which consider the effect of ambient illumination in order to develop higher quality products. The aim of this thesis is to analyse the ability of the human visual system to evaluate the quality of images reproduced on small-size mobile display media, especially for 2-inch liquid crystal display, and to computationally enhance quality of images under a wide range of ambient illumination levels. Specifically, the following four major issues were investigated: analysis of psychophysical attributes affecting image-quality evaluation, quantification of image quality using measurable image-properties, measurement of the ambient-illumination adaptive contrast sensitivity function, and image enhancement which discounts the effect of ambient-illumination. Since small sized mobile display was mainly focused on in the current research, the results can be used for a limited range of display size. Effects 'of display size were remained as future study. Firstly, typical variations of mobile display media that exist in the real world were simulated using a device characterisation technique and psychophysical attributes (e.g. naturalness, clearness, sharpness, contrastness, colourfulness and preference) affecting the image quality evaluation process were analysed. The naturalness and clearness were found to be the most statistically important ( psychophysical-attributes for modelling image quality. As ambient illumination level increases, the significance of clearness (which is attributed to both contrast and sharpness) increased and image quality was impaired exponentially. Secondly, image quality was modelled using the measurable image properties memory colour reproduction ratio (MCRR), mean chroma and 95th percentile luminance - regarding to the physical characteristics of display media. A computational image-colour quality (ICQ) model was developed that consists of three cognitive processes: local and global assessments and scoring the ICQ. The effect of outdoor illumination on the ICQ model estimate could' be 'quantified as an exponential decay function of illuminance (Ix). Thirdly, to estimate the change in image contrast under a variety of ambient illumination levels, the contrast sensitivity function (CSF) of the human visual system was psychophysically measured using the contrast threshold detection method. As the ambient illumination level increased, the overall contrast sensitivity decreased and the spatial. frequency where the maximum contrast sensitivity occurred was shifted towards a lower frequency. Finally, the loss in contrast sensitivity was quantified and compensated for by increasing the amplitude of Fourier transform of a given image. An. ambient- . illumination adaptive weighting function was applied to the' amplitude increase, . according to the normalised CSF difference between the reference (dark) and a given target ambient illumination level. This IEA method resulted in a considerable imageÃ‚Â· quality enhancement under outdoor viewing conditions, as verified through a set of psychophysical experiments.

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Klein, Karsten. « Electro optical effects suitable for internal phosphor photoluminescent liquid crystal displays ». Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620998.

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Fogarty, John Patrick. « Numerical simulation and optimization of triple supertwist nematic liquid crystal displays / ». Full text open access at:, 1998. http://content.ohsu.edu/u?/etd,658.

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Reznikov, Dmytro. « Effect of surface alignment layer on electro-optical properties of ferroelectric liquid crystal displays ». [Kent, Ohio] : Kent State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1227562895.

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Thesis (Ph.D.)--Kent State University, 2008.
Title from PDF t.p. (viewed Jan 5, 2010). Advisor: Philip J. Bos. Keywords: liquid crystal, smectic, display, ferroelectric. Includes bibliographical references (p. 190-194).

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38

Xu, Peizhi. « Electrooptical modes of liquid crystal for shutter and display applications / ». View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20XU.

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Du, Tao. « Single cell gap transflective liquid crystal displays and the use of photoalignment technology / ». View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20DU.

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Varley, Helen. « Photo-induced alignment in polymer films ». Thesis, Durham University, 1997. http://etheses.dur.ac.uk/4982/.

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Currently, alignment films for use in liquid crystal displays are produced via a mechanical rubbing process. The dust produced by mechanical rubbing along with problems due to friction and uneven roller pressure lead to defects in the display. Therefore a novel method for aligning polymers films by irradiation with polarised light has been attempted. Anisotropy introduced into the films by selective irradiation affects liquid crystal alignment. The polymers used in this study are poly (vinyl cinnamate), poly (9- anthraceneoate ethyl methacrylate) and poly (p-azidobenzoate ethyl methacrylate). Poly (vinyl cinnamate) is a classical photoresist polymer which undergoes a [2+2] photocycloaddition in the presence of UV light. Poly (9-anthraceneoate ethyl methacrylate) and poly (p-azidobenzoate ethyl methacrylate) are both novel polymers which have the potential to undergo photo-crosslinking reactions. Poly (9-anthraceneoate ethyl methacrylate) contains an anthracene-terminated side chain which dimerises under the influence of UV light introducing anisotropy into the system. Poly (p-azidobenzoate ethyl methacrylate) contains an azido group which when irradiated with polarised light loses nitrogen to yield nitrenes which can combine to form azobenzene species. UV spectroscopy, infrared dichroism studies, birefringence measurements and fabrication of a simple liquid crystal cell show that poly (vinyl cinnamate) and poly (9-anthraceneoate ethyl methacrylate) undergo selective photoreaction. Poly (p- azidobenzoate ethyl methacrylate) is shown to undergo reaction but not to give the desired products.

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Lowans, Brian Sinclair. « Applications of spatial light modulators in optical information processing ». Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282231.

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Yeung, Fion Sze Yan. « Variable liquid crystal pretilt angles by nanostructured surfaces and their applications / ». View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20YEUNG.

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Yoo, Hyun Seung. « Color Illusions on Liquid Crystal Displays and Design Guidelines for Information Visualization ». Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/36372.

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The influence of color on size and depth perception has been explored for a century, but there is very limited research on interventions that can reduce the color illusions. This study was motivated to identify interventions and propose design guidelines for information visualization, especially where size judgment is critical.

This study replicated the color size illusion and color depth illusion on an LCD monitor and it was found that yellow is the smallest and farthest color among red, yellow, green, and blue on a white background. Three types of interventions (background brightness, border color, and background grid brightness) were tested to identify the conditions that reduce the color illusions, but all of them were not statistically significant.

Based on the experiment results and literature survey, design guidelines were proposed. To extend the guidelines to the bioinformatics field, design recommendations were proposed and implementation examples were illustrated. Evaluations on design implementations were evaluated by interviewing domain experts.

Additionally, the relationship between the color size illusion and the color depth illusion was explored.

Master of Science

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44

Wang, Hsing-Fa, et 王星發. « Quality Improvement for Motion Pictures in Multimedia Liquid-Crystal Displays(LCDs) ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/85804501565136620753.

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碩士
國立中興大學
電機工程學系
93
Abstract The principle of gamma correction, which is based on brightness levels distinguishable by the human eye, have a logarithmic type distribution and not a non-linear distribution. Gamma correction does not affect density range (The levels of black and white are fixed.) due to the characteristics of the gamma curve. It only lightens density range distribution (when gamma is greater than 1). Bright areas are expanded and dark areas are compressed. For darkened (when gamma is less than 1) images, light areas are compressed and dark areas are expanded. As display technology advances, more stringent demands are placed on every tiny pixel. There are currently many new image and tuning technologies. Dynamic gamma correction (DGC), also called dynamic gamma control (DGC), improves image darkness and contrast, and then more accurately displays fine images. It achieves higher brightness and contrast and shows clear, crisp high definition image. As described in chapter 3, an 8-grayscale histogram of dynamic image was construct and immediate gamma voltages were adjusted to improve the image quality of moving pictures on multimedia liquid crystal displays. Since the gamma voltages used on TFT-LCD modules are only 5 externally voltages, it makes rough adjustment to the display. Although, the better image quality is achieved than the before adjustment, but the congenital performance is limited. Chapter 4 introduces a new dynamic gamma correction method using 32 grayscale histogram and image data processing to improve contrast of moving images on LCDs. First, to statistic the 32 grayscale histograms, then arrange the circuits of combined external gamma voltage adjustment with image data processing by software technology. It will become a new gamma curve, thus more accurately display fine images that have higher contrast and show clear, crisp high definition image quality on multimedia LCDs. There are still some problems that exist in this work, so a complete framework is proposed in chapter 5 to take the “improvement of moving image quality” research goal to an advance video system.

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Chiu, Shu-Ping, et 邱姝萍. « A study on the treatment technology ofglass substrate and liquid crystal in Thin Film Transistor - Liquid Crystal Display (TFT-LCD) ». Thesis, 2014. http://ndltd.ncl.edu.tw/handle/rj8bvd.

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碩士
國立臺北科技大學
環境工程與管理研究所
102
The demands for TFT-LCDs are increasing globally year by year, and the TFT-LCD is mainly applied on electronic and informative products, however, the major waste TFT-LCDs processing is landfill which has features of high cost and high risks of secondary pollution, thus, this processing method should not be the permanent way for waste TFT-LCD. Therefore, the proper processing and recycling of glass substrates and liquid crystals of waste TFT-LCDs have major significance. Through literatures analysis, it is learnt that extraction separation of waste liquid crystals could be performed by supercritical carbon dioxide, organic solvent, thermal precipitation and ultrasonic with acetone solvent methods; and the extraction separation of waste glass substrates and polarizing films could be implemented by thermal shock, pyrolysis, organic solvent and winnowing, and the separated waste glass from TFT-LCDs could be recycled and used as materials for concrete bricks, biological bricks, foamed glass and so on. The results from this study showed that the optimum waste liquid crystals processing technique is to use acetone solvent to extract liquid crystals from waste TFT-LCDs, and carry out the purification and tempering of the extracted liquid crystals to make them as custom compound formula for application of TFT-LCD factories. As for the optimum waste glass substrates processing method, they should be grinded by grinders initially and separate glass substrates with polarizing films by winnowing, thereafter, polarizing films could be used as reducing agents in smelting furnaces; and waste liquid crystal panel glass could be used for road and construction materials.

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Chen, Hung-guang, et 陳鴻光. « High quality frame rate up-conversion for high-end liquid crystal display (LCD) panels ». Thesis, 2009. http://ndltd.ncl.edu.tw/handle/18274885047438490484.

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碩士
國立中央大學
電機工程研究所
97
Frame rate up conversion (FRUC) is a technique to convert lower frame rate video to higher frame rate. Recently, FRUC is frequently applied to reduce motion blur of liquid crystal display (LCD). Because LCD is a hold-type display, each frame will be displayed and hold in one frame which is different from CRT. Since human eyes have the characteristic to pursuit moving objects with eye-tracking integration smoothly, the artifact, motion blur. will be perceived by human eyes. Frame rate up conversion, which converts the frame rate from 60Hz to 120Hz, is an effective method in motion blur elimination. This paper presents a motion compensated frame rate up conversion algorithm that adopts the adaptive bilateral motion estimation and the expanded range of the motion trajectory to enhance the accuracy of motion estimation. We used the sub-sampled motion estimation to reduce computational complexity from the expanded search range. Finally, a motion vector smoothing method is applied that alleviates outliers under the assumption that neighboring motion vectors are similar in value and direction. In the experiments, the proposed algorithm improves the average PSNR of interpolated frames by up to 1.21-4.98 dB, compared to the conventional algorithm.

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Hsu, Chao-Kuei, et 許朝貴. « Characterization of the Liquid Crystal Display (LCD) Alignment Layer Grown by an Oblique Evaporation Method ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/18316583339191532549.

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碩士
國立臺灣海洋大學
電機工程學系
93
Abstract The objective of this thesis is to investigate the physical properties of silicon dioxide (SiO2) thin film as conditioned by different deposition angle, thickness, the temperature on the substrate and IAD (Ion-beam Assisted Deposition). In this study, the transmission of the thin film is analyzed by UV-visible spectrophotometer. The surface contours and roughness of the thin films are observed with AFM (atomic force microscope). The surface contours and cross-section microstructures of thin films are examined by SEM (scanning electron microscope). Finally, we apply the SiO2 thin films which are deposited at different growth conditions in the liquid crystal alignment layer and analyze the influence of it on the pre-tilt angle, the contrast ratio, and response time of the liquid crystal. By analyzing experimental results, we find that we can make an alignment layer which have pre-tilt angle from 1 to 4 degrees under different deposition angles, thickness of thin films, and IAD conditions. For a sample with 2kÅ of thickness which was deposited at 200℃ deposition temperature and 15°deposition angle, its contrast ratio is approximately two times higher than that of traditional polyimide (PI) alignment layer, and the response time is comparable to traditional PI alignment layer. Therefore the oblique evaporation technology of non-contact alignment is as good as traditional rubbing method. Besides, it can avoid the defects of the dust, static charge, and scraping during the thin film processing.

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Chen, Chi-Wei, et 陳其偉. « Studies on the Viewing Characteristics of Reflective Super Twisted Nematic Liquid Crystal Displays (RSTN-LCDs) ». Thesis, 2002. http://ndltd.ncl.edu.tw/handle/23918837221307804416.

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碩士
國立成功大學
機械工程學系碩博士班
90
The development of reflective super twisted nematic liquid crystal displays (RSTN-LCDs) is to significantly save electricity power consumption in portable information products. However, there is still much room for improvement of optical characteristic and performance, especially in some parameter adjustment. For example, elastic constants, polarization angle of polarizer, the thickness of liquid crystal cell, birefringence of liquid crystal, twisted and tilt angles of liquid crystal, and rotation angle of retardation film are the most important of all. In this thesis, the effect of the induced flow and the multiple layer reflection are not taken into account in numerical calculations. By using one- dimensional Euler-Lagrange equation, the static state director distribution of liquid crystal is obtained first. 2x2 Extended Jones matrix method is then applied to analyze the viewing characteristics of RSTN-LCDs consisting of one input polarizer and redartation film. In the summary, we recommend some parameter values for RSTN-LCDs to achieve higher performance in practical applications.

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Chen, Jun-Chang, et 陳俊昌. « Studies on the Compensated Characteristics of Reflective Super Twisted Nematic Liquid Crystal Displays(RSTN-LCDs) ». Thesis, 2003. http://ndltd.ncl.edu.tw/handle/00109046509311807284.

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碩士
國立成功大學
機械工程學系碩博士班
91
Reflective LCDs do not require a backlight so that their power consumption and panel weight are both reduced. It is key device for portable information products such as PDA, cell phone and digital camera. The single-polarizer reflective LCD offers a compromise between display brightness and contrast ratio, and has gradually become the mainstream approach. However, reflective LCDs have been studied intensively in recent years. There is still much room for improvement such as brightness, contrast, viewing angle and gray levels stability. The primary factor limiting the contrast ratio and narrow viewing angle achievable in a LCD are the amount of light that leaks through the display in the dark state. In this thesis, a compensator which is the combination of negative a-plate, c-plate and o-plate will be utilized to minimize the oblique leakage light in the wide viewing angle and select some parameter values for RSTN-LCDs to achieve higher viewing characteristics. We followed the standard procedure for LCD simulation. First, the one dimensional Euler-Lagrange equations for the director deformation were solved to give the director angles and for all values of z inside the LC cell for any value of applied voltage. Then reflectance was calculated by the extended Jones matrix approach of dividing the cell which includes liquid crystal layer and compensation films into many layers and treating each layer as a birefringent plate.

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Chang, Che Ming, et 張哲銘. « The new design with mixing R.G.B. LED(Red,Green,Blue Light EmittingDiode) for modern LCD(Liquid Crystal Displsay ) backlight system ». Thesis, 2006. http://ndltd.ncl.edu.tw/handle/84944219590946823096.

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碩士
國立高雄第一科技大學
光電工程研究所
94
ABSTRACT LED(Light Emitting Diode) backlight module for LCD(Liquid Crystal Displsay ) backlight system has its advantages of color saturation, electricity savings and environmental frienldiness,etc. However , white LED(Light Emitting Diode) is not popular and widely used at this moment due to blue light spectrum weights most of all over spectrum range, which degrade color saturation. Therefore, R.G.B LED(Red,Green,Blue Light Emitting Diode) light source plays significant role at modern LCD(Liquid Crystal Displsay ) backlight system. The paper proposes a newly developed light source module with mixing R.G.B. LED(Red,Green,Blue Light Emitting Diode) for modern LED(Light Emitting Diode) backlight system instead of white light LED(Light Emitting Diode) and traditional CCFL （Cold Cathode Fluorescent Lamp）. . This system consists of three parts, a newly designed symmetric mirror for complete color mixing, R.G. B LED(Red,Green,Blue Light Emitting Diode) light source and diffusion plate with newly designed microstructure for the improvement of light uniformity. The light module is designed and simulated by ASAP (Advanced Systems Analysis Program), in which a sample with 160mm×90mm( around 7 inch pane) are presented with sixteen LEDs light source. Good color saturation and excellent light uniformity are reached in this research. According to the result of the final simulation, we doesn’t need the light guide . We can get 75% Uniformity.

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