A roll-to-roll process is used to fabricate amorphous silicon and amorphous multicomponent oxide (MCO) transistors on flexible substrates using self aligned imprint lithography (SAIL). SAIL solves the layer to layer alignment problem. The imprint lithography patterned MCO transistors had a mobility of 15 cm²V^-1 sec^-1 and an on-off ratio of 10⁷. Full display arrays with data, gate, hold capacitors and cross-overs were patterned using SAIL technology. Studies of stability of the MCO transistors indicate the importance of controlling O vacancies in the material particularly the back channel. Devices subjected to -10V gate bias stress at 60C under illumination exhibited behavior consistent with state creation in the upper and lower half of the gap near the back channel interface possibly associated with O vacancy formation.

Existent flat-panel display is mechanically stiff because it requires external connection of IC chips. At its present stage, displays with a-Si, metal oxide semiconductor or organic TFTs require still external connection of data driver and controllers, because of their low carrier mobilities. We will review our recent progress on direct formation of high speed Si circuits fabricated with a plastic compatible temperature. Large Si grains with a diameter of 4 microns were formed on predetermined positions by a pulsed laser crystallization process with a plastic compatible temperature. High performance transistors were fabricated inside a single Si grain.

Electrowetting (EW) technology is shown to be quite flexible in operation and able to operate on flexible substrates. Complementary ON/OFF characteristics of EW devices have been obtained through a plasma irradiation and annealing process. This enables the design of EW array operation in a reduced power mode. Examples of EW operation on flexible substrates are discussed. This includes paper, plastic and metal substrates. Prototypes of flexible EW arrays on plastic substrates are demonstrated to switch reversibly by applying a low voltage difference (20 V). The array operation is maintained even when the display is mechanically flexed. These results indicate the promise of flexible EW devices for mobile and other devices, including video rate flexible e-paper.

There are several paradigms for color generation in reflective displays (e-Paper) including RGBW color filtering or stacked RGB or CMY. Theoretically, the highest white state reflectance and best color gamut are achieved by stacking three layers of pixels. However, stacking 3 layers induces significant optical losses especially at high resolution and typically does not allow for video operation. Therefore RGBW color filtering is currently preferred for higher resolution and single-layer e-Paper, but only provides color at 25% of the area and a maximum theoretical white reflectance of 50%. Presented herein is a new bi-primary color-system that cooperatively displays two complimentary colors inside a single sub-pixel, and therefore doubles the white state reflectance and color gamut for single-layer e-Paper. Also discussed are candidate e-Paper technologies that may be able to adopt the bi-primary color system, including possible advantages and challenges for each technology.

The electrowetting D³ technology ("Droplet-Driven-Displays") was invented by ADT. Those displays have features like bistability and highest reflectivity, which offer unique application options for real "No Power ("green") applications ranging from indicators to billboards. This paper describes the fundamentals of D³ EW displays (Passive Matrix, no Active Matrix needed) and system design incl. electronic driving using commercial ICs. We recently demonstrated all backlight modes (reflective, transflective and transmissive). Pixel size ranges from 0.5 to 10 mm and a wide temperature range is covered; color is realized by subtractive CMY stacks with printer-like gamut. The measurements of ambient light contrast ratio and color gamut clearly demonstrates the excellent performance of ADT's electrowetting displays for applications like "No Power" bistable LED indicator replacements and sunlight readable electronic billboards.

Within the last few years' car industry changed very fast. Information and Communication became more important and displays are now standard in nearly every car. But this is not the only trend which could be recognized in this industry. CO2 emission, fuel price as well as the increasing traffic inside the Mega Cities initialized a big change in the behavior of the customers. The big battle for the car industry will enter the interior extremely fast, and the premium cars need ore innovative design icons. Flexible Displays are one big step that enables totally different designs and a new value of the driver experience.

Electronic paper is now developing fast into an accepted alternative for paper. Its applications nowadays seem focused on books, documents and newspapers. Development of credible color implementations of electrophoretic displays has been initiated, focusing on multi-layer in-plane electrophoresis, but the difficulties associated with these systems (particle drift, aperture, accuracy) were so far not solved. Electro-osmotic principles lead to openings towards multi-layer color displays as well as fast switching, high reflectance grayscale displays. Drift, aperture and accuracy can be brought to the level necessary to create in-plane switching electro-osmotic displays without the need for encapsulation

Emerging screen technologies, such as Electrophoretic Displays (EPD) used in E-book Readers, are changing product power requirements due to their advantageous properties such as bi-stability (effective "zero power" static display) and reflective mode of operation (no backlight). We will first review the emerging screen technologies under the angle of system and IC design impact. We will explain power management consequences for IC design, with a focus on Application Engine SOCs for the wireless/portable markets.

We have developed thin and light weight flexible EPD (electronic paper display) using QR-LPD technology. QR-LPD suits for flexible display because of its simple display structure (no TFT) and robust image holding property. Novel types of thin and light weight flexible electronic paper display are discussed. This technology can realize the "real paper like" flexible electronic paper.

Toner Display is based on an electrical movement of charged particles. Two types of black toner and white particles charged in the different electric polarity are enclosed between two electrodes. The particle movement is controlled by the external electric field applied between two transparent electrodes. The toner is collected to the electrode by an electrostatic force across the insulating layer to display a black image. The toners can be put back to the counter electrode by applying a reverse electric field, and white solid image is displayed. We have studied on the movement of three color particles independently to display color image in Toner Display. Two positively charged color particles with different amount of charge to mass ratio and negatively charged white particles were enclosed in the toner display cell. Yellow, cyan and white images were displayed by an application of voltage.

A low-power, wide-view, and single-cell-gap transflective display using a polymer stabilized blue-phase liquid crystal (BPLC) is proposed. To reduce operating voltage, we use protrusion electrodes to generate strong fringing fields to penetrate deep into the bulk liquid crystal layer. To balance the optical phase retardation between transmissive (T) and reflective (R) regions, we design the R region with a wider electrode gap so that its smaller induced birefringence compensates the double pass of the ambient light. To reduce power consumption, we utilize the fast-response feature of BPLC for field sequential display which triples the optical efficiency and resolution density.

We propose a chiral-nematic liquid crystal (CN-LC) device that reflects the infrared light, where the planar state is transparent over the entire visible wavelengths and the focal conic state scatters the light achromatically. The proposed CN-LC device can be operated at a low voltage because of the long pitch. A liquid crystal display (LCD) switchable between reflective and transmissive modes can be realized by stacking a CN-LC layer and a nematic LC layer.

Major achievements of this research project on rigid and flexible OLEDs are: lifetime enhancement by advanced constant luminance (L) operation, integration into textiles and furthermore, the prototype production on flexible PET/ITO substrates of polymer OLEDs. Our OLEDs were manufactured with spin-coating assisted by ink-jet printing. We introduced constant luminance operation (instead of the usual constant current) which was implemented in order to extend the overall lifetime of OLEDs. A threefold lifetime improvement was achieved by maintaining 50% luminance using an advanced microcontroller-based lifetime(LT) model. Various approaches to textile integration and evaluation of environmental issues in clothes (e.g. moisture) were investigated.

Innovative systems for carrier-gas enhanced vapor phase deposition of organic layers offer advanced methods for the precise deposition of complex thin-film layer stacks. The approach inherently avoids potential short-comings from solvent-based polymer deposition and offers new opportunities. The process operates at low pressure (thus avoiding complex vacuum setups), and, by employing AIXTRON's extensive experience in freely scalable solutions, can be adapted to virtually any production process and allows for R&D and production systems alike. Deposition of organic layers and stacks recommends the approach for a wide range of organic small molecule and polymer materials (including layers with gradual change of the composition), for conductive layers, for dielectric layers, for barrier systems, for OLED materials, and surface treatments such as oleophobic / hydrophobic coatings. With the combination of other vapor phase deposition solutions, hybrid systems combining organic and inorganic materials and other advanced stacks can be realized.

Significant progress has been made in recent years in flexible AMOLED displays and numerous prototypes have been demonstrated. Replacing rigid glass with flexible substrates and thin-film encapsulation makes displays thinner, lighter, and non-breakable - all attractive features for portable applications. Flexible AMOLEDs equipped with phosphorescent OLEDs are considered one of the best candidates for low-power, rugged, full-color video applications. Recently, we have demonstrated a portable communication display device, built upon a full-color 4.3-inch HVGA foil display with a resolution of 134 dpi using an all-phosphorescent OLED frontplane. The prototype is shaped into a thin and rugged housing that will fit over a user's wrist, providing situational awareness and enabling the wearer to see real-time video and graphics information.

In this paper, we demonstrate two types of optically isotropic liquid crystalline states; (1) nano-segregated droplets of a nematic liquid crystal, dispersed in a photo-crosslinked polymer matrix, and (2) BPIII with a very short pitch of the UV region using bent-core nematogens with chiral-dopant. In both cases, we realize a complete dark state (OFF-state), switchable to ON-state by applying an electric field. These optically isotropic states are expectable as a principle for applications to extremely high-contrast and highly-responsive liquid crystal displays.

We proposed a surface treatment technology for improving the performance of the liquid crystal displays (LCDs). The alignment surfaces are modified with the reactive mesogen (RM) which are mixed with alignment layers and directionally polymerized along the LC directors during UV curing process. Since the polymerized RMs within the alignment layers could control and memorize the specific pretilt and azimuthal angles of liquid crystal molecules at the specific panel region, we could improve the display performance such as response time and wide viewing angle with multi-domains and design the new LC modes.

We propose a fast switching method for a homogeneous-aligned liquid crystal (LC) cell using 3-terminal electrode structure. LCs are vertical-aligned momentarily before they are in-plane switched to show a bright state, by which LCs are in a transient state rather than the stable state. The turn-on can be faster, whereas LCs start to relax along the rubbing direction so that the relaxation is optically hidden. The turn-off time of about 0.6 ms could be obtained. Experimental results show that fast gray-to-gray response as well as turn-on and turn-off can be achieved by using the proposed switching method.

New conceptual display structure is introduced by using TIR characteristics and BPLC as alight shutter. In our structure, non-polarized light source can be used as incident light due to the isotropic characteristics of BPLC unlike previously suggested waveguide display concept using nematic LC at '0' bias voltage. In addition, light leakage in the case of BPLC is smaller than that in the case of nematic LC. According to the wave mode, TM mode or TE mode, the critical angle is different from each other due to homeotropical characteristics of BPLC at bias voltage. Then, each critical angle is measured and optoelectronic characteristics of BPLC are estimated with increasing applied voltage. In addition, the intensity characteristics according to bias voltage across BPLC are studied with various waves. We confirm the nonpolarized light source can be automatically filtered, and directly used for waveguide display by BPLC. Consequently, BPLC can be nominated as a new light shutter in waveguide display structure using TIR mechanism.

The fast response Fresnel liquid crystal lens with multiple electrodes structure had been proposed and optimized. The multi electrodes in the new Fresnel LC lens were placed at both inner surfaces of LC cell. By supplying specific operating voltages on each electrode, the optimized Fresnel LC lens was closed to the ideal Fresnel lens. The experiment results indicated that the Fresnel LC lens not only performed fast switching rate without over-drive method, but also had the advantage of low operating voltage. Furthermore, by using overdriving method, the response time could be further reduced but just need 15volts in a short time. It meant that a fast switching between 2D and 3D image display could be obtained by switching Fresnel LC lens on and off. In the end, the fast switching display was also demonstrated.

Accommodative response measurement according to angular resolution in autostereoscopic display based on lenticular lens and lens array method is presented. Conflict between accommodation and convergence is one of the most dominant factors leading to visual fatigue in viewing three-dimensional display. The conflict originates from directional rays that do not have enough angular resolution density. Therefore the purpose of this paper is to verify the relationship between angular resolution density of elemental images and accommodation-convergence conflict. For measurement of accommodation response of a single eye, we used lens arrays and elemental images with different resolution densities.

In this paper, we report development of a high-frame-rate LED display. Full-color images are refreshed at 480 frames per second. In order to transmit such a high frame-rate signal via conventional 120-Hz DVI, we have introduced a spatiotemporal mapping of image signal. A processor of LED image signal and FPGAs in LED modules have been reprogrammed so that four adjacent pixels in the input image are converted into successive four fields. The pitch of LED panel is 20 mm. The developed 480-fps LED display is utilized for stereoscopic 3D display by use of parallax barrier. The horizontal resolution of a viewed image decreases to one-half by the parallax barrier. This degradation is critical for LED because the pitch of LED displays is as large as tens of times of other flat panel displays. We have conducted experiments to improve quality of the viewed image through the parallax barrier. The improvement is based on interpolation by afterimages. It is shown that the HFR LED provides detailed afterimages. Furthermore, the HFR LED has been utilized for unconscious imaging, which provide a sensation of discovery of conscious visual information from unconscious images.

In three-dimensional (3D) display based on lenticular lens method, the focal mode in which the gap between lens and display panel is almost equal to the focal length is widely used nowadays. However, because each pixel of the display panel has a finite size, reconstructed 3D image is displayed in virtual mode instead of focal mode. Because the elemental image which is a source of reconstructed image was generated for focal mode, the 3D image could suffer from image distortion. In this paper, view image error analysis based on autostereoscopic lenticular lens method and integral imaging method is presented based on numerical analysis and simulation results.

The common feature of bistable liquid crystal displays (LCDs) is the existence of the two stable states without an external field. In the bistable chiral splay nematic (BCSN) mode, the splay and π twist states are used for the two stable states. The BCSN mode is a potential candidate of bistable modes, because it can be operated not only as a storage device, but also as a monostable device with a fast response time in the same panel. The transition between two memory states of the BCSN LCD is strongly coupled with the strength of applied electric fields. In this paper, we investigated the bistable property by calculating the bistable curves and the correlation between the horizontal electric fields strength. To realize the gray scale of BCSN LCD, We also propose a grid electrode structure with the varying-space between electrodes which causes the varying strength of the horizontal electric fields. The selective transitions by the electrode structure are demonstrated in this paper.

In laser projection displays, countermeasure technique against glares on the screen called speckle noise is one of the focuses. In the experiments, a quarter-waveplate with slow axis rotated by 45 degrees against the polarization axis of the incident green laser source was inserted into the optical path of our laser projection display system. Only in such a setup, an enough coherence alleviation was attained. We have also carried out quantitative evaluations of the speckle noise by overlaying the projected images using a CCD camera on the histogram-based estimations of speckle noise intensities. Noise reduction of about 20% was accomplished.

A range of polymerisable liquid crystals mixtures have been developed (so called, Reactive Mesogen) that are ideally suited for the fabrication of patterned retarder films. Such films, made using a combination of Merck Reactive Mesogen Mixtures coated on a plastic substrate containing a photoalignment layer, are commercially employed to produce 3D displays. Different methods of patterning Reactive Mesogen Mixtures are discussed and the merits of each considered. Although the first commercial products use normal dispersion Reactive Mesogen Materials, the advantages of using the next generation of materials, which have improved wavelength dispersion, are introduced with a focus on their use in 3D patterned retarder films.

While today's display technology is mainly based on rigid-based substrate, flexible display technology has been significantly growing since the last decade. However, Flexible displays are susceptible to many types of stresses during processing and usage. Thin films on flexible substrate are sensitive to ambient conditions. Therefore devices are usually laminated with a protective layer. In this study high cyclic bending fatigue experiments were conducted on 2000 oA thick copper thin films sputter deposited on 127 μm polyethylene terephthalate (PET) substrate laminated with another 127 μm PET layer. High magnification images were used to observe crack initiation and propagation in the thin film layer. Initial results showed a great influence of laminate layer on stress reduction in the thin film. Furthermore, a lamination layer causes cracks to spread out on a larger area with fine cracks and therefore reduce the chance of the cracks to meet and grow.

Display technologies always seem to find a wide range of interesting applications. As devices develop towards miniaturization, niche applications for small displays may emerge. While OLEDs and LCDs dominate the market for small displays, they have some shortcomings as relatively expensive technologies. Although CMOS is certainly not the dominating semiconductor for photonics, its widespread use, favourable cost and robustness present an attractive potential if it could find application in the microdisplay environment. Advances in improving the quantum efficiency of avalanche electroluminescence and the favourable spectral characteristics of light generated through the said mechanism may afford CMOS the possibility to be used as a display technology. This work shows that it is possible to integrate a fully functional display in a completely standard CMOS technology mainly geared towards digital design while using light sources completely compatible with the process and without any post processing required.