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• There is a critical band of surrounding luminance gradients for self-luminosity. • The critical band is not determined by local contrast or luminance energy. • The critical band is aligned with human experience to real and virtual light sources. It is a great challenge to present realistic light sources in a virtual environment given the limited luminance range of an electronic display. Previous studies show that a glare illusion can enhance the perceived luminance of an area, which is an effective way to improve the realism of light sources in virtual environments. However, it is unclear what kinds of luminance gradients are appropriate for generating virtual light sources. In this study, we investigated the quantitative rule governing the perception of self-luminosity and applied the rule to improve the fidelity of light sources in virtual environments. In particular, light spots with different luminance gradients were presented on a liquid-crystal display (LCD). The participants were asked to report whether or not a luminance spot looked like a self-luminous light source. The probability of the spot being identified as a light source was calculated at each luminance gradient. We observed a critical band of luminance gradients which are a range of power-law exponent. Once the luminance gradient of an image fell into that range, the image was mainly perceived as self-luminosity. The critical band could not be explained by either the local luminance contrast or the total luminance energy. Interestingly, natural image statistics showed that the band matched with the luminance gradients of light sources in natural images. The perception of self-luminosity depends on the specific luminance gradients which are accumulated by human perceptual experience to light sources on natural images. Moreover, we generated virtual light sources with different surrounding luminance gradients and the gradients around the peak of the critical band won the highest rating of perceptual fidelity. These results provide a quantitative description of the perception of self-luminosity, which offers a guideline of how to improve the fidelity when rendering light sources in a virtual environment. [ABSTRACT FROM AUTHOR]

Highlights • We formulate adaptive tone mapping under ambient light as a constrained optimization problem. • We propose adaptive luminance enhancement based on HVS model under ambient light. • We introduce distortion minimization to minimize information loss caused by excess of the displayable range. • We enhance visibility of displayed images under strong ambient light conditions. Abstract We propose adaptive tone mapping for display enhancement under ambient light using constrained optimization. To deal with the visibility reduction caused by ambient light in displays, we perform different operations for display enhancement according to the intensity of ambient light. Since weak ambient light has little effect on displayed images, we only perform contrast enhancement for them. However, strong ambient light makes displayed images dark for human eyes, causing severe visibility reduction in luminance and contrast. To enhance the visibility of displayed images under strong ambient light, we formulate a constraint optimization problem which consists of luminance enhancement, contrast enhancement, and distortion minimization terms, and find an optimal trade-off among them by solving it. Finally, we conduct color scaling to reproduce vivid colors in displayed images. Experimental results demonstrate that the proposed method significantly enhances the brightness, contrast, details, and colors of displayed images and outperforms other state-of-the-art methods under ambient light. [ABSTRACT FROM AUTHOR]

Three-dimensional light-field displays (3D-LFDs) can provide viewers with glass-free 3D images. The display effect of reconstructed 3D images is closely related to the number of 3D object points that the 3D display system can construct, which can be regarded as the information quantity of the 3D-LFDs. However, the information quantity presented by a 3D-LFD is limited by fixed hardware parameters such as display panels and optical components. It is difficult to present an ideal 3D visual experience with the increase in display depth. In this paper, an analytical model based on voxel construction for 3D-LFDs is proposed, which can estimate the information quantity that a 3D-LFD can reproduce. The variation regularity of information quantity with display depth is analyzed and the influence of hardware parameters on display effect is discussed. With the proposed strategies, the display effect can be improved in a targeted manner without blurring and aliasing by adjusting the hardware parameters in display systems and matching the information quantity at different display depths. • A general analytical model of 3D light field displays was constructed. • The influence of optical components parameters on display effect were analyzed. • Derive the variation regularity between display depth and information quantity. • Experiments were conducted to verify the validity of the analysis model. [ABSTRACT FROM AUTHOR]

Electrophoretic display (EPD) has become one of the most important display technologies due to its bistability, low power consumption and outdoor readability. In this work, an image processing algorithm, which aims to enable video playback on EPD device without image distortion and grayscale loss by reducing the particle moving distance in EPD, is proposed and verified. The refresh time could be shortened by 22.2% with a video playback speed of more than 10 frames per second (fps) being achieved. This method could reduce the EPD switching time for quicker information displaying, and potentially extend the applications of EPD with video-like display property in the future. [ABSTRACT FROM AUTHOR]

Abstract: Large light-emitting diode (LED) displays have undergone a great deal of development in recent years. One of their main characteristics is their potential for great diversity in their physical parameters (size, brightness, power consumption, etc.) and in the configuration of the LED pixel arrays. The physical parameters can vary by several orders of magnitude, while the matrix can be organized in discrete real RGB pixels or in several types of virtual pixel distributions such as Bayer, Hexagonal and Diagonal. For this reason, it is particularly difficult to make a complete and exhaustive evaluation of any type of displays based only on objective parameters. In this paper we have developed and used a subjective method for evaluating the image quality of various types of LED displays. The results obtained show that there is not a perfect display solution and that for each particular project it is possible to find an optimal LED matrix solution based on quality performance and the number and distribution of LEDs used (that marks pixel resolution, overall manufacturing cost and power consumption). For displays with the same number of LEDs the array of emitters formed by real pixels are desirable for applications viewed at short distances and for predominantly alphanumeric content, while virtual pixels arrays are advantageous in applications requiring greater viewing distances and a higher content of complex images. [Copyright &y& Elsevier]

Highlights: [•] Large screen displays should be designed from the ground up. [•] We have built an approach that we call Information Rich Design. [•] Use of pattern recognition and animation of new alarms tested well. [•] Grey colour layering was difficult through video projectors. [•] We propose design principles for large screen displays for complex processes. [ABSTRACT FROM AUTHOR]

Highlights: [•] Electronic paper displays with large screen have faster reading speed. [•] Both sun light and fluorescent light are proper for reading on E-paper display. [•] Ambient illuminances 1000lx and 1500lx have better visual performance. [•] Ambient illuminances 200lx have more visual fatigue. [ABSTRACT FROM AUTHOR]

Abstract: We have shown that people steer toward a target by aligning their heading with the target when target egocentric direction is not available for steering [24]. Here we examined what visual strategies people use to steer toward a target when target egocentric direction is available for steering. The display simulated a participant walking over a ground plane with a target placed off to one side. The participant’s simulated heading in the display was displaced 10° away from the participant’s straight ahead. A textured ground display that provided dense global optic flow and an empty ground display that provided nearly no flow were tested. Participants were instructed to use a joystick to control their simulated self-motion in the display to (a) steer toward the target, (b) center the target at their straight ahead, or (c) minimize the target drift on the screen. We found that participants produced similar heading error profiles when they were instructed to steer toward the target or to center the target straight ahead, but not when they were instructed to minimize the target movement on the screen. Furthermore, regardless of the instructions received, final heading errors were about 5° smaller with the textured than with the empty ground display, indicating the effect of optic flow on the control performance. We conclude that when target egocentric direction is available for steering, people do not steer toward the target by canceling its optical drift. Optic flow contributes to steering toward a target even when control could be based on egocentric direction alone. [Copyright &y& Elsevier]

Abstract: A quick-response liquid powder display (QR-LPD) is a favorable candidate for flexible electronic papers because it can be simply operated by passive-matrix driving. However, the slow image refreshing rate is its major problem. In this study, multiline addressing (MLA) schemes for QR-LPD have been developed for improving the driving efficiency. Non-negative matrix factorization (NMF) with boundary constraints is used for the MLA scheme. A hybrid pulse modulation (HPM) is proposed for further shortening the driving waveform. The experimental results reveal that the MLA using NMF produces a noisy image on QR-LPD. The root cause for this is that NMF is a linear factorization but the electro-optical response of QR-LPD is not a linear curve. Therefore, we have proposed a lossless matrix factorization (LMF) method. The MLA scheme using LMF not only improves the image refreshing rate but also shows images without loss. [Copyright &y& Elsevier]

Abstract: The effects of various sustain waveforms, such as non-overlapped, half-overlapped, and overlapped sustain waveforms, on the recovery characteristics of temporal bright image sticking in ac-PDPs were examined. The overlapped sustain waveform was found to be the most effective for a fast recovery from temporal bright image sticking based on intensifying the sustain discharge intensity without increasing the sustain voltage level. [Copyright &y& Elsevier]

Abstract: This study investigated the effects of bending curvature of simulated e-paper displays (−10cm, plane and 10cm) and ambient illuminance (50, 500, 6000 and 12,000lx) on the visual performance of young and elderly users for simulated electronic-paper displays. In total, 24 people comprising 12 young and 12 elderly users participated in this study. Young users demonstrated significantly enhanced visual performance using the simulated electrophoretic ink (E ink) e-paper display with ambient illuminance set at 50 and 500lx; however, participants did not demonstrate significantly different visual performance using the 2 simulated e-paper displays with ambient illuminance set at 6000 and 12,000lx. The bending curvature did not exhibit significant effects on the visual performance of young participants under various ambient illuminances. The elderly participants exhibited significantly enhanced visual performance using the simulated E ink e-paper display only when ambient illuminance was set at 50lx; however, participants did not exhibit significantly different visual performance using the two simulated e-paper displays with ambient illuminance set at other levels. Elderly users exhibited significantly enhanced visual performance when the bending curvature was set at 10cm, with ambient illuminance set at 50lx. Elderly users also demonstrated significantly enhanced visual performance under bending curvature settings of 10cm and plane, with ambient illuminance set at 500lx. However, the bending curvature of the simulated e-paper did not exhibit significant effects on the visual performance of elderly participants under ambient illuminance settings of 6000 and 12,000lx. [Copyright &y& Elsevier]

Abstract: This study was conducted by subjective and objective measurement, to clarify the complex relationships among human visual preference and fatigue of major Flat Panel Display TVs with related physical and physiological factors. In the subjective measurement, comparison tests with 24 subjects were conducted and the semantic differential method with factor analysis was carried out for six TVs with different room luminance and length of watching time. The comparison test yielded identification of the most preferable display, which showed little connection with the TV luminance for any length of watching time and room luminance. From the statistical factor analysis of semantic differential method, significant factors were extracted for describing human visual preference. In the objective measurement, the eye motion tracking camera was used to detect the eye response and thus generated physiological data corroborated the significant factors extracted from the subjective measurement. This study allows the human perceptual preference and fatigue of electronic displays to be quantitatively measured with psychological and physiological factors and will tell which parameters are significant and guide the manufacturer in making the optimum TVs. [Copyright &y& Elsevier]

Abstract: A simulator study has been conducted demonstrating a positive effect on airsickness by utilizing a 3D artificial Earth-fixed visual pattern. Participants were exposed to the same turbulent physical aircraft motion in a simulator three times in a row, each time using a different visual cue. In one condition only the interior of the simulator cabin was visible. In another condition an Earth-fixed star field moving opposite the simulator cabin was projected in front of the participant. In a third condition the same star field was used, however with additional anticipatory information by means of a rollercoaster like track showing the trajectory to go. Participants were asked for their misery and joyfulness ratings at fixed time instants using an 11-points misery scale (no problems–vomiting) and joyfulness scale (unpleasant–pleasant). The results showed that viewing an Earth-fixed visual frame moving instantaneously opposite the cabin motion did reduce motion sickness significantly by a factor of 1.6, thereby improving comfort. This condition could be applied in air transport, where often a monitor is available in the back of the seat ahead. The largest effect, i.e., a reduction by a factor of 4.2 was realized by adding anticipatory information. Although it is not possible to predict the effect of turbulence on the aircraft motion yet, an anticipatory display might already be applicable in other domains, such as at sea by using a wave radar and a ship motion model. [Copyright &y& Elsevier]

Abstract: The experience of simulator sickness (SS) during head-mounted display (HMD) exposure continues to be a problem. The aim of these two experiments was to examine the effect of delay on SS while viewing a real, live video scene via an HMD. An object search task was performed in both experiments. Experiment 1 examined 0 and 200ms of delay and Experiment 2 examined 0, 145, and 300ms of delay. SS did not differ as a function of delay. However, SS increased as duration exposure increased in both experiments. In Experiment 1, SS was greater during the first experimental session than the second. SS did not differ between those who donned an HMD and a No HMD control condition in Experiment 2. It is possible that this is due to adaptation to repeated exposure to the sickening stimulus. This adaptation could have confounded the delay effects from Experiment 1. For this reason, a second experiment with an increased intersession interval was conducted. Intersession intervals for Experiment 2 were increased to 11–14days from 7days in Experiment 1. However, no effect of delay or session was found in Experiment 2. These results suggested that SS does not increase as a function of delay, but exposure duration increases SS. Also, performing repetitive head movements alone may have elicited symptoms of SS. As reported by other researchers, it appears that adaptation can occur to motion sickness stimuli with intersession intervals of up to 7days, but not with 11–14days. Other characteristics of HMD VEs need to be examined because SS occurs and delay does not appear to be as strong of a causal factor as once thought. [Copyright &y& Elsevier]

Abstract: Motion sickness (MS) can be a debilitating side-effect not just of sea travel, but also when immersed in video games or virtual environments (visually induced MS). To explore the impact of visual display parameters on motion sickness, we presented footage taken on an automobile race track to different groups of observers during three experiments. In Experiment 1, one group watched the movie wearing a head-mounted display (HMD) and a second group looked at a large projection screen with unrestricted view. Resolution and visual angle were equated. In contrast to common assumption, the projection screen produced significantly higher motion sickness scores than the HMD. To understand this rather surprising result, two further groups watched the movie with a limited field of view and reduced display angle, either through a synoptic device or a reduction screen (Experiment 2). Visually induced MS was reduced in both groups to the same extent. In Experiment 3, a fifth group of observers looked at the large screen with a limited field of view, but with unrestricted display angle. Results again showed decreased sickness scores. We conclude that another factor above and beyond display angle is critical to explain visually induced MS, namely the visual surround of the display. If present, the surround increases visually induced MS by causing an additional intra-visual conflict that makes it harder for the visual system to dominate the vestibular information and thus increases the nauseogenic conflict between visual and vestibular information. [Copyright &y& Elsevier]

Abstract: In this paper we investigate human binocular depth perception on 3D electronic display technologies. Our study is motivated by the increasing use of 3D displays in applications, including geo-science and medicine, where critical decisions are made using fine binocular depth judgements. We predict subject performance for a depth judgement task using published specifications for seven different 3D displays. A repeated measures, within subjects experimental design is used to determine the effect that display and binocular disparity have on subject scores in the task. We find that there is reliable variation in participant performance with display and disparity, however this variation is not always consistent with our predictions from the display specifications. We also present subjective results that suggest user preference for a 3D display is not always a reliable guide to their ability to perform the task. We conclude that care must be taken in selecting 3D display systems for tasks that critically rely on human depth judgement. [Copyright &y& Elsevier]

Abstract: A series of experiments have been conducted to examine ball milling parameters, such as the size of beads, ball milling time, the ratio of beads/phosphor/water, and the material composition of the ball milling beads to optimize the milling conditions for phosphor powders. It is concluded that longer time, smaller size of Φ2 Al2O3 beads, and higher ratio of beads/phosphor/water=2:1:0.5 can produce phosphor powder with higher dispersibility which in turn creates a densely packed coating of phosphor particles on the screen, a necessity for high resolution and high cathodoluminescence. When harder material with higher density are applied in the disagglomeration process or lower density beads which have undergone a longer ball milling time, the dispersion result is more effective. Nevertheless, the brightness of phosphor powder may deteriorate, a side effect which is undesirable for high quality phosphor powders. The concept of dispersibility is also proposed by evaluating the sediment volume, hardness, and ratio of water absorption. [Copyright &y& Elsevier]

Abstract: In the early 1980s the U.S. Army fielded the first integrated helmet-mounted display (HMD) for use in the AH-64 Apache helicopter. To reduce head-supported weight and minimize center-of-mass offsets, a monocular optical design was selected. Although early design concerns of binocular rivalry and the Pulfrich phenomenon never materialized, user surveys have documented persistent reports of visual complaints and illusions in peacetime training flights. However, a recent evaluation conducted under battle conditions in Operation Iraqi Freedom found statistically lower reports of complaints and illusions. While these reported problems are short-term, questions have been raised regarding potential long-term physiological effects resulting from long-term use of this monocular display. A 10-year longitudinal study, currently underway in the U.K., has been implemented to definitively answer the question of whether long-term exposure produces any degradation in binocular visual function. [Copyright &y& Elsevier]

Abstract: Virtual reality (VR) systems are used in a variety of applications within industry, education, public and domestic settings. Research assessing reported symptoms and side effects of using VR systems indicates that these factors combine to influence user experiences of virtual reality induced symptoms and effects (VRISE). Three experiments were conducted to assess prevalence and severity of sickness symptoms experienced in each of four VR display conditions; head mounted display (HMD), desktop, projection screen and reality theatre, with controlled examination of two additional aspects of viewing (active vs. passive viewing and light vs. dark conditions). Results indicate 60–70% participants experience an increase in symptoms pre–post exposure for HMD, projection screen and reality theatre viewing and found higher reported symptoms in HMD compared with desktop viewing (nausea symptoms) and in HMD compared with reality theatre viewing (nausea, oculomotor and disorientation symptoms). No effect of lighting condition was found. Higher levels of symptoms were reported in passive viewing compared to active control over movement in the VE. However, the most notable finding was that of high inter- and intra-participant variability. As this supports other findings of individual susceptibility to VRISE, recommendations are offered concerning design and use of VR systems in order to minimise VRISE. [Copyright &y& Elsevier]

Abstract: The article presents the results of an experiment where a 7in. TFT LCD display was exposed to harmonic vibration with acceleration amplitudes up to 200m/s2 and frequency sweep in the range between 40Hz and 1.5kHz. The display was mounted on a shaker in three different positions: landscape, portrait, and face-up. Colorimetric measurements were taken during and after the loading. Euclidian distance in the CIE Lab color space was used as measure of color change due to the loading. The results show that color gamut tends to narrow when increasing the acceleration amplitude. In practical terms however the color change is barely perceptible. In most cases the color changes disappear within 5h after the stop of the loading. Micro- and macroscopic examination of the LCD was performed to establish an indication of the cause of color change. [Copyright &y& Elsevier]

Abstract: Effects of character size under ambient illuminances and light sources on legibility of electronic paper displays (electrophoretic display and cholesteric liquid crystal display) were studied and compared with paper. Sixty subjects participated in a letter-search task in the experiment. The results showed that search speed depends on the illuminance but not light source. Search speed increased as the illuminance increase from 300, 700 to 1500lx. Search speed also increased with the increase of character size, from character height of 1.4mm (9.6min visual angle), 2.2mm (15.1min visual angle) to 3.3mm (22.7min visual angle), and the increase leveled off at 4.3mm (29.6min visual angle). The effect of character size on accuracy was also significant. Accuracy increased with the increase of character size. However, the effect of illuminance and light source on accuracy was not statistically significant. Based on the results of this study, it seems that E-paper displays may need greater illumination (700lx or higher), greater character size (3.3mm or 22min of visual angle). [Copyright &y& Elsevier]

Abstract: Despite current advances in multimedia environments, tracing the geometrical structures of graphical images using force feedback remains an important research issue. In this paper, the development and implementation of a multi-modal display system (MMDs) for tracing 2D boundaries in graphic images are discussed. A method is proposed that provides a type of haptic feedback designed to assist a user to trace the contours of objects seen in images. This method is an example of a family of haptic synthesis methods whereby the force field explored by the user is dynamic in the sense that it depends both on movement as well as on the object being haptically represented. The proposed performance-based method provides users with a movement guidance through an active haptic sense rather than common impedance technique. The tracing effectiveness of the proposed method is verified experimentally. [Copyright &y& Elsevier]

Abstract: This paper reviews the literature on factors that influence the visual (ocular) accommodation response when using see-through virtual image displays (VIDs) such as head-up and helmet-mounted displays. This review suggests that the overall accommodation response is determined by a complex interaction of many factors, some of which are associated with the visual stimulus (such as blur and chromatic aberration) and some of which are cognitive in nature (such as workload and attention). When using VIDs, the effects of these different influences on the accommodation response may not be congruent, leading to the level of accommodation being inappropriate for the task. [Copyright &y& Elsevier]

Abstract: This study constructed an evaluation framework to obtain the perceptual quality on liquid crystal display-television (LCD-TV) from the user’s point of view. Due to the difficulty for subjects to evaluate too many LCD-TVs simultaneously, the pairwise comparison of analytical hierarchy process (AHP) method was implemented in this study. After investigating the relationship between subjective assessments and physical measurements, some useful information can be provided for the industry to improve the quality of LCD-TVs. Results indicated that luminance, contrast and response time are the important factors in selecting an LCD-TV from a user’s point of view. However, after realizing the effect of sharpness, subjects considered that it is the most differentiable factor for selecting an LCD-TV. Therefore, LCD-TV manufactures should emphasize these important factors to improve the quality. [Copyright &y& Elsevier]

Abstract: Inkjet-printed greenish color filter layer for the application of active-matrix TFT-LCD had been significantly fabricated by the modified inkjet printing technology. The greenish ink with nano-particle pigments was injected in the stripe-type pattern with 90μm in width and 250μm in length by pre-designed inkjet head and driving system, and only green color was tested. The height of transparent rib wall, prepared by lithographic processes, on black matrix is 5.0μm. The chromatic coordinates of color filter with greenish subpixel patterns in CIE 1931 standard diagram can achieve in the region of x=0.3095±0.04, y=0.5912±0.04, brightness of Y=58.887 for 50 droplets and x=0.3103±0.04, y=0.5784±0.04, brightness of Y=60.328 for 41 droplets. The structural surface morphologies of the greenish subpixel patterns remain homogenous, smooth and flatten. [Copyright &y& Elsevier]

Abstract: In this study, attempts were made to develop a reliable and low cost chip on plastic (COP) bonding process by using electroplated Sn bump and non-conductive adhesives. Results showed that the bumped chip was successfully bonded with PES, and the initial average contact resistance was less than 30mΩ, which is much lower than that of ACF bonding. Thermal cycling (TC) test was performed to study the reliability of the COP assembly. The joints passed over 1000 thermal cycles without failure. The contact resistance decreased and leveled off during the TC test. 30μm fine pitch joints were fabricated and electrically tested. Microstructure observation disclosed that interfacial intermetallic compound formed at the Sn/pad interface, indicating a chemical bonding was achieved. EDS analysis showed that its average composition was very close to (Cu, Au)6Sn5. During thermal cycling, the interfacial IMC layers were observed to gain dramatic growth. [Copyright &y& Elsevier]

Abstract: Glasses within the Bi2O3–B2O3–BaO–ZnO system were examined as potential replacements for PbO-based glass frits with low firing temperatures. These frits are used in the transparent dielectric layer of plasma display panels (PDP). The glass transition temperature (T g) of the prepared glasses varied between 450 and 460°C. These glasses display dynamic dielectric properties, high transparency and thermal expansion as well as matching well with substrate glass. The thermal coefficient of expansion (TCE) was with the desired range of 81–86×10−7/K. Moreover, when the screen printed film was heat-treated at 570°C for 30min, optical transmittance (83%), root-mean square (rms) roughness (177.6Å), dielectric constant (10.25) and withstand voltage (4.15kV) satisfied the requirements necessary for transparent dielectric layers to be used in PDP applications. [Copyright &y& Elsevier]

Abstract: This paper presents a cell parameter extraction method for three-electrode AC plasma display panels (PDPs). This method uses three different two-electrode AC discharges to extract the cell capacitances. The drive point capacitances of the cell with and without a two-electrode dark discharge were measured, and the cell capacitances were extracted from them. The extracted cell capacitances agree well with those obtained from a three-dimensional electromagnetic simulation. Electrical equivalent circuits of the plasma were constructed using Jung''s model [Y.K. Jung, J.W. Seo, Y.H. Kim, B.K. Kang, Circuit model for two-electrode AC discharge, IEEE Trans. Plasma Sci., 31(3), pp. 362–368, 2003.] and the measured firing voltages. A circuit model for the cell was constructed using the cell capacitances and the equivalent circuits for the plasma. The results of electrical simulation using this circuit model agree well with the measurements, indicating that the presented circuit model would be useful for simulating the electrical behaviors of a three-electrode AC PDP. [Copyright &y& Elsevier]

Abstract: A running screen method is applied to remove hot spot speckle on projection screen by a laser display system with one DLP panel. We have commercially displayed a projection image from a DLP (720 Pi) display system using a minimized RGB high power laser source. Then we successfully obtained a high-quality image with low speckle contrast as if hot spot speckle are not recognized on the screen when both the rotating diffuser and the rotating screen by piezoelectric motor are used. [Copyright &y& Elsevier]

Abstract: This paper introduces a novel compact approach to measurement and characterization of the visual performance of LCD-screens when high visual fidelity of displayed images is a prime issue. We present instrumentation, procedures and evaluations for assessment of the visual properties of LCD-TV screens with minimum efforts as a basis for a clear and objective rating of their performance. Measurement and evaluation of color and gray-scale fidelity across the viewing-cone and under ambient illumination are the main topics of this paper. Typical results for a high-quality LCD-monitor are presented and discussed. A novel concept for scanning of the viewing-directions with simultaneous acquisition of nine spectra at nine angles of inclination is introduced as a solution for the dilemma of measurement time and colorimetric precision. [Copyright &y& Elsevier]

Abstract: Optical thin films used at oblique incidence exhibit inevitable polarization dependent properties. In reflective projection display systems, Philips prisms with color splitting filters are widely used. Generally, illuminating light at different polarization components passes the color splitting filters twice in such Philips prism. Color splitting filters operate as color separation for s-polarization and as color recombination for p-polarization, and thus performances of the color splitting filters for s- and p-polarization are equally important. In order to reduce stray light, it is necessary to design non-polarizing thin film edge filters for color separation and recombination system in projectors. The novel design method is based on a broad-band Fabry–Perot interference filter in which both sides of transmittance band can be used as initial designs for long-wave-pass filter or short-wave-pass filters, and through suitable refinement to reduce the transmittance ripples, it is possible to achieve zero separation between two polarization components. [Copyright &y& Elsevier]

Abstract: The effect of water absorption and thermo-physical properties on the warpage of a diffusing plate fabricated with poly(ethylene terephtalate)/polycarbonate/polybutylene terephtalate copolymer in a direct-lit backlight unit (BLU) of a liquid crystal display (LCD) has been investigated. The warpage of the new diffusing polymer was significantly reduced relative to that of a conventional PMMA diffusing plate. To improve the diffusivity of a diffuser, a new manufacturing technology, a stripe coating method, was suggested. By using this method, scattering characteristics of the new diffusing material was measured and compared to that of the diffuser which was not treated with stripe coating. Spatial profiles of the luminance are displayed for a BLU having cold cathode fluorescent lamps (CCFLs) array and a flat fluorescent lamp (FFL). As with the superior thermo-physical property that alleviates the warpage, the diffuser plate partially coated with diffusing agents is expected to achieve better uniformity and/or slimmer BLU. [Copyright &y& Elsevier]

Abstract: In order to achieve fast driving for reflective cholesteric liquid crystal display (Ch-LCD) we have developed a novel 3+2 dynamic driving scheme (3+2 DDS), which uses 3 and 2 level driver ICs for row and columns, respectively. From the transient dielectric study, the selection period of around 1.0ms/line showed the best contrast ratio at 30°C in our system. The time of the homeotropic to transient planar state is strongly dependent on temperatures. The row driver IC has 3 level outputs of R H, R M (R H/2), and R L; 32, 16, and 0V, respectively. And the outputs of the column driver IC are composed of 2 levels. We found that a preparation period of more than 40 times and an evolution period of around 40 times of the selection period are suitable. Also, we have accomplished a stable gray scale by using, as we call it, the pulse position modulation (PPM) in which the root mean square (RMS) value of the applied field during the evolution period does not change, even under cross-talk pulses. The driving condition made by PPM is more stable than that made by the usual PHM and PWM techniques. By adopting the 3+2 DDS, we have made 8.4in. foldable VGA Ch-LCD (640×480×2) that shows an addressing speed of around 1.0ms/line. [Copyright &y& Elsevier]

Abstract: In order to achieve a lower driving voltage of a cholesteric liquid crystal display (Ch-LCD) we formulated new nematic liquid crystal mixtures with dopants. The interesting thing is that the driving voltage is decreased more by adding the low molecular weight of liquid crystal materials in the cholesteric mixtures without decreasing its reflectivity. The cholesteric mixture is optimized by adding 20wt% of CN-007 enough to drive the display, necessary for using a commercial STN driver. Homogeneous alignment layers provide a higher reflective panel because of stabilizing the planar texture of cholesteric liquid crystal, while homeotropic alignment layers provide a higher contrast ratio because of stabilizing focal-conic structure. The rubbing condition depending on the driving scheme also affects the panel properties. The combination of the panel structure and the process condition of cholesteric mixtures make the Ch-LCD high reflectivity and contrast ratio. Two 5.7in. VGA monochromic cholesteric reflective liquid crystal displays with a high resolution like this folding type are demonstrated using a STN driver. [Copyright &y& Elsevier]

A concealment method is proposed to prevent the displayed images and texts from being seen by onlookers, while letting the authorized user see the full dynamic content. The concealment method is based on sequentially displaying the data frame and a compensating inverse data frame. The eye cannot discern the two frames and can only see a gray screen or a public image. The authorized user wearing LCD shutter glasses, on the other hand, can see the regular data frame. An optimum inverse data frame construction is achieved. Furthermore, the real time computation problem is solved, which makes the proposed method practically applicable to most PC systems. [Copyright &y& Elsevier]

Investigations of the relative merits of graphical (analog) and numerical (digital) formats have a long tradition in the display design literature. These issues are re-examined for the design of configural displays (displays that map multiple individual variables into a single graphical format). Six displays that varied with regard to the presence, spatial location, and dynamic behavior of digital values were evaluated. Performance was assessed for two tasks that imposed different cognitive demands. The results indicate that the presence of digital values had a substantial and positive impact on performance. The results also indicate a display by task trade-off. Placing a digital value in a spatially dedicated location improves performance when the variable of interest is known before the display is accessed. On the other hand, providing a dynamic spatial link between graphical elements of the configural display and the digital value improves performance when the variable of interest is dependent upon data relationships. Design recommendations based on these findings and practical considerations are discussed. [Copyright &y& Elsevier]

Projection technology has made large tiled displays an exciting feature of advanced visualization systems. However, one challenge to using such systems effectively is the development of input technologies that comfortably allow collaborative interaction with the displayed data on these large surfaces. We have developed an input system that allows any number of users to interact simultaneously with data on a large display surface. In this system, each user utilizes a laser pointer as a pen or pointing device. Using computer vision techniques, the system determines the beginning, continuation, and end of all currently active pointer strokes. The coordinates of each stroke are available for use by applications. This system scales well with display size, display resolution, and number of users. [Copyright &y& Elsevier]

• Facilitates designing color codes for electronic visual displays that comply with established human factors usability principles. • Calculates colorimetric figures of merit for a user-specified color set and flags colors and color combinations that may be problematic. • Draws figures that help users visualize important characteristics of the color set and find ways to improve it. • Can be used by itself or in conjunction with software that uses aesthetic considerations such as color harmony to create color sets. The US Federal Aviation Administration (FAA) has developed a standard set of colors for coding information on air traffic control (ATC) displays. A significant complication was that the air traffic controller population includes people who have color-vision deficiencies (CVDs). We wrote a software tool to assist the FAA in selecting a preliminary color set. It accepts a set of luminances and chromaticity coordinates as input and: (1) Draws graphics and calculates color-related figures of merit to predict whether the set will be acceptable for color-normal and CVD users; (2) Flags colors and pairings that violate human factors criteria; and (3) Allows designers to adjust the colors and see the resulting changes immediately. The tool has been used to perform a pilot study for the FAA's color-set development project and should be useful for designing other color-coding sets, also. [ABSTRACT FROM AUTHOR]

Polymer-stabilized FLCDs exhibiting V-shaped switching called PS-V-mode FLCDs are fabricated using newly synthesized photocurable monomers and new FLC materials. These FLCDs show good temperature reliability and high enhancement in the optical throughput, and the reduction of the operating voltage. The device is defect-free and exhibits high contrast ratio 700:1 and further fast response with τ=300–500 μs with continuous grayscale operation. We demonstrate a full color LCD with resolution 254 ppi and 4 in. diagonal using color sequential tecnique. [Copyright &y& Elsevier]