Displays

Published by Elsevier
Online ISSN: 0141-9382
Publications
Article
This chapter describes the human and environmental factors that dictate the way that displays must be designed for, and used in space. A brief history of the evolution of such display systems covers developments from the Mercury rockets to the International Space Station.
 
Conference Paper
Previous papers have described the development of a 5×5 tactile array based on electrorheological fluids whereby the compliant rubber surface of the array offers a variable and controllable resistance to finger motion as the user's finger is pressed onto or is moved across the array. Different shapes with arbitrary compliance can therefore be set up under computer control. The main new feature described here is the utilisation of a layer of fabric within the fluid layer. It is shown that this results in at least a doubling of the perceived forces at the same time as at least a three-fold decrease in current. The fabric layer improves the safety of the device since it provides an insulative layer between the electrodes thereby preventing electrical shorting of elements during use. Similar, but reduced effects have been observed with experimental liquid crystalline based electrorheological fluids and added fabric
 
Conference Paper
The evolution of scientific activity related to HDTV is summarized from its first steps to the present and future situation. The problems connected to the definition of HDTV standards are examined, and an overview of the programs of the main international standards bodies (CCIR, CCITT) is given. The HDTV systems already realized and the most important projects regarding HDTV, which include MUSE, HD-MAC, SMPTE, and various Eureka projects, are discussed. A brief overview of Italian activity concerning HDTV is reported, focusing on the CNR-Telecommunicazioni project. The HDTV coding scheme realized by CSTV-CNR is presented, and its performance on two test sequences is evaluated
 
Article
A new 23-in. diagonal in-plane-switching (IPS) mode TFT-LCD with H1920×V1200 pixels has been developed. This TFT-LCD, which is a new structure with zigzag shaped pixels, has been adopted as an advanced IPS technology. Using this structure, the aperture ratio becomes 25% larger than that of conventional liquid crystal displays (LCDs). Furthermore, uniform image quality has been obtained by using the new dual-line driving method where the design has optimized storage-capacitance for each pixel.
 
Article
BackgroundAbout 30% of the population has difficulties detecting the sign and the magnitude of binocular disparity in the absence of eye movements, a phenomenon called stereo-anomaly. The stereo-anomaly tests so far are based on disparity only (e.g. red–green stereograms), which means that other depth cues cannot be used and even provide conflicting depth information.ObjectiveHere we investigate whether stereo-anomaly also occurs using a “true-3D” display which provides other depth cues that are all consistent with one particular distance in depth. Secondly, we examine differences in depth perception between red–green (anaglyphic) and true-3D displays. Finally, we test the displays’ relative viewing comfort.MethodSixteen observers (four of which were stereo-anomalous) judged the distance in depth between a fixation square and one or two bars. They were presented on an anaglyphic and a true-3D display, both in the fovea and 5 deg in the visual periphery. Observers were asked about the viewing comfort of both displays.ResultsStereo-anomalous observers also showed difficulties in perceiving depth with the true-3D display. Yet the true-3D display increased the perceived depth range compared to the red–green display for practically all observers at both eccentricities. All observers reported greater viewing comfort for the true-3D display.ConclusionStereo-anomaly is a robust phenomenon. True-3D displays improve depth perception and viewing comfort, most likely because retinal blur provides depth information consistent with disparity.ApplicationThe true-3D display shows potential for clearly and comfortably displaying objects at different depth planes.
 
Article
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.
 
Article
This chapter describes 3D displays for stereoscopic images. The 3D display system will be used in broadcasting and other applications the world over in and after 2010. In this chapter, principle, technological trend and effects on human body of 3D displays are described. In addition, the activities of authors for application of 3D displays are introduced.
 
Article
This study investigates the permissible value of horizontal binocular disparity when gazing at a three-dimensional (3D) display based on ocular accommodation function. For the closely perceived image on the 3D display screen, the crossed disparity of +1.0° and of +0.5° were given and for the far image, which gave the image far away from the screen, the uncrossed disparities of −1.0° and of −0.5° were taken. The disparity was 0° when the image was displayed on the screen. When the disparity was +1.0° and the stereoscopic image had been perceived, the accommodative response became significantly larger in comparison to that at 0°. An accommodation lead was observed significantly at a disparity +1.0°. The tolerance of binocular disparity on the 3D display based on the physiological aspect of ocular accommodation is thus suggested to be less than +1.0°.
 
Article
We compared visual fatigue caused by HDTV and stereoscopic HDTV at the viewing distance of 4.5 m. We measured the degree of visual fatigue using a subjective test method and compared it to an objective measure, namely the change in accommodation before and after viewing images. We also detected visual discomfort image scenes from the best program using the single stimulus continuous quality method. As a result, the mechanism between convergence eye movement and the accommodation function in the depth of focus in addition to conflict of convergence eye movement and accommodation function appears to affect visual fatigue. From the examination between the results of single stimulus quality evaluation and the feature characteristics of test stereoscopic images, we found that a local low subjective evaluation appeared for both high degree of parallax and amount of motion in the test stereoscopic images. But motion components were very small, the subjective evaluation value was rarely very low.
 
Article
Three-dimensional displays provide an unambiguous visual representation of the spatial structure of natural scenes and computer-generated virtual environments and thus have proven substantial advantages over conventional displays in remote guidance and inspection tasks and in application fields such as medical imagery and architectural and molecular modelling. Recent years have seen increasing efforts to extend 3D technologies into the domain of image communications. These efforts received support from human factors studies indicating that 3D displays are highly appreciated by prospective users of image communications systems for their enhanced psychological effects (telepresence and communicative presence). On the other hand, these studies have revealed heavy technological requirements that must be met in order to avoid visible image distortions and increased visual strain.
 
Article
An active-matrix a-Si thin-film transistor liquid-crystal display (TFT-LCD) with 720 × 480 pixel resolution has been developed as a projector, enabling the display of sharp images on extended definition TV (EDTV) and computer monitors that support a full range of multimedia applications. To enhance picture quality, an LC transmission-voltage (T-V) correction circuit has been developed that incorporates a nonlinear video signal amplifier based on curve-fitting. To extend the panel's capabilities so that it can project images on computer display monitors, a ew drive circuits have been developed that incorporate 8-MHz analogue driver LSIs and sample-and-hold circuits.
 
Article
Usability is in danger of becoming simply another buzz word. Usability must be translated into a set of working principles which can be incorporated into the design and implementation of computer systems. This would require objectives for usability to be set. In its current form EC Directive addresses minimum requirements necessary to meet such objectives. However, it does not yet provide details concerninh how these requirements can be met, and potential techniques for this purpose are discussed in this paper. Responsibility for usability should not rest solely with designers, but must be shared between employers who purchase and install systems, designers, manufacturers and end users.
 
Article
ISO 9241-7 is the first international specification for quality comparison of anti-glare treatment of CRT-displays. The importance of anti-glare treatment and control of the lighting environment has always been considered important, but there has not been a repeatable and ergonomically validated method available for testing CRTs. The ergonomic validity of the method has been analysed and reported before the standard was approved. However, no research on the metrological quality of the new method has been published. In this paper accuracy and repeatability is defined as the accuracy and international repeatability that can be achieved when the same CRT-display is tested in any competent laboratory. We report research conducted in one laboratory in Europe and report the preliminary results from an interlaboratory comparison testing with two laboratories from Europe and five laboratories from Japan. The focus is on testing two hypotheses. The first hypothesis “the defined test methods are repeatable and reliable” was found to be false, but the problems are small and can be covered by interlaboratory agreement or a future minor update of ISO 9241-7. The second hypothesis “if an integrating sphere is used as light source then it can be used at any distance to the EUT” was true and confirmed the theoretical prediction, which means that one of the limiting requirements on the test set-up, defined in ISO 9241-7, is unnecessary and should be removed from the standard.
 
Article
An alternating current electroluminescent display has been direct written onto a flexible plastic substrate. A hybrid layer of poly(2-methoxy,5(2-ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV) and CdSe quantum dots (QDs) were used to convert the light emitted by electroluminescent ZnS phosphor into red light. The emission wavelength of the display is found to be directly related to the emission of CdSe quantum dots. The integration of QDs into thin film electroluminescent (TFEL) displays has the potential to enhance its color spectrum.
 
Article
Development of the first high-altitude ac plasma displays is reported. These displays are fully operational to 45 km. Also described is the development of a multicolour photoluminescent ac plasma display. The luminance of the colour display is comparable to that of a neon-orange panel and the inherent memory of the standard ac drive has been retained. Finally, development of a 1.5 m diagonal ac plasma display is reported. This device constituted the world's largest fully-populated dot-matrix flat-panel display.
 
Article
In this paper, an equivalent circuit model for discharge cells of alternating current plasma display panel (AC PDP) is developed. In this model, a voltage controlled switch is introduced to describe the breakdown process of the gas discharge. And two zener diodes are introduced to describe the sustain process of the gas discharge. Three internal discharge characteristic parameters, the breakdown voltage of discharge gap, the minimum sustain voltage of discharge gap and the discharge cell capacitance ratio, are proposed. The formulas for expressing external discharge characteristic parameters by internal discharge characteristic parameters are derived. The experimental method for measuring internal characteristic parameters is developed and the measurement results for a macro discharge cell are presented.
 
Article
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.
 
Article
The acceptance, appearance, clarity and beauty of letters with jagged edges to be shown on liquid crystal display (LCD) computer screens were determined. Two psychophysical experiments were conducted. In both, 18 participants, judged texts presented in different simulated screen resolutions on LCD screens. The two experiments differed according to the viewing distances, short and long, and in how the different measurable screen resolutions were simulated on the screen. Judgements varied as a function of jaggedness. The observers were more tolerant of judging the Clarity scale as compared to the Aesthetics, Jaggedness, and Appearance scales. It was not possible to combine the results from the two different viewing distances, presumably because of different eye movements. For both distances Aesthetics was important for the judgements of Appearance. The recommendation for future requirements for jagged edges on LCD displays is that the minimum resolution of a screen should be at least 5 pixels/mm.
 
Article
Work in progress at BT Labs to investigate the use of a haptic display as a component of an emerging de facto standard (VRML) for the display of three-dimensional images on the WWW is reported. Use of a simple haptic interface to provide access to three-dimensional virtual images is discussed. This is based on experience of developing a browser capable of driving a force-feedback probe from a VRML file.
 
Article
A London HCI Centre (LHC) project to produce a user interface development environment for screen-based, nondirect manipulation, public use computer systems is described. A survey of available public access computer systems was undertaken to characterize and critically assess the usability of current designs. That part of the survey relating to four particular information retrieval systems is presented. Some serious weaknesses in the user interfaces to these systems are highlighted along with recommendations for improvements. The paper concludes with a general discussion of the major areas of weakness and how human factors guidelines can be used to improve usability.
 
Article
Being in the midst of the evolution of the species Homo termino-videns, demands for (eye) rest-time allowances are commonplace among vdu operators the world over. Today some 13 per cent of Swedish salaried employees daily sit at a vdu and Sweden is the first country to have issued national safety and health directives on vdu work. Experiments using a laser optometer have shown that visual tasks in vdu work may induce temporary effects in the visual accommodation system; increased refractive power in darkness (‘night myopia’) and levelling-out of accommodation responses in good lighting (‘distance myopia’ and ‘near hyperopia’). It is believed that laser optometry will eventually make possible the formulation of objective criteria of visual fatigue and its prevention.
 
Article
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.
 
Article
This paper investigated some effects of viewing a laser scanned display (LSD) on visual perception. LSDs potentially provide a high-brightness, monochromatic, image which could have particular effects on the visual system. As a monochromatic image may reduce a potential cue for visual accommodation (chromatic aberration), participants’ accommodation was measured while they viewed an image on either a laser-scanned, or video-projected, display. Furthermore, monochromatic diplays may lead to effects on perception as a result of chromatic adaptation. Colour vision was also assessed before and after using the displays. Increased variability of the level of accommodation was found when using the laser-scanned display, but the magnitude of the effect was mediated by how fast elements of the display were moving. The greatest difference in accommodative variance was between a video display with slow-moving elements (0.016 D) and an equivalent laser-scanned display (0.118 D). Viewing of the laser-scanned display also led to measurable changes in colour perception in some participants. Thus, although further research is required, this paper suggests that viewing a laser-scanned display may have some effect on the accommodation response and on colour perception.
 
Article
When designing a multimodal human–machine interface, the human function allocation must be considered. To reduce the load on the visual sense, the other sensory channels must be utilized. Here, the authors put forward a HMI which provides unique concepts called acoustic user interface (AUI).With an AUI, information can be removed from the visual channel and presented through the auditory channel. The head-related transfer function is used to create the impression of sounds arriving from any direction, either inside or outside the visual field of view. As well as reducing the loading on the visual sense, aural ‘images’ can be ‘projected’ coincident with the location of images displayed on the visual displays, in order to co-ordinate and communicate more effectively multimedia information.
 
Article
Virtual environment (VE) technology exposes users to a variety of intersensory and sensory-motor discordances to which they must adapt for optimal performance. Our research has distinguished two types of adaptation: Visual-motor skill acquisition and perceptual recalibration. The first involves learning a new way to coordinate hand and eye, while the second is an automatic, restricted process of perceptual learning. We conclude that an understanding of the controlling conditions and defining characteristics of these two adaptive mechanisms allows one to predict which is the more likely to occur with a given VE and how best to train its users.
 
Article
Alkaline earth monoaluminate phosphors activated with Eu2+ were synthesized by microwave processing and alkaline earth hexaaluminate phosphors activated by Eu2+ were synthesized by hydrothermal reactions. The emission spectra of the monoaluminates are similar to phosphors prepared by high-temperature firing except for BaAl2O4 which emits farther in the blue. The spectra of the hexaaluminate phosphors in general have their emission peak at different wavelengths than what are nominally the same compositions prepared by high-temperature firing.
 
Article
The present research aimed to employ dynamic and static emotions as social cues in e-learning environments for computers to be able to convey social presence and increase children’s motivation with learning. To understand how children of different gender react to the two types of emoticon in e-learning environment, a math problem-solving practice program was designed to test their reactions. The program features two treatments, dynamic emoticons and static emoticons. A 2 × 2 (emoticon style × gender) between-subjects factorial design was adopted for this study. One hundred seventy-three sixth graders participated in this study. Data were collected via questionnaire regarding the perceived social presence and children’s intrinsic motivation, and then analyzed by means of two-way ANOVA. The results show that the children in dynamic-emoticon condition perceived a higher degree of social presence and reported greater intrinsic motivation than those in static-emoticon condition. The feelings of social presence created by the computer itself can mediate children’s intrinsic motivation. Besides, no gender differences in children’s attitudes toward computers were observed. It suggests that the use of dynamic emoticons as social cues incorporating in e-learning environments can enable children to perceive computers on social dimension and lead to increase their motivation with learning.
 
Article
In this paper, our contribution is to propose an adaptive-hierarchical filter that can remove the impulse noise while preserving the details in an image. The global image structure, which is estimated from a set of pyramid images, can be used as prior information in order to apply different filters adaptively. The proposed filter outperforms other methods in that it can make use of both local and global information efficiently. Experimental results show that the proposed method produces better performance than many other well-known methods do.
 
Article
The comparison between modified and/or compressed digital images and original digital images, i.e. reconstructed digital images, may be simply demonstrated by means of two-dimensional orthogonal transform techniques and adaptive spatial filters in the domain of the spatial frequency. The main purpose of this study is to examine how much the visual appearance of the reconstructed images is essentially affected by two types of parameters: the number of the threshold value and the value of the weighting coefficients necessary to the concept of an adaptive spatial filter, which is generally used in a small divided block domain in connection with simplified digital image compression techniques. Moreover, the suitability of 3D visualization and/or quasi-colour representation techniques is verified as a means for intuitively understanding the discriminating features of reconstructed images. To sum up, this study is executed to examine the contrast between the visual appearance of difference images and fidelity evaluation of image quality.
 
Article
An adaptive address energy recovery circuits (AAERCs) for plasma display panels (PDPs) is proposed after analyzing the address power of address methods such as the address energy recovery circuits (AERCs), no-AERC, and interlaced/progressive scan (IPS). Also the detecting method for change rate of address data to calculate address power is proposed. Then AAERCs can work as AERCs, no-AERCs, or IPS in one subfield according to calculating result of address power to get the lowest address power comparing with other methods. There is no change on prototype address circuit but only control timing of scan ICs and address data processing in software. The experiment results with a 50-in. HD dual-scan PDP shows that the address power of AAERCs can keep the lowest at any picture comparing with other address methods, and the maximum address power saved is 81 W.
 
Article
The Adaptive Iterative Multistage Multichannel halftone algorithm is described as an adaptive, iterative halftone technique based on multichannel, multistage processing of frequency characteristics. The algorithm produces high-quality halftones that exhibit different characteristics of smoothness and sharpness as appropriate for local image content. The desired visual effect is determined in an unsupervised manner in natural images by generating a feature vector at each pixel identifying local frequency characteristics, selecting an error metric at each pixel based on the feature vector information, and minimizing the error weighted by the metric.
 
Article
Active AddressingTM is a new electronic drive technique that makes it possible for fast-responding supertwisted nematic (STN) LCDs to deliver full-motion video images without loss of brightness or contrast. Beginning with an explanation of the breakdown of standard addressing techniques at video rates, this paper explains how to choose Active Addressing row waveforms and derives the algorithms for generating column signals to display many grey shades without flicker or noise. Several practical circuits are presented for implementing Active Addressing, including an integrated circuit design. Because of the low manufacturing cost of STN displays compared with thin film transistor displays, Active Addressing is expected to make high-performance video-rate LCDs available for a wide variety of affordable products.
 
Article
Recently, various wide color gamut displays have been developed. Because of color gamut differences between wide gamut displays and the standard definitions, the color reproduction on such display system is not equal to original images. To overcome this, a color transformation such as gamut mapping algorithm is applied in conventional systems. But this manipulates only the video signal that would reduce the signal dynamic range and produces quantization error of video signal.In this paper, we propose a new optical Color Gamut Processing instead of an image data mapping. In the method, an individual color gamut of the standard definitions can be composed of an optical mixture of original primary colors. As a result, a perfect color match for the various standards can be realized within a display gamut without any signal artifacts.Moreover the same concept is applied to the video stream in order to elevate scene luminance. A scene-adaptive Dynamic Color Gamut Processing measures a color gamut for every video frame and adjusts a matched display color gamut so that it is able to increase display contrast in comparison to conventional display systems.
 
Article
The work described was undertaken for the Office of Special Education in the U.S. Department of Education to help them plan future funding for technology development. The agency has supported a large body of research out of which have come a number of innovative technologies (e.g. the Kurzweil Reader) but funding decisions in the past have been somewhat hit-or-miss.In this paper I discuss the process by which we identified some critical learning needs of children with disabilities and how we then arrayed the emerging technologies and selected those that matched the needs. Technologies investigated include interactive multimedia, speech recognition and natural language, intelligent tutoring systems, ‘pocket intelligence’, and virtual reality.From the information gathered from research and development laboratories across the country we have prepared detailed scenarios to describe the needs, illuminate the technology (including its background, development costs, and future development issues) and describe the process of technology transfer. I discuss in some detail the scenario we have prepared on virtual reality—a technology that has generated a great deal of public interest in the past 12 months.
 
Article
Sixteen younger and 16 older drivers participated in this simulated driving experiment. They were instructed to perform a push button task and a navigation task while using the displayed traffic information to drive through each scenario. The Advanced Traveler Information (ATI) was presented visually only, aurally only, or by multi-modality display. All drivers made significantly fewer errors in responding to hazard warnings when using multi-modality and auditory displays compared to visual-only displays. When the ATI system presented complex information, multi-modality display led to significantly faster and more accurate recognition of hazards and better control of car direction and speed. The results indicate that multi-modality display of ATI is optimal, particularly for older drivers.
 
Article
Tactation is the sensation perceived by the sense of touch, and is based on the skin’s receptors. Touch is a common medium used by the general population and the sensory impaired. Tactile substitution can be used by the blind or deaf in order to: (a) enhance access to computer graphical user interfaces and (b) enhance mobility in controlled environments.The skin nerves can be stimulated through six types of receptors by mechanical, electrical, or thermal stimuli. Modalities, such as vibration and pressure, can stimulate these receptors. Advances in tactile communication using implementations of the actuating devices have been developed via several new technologies. These technologies include static or vibrating pins, focused ultrasound, electrical stimulation, surface acoustic waves, and other.This paper is a review of the state-of-the-art in the physiological and technological principles, considerations and characteristics, as well as latest implementations of microactuator-based tactile graphic displays. We also review fabrication technologies, in order to demonstrate the potential and limitations in tactile applications.
 
Article
Given the critical role that screen aesthetics plays in human-computer interaction, it is important to understand what characteristics of screens influence user acceptance. The purpose of this paper is to present a set of screen characteristics that appear to be important determinants of acceptance, and to present the results of two experiments used to developed and validate a system for predicting user acceptance based on the screen characteristics.
 
Article
IntroductionLag between head movement and the time to render the visual consequences of the movement during head mounted display (HMD) applications presents challenges in the appearance of a stable image. This appearance of an image to “lag” behind or “swim” about may cause detriments in user performance, lack of user acceptance, and simulator sickness. These known potential consequences of HMD use motivated the current work to explore the human capability to detect display lag. The aim in this study was to gain a better understanding of the threshold for display lag detection and what variables affect this threshold.MethodsTwenty four subjects completed a repeated-measures three field of view (FOV; 10°, 38°, and full monocular) X two psychophysical technique (forced-choice and simple) experimental design. Passive sinusoidal head movements about the yaw axis were generated by an oscillating chair. A visual scene consisting of vertical bars was projected by an optokinetic drum moving in a sinusoidal fashion with the subjects. Subjects reported whether the scene lagged behind head movement.ResultsThe grand threshold mean for lag detection was 147.64 ms (SD = 84.91). The median was 130 ms and the 25th and 75th percentiles were 84.17 ms and 206.25 ms, respectively. Lag thresholds were not systematically influenced by either FOV or psychophysical technique.DiscussionNaïve subjects in the current study were less sensitive to lag as compared to thresholds reported in previous HMD studies, which provided lag detection strategies and practice [e.g., 77 ms; Ellis, Mania, Adelstein, & Hill, 2004]. Future examinations using the current paradigm should provide detection strategies and more practice.
 
Article
The factors affecting the differences in appearance between colours in original scenes and in their reproductions are reviewed. These factors include the border of the display, its angular magnification, its luminance, the colour of its effective illuminant, its surround, and the extent to which it is itself perceived as an object. Different criteria for evaluation of displays are needed according to the circumstances.
 
Article
The evaluation of colour within real-time air traffic control simulations is described with particular reference to distinguishing categories of information, designating tasks and highlighting specific information. Further consideration is given to the advantages and disadvantages of colour coding within an air traffic control context, with reference to relevant literature. Some recommendations are made for the utilization of colour coding, which are particularly relevant to electronic air traffic control displays.
 
Article
Air traffic controllers of the future will be working with full-colour raster-scan displays. This paper describes an approach to the use of colour whereby the objects on the display are assigned to a series of conceptual layers which are in turn represented as visual layers. Background map features are shown as opaque infills, overlaid with transparent infills for overlapping areas; alphanumeric labels in the foreground are shown in black, each with an attached infill to ensure good legibility and effective colour coding. Colour palettes are provided for each layer so that the display designer has flexibility but can be confident that the display will be free of colour illusions and ambiguities. The resulting displays can be used in normal office lighting. The work was undertaken for the Chief Scientist's Division of the National Air Traffic Services (part of the UK Civil Aviation Authority).
 
Article
A GaN-based light-emitting diode (LED) with an air–buffer layer and textured sidewalls is fabricated and investigated. After the deposition of a 1-μm silicon dioxide (SiO2) passivation layer on the whole device region except for the sidewall, a hot KOH etching solution is used to develop the desired textured sidewall. Many sidewalls with triangular-like shape are produced along the specific direction of , where photons introduced within multiple-quantum-well (MQW) exhibit more opportunities to scatter into the air. Based on the lateral etching, many triangular-shaped cones are formed on the patterned sapphire substrate (PSS). The device sidewall inclines with a 24° angle which results in an improved reemission of photons in the vertical/lateral direction. At 20 mA, as compared with the LED without KOH treatment, the studied device exhibits improved output power by 11.7% without deteriorating its electrical characteristics. This phenomenon can be attributed to the enhanced output light from vertical and lateral directions due to the formation of an air–buffer layer, textured and inclined sidewalls.
 
Article
Rapid appreciation of spatial orientation is essential when recovering from unusual attitudes during aircraft combat and emergency manoeuvres. This paper is concerned with attitude awareness derived from aircraft instruments, in particular the comprehension of pitch, roll and horizon information from head-up displays. Human visual orientation is discussed with respect to dual-mode theory of focal and ambient visual information processing, with particular emphasis on the perception of pattern orientation and the relative contributions of global and local features of multidimensional structures. It is argued that global organizational characteristics of display formats are important and neglected sources of cues for attitude awareness. An improved pitch scale symbology for head-up displays is proposed, based on empirical evidence from studies of operator performance on unusual attitude recovery tasks.
 
Article
In the multi-role combat aircraft Gripen, the monochrome head-down displays in the cockpit are to be upgraded in colour. In the present study, the effects of colour-coded displays on visual search and situation awareness (SA) were studied in a real-time simulation of an air-to-air mission with test pilots as subjects. Gripen's monochrome colour scheme was compared to two chromatic (dichrome, polychrome) colour schemes. A 3×2×2 factorial within subjects design was used; the three colour schemes each with two different background conditions (simple and complex) and two different symbol configurations. The pilot had two tasks during the simulation: (1) to track a manoeuvring aircraft within specified limits by using the head-up display (HUD), and (2) to detect the appearance of a priority target on the head-down horizontal-situation display (HSD). Deviations in flight path angle and reaction times for target detection were recorded. After the test runs, the pilot answered questions and ranked the colour schemes in different respects. The pilot also rated them for SA using a subjective rating technique on cognitive compatibility (CC-SART). The results show that colour is advantageous in comparison to the monochrome display: The ranks on situation awareness and preference ratings were higher for the chromatic schemes, and with the complex background, the reaction times were significantly lower for the polychrome colour code. In summary, the results indicate that colour can improve tactical SA in combat aircraft.
 
Article
This report presents two experiments in the area of perspective aircraft displays. The research focus was to explore the possibilities to understand symbolic and symbol relations in the 3D environment. In the first experiment the subjects' ability to distinguish between five different aircraft symbol shapes were investigated together with the perception of their heading in the 3D space. The perspective used in this experiment was egocentric. In the second experiment the judgment of the spatial relation between an own-ship symbol and a target symbol was investigated. Thus, in this case, the perspective was exocentric and two aspect angles were used for the camera position. Both experiments were carried out in non-dynamic scenarios. The display character was topographic with a superposed grid at the ground surface. The overall conclusion from the experiments is that judgment of direction in 3D presentations is very difficult in these static scenarios. Symbol recognition of 3D pictorial symbols is problematic for complicated symbol shapes as well, depending on different appearances for various symbol headings in the 3D space.
 
Article
Photo-induced alignment of ferroelectric liquid crystals (FLCs) based on photochemical stable azo-dye films was studied. The alignment quality of FLC display depends mainly on an asymmetric boundary structure and preparation of photo-aligning/planar layers. The photo-aligned FLC display was optimized to obtain both a steadiness of multiplex operation and a high contrast ratio. A prototype of passively addressed 64×64 FLC display based on the photo-alignment technique has been developed with perfect bistable switching in the multiplex driving regime.
 
Article
This research investigated the effects of text presentation on online behaviour and preferences in order to generate design guidelines for the production of web pages. Previous research has indicated that method of text presentation has a significant impact on usability. The present research found that varying text presentation had a significant effect on task performance, with wider line spacing leading to better accuracy and to faster reaction times. Left-aligned text led to better performance, although participants preferred justified text. Implications of these results for the design of web pages are discussed and recommendations given.
 
Article
This work is concerned with the investigation of the possibility of increasing the tilt angle in the surface alignment of liquid crystals using rubbed polymer layers. Higher tilt angles (than are currently possible using rubbed polymers) are necessary to exploit the new electro-optic effects reported recently. Tilt angle results are quoted for a range of commercially-available polyimide materials, along with the results of varying the processing parameters, such as temperature and rubbing pressure. The effect of the liquid crystal material used to fill the cells is also described. These results are discussed in terms of changes in the surface properties of the alignment layers.
 
Article
Ultraviolet (UV) embossed alignment layers having patterned spacers for the flexible liquid crystal display (LCD) were designed and fabricated to prevent the problems caused by residual monomers in photopolymerization-assisted manufacturing of liquid crystal (LC) devices. UV embossed alignment layers with patterned spacers provided mechanical stability and better alignment properties of LC molecules in a bent environment, compared with LC device with the phase-separated polymer walls. In the patterned spacers of UV embossed LC cell, the column-shaped spacer which has isotropic configuration of spacers provided good LC alignment during bending process.
 
Article
We report a novel non-lithographic technique to produce gridded field emitter arrays. Porous anodic alumin membranes with well-defined pores (≈160 nm) and high pore density have been exploited to fabricate a very high density of filed emitters An additional advantage is offered by the small size of the individual emitter devices (≈160 nm grid aperture), allowing operation with only moderate extraction voltages. The lowest extraction voltage at which emission was observed (0.1 nA) was 15 V. Arrays containing approximately 200,000 emitters have shown that emission current densities of up to 30 mA cm−2 (50 V extraction voltage) can be achieved. Recent results have shown a performance suitable for display devices and this technique is a potential route for the development of large, inexpensive displays.
 
Top-cited authors
Aubrey Dyer
  • Georgia Institute of Technology
Peter Alan Howarth
  • Loughborough University
Sarah Sharples
  • University of Nottingham
Sue Valerie Gray Cobb
  • University of Nottingham
Wijnand A Ijsselsteijn
  • Eindhoven University of Technology