A curvature estimation for pen input segmentation in sketch-based modeling

A proper segmentation of pen marking enhances shape recognition and enables a natural interface for sketch-based modeling from simple line drawing tools to 3D solid modeling applications; user input is otherwise restricted to draw only one segment per one stroke. In general, the pen marking segmentation is achieved by detecting the points of high curvature-called, segmenting points-and splitting the pen marking at those points. This paper presents a curvature estimation method, which considers only local shape information. The proposed method can therefore estimate curvature on-the-fly while user is drawing on a pen-input display, such as tablet PCs.     

Exploring and modeling unimanual object manipulation on multi-touch displays

Touch-sensitive devices are becoming increasingly wide-spread, and consequently gestural interfaces have become familiar to the public. Despite the fact that many gestures require frequently dragging, pinching, spreading, and rotating the finger-tips, there currently does not exist a human performance model describing this interaction. In this paper, a novel user performance model is derived for virtual object manipulation on touch-sensitive displays, which involves simultaneous translation, rotation, and scaling of the object. Two controlled experiments with dual-finger unimanual manipulations were conducted to validate the new model. The results indicate that the model fits the experimental data well (with R² and R values above 0.9), and performs the best among several alternative models. Moreover, based on the analysis of the empirical data, the simultaneity nature of manipulation in the task is explored and several design implications are provided.     

EL displays for automotive applications

Abstract— This paper presents an overview of the display requirements for automotive applications and introduces alternating‐current thin‐film electroluminesent (ACTFEL) displays for automobiles. An ACTFEL has advantages over other displays under sunlight and low temperature conditions. Several automotive applications for transparent and multicolor EL displays are introduced in this paper.     

Effects of 3D displays: A comparison between shuttered and polarized displays

The current study investigates the effects of 3D displays (shuttered display vs. polarized display). People experienced superior fidelity and brightness when they watched 2D still images on a shuttered display, rather than on a polarized display. Conversely, people experienced greater brightness when they watched 3D still images on a polarized display, rather than on a shuttered display. Second, people were able to read a smaller font or characters on a shuttered display than on a polarized display. Third, people noticed flickering on a shuttered display when they watched 3D images. Fourth, people experienced greater brightness when they watched 3D moving images on a shuttered display, rather than on a shuttered display. The perceived brightness of the screen positively correlated with enjoyment, content satisfaction, and 3DTV satisfaction when the viewers watched a 3D movie. The flickering, on the other hand, has a negative correlation with enjoyment and 3DTV satisfaction.     

A practical approach to processing flexible displays

Abstract— The materials and fabrication aspects of flexible displays will be reviewed. The fabrication of flexible displays requires the consideration of proper material selection, handling of plastic‐film substrates, and a low‐temperature process for the fabrication of active‐matrix devices on plastic substrate. In addition, for the low‐cost fabrication approach, direct printing of active‐matrix patterning without a photolithography process is also required. Before commercial‐level production of flexible displays is considered, the factors of product reliability and practical value are considered. Samsung LCD Division's approach to the fabrication of flexible displays and future plans to develop a practical method that will lead to the production level of flexible displays will also be described.     

Advanced MEMS-based technologies and displays

MEMS (microelectromechanical systems) are used in many fields including display applications, which are extensively studied both in academia and industry. For practical devices, numbers of advanced technologies have been developed based on MEMS concept. For display technologies, projection displays, reflective displays, transmissive displays and other display modes have been achieved by different MEMS modes. In this review, the current MEMS-based display technologies are introduced and discussed including digital micromirror device (DMD), laser scanning display (LSD), interferometric modulator display (IMOD), digital micro-shutter (DMS), time multiplexed optical shutter (TMOS), grating light valve (GLV) and others. The typical structure and fundamental of each display mode are interpreted.     

Vacuum fluorescent displays for automotive applications

Vacuum fluorescent displays are now widely used in automobiles. This paper describes the various technical requirements for their automotive application. Although VFDs originated in the mature technology of electron tubes, continous development such as introducing thin film technology, thick film technology by photolithography and new phosphor materials, will create a breakthrough for a new generation of VFDs. The current status of the VFD product adopting new technologies and the future trends are presented. In the near future meanwhile, flat panel graphic displays in full colour are expected for practical application.     

A first demonstration and analysis of the biprimary color system for reflective displays

A new biprimary color system is demonstrated for single‐layer reflective displays, capturing much of the improved color performance of multilayer displays while potentially maintaining single‐layer display advantages in high resolution and faster switching. Electrophoretic pixels were operated with dual‐particle complementary‐colored dispersions such as green/magenta (G/M). Using simple interdigitated three‐electrode architecture, four colored states (KWGM) were achieved with a preliminary contrast ratio of 10 : 1. Furthermore, biprimary ink dispersions were shown to be functional in a more advanced electrokinetic pixel structure. A full‐color biprimary pixel contains three complementary subpixels (G/M, B/Y, R/C), and the requisite electrophoretic ink dispersions were also formulated and spectrally characterized in this work. Lastly, theoretical color space mapping confirms that the biprimary concept provides twice the brightness and twice the color fraction compared with the conventional RGBW subpixel approach, and that the biprimary concept can approach performance close to that of magazine print (Specifications for Web‐Offset Print).     

Medical displays in the healthcare system

Abstract— As the healthcare system changes and progresses, the need for different types of high‐performing displays is also evolving. There are three categories of displays: (a) embedded (as part of life saving devices), (b) informative (for patient data and history, and managing workflow), and (c) imaging (high performing for diagnosis). The challenges of AMLCDs, which are the display of choice at the moment mainly in digital imaging, will be discussed. These challenges include very high resolution, high brightness, and wide viewing angle. The current performance of AMLCDs and the areas which they need to improve will be reviewed. A brief summary of the standards used to specify medical (diagnostic) displays will follow. A look into the future will predict the role of displays in hospitals.     

Measuring and modeling per‐element angular visibility in multi‐view displays

Abstract— Multi‐view displays employ an optical layer which distributes the light of an underlying TFT‐LCD panel in different directions. Certain properties of the layer create specific artifacts, such as ghost images, moiré patterns, and masking. The layer was modeled as an image‐processing channel, and the display parameters related with the model were identified, which are importantfor the design of image‐processing algorithms for artifact mitigation. The identified parameters are interleaving pattern, angular visibility, and frequency throughput of the display. A methodology for deriving these parameters for an arbitrary LCD‐based multi‐view display are presented, which does not require precisely positioned measurement equipment. As a case study, measurement and modeling results for a particular multi‐view display are also presented.     

Advances towards high‐resolution pack‐and‐go displays: A survey

Abstract— Tiled displays provide high resolution and large scale simultaneously. Projectors can project on any available surface. Thus, it is possible to create a large high‐resolution display by simply tiling multiple projectors on any available regular surface. The tremendous advancement in projection technology has made projectors portable and affordable. One can envision displays made of multiple such projectors that can be packed in one's car trunk, carried from one location to another, deployed at each location easily to create a seamless high‐resolution display, and, finally, dismantled in minutes to be taken to the next location — essentially a pack‐and‐go display. Several challenges must be overcome in order to realize such pack‐and‐go displays. These include allowing for imperfect uncalibrated devices, uneven non‐diffused display surfaces, and a layman user via complete automation in deployment that requires no user invention. We described the advances we have made in addressing these challenges for the most common case of planar display surfaces. First, we present a technique to allow imperfect projectors. Next, we present a technique to allow a photometrically uncalibrated camera. Finally, we present a novel distributed architecture that renders critical display capabilities such as self‐calibration, scalability, and reconfigurability without any user intervention. These advances are important milestones towards the development of easy‐to‐use multi‐projector displays that can be deployed anywhere and by anyone.     

A model of scrolling on touch-sensitive displays

Scrolling interaction is a common and frequent activity allowing users to browse content that is initially off-screen. With the increasing popularity of touch-sensitive devices, gesture-based scrolling interactions (e.g., finger panning and flicking) have become an important element in our daily interaction vocabulary. However, there are currently no comprehensive user performance models for scrolling tasks on touch displays. This paper presents an empirical study of user performance in scrolling tasks on touch displays. In addition to three geometrical movement parameters—scrolling distance, display window size, and target width, we also investigate two other factors that could affect the performance, i.e., scrolling modes—panning and flicking, and feedback techniques—with and without distance feedback. We derive a quantitative model based on four formal assumptions that abstract the real-world scrolling tasks, which are drawn from the analysis and observations of user scrolling actions. The results of a control experiment reveal that our model generalizes well for direct-touch scrolling tasks, accommodating different movement parameters, scrolling modes and feedback techniques. Also, the supporting blocks of the model, the four basic assumptions and three important mathematical components, are validated by the experimental data. In-depth comparisons with existing models of similar tasks indicate that our model performs the best under different measurement criteria. Our work provides a theoretical foundation for modeling sophisticated scrolling actions, as well as offers insights into designing scrolling techniques for next-generation touch input devices.     

Electrofluidic displays: Fundamental platforms and unique performance attributes

Abstract— Electrofluidic displays transpose brilliant pigment dispersions between a fluid reservoir of small viewable area and a channel of large viewable area. Recent progress in the technology, a new multi‐stable device architecture, and a novel approach for segmented displays that can display pigment without the optical losses of pixel borders is reported. The fundamental aspects of electrofluidics that make it compelling for the next generation of e‐paper products is reviewed.     

Comparative studies of single-polarizer reflective liquid-crystal displays

Abstract— The electro-optic effects and viewing-angle characteristics of some recently developed single-polarizer reflective liquid-crystal displays are compared under the same material parameters. The mixed-mode twisted-nematic cells and biaxial film-compensated thin homogeneous cells are promising for both direct-view and projection displays employing crossed polarizers. How to improve contrast ratio for the parallel-polarizer displays remains a technical challenge.     

Design of relative primary luminances for four-primary displays

Multi-primary displays have the advantage of large color gamut. The relative primary luminances of a conventional three-primary display are uniquely determined by its white point. There are N−3 degrees of freedom for choosing the relative primary luminances of an N-primary display with a given white point. This paper presents the methods designing the relative primary luminances of four-primary displays. A four-primary LED display is taken as an example for showing the methods. The maximum display luminance and color gamut are, respectively, taken as an additional requirement for determining the relative primary luminances of the display. The requirement of the maximum display luminance is taken for a set of available primary luminances. The gamut volume in CIELAB color space is defined for maximizing the display gamut. In practice, the design of the relative primary luminances may be a compromised result of the two additional requirements.     

Comparison of helmet-mounted visual displays for flight simulation

The objective was to determine if there are performance differences among pilots accomplishing simulated aerial refuelling using five different visual display configurations. The displays were all used in the A-10 cockpit of the Advanced Simulator for Pilot Training (ASPT). The configurations were (a) a helmet-mounted binocular display, (b) lead lanthanum zirconate titamate (PLZT) goggles (binocular) used with one channel of the ASPT display, (c) a helmet-mounted biocular display, (d) the ASPT 300° field-of-view (FOV) dodecahedron display, and (e) the ASPT display masked to present an FOV equal to that of the helmet-mounted displays. Forty subjects participated in this effort: eight per display condition. After an initial practice period, the subject's first task was to estimate distances behind the refuelling tanker while the A-10 was flown automatically to the contact position. The pilots then flew the refuelling task three times. Dependent variables measures were the oscillation of the A-10 receiver receptacle around the centre point of the acceptable refuelling boom movement envelope in three dimensions. The results show that the subject's ability to estimate distance does not differ significantly among the display configurations. Although performance measures were recorded during both the approach and contact phase of the refuelling task, a computer malfunction negated the value of the approach measures. Measures obtained during the contact phase clearly indicate the value of a wide FOV and of stereoscopic depth cues. Optics in front of the eyes were shown not to be detrimental, and the helmet-mounted stereoscopic display proved superior to the PLZT goggles.     

Front glass thickness requirements for high resolution polarized stereoscopic displays: A simulation platform

The tendency of the display market is towards displays with higher resolutions. Therefore, patterned retarder‐based stereoscopic displays require smaller front glass thickness to maintain good vertical viewing angle and limited crosstalk. To properly design these stereoscopic displays and quantify these requirements, we developed a simulation platform to predict radiance, polarization profile, and crosstalk over viewing angles and over wavelengths. Tunable parameters such as the distance between the pixels and the patterned retarder, and the optical properties of the patterned retarder are included. The simulation platform has been validated by comparing outcomes of simulations with measurements. We predict crosstalk accounting for both the human eye field of view and the diameter of the pupil. We found that to obtain a vertical viewing angle of at least ± 30° and crosstalk of at most 0.11 for a display with a pixel pitch beyond 0.27 mm, the display should include black absorbers, and the thickness of the front glass should be at most 0.5 mm. For higher resolution displays (pixel pitch no more than 0.21 mm), a front glass thickness at most 0.15 mm is required to produce a vertical viewing angle beyond ± 14° and a minimum viewing distance of 0.3 m.     

Reliability of transparent conducting substrates for rollable displays: A cyclic loading investigation

Abstract— Failure mechanisms for flexible conducting substrates are investigated herein in the context of rollable/flexible display applications. Cyclic loading experiments (substrates subjected to multiple cycles of tensile strain) were carried out on both ITO‐coated PET and PEDOT:PSS‐coated PET substrates. The resistance was measured after each bending cycle. The resistance increased with the number of cycles and was not reversible. Even when the tensile strain on the ITO/PET was below the virgin cracking threshold (～2%) previously reported [Appl Phys Lett ⁷⁶, 1425 (2000)], slight increases in resistance were measurable after just a few cycles.     

Multiple color high resolution reflective cholesteric liquid crystal displays

Abstract— A high-resolution multiple-color and black-on-white surface-stabilized reflective cholesteric liquid-crystal display with reflectivities as high as 40% is reported. The double-stacked 1/8-VGA, 100-dpi prototype shows four vivid colors with negligible parallax. The potential for eight colors and ultimately full color is demonstrated in a high-resolution triple-stacked prototype.